Stock TBI 350 with Headers

[Kitch]

​​As the heading says, I have basically a stock 94 TBI 350 in a G20 conversion van, but I have fitted Headman 6941 (yep, had to cut off the air injection tubes) ultra duty HPC coated full length headers to it and a free flowing 3" single exhaust system.
I'd appreciate any advice on some of the items I could look at changing in my BDTZ bin $OD PCM to improve of the stock values that it currently has.
I think I read somewhere there is a time delay I can change to compensate for the fact that the new heated narrow band O2 sensor has moved from near the engine to down past the header collector, does that sound right?

Dave W, I've attached my .bin for your library.

[Kitch]

The "similar threads" links that appeared on the bottom of this post helped with some info. I looked a my "Integrator Delay vs Airflow" settings, the values in there seemed quite a bit larger compared to the only other ones I've seen in this post:
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?3724-Tuning-for-headers

What should the values be approximately?
Is this one of the first things I should look at changing or are there more important items I should address first?

[dave w]

​​As the heading says, I have basically a stock 94 TBI 350 in a G20 conversion van, but I have fitted Headman 6941 (yep, had to cut off the air injection tubes) ultra duty HPC coated full length headers to it and a free flowing 3" single exhaust system.
I'd appreciate any advice on some of the items I could look at changing in my BDTZ bin $OD PCM to improve of the stock values that it currently has.
I think I read somewhere there is a time delay I can change to compensate for the fact that the new heated narrow band O2 sensor has moved from near the engine to down past the header collector, does that sound right?

Dave W, I've attached my .bin for your library.

Thanks for posting the BDTZ.bin file. It's $OD

dave w

[Roadknee]

The "similar threads" links that appeared on the bottom of this post helped with some info. I looked a my "Integrator Delay vs Airflow" settings, the values in there seemed quite a bit larger compared to the only other ones I've seen in this post:
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?3724-Tuning-for-headers

What should the values be approximately?
Is this one of the first things I should look at changing or are there more important items I should address first?

Like Dave mentioned, you need to use a $0D XDF to read this bin. In the pic above you were using something else, and that's why the numbers are so high.

For your longtubes, I'd recommend 750 at zero, draw a straight line to 350 at 64, and draw another straight line to 150 at 128. That should get you in the ballpark.

If you experience any part throttle surge the other fuel trim parameters will need some work. Visit BLG355's Idle BLM thread for more info.

[Kitch]

Thanks for the reply, I should have figured that out myself.
When my friend first set me up for data logging he wasn't sure what the PCM's MASK ID was so he wen't with a $OE XDF/ADX. Once I managed to get my actual .bin file I was able to read the ID so I had been using a $OD XDF but wen't back to the $OE to see what some of the difference were and forgot that I had done that when I posted the screenshot.
750 at zero makes sense but you have lost me with "draw a straight straight line to 350 at 64, and draw another straight line to 150 at 128" could you expand on your description a bit for me?

Screen shot is now with $OD XDF :-)

[Roadknee]

750 at zero makes sense but you have lost me with "draw a straight straight line to 350 at 64, and draw another straight line to 150 at 128" could you expand on your description a bit for me?


Input 750 ms at zero airflow and 350 ms at 64 airflow and use the graphing function to draw a straight line between the two. Do the same between 350 at 64 and 150 at 128. Your table will look like this.

0 750
16 650
32 550
48 450
64 350
80 300
96 250
112 200
128 150

[Kitch]

Thanks for showing it in table form, I get it now. Start at 750ms then decrease in 100ms steps from 0 to 64 and then 50ms steps from 64 to 128.

After a test drive, what visible changes should I be looking for in the TunerRT logs to indicate it's made an impovement? Less swing in the closed loop narrow band O2 sensor output and my wide band fluctuating less?

[Fast355]

Input 750 ms at zero airflow and 350 ms at 64 airflow and use the graphing function to draw a straight line between the two. Do the same between 350 at 64 and 150 at 128. Your table will look like this.

0 750
16 650
32 550
48 450
64 350
80 300
96 250
112 200
128 150

That is exactly opposite of how I tune that table. Headers naturally make the 02 sensors cycle richer than stock at low flows and the scavenging action leans out the mid-upper flow range. I don't go under about 350mv or above 650 on that table.

0 450
16 475
32 500
48 525
64 550
80 575
96 600
112 625
128 650

My way runs a little fatter but also gives more torque at part-throttle requiring fewer power enrichment events. Being able to accelerate without having to floor it and kickdown saves a ton of fuel in something as heavy as a van.

My Thorley headers designed as a replacement for the manifolds of my Express van are designed and have a CARB EO# for use in California with the stock tune set at 450mv across the board. 02s are roughly in the stock locations though.

[brian617]

Fast, that table is airflow vs msec, not mv.

[Fast355]

Fast, that table is airflow vs msec, not mv.

