$0d Code with turbo, boost

[96lt4c4]

Been thinking about buy a cheap ebay single turbo kit to put on my old Blazer. I have looked around and cant find anyone that has done it. I thought maybe it could be doable with the MAF code. Let me know what you guys think.

I helped a buddy of mine put a Chevy 6.5 liter diesel turbo on a 91 Ford 300 6 cylinder in an F250. We converted his truck from MAP to MAF by installing a Mustang ECM. I used Tuner Pro to tune it. Worked out really nice.

I have had the turbo itch ever since.

[dave w]

I kicked around the idea of using a 2 bar MAP with $OD. The downside is the Kpa resolution, 0 volts to 5 volts is less with a 2 bar MAP. The PLUS side for using a 2 Bar MAP with $OD, very affordable!:thumbsup:

dave w

[96lt4c4]

I kicked around the idea of using a 2 bar MAP with $OD. The downside is the Kpa resolution, 0 volts to 5 volts is less with a 2 bar MAP. The PLUS side for using a 2 Bar MAP with $OD, very affordable!:thumbsup:

dave w

I found this chart that shows the resolution on the 2 bar map. Looks like it reads up to almost 15 pounds of boost. I wouldn't run anymore than 10. So the resolution on the 3 bar would be even worse.

http://www.robietherobot.com/storm/mapsensor.htm

Man my wheels are turning....

http://www.ebay.com/itm/GT45-10PC-TURBO-CHARGER-KIT-MANIFOLD-OIL-FEED-LINE-CHEVY-SMALL-BLOCK-SBC-CAMARO-/271519862683?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f37d84f9b&vxp=mtr

There are guys with LS motors making good power with these cheap Ebay turbos. Most are really cranking the boost up and using them for drag racing. They seem to be holding up pretty good too. I am just looking for 8-10 pounds of boost on my 383 TBI. Mostly for some extra power while towing.

[Six_Shooter]

I don't think anyone that suggests that the resolution "will be poor" has actually driven a vehicle with a 2 BAR MAP sensor. The stock courses that run 2 BAR MAP sensors seen to be just fine. I'm running a 3 BAR on my ca with code $59 and it has way more resolution than its really needed. Granted it does have improved tables over the stock $58, but my car drives fine,along with many other papers vehicles running 2 and 3 BAR MAP sensors.

Do you have a 4L60E in the vehicle now? If not you could run other cod that is already set up for 2 BAR MAP sensor.

[96lt4c4]

Yes its a 94 Full Size Blazer, built 4L60E. 383 TBI. 4.10 gears, Had the old truck for 15 years. it mainly sits around until I need to to pull my boat or enclosed trailer. I sprayed it with bed liner.

http://i105.photobucket.com/albums/m232/tapyz250/IMAG1711.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG1711.jpg.html)

[steveo]

how much more does it cost to source a used turbo and throw the chinese one in the garbage, though? i do know of a guy that ended up with a few turbo fins wedged in his intake valves... scary stuff

[96lt4c4]

how much more does it cost to source a used turbo and throw the chinese one in the garbage, though? i do know of a guy that ended up with a few turbo fins wedged in his intake valves... scary stuff

Ouch....I figured if the turbo shit the bed, then I would just buy a new GOOD turbo. I have seen where they start getting play in the bearings.

[dave w]

how much more does it cost to source a used turbo and throw the chinese one in the garbage, though? i do know of a guy that ended up with a few turbo fins wedged in his intake valves... scary stuff

Cheap is not good ... good is not cheap :thumbsup: The joy of a good deal diminishes, shortly after the part fails!:thumbsup:

Just saying

dave w

[1project2many]

I don't think anyone that suggests that the resolution "will be poor" has actually driven a vehicle with a 2 BAR MAP sensor.

I'll second that. I'm using $58 with a 3 bar. The most likely practical issue is going to be with BARO updates. When the ecm does a BARO update at high throttle with boost present it will believe atmospheric pressure has exceeded 14.7 psi!

