Stock TBI 350 with Headers

[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.

[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.