Sorry I thought that was the mv table. On a G-Van (The 95 I pulled my 7427 and BJYN memcal out of) I would not expect the delays needing much change. The 02 sensor on the newer G-vans from the factory is after the Y merge right before the cat. If anything the delays need to be shorter than stock because the 02 will be closer to the cylinder head if it is in a header collector. I had Thorley Tri-Ys, Vortecs, mild 114 lsa cam and did not experience any surging due to 02 placement.

[PJG1173]

I take it this is another setting that just needs to be played with? I know when I put long tubes on my truck the NB went all out of wack since it moved about 16" or so from the stock location.

[Fast355]

I take it this is another setting that just needs to be played with? I know when I put long tubes on my truck the NB went all out of wack since it moved about 16" or so from the motor.

Seems like it! I have also had to play with this setting when I switched intakes from dual to single plane and again when I went to TPI.

Playing with proportional duration can also help in some situations.

[Kitch]

I've made the changes Roadknee suggested, burn't a new chip, installed it and took the van for a test drive. Once the vans warmed up low speed cruising has a noticeable surge, more so than before and the way the O2 sensor reacts on the dashboard display has changed.
Could there be some other things going on I need to address before changing the Integrator delay vs airflow?
I've attached the .bin, xdf and a xdl log of my last test drive if anyone would like to take a look. The first three quarters of the log is mostly motor way running, idle and low speed driving are in the final quarter.

[Fast355]

I've made the changes Roadknee suggested, burn't a new chip, installed it and took the van for a test drive. Once the vans warmed up low speed cruising has a noticeable surge, more so than before and the way the O2 sensor reacts on the dashboard display has changed.
Could there be some other things going on I need to address before changing the Integrator delay vs airflow?
I've attached the .bin, xdf and a xdl log of my last test drive if anyone would like to take a look. The first three quarters of the log is mostly motor way running, idle and low speed driving are in the final quarter.

Try putting the integrator delay back stock and putting my 02 MV target values in the lean/rich/median 02 sensor values.

[dave w]

Attached is a screen shot of the BLM averages from the data log posted.

dave w

[Kitch]

Fast355, I'll try out your settings as soon as I've run a baseline with my cold air intake on.
The van has a stock air intake pick up point from behind the grill but because I don't have a hot air riser tube from the cast iron exhaust manifold anymore (due to now having headers) the air cleaner housing has probably been stuck in the hot air position. I just fitted a small self tapping screw to hold it in the open position. It's 1 degree C outside at the moment so I should have plenty of cold air :-)

Dave W, that's a very cool spreadsheet. Could you tell me how to do that or provided me with a link that shows me how to set it up?

[dave w]

Dave W, that's a very cool spreadsheet. Could you tell me how to do that or provided me with a link that shows me how to set it up?

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?3505-7427-VE-Correction-using-Excel-Averageifs-OD-31-OE-and-E6

dave w

[Kitch]

Thanks, for the info Dave. I probably know even less about Excel than I do about tuning EFI, I guess it will make for an interesting few weeks :-)

Just got back from another run in the van, does a max "Injector DC%" of 49.95% sound right at full throttle?

[Fast355]

Thanks, for the info Dave. I probably know even less about Excel than I do about tuning EFI, I guess it will make for an interesting few weeks :-)

Just got back from another run in the van, does a max "Injector DC%" of 49.95% sound right at full throttle?

Not for stock injectors it doesn't. I was somewhere in the 90-110% range with a stock L05 longblock, 61# injectors at 13 psi and still leaning out up top above 4,000 rpm.

[Kitch]

Is it possible that for some reason it's only showing 50% of the actual injector DC% value?

[Kitch]

Just wen't for another run in the van, the wide band O2 is showing 11.9-12.0 at full throttle and I'm still getting knock counts at W.O.T.

[Fast355]

Just wen't for another run in the van, the wide band O2 is showing 11.9-12.0 at full throttle and I'm still getting knock counts at W.O.T.

I know this may sound weird, but try leaning it out some more. Get it to the 12.8 to 13.2 range up top and about 12.6 down near peak torque at 2,400.

[Roadknee]

Is it possible that for some reason it's only showing 50% of the actual injector DC% value?

Yes. Your adx is probably set up for MPFI instead of TBI. In Tunerpro, go to Acquisition, Edit Definition, Values, Injector Duty Cycle. You'll see some text there on how to change the conversion calculation for TBI.

[Roadknee]

Just wen't for another run in the van, the wide band O2 is showing 11.9-12.0 at full throttle and I'm still getting knock counts at W.O.T.

Knock counts are the story of my life with my LO5. Lots of good discussion here on things to check, change and rule out.

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?2761-1995-K1500-LO5-tuning-Autoprom/page3

[Kitch]

Just got the van back after a couple of days on the dyno.
Drive in peak HP was 160.8 @ 3343, drive out was 196.5 @ 4511. Managed a 35.7 HP increase between peak horsepower and effective gain of 64 HP @ 4500 at the wheels :-)

[Fast355]

Just got the van back after a couple of days on the dyno.
Drive in peak HP was 160.8 @ 3343, drive out was 196.5 @ 4511. Managed a 35.7 HP increase between peak horsepower and effective gain of 64 HP @ 4500 at the wheels :-)

I bet that feels very nice seat of the pants.