[fastacton]

Speaking of these eBay turbos, has anyone seen any data on failure rates vs. the more expensive ones? Or what are the most common failures? I don't have any experience with turbos (yet), but I used to be in a helicopter maintenance unit that had a turbine engine diagnostics system and they built & rebuilt engines. I saw brand new turbine sections fail during the first run, so expensive doesn't always mean better or more reliable.

[96lt4c4]

Speaking of these eBay turbos, has anyone seen any data on failure rates vs. the more expensive ones? Or what are the most common failures? I don't have any experience with turbos (yet), but I used to be in a helicopter maintenance unit that had a turbine engine diagnostics system and they built & rebuilt engines. I saw brand new turbine sections fail during the first run, so expensive doesn't always mean better or more reliable.

Just google ebay gt45 turbo ___. A lot of them going on LS based engines and making good power.

http://ls1tech.com/forums/dynamometer-results-comparisons/1469506-bone-stock-5-3-ebay-turbo-6psi.html

In 2011 Hot Rod did a dyno test on a junk yard 5.3, using twin Ebay turbos from Cxracing. The pushed that sucker to 1200 peak hp, and it still didn't blow up.

http://www.hotrod.com/techarticles/hrdp_1109_stock_gm_ls_engine_big_bang_theory/

[trippyjoey]

I'm interested in this cause I was thinking on trying the same thing on my 95 Yukon.

[96lt4c4]

Well, looks like I might try to make this happen this winter. I bought some parts today. Decided to convert the truck over to MPFI. Get it up and running and tuned this way first. Then start looking into the turbo kit. Should be easier to hook the cold air side to a setup like this anyway. I will be using an LS1 throttle body. I have a set of LT1 injectors that I am going to try running at 60 psi fuel pressure, would make them 30 pound injectors. I ran the numbers and with boost, 400 hp at the crank, 60 psi fuel pressure, 85% duty cycle, comes out to a 30 pound injector, actually a 28. I am going to try and do this right, but cheap...LOL. If that makes sense.

http://i105.photobucket.com/albums/m232/tapyz250/download_zpse9f53100.jpg (http://s105.photobucket.com/user/tapyz250/media/download_zpse9f53100.jpg.html)

http://i105.photobucket.com/albums/m232/tapyz250/gm-ls6-ls1-throttle-body-adapter-professional-products-70215-4_zpsb34ffdc7.gif (http://s105.photobucket.com/user/tapyz250/media/gm-ls6-ls1-throttle-body-adapter-professional-products-70215-4_zpsb34ffdc7.gif.html)

This elbow setup is pretty cool, it can be rotated 360 degrees.

[Fast355]

Well, looks like I might try to make this happen this winter. I bought some parts today. Decided to convert the truck over to MPFI. Get it up and running and tuned this way first. Then start looking into the turbo kit. Should be easier to hook the cold air side to a setup like this anyway. I will be using an LS1 throttle body. I have a set of LT1 injectors that I am going to try running at 60 psi fuel pressure, would make them 30 pound injectors. I ran the numbers and with boost, 400 hp at the crank, 60 psi fuel pressure, 85% duty cycle, comes out to a 30 pound injector, actually a 28. I am going to try and do this right, but cheap...LOL. If that makes sense.

http://i105.photobucket.com/albums/m232/tapyz250/download_zpse9f53100.jpg (http://s105.photobucket.com/user/tapyz250/media/download_zpse9f53100.jpg.html)

http://i105.photobucket.com/albums/m232/tapyz250/gm-ls6-ls1-throttle-body-adapter-professional-products-70215-4_zpsb34ffdc7.gif (http://s105.photobucket.com/user/tapyz250/media/gm-ls6-ls1-throttle-body-adapter-professional-products-70215-4_zpsb34ffdc7.gif.html)

This elbow setup is pretty cool, it can be rotated 360 degrees.

Remember that the nozzle side of your injector and fuel pressure regulator are both going to see boost. You will likely need something along the lines of a Racetronix or Walbro high pressure 255 lph fuel pump to keep it fed and a very good quality fuel line and fittings. With the regulator set at 60 psi fuel pressure and 10 psi of boost reference you will be at 70 psi fuel pressure.

Good to see you around! You ever get that TBI PCM MPFI run 305 with the edelbrock setup running right??

[96lt4c4]

Remember that the nozzle side of your injector and fuel pressure regulator are both going to see boost. You will likely need something along the lines of a Racetronix or Walbro high pressure 255 lph fuel pump to keep it fed and a very good quality fuel line and fittings. With the regulator set at 60 psi fuel pressure and 10 psi of boost reference you will be at 70 psi fuel pressure.

Good to see you around! You ever get that TBI PCM MPFI run 305 with the edelbrock setup running right??

LoL...cool that you remember me. Yes I had it running good on my boat. Was hard to tune without 02 sensors though. Put the carb back on and sold the boat. Bought bigger one with a 350 and stock TBI EFI. Runs good enough as is.

The truck already has a Walbro 255 in it and has AN lines from the fuel filter forward. The TBI has AN adapters. Should be a direct hook up to the rails. Should be a fun little project. Unless my old 383 decides it doesn't like boost.

[trippyjoey]

How are you gonna run the IAC on an LS1 throttle body?

[Fast355]

How are you gonna run the IAC on an LS1 throttle body?

Same way it is run on a TBI!

[trippyjoey]

Same way it is run on a TBI!

I mean wiring it and are the voltage values the same, or would you need to do some tune adjustments?

[Fast355]

I mean wiring it and are the voltage values the same, or would you need to do some tune adjustments?

No issue wiring it and the voltages are the same. Its a stepper motor with an extend and retract coil. Tune adjustments would be very minor. Big Block 454 TBI units used a very similar IAC. LT1, CPI 4.3 and the Vortecs used practically the same as well.

[trippyjoey]

No issue wiring it and the voltages are the same. Its a stepper motor with an extend and retract coil. Tune adjustments would be very minor. Big Block 454 TBI units used a very similar IAC. LT1, CPI 4.3 and the Vortecs used practically the same as well.

Awesome!
I'll ask a friend of mine to see if he has his old TB since he put a 408 in his Trans AM to try it since I want to go MPFI on my tbi.

[Fast355]

Awesome!
I'll ask a friend of mine to see if he has his old TB since he put a 408 in his Trans AM to try it since I want to go MPFI on my tbi.

I would use a 454 TBI unit, without the injectors (fabricate a block-off) on a TBI-carb adapter on a marine dual plane MFI intake.

[trippyjoey]

I would use a 454 TBI unit, without the injectors (fabricate a block-off) on a TBI-carb adapter on a marine dual plane MFI intake.
I was originally thinking of using a 454 TBI and the injectors for this build but for the price I keep on finding the tbi units here locally and the internet this seems like a better option. I was thinking of originally using a tpi throttle body.

[96lt4c4]

Some parts came in, waiting on my elbow. I got a throttle body off a 6 liter truck motor. Its pretty nasty, needs cleaned up. The intake has no vacuum ports so I am going to have to fabricate something to bolt a MAP sensor too and some way to hook the power brake booster up. I have a friend with a tig so that's no problem.

For the whole setup being Chinese, I am pretty happy with the quality. The ports need a little cleaning up, and some gasket matching.

LT1 injectors went right in.

This thing might make some serious power...LOL

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0669_zps6qn30r0r.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0669_zps6qn30r0r.jpg.html)

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0670_zpsfxfcpzjp.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0670_zpsfxfcpzjp.jpg.html)

[trippyjoey]

Looks great you got a link to where you got the setup?