What are you running for air/fuel ratio and timing? 12.8-13.4:1 and 28-32° of timing all in by 2,600??

[Kitch]

I've only managed to drive the van home in peak hour traffic so far, so not much of a chance to see what it now feels on the open road.

Going on what the dyno operator told me, he was targeting on 12.6:1 in the VE table for air/fuel for power runs, my wideband was showing 12.1:1 and the dyno operators wideband in the tail pipe was showing 12.3:1. I'll have to transfer a copy of the modified .bin from the APU1 to my laptop to check what the new spark table looks like.

[Kitch]

Can someone confirm for me if the values show in a TunerPro Main spark table are crankshaft degrees or distributor degrees?
Looks like it has been bumped from a stock 16.2 to 24.3 in the new modified version, so it's either a bit low for crankshaft degrees or a bit high for distributer degrees.
Or am I missing something here?

[Fast355]

Can someone confirm for me if the values show in a TunerPro Main spark table are crankshaft degrees or distributor degrees?
Looks like it has been bumped from a stock 16.2 to 24.3 in the new modified version, so it's either a bit low for crankshaft degrees or a bit high for distributer degrees.
Or am I missing something here?

Crank degrees but you also have PE adder as well as about 2° above 3,200 rpm coming from your 369 ignition module. PE adder is 4* up top on a stock van. If your distributor is set at TDC or ZERO that would give you about 30° of timing.

[Kitch]

Thanks for confirming that, I did search for the answer but like many things on the internet I got conflicting answers.

I had a look at my stock PE spark vs RPM and it looks like it starts adding 2.1° from 1600-6400 RPM, what do you mean by "PE adder is 4* up top on a stock van"?

I have about 2° initial at the crank, potentialy 24.3° main spark advance and another 2.1° from PE at W.O.T. = 28.4°, is there another variable that I'm missing?

28.4° total timing sounds a bit conservative on a 350 but if I'm looking at the comparison between the stock table and the modified one correctly I'm getting 9.1° @ 4400 more than the stock chip!

[Fast355]

Thanks for confirming that, I did search for the answer but like many things on the internet I got conflicting answers.

I had a look at my stock PE spark vs RPM and it looks like it starts adding 2.1° from 1600-6400 RPM, what do you mean by "PE adder is 4* up top on a stock van"?

I have about 2° initial at the crank, potentialy 24.3° main spark advance and another 2.1° from PE at W.O.T. = 28.4°, is there another variable that I'm missing?

28.4° total timing sounds a bit conservative on a 350 but if I'm looking at the comparison between the stock table and the modified one correctly I'm getting 9.1° @ 4400 more than the stock chip!

If you have a stock Delco ignition control module it should have the numbers 369 on top. The 369 module ends up adding 2° of timing above 3,200 rpm due to latency within the module and PCM. 28~32° of advance is all these heads need. I have found most like 26~30° of total timing. I find it odd that your PE table only has 2°. I have not opened the stock BJYN van calibration I was using from a 1995 G20 in years but I am 99.95% certain that it is adding 4.0° in the PE table at 4,400 rpm.

If you happen to have an 048 module it removes 6° at 5,000 rpm.

http://i243.photobucket.com/albums/ff172/Fast355_album/048vs369.jpg (http://s243.photobucket.com/user/Fast355_album/media/048vs369.jpg.html)

[Fast355]

I also find it odd they did nothing below 1,600 rpm. With a torque converter that stalls probably under that you probably have some nice throttle response and low end power gains to be realized. Try bringing those 0-1,000 rpm cells up to about 8-10° and smooth over to the idle area. I have run as much as 14° on a stock TBI at 800 rpm and 100 kpa without tip-in knock and they jump to life when you hit the go pedal.

[Kitch]

Great info on the modules.
Purely out of interest how do you confirm that the 369 is adding 2° above 3200 RPM? I guess with a dial back timing light or a timing tape on the ballancer and checking on a full power run a dyno is one way but is there an easier way to check?
I had look and I have a 369 module in the van at present but the new L31 has a 0724 module in the MSD Pro billet distributor, do you have any info on the latency of that module and how it might react?

[Fast355]

Great info on the modules.
Purely out of interest how do you confirm that the 369 is adding 2° above 3200 RPM? I guess with a dial back timing light or a timing tape on the ballancer and checking on a full power run a dyno is one way but is there an easier way to check?
I had look and I have a 369 module in the van at present but the new L31 has a 0724 module in the MSD Pro billet distributor, do you have any info on the latency of that module and how it might react?

Set the timing to say 10° across the entire rpm range, take the belt off and have someone rev the engine slowly up to 5,000 rpm while the timing is being checked. Chock the wheels, set the ebrake and make sure you trust the person not to drop it into gear.

[Kitch]

Over the years my personal experience with dynos and their operators is that for the time your vehicle is on the dyno they just try to tune for best W.O.T. power and torque figures. I was pleasantly surprised with the 196 rear wheel HP from a basically stock LO5 with a good exhaust.