[96lt4c4]

Looks great you got a link to where you got the setup?

http://www.professional-products.com/

Just look around online for the cheapest prices, most of this came from Amazon

[96lt4c4]

Thinking about buying a boost gauge with a 0-5 volt output so I can log boost. I have my wide band connected to my Autoprom and log AFR through it. Can the boost gauge be hooked to a unused 0-5 volt input on the PCM. Its been a while, I cant remember, seems like it could be done through the EGR or the CPI stuff.

[Six_Shooter]

You could use a MAP sensor (2 or 3 BAR), and connect it to another ADC channel of the AutoProm.

I'm not aware of any boost gauge that has a 0-5V output similar to a WBO2, but if you find one, definitely post back, because that would be interesting and useful.

[96lt4c4]

Here you go.
http://www.amazon.com/gp/aw/d/B001DX7KMY?pc_redir=1411126725&robot_redir=1

[96lt4c4]

Mocked this bad boy up last night. Going to have to get creative with my throttle bracket. I need and extra vacuum port for my power brake booster, so I will have to drill and tap the intake for that. This intake has no vacuum ports. Not sure what water neck I am going to use. Going to clean some wiring up while I am in there too. Getting ready for a hair dryer...

I also decided against the intake elbow, apparently when you run one of these NA it can cause the back cylinders to run lean. So I went with this style TB and will be using a carb hat to blow through.

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0712_zpsfb8179db.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0712_zpsfb8179db.jpg.html)

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0714_zps826873e5.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0714_zps826873e5.jpg.html)

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0715_zpsfd29ef1d.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0715_zpsfd29ef1d.jpg.html)

[buddrow]

Looks nice, now I have something else to put on the Christmas list. :rockon:

Buddrow

[hammered94]

Cant wait to see how this turns out, I've always wanted to turbo my 94 Blazer.

[96lt4c4]

Here you go. running on the current tune it had while still TBI. I Just set the timing and played with the fuel pressure set to 40 PSI. I didn't have time to do an logging. That is an Edelbrock TB.

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0728_zpspkl284sl.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0728_zpspkl284sl.jpg.html)

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0729_zpsbvuwt3le.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0729_zpsbvuwt3le.jpg.html)


https://www.youtube.com/watch?v=8X7r87w1icI

[trippyjoey]

Love it man can't wait till I can do that to mine.

[96lt4c4]

Turns out the old LT1 fuel injectors don't like 60 pounds of fuel pressure..LOL. They couldn't open against the pressure. Turned it back down to 40 and everything seems fine. Just did some tuning at idle tonight for about an hour.

[trippyjoey]

Did you have to switch the fuel lines for this or did you use the factory metal fuel lines? Minus that rubber section of fuel line after the filter I'm guessing you swapped that out to hold the high fuel pressure.

[96lt4c4]

Did you have to switch the fuel lines for this or did you use the factory metal fuel lines? Minus that rubber section of fuel line after the filter I'm guessing you swapped that out to hold the high fuel pressure.

I have an adapter at the fuel filter to convert over to AN -6 lines, same with the return line.

[96lt4c4]

Borg Warner S366 Turbo. So far I have a boost gauge, 2 bar map, turbo and carb hat. Ordered all the stainless piping to make up the hot side today.

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0858_zpsffnz7jca.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0858_zpsffnz7jca.jpg.html)

[scottyd]

Cool stuff looking forward to seeing how u tune for the boost

[96lt4c4]

So I modified my XDF for boost, really all I did was re-scale the Main Spark and VE tables, for the 2 bar MAP. I found a chart that shows the output voltages of both sensors (1- 2 bar) and used it to convert the tables to show boost. I really cant find any other tables that would need to be changed. If I do I will change them as I go. This should get me started. I did change that MAP AE table too.

Now I need to figure out how to re scale the ADX file to show boost, should be all good.

Just added an ADX file that I modified for boost, not sure if it will work. I will test it out and see.

[scottyd]

Very cool! I've read that you can rescale the values for a 2 bar by cutting them in half but the chart I saw comparing 1,2,&3 bar maps weren't exactly half. Do you recommend a formula too use?

[96lt4c4]

Very cool! I've read that you can rescale the values for a 2 bar by cutting them in half but the chart I saw comparing 1,2,&3 bar maps weren't exactly half. Do you recommend a formula too use?

No formula needed really. all you do is change the tables to read boost, so originally the 1 bar KPA value for 2.5 volts is 60 KPA, where 2.5 volts is 110 KPA or about 2 PSI of boost on the 2 bar.

http://www.robietherobot.com/storm/mapsensor.htm

110 KPA is about 16 psi so 16 psi - 14.7 = 1.2 psi
14.7 is barometric pressure at sea level.

[scottyd]

Thanks for that link, lots of good info there.

[96lt4c4]

Tried driving the truck today with the 2 bar map. Didn't go so good, I have some research to do.

[Roadknee]

Could it be that the MAP values in your modified XDF are not exactly double those in the stock XDF? For example in the stock XDF the lowest value is 20 and yours is 30.

[Six_Shooter]

This is what most people find when they use a 2 BAR MAP on a 1 BAR code and only try to modify the VE and spark tables based on scaling for the different MAP sensor.

The BARO updates don't update correctly, and a few other parameters that rely on a 1 BAR MAP sensor being attached and knowing that 5V = (approx) 100 kPa. Many people have got it to work, but it always seems to be a compromise.

[dave w]

This is what most people find when they use a 2 BAR MAP on a 1 BAR code and only try to modify the VE and spark tables based on scaling for the different MAP sensor.

The BARO updates don't update correctly, and a few other parameters that rely on a 1 BAR MAP sensor being attached and knowing that 5V = (approx) 100 kPa. Many people have got it to work, but it always seems to be a compromise.

Interesting information. I'm thinking the Baro updates at startup? I'm wondering if two MAP sensors could be used, 1 bar MAP at startup for Baro then the 2 bar after startup? Maybe use a DPDT relay to switch between MAP Sensors for the Baro reading?

dave w

[Six_Shooter]

Baro updates more than just at start up. It'll somehow do it while the engine is running and at WOT.

[delcowizzid]

we used to use 1 bar code with 2 bar sensor pretty much set default map at key on at 50kpa.it may not be defined in your xdf or may not exist. halve all the table kpa values and fudge the injector rate to double fueling so the ve table didnt max out LOL

[scottyd]

I had worries that it wasn't as easy as that seemed. I read a thread not long ago where a fellows solution was to use a 1 bar map and just up the fuel in the 100 setting only, basicly I suppose any time the engine was in boost it got more fuel and the higher the rpms the more fuel based off a single column for tuning... seems simple but also seems crude and not very linear.

[96lt4c4]

we used to use 1 bar code with 2 bar sensor pretty much set default map at key on at 50kpa.it may not be defined in your xdf or may not exist. halve all the table kpa values and fudge the injector rate to double fueling so the ve table didnt max out LOL


I have been researching, looks like a lot of people just keep right on using the 1 bar map sensor. I guess I will just have to see at what RPM this thing starts to build boost and use the PE parameters to subtract timing and add fuel. If it starts building boost at say 2500 RPM then just make sure I am entering PE early enough to use the PE AFR and PE timing tables to do what I need to do. I may revisit the 2 BAR map after I get it up and running. I will look around in the hack and through the .XDF file to see if I can find anything.

Trying to figure out why I would need to fudge the injector rate? I had thought about lowering mine to richen the whole thing up. No mater what I did to the VE tables I was still way lean. So i could see where lowering the injector value would richen everything up but don't understand why.