I had asked for them to sort out my idle and light throttle cruise which they didn't really do anything about but it soon became clear they just weren't experienced at doing that sort of tuning with an OBDI system. While I'm sure they were good at tuning LS1's and turbo Jap car's, I think my old van was just not something they would normally do.

So I'm back to doing that part by myself and with the help from the information here and the help from you guys.

Fast355 you are right load came on from the dyno at 2000 RPM and I guess they didn't bother about anything below that. I'll look at trying to add timing like you've suggested but I need to figure out whats going on with my knock counts at this stage.

The dyno operator disabled knock retard because he couldn't hear any actual knock and the knock retard was pulling more and more timing out every time he did a power run. My fist couple of test drives since the tune seem to have a lot more knock counts than before at anything above half throttle.
I have noticed that I get over 1000 knock counts in the first second of the motor cranking on the starter before it fires (it was like that before dyno tuning). Once it started and idling it's fine, it seems to get the knock counts only when it's cranking. So I normally have 1000 knock counts before I've even driven down my drive, has anyone else experienced that? Is that a sign that the other knock counts I'm getting above half throttle could be false?
The other thing I thought of is logging a few more test runs then try changing from the 95 octane I'm currently to some 98 octane fuel and see if the knock counts reduce (I think our NZ 95 octane is between your US 89 and 91 octane).

Fast355, is that 10° in the "Main spark table vs MAP vs RPM(Open throttle)" and when you say "take the belt off" are you referring to the serpentine belt?

[Fast355]

Over the years my personal experience with dynos and their operators is that for the time your vehicle is on the dyno they just try to tune for best W.O.T. power and torque figures. I was pleasantly surprised with the 196 rear wheel HP from a basically stock LO5 with a good exhaust.

I had asked for them to sort out my idle and light throttle cruise which they didn't really do anything about but it soon became clear they just weren't experienced at doing that sort of tuning with an OBDI system. While I'm sure they were good at tuning LS1's and turbo Jap car's, I think my old van was just not something they would normally do.

So I'm back to doing that part by myself and with the help from the information here and the help from you guys.

Fast355 you are right load came on from the dyno at 2000 RPM and I guess they didn't bother about anything below that. I'll look at trying to add timing like you've suggested but I need to figure out whats going on with my knock counts at this stage.

The dyno operator disabled knock retard because he couldn't hear any actual knock and the knock retard was pulling more and more timing out every time he did a power run. My fist couple of test drives since the tune seem to have a lot more knock counts than before at anything above half throttle.
I have noticed that I get over 1000 knock counts in the first second of the motor cranking on the starter before it fires (it was like that before dyno tuning). Once it started and idling it's fine, it seems to get the knock counts only when it's cranking. So I normally have 1000 knock counts before I've even driven down my drive, has anyone else experienced that? Is that a sign that the other knock counts I'm getting above half throttle could be false?
The other thing I thought of is logging a few more test runs then try changing from the 95 octane I'm currently to some 98 octane fuel and see if the knock counts reduce (I think our NZ 95 octane is between your US 89 and 91 octane).

Fast355, is that 10° in the "Main spark table vs MAP vs RPM(Open throttle)" and when you say "take the belt off" are you referring to the serpentine belt?

Sounds about right for a light duty LO5 with a good exhaust and tune to me. My L03 w/081 TPI heads and flat top pistons put out 181 RWHP and 268 RWTQ and the heavy duty 8600 GVW+ low compression L05 put down 178 RWHP and about 280 RWTQ breathing through the same headers and exhaust in my G20.

Knock retard while cranking is normal, it is the noise of the starter gear on the ring gear being picked up by the knock sensor. Simple solution is do not start logging until after you have started the engine. I seem to remember your octane being higher than our octane. I run 91 to 93 octane in my Express van with aluminum heads and 9.4:1 compression and run up to 32-33* timing at wide open throttle with a very aggressive advance curve. I am running with the knock sensor disabled and turned off in the tune. I put an aftermarket sensor on when I put the headers on it back in November. Recently it started maxing out the retard as soon as the PCM enables it. Then the PCM went into low octane mode and it ran absolutely horrible starting at 50KPA and beyond as well as in PE. The engine in my Express has been plagued with knock counts and knock retard since I have switched it to the 0411 LS1 style PCM. Before I was running with an older black box and had the LT4 knock module from a Corvette in the PCM in place of the stock knock module. I NEVER had knock retard at all and found out years later that the Corvette knock module more or less completely disables knock retard on a Vortec black box. At the time I was running 28-30* of total timing on iron heads and 87 octane and never heard audible detonation. Plugs always looked good and the power was great. This Hecho en Mexico crate engine short block has always been a bit noisy as well and never ran quite as well as the stock engine when it was stock. When I threw the LT4 cam, 1.6 rockers and knock module in the mix it woke up nicely.

For testing purposes I would set both the Open and Closed throttle tables to 10* across the boards and remove the belt(s). I would not feel comfortable reving the engine up to 5,000 rpm using a timing light with a belt and mechanical fan spinning in my face.