[Roadknee]

Trying to figure out why I would need to fudge the injector rate? I had thought about lowering mine to richen the whole thing up. No mater what I did to the VE tables I was still way lean. So i could see where lowering the injector value would richen everything up but don't understand why.

An engine with decent induction, heads, cam, exhaust, etc., will need more fuel than you can provide by setting VE cells to 100. Since the code won't accept VE over 100 you need to reduce the injector value.

[96lt4c4]

An engine with decent induction, heads, cam, exhaust, etc., will need more fuel than you can provide by setting VE cells to 100. Since the code won't accept VE over 100 you need to reduce the injector value.

I was trying to drive the truck with no boost. Just the 2 bar map installed thinking that by re-scaling my tables that it should still run to 100 KPA just like normal. But it ran horrible. I am going through the MAP and Baro update tables right now, comparing them to a GMC Syclone bin but I am not real sure what I am looking out or how these tables work.

[scottyd]

Have you ever considered a FMU? raises fuel pressure at a determined ratio based off boost to push more past the injectors. For example 1:6 one pound boost raises 6lb fuel.. Iirc thats what Paxton and other supercharger companys were doing with TBI and early mpfi applications.

[96lt4c4]

Well drove the truck last night, boost comes in quick, around 2000 RPM. I had to set my PE enable TPS to about 25 % to get it to richen up, which it does. But, it starts to lean out as the RPM picks up, so I have to let off pretty quick. Only about 5 pounds of boost right now. I retarded my timing table about 7 degrees in high load area, not getting any spark knock. I am thinking about putting main spark table back where it was and pulling timing with the PE spark table.

Today I am going to try hooking my AFPR back up to vaccum/boost source and raising the fuel pressure back up to about 60 psi, about 43 psi right now. 5 psi boost should raise raise fuel pressure 5 psi. I may have to fudge the PE AFR table to get it to richen up as RPM climbs. Open to any ideas here.

But man! turbo is freaken awsome! until lit goes lean...lol

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0920_zps6xof4hhl.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0920_zps6xof4hhl.jpg.html)

[Six_Shooter]

Wait, you're running an MPFI setup without vacuum(/boost) referencing the FPR? If that's the case, connecting a vacuum source will help lean out idle and richen up high load/in boost areas.

[96lt4c4]

Wait, you're running an MPFI setup without vacuum(/boost) referencing the FPR? If that's the case, connecting a vacuum source will help lean out idle and richen up high load/in boost areas. Yes I am, I had it connected to vacuum but had disconnected to troubleshoot other issues. I am hooking it back up today.

[delcowizzid]

start with a standard base fuel pressure 38psi or so idling withe the vacuam diss connected .running 60 psi base will just drop the flow rate of the pump so much right off the bat even before boost adds more pressure

[Roadknee]

I am impressed with how quickly you got that put together. Are you still running the 2-bar MAP?

I'm pretty sure the PE spark table won't accept negative values.

The fuel regulator that scottyd mentioned in post53 might be worth a look.

[96lt4c4]

We did get it done really quick, worked on it over the holidays, had vacation days. You are right PE timing won't take negative numbers. Right now I have about 50 psi fuel pressure with the vacuum hooked up. I have the same style injectors and pump thats in my Camaro and it runs 62 pounds all the time. It has really only taken me a few days to get the major bugs worked out, the thing runs like a raped ape...lol. Still on 1 bar, 2 bar is going to take some effort.

[96lt4c4]

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0944_zpswgixfob6.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0944_zpswgixfob6.jpg.html)Doing some painting and rerouting wires.

[96lt4c4]

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0942_zpslvw8nyym.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0942_zpslvw8nyym.jpg.html)

[delcowizzid]

be very carefull with that before turbo flexi joiner if its stainless weave inside you should only use coviluted pipe internal ones or you will end up with all the stainless wire inside your turbine housing the hot and cold cycles snap the wires and it turns into a ball and ends up in the turbo looking like a steelo scrub pad LOL

[delcowizzid]

if youre lucky only one end lets go kills power real fast but less damage

[96lt4c4]

if youre lucky only one end lets go kills power real fast but less damage
I researched that, only stainless wire on the outside.

[scottyd]

Looks great!! Bet it sounds great too.

[96lt4c4]

Still looking for some info on the possibility of running a 2 bar map. Any ideas?

[96lt4c4]

Alright guys, I have this thing back up and running on the 2 BAR map and so far its running pretty good. I did this yesterday and did not have a whole lot of time to do any VE tuning but its driveable.

Sat night I studied the hack and found 2 parameters that I thought might help make this possible. The main one is at 5D06 and is labeled "BARO sensor at 0 press" the stock setting is .55 mvdc. The way I take this is the voltage the PCM is looking for at zero pressure. Well the 2 BAR at 0 is 2.25 vdc. So I changed that. The other parameter I found, which I am not really sure needs to be changed is at 5D05 "BARO SENSOR VOLTAGE CHANGE PER KPA" stock is 53 mvdc.

So I have a .xdf and .adx file setup to log boost. Its show's boost, 2 BAR KPA and 1 BAR KPA as if the stock 1 bar map was still installed. It also shows MAP voltage. I also have the Data Trace features working on the Timing and VE tables VS. the 2 BAR map and it seems to be accurate on the timing but I am not real sure about the VE. I have read that you need to halve your VE table, which I am trying to figure out if am using half or the whole thing. Is there anyway to log what VE percentage the PCM is using? The data trace shows that I am using the entire table but I am not sure if that's correct. I do know the timing is spot on by comparing my data log to the data trace. Which VE and timing are both MAP VS RPM, I cant figure out why one would use the whole table and the other not.

I also lowered the injector constant to give me more fuel, so this bin is just a starting point.

If you don't mind to take a look at what I have and let me know what you think

[96lt4c4]

When you guys talk about halving the VE table, are you talking about halving it because the upper half is now used for boost? As in the PCM still uses the whole table but now where you had the whole table for 0-100 KPA you now have the whole table for 0-200 KPA. Lower half no boost, upper half boost.

Or the computer only uses half the table and you now have 0-200 KPA crammed in the lower half of the table?

If the first is correct then thats the same resolution as the stock $58 code. I don't see a problem there. If the second is correct then that kinda sucks.

http://i105.photobucket.com/albums/m232/tapyz250/VEtable_zps8b36af0a.jpg (http://s105.photobucket.com/user/tapyz250/media/VEtable_zps8b36af0a.jpg.html)

[brian617]

When you guys talk about halving the VE table, are you talking about halving it because the upper half is now used for boost? As in the PCM still uses the whole table but now where you had the whole table for 0-100 KPA you now have the whole table for 0-200 KPA. Lower half no boost, upper half boost.

Thats the way I understand it as well.

[dave w]

I don't think it will be exactly have. I don't think the "boost" will achieve 5VDC. Maybe the "boost" will send to the PCM something in the range of 3.8 ~ 4.2 VDC?

dave w

[Six_Shooter]

Dave, it depends on how much boost is being used. If there is 15PSIG+ of boost then the (2 BAR) MAP sensor will go to or very near 5V, which would be full scale.

[dave w]

Dave, it depends on how much boost is being used. If there is 15PSIG+ of boost then the (2 BAR) MAP sensor will go to or very near 5V, which would be full scale.

I agree, it will depend on how much boost.

Below is a conversion I did, Inches Mercury (In Hg) to Kpa. The MAP voltages are from based on the data provided at http://www.robietherobot.com/storm/mapsensor.htm

In my thinking Non Boost is going to measured from 0 VDC to about 2.5 VDC. I think it's not be the best system for using a 2 Bar MAP, because only half of the VE table is used for Non Boost. I think having some VE Table for Boost is much better than not having any VE Table for Boost.:thumbsup:

dave w

[Six_Shooter]

If you're worried about resolution, don't be.