[Kitch]

I may have picked up a couple of extra HP on the dyno with the electric fans, instead of the factory mechanical fan.
Thanks for the advice on the knock sensing during cranking, that makes sense.
I'm keen to try the changes to my spark table but I want to learn more about altering the VE table and the order I should look at making tuning changes before I do too much more

Is there an easy way to raise the W.O.T. shift point of my 4l60e? At the moment in drive and at 100% throttle position the trans up shifts at about 4100 RPM, it would be nice if I could raise it to 4500.

[Fast355]

I may have picked up a couple of extra HP on the dyno with the electric fans, instead of the factory mechanical fan.
Thanks for the advice on the knock sensing during cranking, that makes sense.
I'm keen to try the changes to my spark table but I want to learn more about altering the VE table and the order I should look at making tuning changes before I do too much more

Is there an easy way to raise the W.O.T. shift point of my 4l60e? At the moment in drive and at 100% throttle position the trans up shifts at about 4100 RPM, it would be nice if I could raise it to 4500.


There is a program called Bluecats that allows you to completely retune your shift points. If you are happy overall with how the transmission shifts the rest of the time, you can go into the kickdown mode shift settings and raise the upshift rpm from ~4,000 up to about 4,300-4,400 rpm. You need the shift points in the PCM programmed a couple of hundred rpm lower than you want the engine to actually rev. I noticed a small difference in power with both my electric fans and underdrive crank pulley. Neither helped my power as much as a set of 1.6:1 full roller rockers though. I also slotted the center 4 bolts on an edelbrock performer rpm intake and put a marine 454 tbi unit on a marine TBI to square bore adapter back in the day on a stock long block L05. With the TBI/Intake/1.6s/Tuning/Headers/Exhaust/E-fan/Underdrive it had a ton more power than stock and pulled well up to about 5,200 rpm with the stock cam and heads.

VE tables can be done with a spreadsheet on here and some datalogging. It is easier to tune in open loop with the canister purge and egr turned off and a wideband, but it can also be done in closed loop using BLM feedback.

[Kitch]

Had a very quick look at the Bluecats software, looks very good but I will concentrate on tuning the engine before I get right into trans control.

I found a couple of things I could look at changing, one was the "Upshift RPM vs shift" at present it looks likes it's set at 4000 RPM, was that the parameter you were referring to?
The other one I found was in the "Upshift/Downshift MPH vs TPS" table, I was thinking about raising the 100% TPS upshift values by 5 MPH, what are your thoughts on that one?

I have a set of Comp Cams 1.6 roller tip rockers but the aren't the self aligning type so they're no good for the stock L05.
I do have the new factory roller cam and lifters that came out of my L31 that I could put into the L05 but I would need to buy a spider plus cam thrust plate for the L05 and then possibly drill and tap the holes in the block to suit. I'm not really sure if I would get much of a gain from the L31 cam, although a roller cam is always nice.

[Kitch]

Was going to have a go following through the "Adjusting VE Fueling tables with BLM data tutorial" but I can only find a "Idle VE vs MAP vs RPM" and "Open throttle VE vs MAP vs RPM", I can't find the "Off Idle vs MAP vs RPM" table thats shown in the tutorial, where should I look for it?

[PJG1173]

that is all there is in $0D

[Fast355]

Had a very quick look at the Bluecats software, looks very good but I will concentrate on tuning the engine before I get right into trans control.

I found a couple of things I could look at changing, one was the "Upshift RPM vs shift" at present it looks likes it's set at 4000 RPM, was that the parameter you were referring to?
The other one I found was in the "Upshift/Downshift MPH vs TPS" table, I was thinking about raising the 100% TPS upshift values by 5 MPH, what are your thoughts on that one?

I have a set of Comp Cams 1.6 roller tip rockers but the aren't the self aligning type so they're no good for the stock L05.
I do have the new factory roller cam and lifters that came out of my L31 that I could put into the L05 but I would need to buy a spider plus cam thrust plate for the L05 and then possibly drill and tap the holes in the block to suit. I'm not really sure if I would get much of a gain from the L31 cam, although a roller cam is always nice.

Yea that is the one under the "Kickdown" tab.

Someone on here put a L31 roller cam in a TBI head engine and said it ran alot better than the stock TBI. My favorite setup for these was the F-car or Y-car LT1 cam.

[Kitch]

So for the purpose following the tutorial can I assume the "off idle" table shown in the tutorial is the same as the "Open throttle" table I have?

[Fast355]

So for the purpose following the tutorial can I assume the "off idle" table shown in the tutorial is the same as the "Open throttle" table I have?

Off idle should be open throttle.

[Fast355]

Also forgot to say I would not raise the mph in the 100% range to dial in your upshift. The PCM has to meet both RPM and MPH to shift. 5 mph is a big jump in the lower gears. WOT shifting (above 90-95%) is done off that simple RPM/MPH table that has like 3 and 6 entries anyway. I like to use Bluecats to get the part throttle close to where I want it, then use the kickdown mode RPM table to fine tweak where it shifts at WOT. I always set Bluecats up with the desired RPM about 300-400 rpm low to keep the MPH table a little lower than where it shifts so that I can dial it in with RPM alone by datalog.