I use $59, which uses a 3 BAR MAP sensor and have never found that I needed more resolution. Granted there are more overall points, but to be honest I think that the amount of tunable points in the $59 VE table is overkill.

[96lt4c4]

If you're worried about resolution, don't be.

I use $59, which uses a 3 BAR MAP sensor and have never found that I needed more resolution. Granted there are more overall points, but to be honest I think that the amount of tunable points in the $59 VE table is overkill.

OK cool, that confirms what I am seeing then.

Took it out for a quick drive today after work to log some wide band data and maybe try to get my VE a little closer. Seems like I am having issues getting my VE dialed in. Its rich at idle and lean at cruise. I have made some small changes but they don't seem to be doing anything.

Do you guys know if the injector duty cycle would still be correct going from TBI to MPFI? If it is I may be maxing out my injectors...LOL. I am getting 100% duty cycle at 5200 RPM. Also would it make sense for my VE to go over 100% in the boost areas? Seems like it should right? Right now I am just riching it up in the PE AFR table.

Awww....VE table wont take anything over 100%, just tried. I think this is why you have to fudge the injector constant.

[delcowizzid]

this is why you halve all your ve values and fudge the injector constant as ve cant go over 100%.closed loop probably wont have a chance of working any good disable all closed loop and run pure open loop.the tune will probably change a lot day to day being so fudged

[dave w]

OK cool, that confirms what I am seeing then.

Took it out for a quick drive today after work to log some wide band data and maybe try to get my VE a little closer. Seems like I am having issues getting my VE dialed in. Its rich at idle and lean at cruise. I have made some small changes but they don't seem to be doing anything.

Do you guys know if the injector duty cycle would still be correct going from TBI to MPFI? If it is I may be maxing out my injectors...LOL. I am getting 100% duty cycle at 5200 RPM. Also would it make sense for my VE to go over 100% in the boost areas? Seems like it should right? Right now I am just riching it up in the PE AFR table.

Awww....VE table wont take anything over 100%, just tried. I think this is why you have to fudge the injector constant.

I think Wide Band data in the data log would be very helpful. Maybe a good plan going forward would be Open Loop tuned with Wide Band in the data log?

dave w

[96lt4c4]

I think Wide Band data in the data log would be very helpful. Maybe a good plan going forward would be Open Loop tuned with Wide Band in the data log?

dave w

I don't know, I am going to play with it some this weekend. For the most part the truck is running really good. I took a couple more degrees of timing out of it. I was getting a little knock at 100 KPA (no boost) no knock at all under boost that I can hear. I know when the weather warms up this thing is going to be a whole different animal. I really need to get a MAT installed as well. Also need to put the knock sensor back on. Truck has not had one for years.

I would really like to keep the thing in closed loop if at all possible, don't really see why that cant be done, its running that way now and makes fuel corrections.

[96lt4c4]

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0974_zpseu8bhq7r.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0974_zpseu8bhq7r.jpg.html)

http://i105.photobucket.com/albums/m232/tapyz250/IMAG0976_zpsssfk0ezb.jpg (http://s105.photobucket.com/user/tapyz250/media/IMAG0976_zpsssfk0ezb.jpg.html)

Building a new motor, adding a MAT sensor and putting the knock sensor back on, but I need a V8 Memcal, mine is V6. Anybody have one?

I let a friend borrow the stock one out of my truck, was tuning for him, and his truck caught fire with my memcal in it....years ago... I have been running a V6 memcal since with knock disabled.....:mad1:

[dave w]

OUCH$$$

I think you should strongly consider "Tuned OPEN LOOP". The VE Table in "Tune OPEN LOOP" is adjusted the same was as an running engine closed loop. BLM's are not as accurate as AFR data. The '7427 still uses the VE tables in OPEN LOOP.

dave w