[Kitch]

I've followed the tutorial and have smoothed the Open throttle VE table. I then disabled EGR, PE, DE and DFCO, is there anything else I should do before data logging?
Should I tweak the spark advance before or after I've worked on the VE table and data logged? I'm assuming if it's after I would need to redo the VE table again?

[Fast355]

I've followed the tutorial and have smoothed the Open throttle VE table. I then disabled EGR, PE, DE and DFCO, is there anything else I should do before data logging?
Should I tweak the spark advance before or after I've worked on the VE table and data logged? I'm assuming if it's after I would need to redo the VE table again?

Anytime you tweak one you are going to have to go back and tweak the other. I personally do timing then fuel.

[Kitch]

Spark map smoothed and loaded, I'll data log tomorrow.

One thing that we picked up on the dyno was how restrictive the stock air cleaner assembly appeared be.
As shown at the start of this post I had locked the hot air intake flap inside the factory air cleaner open so that only cool intake air would get to the air filter.

I had dropped my van off at the workshop in the morning and hung around to help them if they had any issues connecting to the APU1 and they did, it wasn't the sort of vehicle they were used to working on and they gave up on the APU1 and connected up there own Ostrich.
I asked the dyno operator to give me a call when it was ready to make a few runs and I'd come back and have a look.
I had a phone call from the dyno operator asking me how much HP I thought the van would make, I said anything above 170 would be okay he said it was only making 165 but something was strange going on because the motor would just falling on it's face above 3500 RPM.

I headed over to see what was going on, he showed me on the computer screen the initial runs he had made and you could see the HP curve just keel over after 3500.
While I was there he decided to take the lid off the air cleaner assembly and try another run, we were both surprised to see the HP jump up by 13 to 178.
After that run he then put the lid back on and sure enough back down to 163HP. I suggested we disconnect the factory duct supplying fresh air from the front of the van to the air cleaner to see if there was a restriction caused by that but another run revealed not much difference, still around the 167 mark.

So at that point I suggested the old air cleaner lid flip trick to see if the air filter was the problem and the HP came up near 176 HP, one more run with the lid back on correctly to confirm the air cleaner was the problem and sure enough the HP dropped back down again.
At that point it appeared clear that the factory air cleaner assembly was costing 13 HP, with no other changes you could watch the AFR drop to 10:1@ 4500 RPM with the air cleaner lid on and jump to 12.3:1 with the lid off.
Not wanting to give up on the cool air provided by the duct running from the front of the van but having to conceded that something needed to change, I took the air cleaner assembly home and within ten minutes with a holesaw and an air nibbler modified it to let some more air in but still have a little cool air flowing towards the filter.
I dropped it off the next morning with the dyno operator and he reported when he later made a run with it on the HP levels were back up to levels with no lid on.
The improvements made from 176HP to 196HP were then made from basic chip tuning.

[Fast355]

Spark map smoothed and loaded, I'll data log tomorrow.

One thing that we picked up on the dyno was how restrictive the stock air cleaner assembly appeared be.
As shown at the start of this post I had locked the hot air intake flap inside the factory air cleaner open so that only cool intake air would get to the air filter.

I had dropped my van off at the workshop in the morning and hung around to help them if they had any issues connecting to the APU1 and they did, it wasn't the sort of vehicle they were used to working on and they gave up on the APU1 and connected up there own Ostrich.
I asked the dyno operator to give me a call when it was ready to make a few runs and I'd come back and have a look.
I had a phone call from the dyno operator asking me how much HP I thought the van would make, I said anything above 170 would be okay he said it was only making 165 but something was strange going on because the motor would just falling on it's face above 3500 RPM.

I headed over to see what was going on, he showed me on the computer screen the initial runs he had made and you could see the HP curve just keel over after 3500.
While I was there he decided to take the lid off the air cleaner assembly and try another run, we were both surprised to see the HP jump up by 13 to 178.
After that run he then put the lid back on and sure enough back down to 163HP. I suggested we disconnect the factory duct supplying fresh air from the front of the van to the air cleaner to see if there was a restriction caused by that but another run revealed not much difference, still around the 167 mark.

So at that point I suggested the old air cleaner lid flip trick to see if the air filter was the problem and the HP came up near 176 HP, one more run with the lid back on correctly to confirm the air cleaner was the problem and sure enough the HP dropped back down again.
At that point it appeared clear that the factory air cleaner assembly was costing 13 HP, with no other changes you could watch the AFR drop to 10:1@ 4500 RPM with the air cleaner lid on and jump to 12.3:1 with the lid off.
Not wanting to give up on the cool air provided by the duct running from the front of the van but having to conceded that something needed to change, I took the air cleaner assembly home and within ten minutes with a holesaw and an air nibbler modified it to let some more air in but still have a little cool air flowing towards the filter.
I dropped it off the next morning with the dyno operator and he reported when he later made a run with it on the HP levels were back up to levels with no lid on.
The improvements made from 176HP to 196HP were then made from basic chip tuning.

I used the air cleaner and ducting from a 454 van on my old 350 G20. Built in powerbowl from the factory and oversized ducting all the way through the radiator core support. I grabbed the 454s core support at the junkyard too.

[Rally Smith]

I also find it odd they did nothing below 1,600 rpm. With a torque converter that stalls probably under that you probably have some nice throttle response and low end power gains to be realized. Try bringing those 0-1,000 rpm cells up to about 8-10° and smooth over to the idle area. I have run as much as 14° on a stock TBI at 800 rpm and 100 kpa without tip-in knock and they jump to life when you hit the go pedal.

I don't mean to hijack this but, a question for you Fast. When you say, "as much as 14* on a stock tbi" is that at the distributor with the wire unplugged or just in the Spark Table?

Thanks,

again sorry for the interruption.

[Fast355]

I don't mean to hijack this but, a question for you Fast. When you say, "as much as 14* on a stock tbi" is that at the distributor with the wire unplugged or just in the Spark Table?

Thanks,

again sorry for the interruption.

In the low rpm/high map area of the spark table. I have run the distributer as much as 8-10° on stock engines on 91-93 octane fuel and 160-170°F thermostats. Not both at the same time however.

[Kitch]

Working through the adjusting VE fueling tables with BLM data tutorial, it asks to "open your spreadsheet to the correct mask ID" but I only seem to have a "$42 VE correction table" tab not a $OD?
The spreadsheet states correction table E6~OD~OE~31 at the top but the tab down the bottom only shows $42, do I need to change it or is $42 okay?

I've entered all the data in the spreadsheet and I can see the automatic changes in the correction factors but nothing has happened to the values in the VE table, how do I make the spreadsheet apply those changes?

[Fast355]

Working through the adjusting VE fueling tables with BLM data tutorial, it asks to "open your spreadsheet to the correct mask ID" but I only seem to have a "$42 VE correction table" tab not a $OD?
The spreadsheet states correction table E6~OD~OE~31 at the top but the tab down the bottom only shows $42, do I need to change it or is $42 okay?

I've entered all the data in the spreadsheet and I can see the automatic changes in the correction factors but nothing has happened to the values in the VE table, how do I make the spreadsheet apply those changes?

You need to copy the ECMs VE table into the spreadsheet and paste the end result into the VE table in the PCM.

$42 and $OD are completely different. Can you screenshot what you are talking about with the tabs and post it up?

[myburb]

I have the same thing. Three tabs, $42, on idle, off idle. The $42 just goes to 3200 rpm. I just use the other two but think the math in them all is the same. My spreadsheet laptop battery just died so I can't check that.

[Kitch]

Hi Fast,
Thanks for your help with this.

I've attched three images one of the VE correction table I downloaded and the other of my excel spreadsheet, I'm using the "Off Idle" table.
In the tutorial it shows a few different mask ID's in tabs along the bottom of the screen but that's not what I get on my spreadsheet?

At this stage I've cut and pasted my VE table to where it says to "insert off idle VE table from TunerPro here" and after a bit of playing around cut and pasted indivdual columns into the "insert BLM off idle running average here" (there were more cloumns in the TunerPro history table and less in the spreadsheet so cut and paste for the whole table wouldn't work). It must have been late last night because I can now see the changes in the "Insert new" tables.

Whats the difference between the "with averaged BLM table and the "without averaged BLM table"? The values in my "without averaged" table seem higher.

[CFI Z51]

Kitch
in the spread sheet i posted below go to the $0D-$0E tab, paste the blm (running average) history table from your adx in lines 5-20
paste your ve table from the bin / XDF(under BPW parameters - VE.. in Advanced $0D TP5 v250) in lines 41-56
then paste the corrected VE (averaged = smoothed ) data from lines 77-92 into the ve table in your bin..

hope this helps...

[Kitch]

CFI
That's exactly what I was looking for, maybe one of the mods might like to put your TBI calculator in $OD tuner info where I found the other spreadsheet.

I'm still not sure what's the main reasons for using the coarse or the fine tables? Should I start with coarse and smooth it or just go straight to to fine?

My BLM were quite lean at W.O.T. in the 80-100 kPA ranges and I see how the spread sheet will help correct that but when I turn PE back on will it then make my newly corrected BLM's go rich at W.O.T?

[Fast355]

CFI
That's exactly what I was looking for, maybe one of the mods might like to put your TBI calculator in $OD tuner info where I found the other spreadsheet.

I'm still not sure what's the main reasons for using the coarse or the fine tables? Should I start with coarse and smooth it or just go straight to to fine?

My BLM were quite lean at W.O.T. in the 80-100 kPA ranges and I see how the spread sheet will help correct that but when I turn PE back on will it then make my newly corrected BLM's go rich at W.O.T?

You would want to start coarse, it will make bigger changes more quickly, then fine tune with fine. You want your BLMs to be a touch on the rich side. Target 124-128 values. When you re-enable PE your fuel mixture will richen up for WOT.

[CFI Z51]

Glad to help :thumbsup:,i take no credit for the spreadsheet ,it was made by dave w@oldshool efi, found it here, this site is full of hidden gems :rockon:

[dave w]

I've developed a new spreadsheet to tune the '7427 PCM.

The new spreadsheet is located here: http://www.gearhead-efi.com/Fuel-Injection/showthread.php?3505-7427-VE-Correction-using-Excel-Averageifs-OD-31-OE-and-E6

The "Averageif" function in Excel allow an exported data log .csv file to be pasted into the spreadsheet. The "Averageif" function can be used to average near idle data when the idle flag is active, average data when closed loop is active, average when PE is active and other tuning data like WBO2. The history tables in TunerPro RT does not filter the data like the "Averageif" spreadsheet can do. The posted "Averageif" spreadsheet is not the final version I've developed. I posted the "Averageif" spreadsheet to help others develop their own "Averageif" spreadsheet.:thumbsup:

dave w

[Kitch]

CFI, you're right there seems to be some great info on this site, the hard part can be finding just what you're looking for.

Thanks again Dave, I'm sure your spreadsheet is more efficient way of doing it but I'm not an experienced spreadsheet user so I will have to revisit yours once I've become more than just a basic spreadsheet user :-)

Looks like I'll have to redo my logging again, two things may have affected my results:
The first one is looking back at my logs the EGR valve rather than being turned off was actually turned on at anything above closed throttle. To disable the EGR for logging I set the "Temperature for EGR on" to the maximum of 149.8° thinking the motor will never get that hot so EGR won't turn on but it appears it did. I've now also changed the "minimum speed for EGR" from 0.0MPH to 102MPH and that's stopped the EGR from turning on. The test drive to confirm the change seemed to reveal an unusual surprise, previously very light acceleration from 50- 60MPH up a gentle incline and in OD at times would show 2-3" of vacuum on my external vacuum gauge (which I always thought was too low).
I need to do more logging but now driving the same stretch of road with EGR turned off has raised the vacuum to around the 8-10" mark. I might try some back to back testing with EGR on and then off to get a more accurate picture.

The other thing that may have altered my initial logging was the near new Schrader valve that allowed my fuel pressure gauge to connect with the TBI fuel inlet decided to let fuel flow past without the fuel gauge connected. When I got back home after my logging run I thought I heard a strange noise coming from under the van while it was still running I got down and saw a puddle of fluid on the ground and it streaming down the side of the transmission, didn't take long for me to realise it was fuel right beside the headers! Turning the engine off and pulling the dog box off the motor soon showed where it was coming from and a quick key on confirmed it was the Schrader valve, that incident could have ended up much worse.
It was quite hard to bend the factory fuel line to fit the inline adaptor for the fuel pressure gauge so the thought of bending it back wasn't doing it for me. At this stage I've just capped it off with another Schrader valve from the replacement inline adaptor.... after I sheared apart the first one tightening it up (then had to wait for new one to arrive from the States).

[Kitch]

I've been busy working on my "open throttle" VE table and spark table, does anyone have a suitable spark table that I can compare to mine to see if I'm heading in the right direction?
I'm finding the 3.42 gears in the van are loading up the motor and I'm having to be a bit more conservative with the spark timing to try and control the knock counts. It's not really helped by the factory shift points and TCC settings. I'm thinking a lower set of gears might be in order, especially once the Vortec motor is in there.

[Roadknee]

I've been busy working on my "open throttle" VE table and spark table, does anyone have a suitable spark table that I can compare to mine to see if I'm heading in the right direction?
I'm finding the 3.42 gears in the van are loading up the motor and I'm having to be a bit more conservative with the spark timing to try and control the knock counts. It's not really helped by the factory shift points and TCC settings. I'm thinking a lower set of gears might be in order, especially once the Vortec motor is in there.

This is what I'm using with the stock LO5 in my 1995 K1500. I've always fought knock counts and recently disabled knock retard. I get some knock counts with this map, but no audible ping. Note that I also have PE spark zero'd out and EGR disabled so there are no spark adders. What you see in this table is what my engine gets, plus any latency from the stock ignition module. I'm running 92 octane fuel.

[Fast355]

I've been busy working on my "open throttle" VE table and spark table, does anyone have a suitable spark table that I can compare to mine to see if I'm heading in the right direction?
I'm finding the 3.42 gears in the van are loading up the motor and I'm having to be a bit more conservative with the spark timing to try and control the knock counts. It's not really helped by the factory shift points and TCC settings. I'm thinking a lower set of gears might be in order, especially once the Vortec motor is in there.

I had 3.08s in mine and ran the timing advance values for the GMPP HEI distributor with little issue. That was 12° @ 1000 rpm @ 100 KPA, 22° @ 2100 rpm, 32° @ 3,600 rpm. 10° @ 10 in/hg vacuum advance tappered smoothly down to 0° @ 3 in/hg. So basically ramped up smoothly starting at 90 kpa up to about 50 kpa.