2003-2005 Cavalier Fake Bar with S/C

[kiwiracer]

Hi, I see these threads from 8 years ago, about allowing the tables to be configured above standard values..

http://www.hptuners.com/forum/showth...light=fake+bar
http://www.hptuners.com/forum/showth...light=fake+bar

Then I see FakeBar configurations for Ecotec's in the downloads..

Im trying to tune my M62 (Cobalt SS) supercharger on a L61 Engine. The ECU is a 2003 Cavalier.

When I attempt to set values in the tables, the Max hits, and Im not able to do the 2.5X multiplication to adjust for the TMAP 2.5 BAR sensor vs the old 1.0 bar sensor on the stock engine.

How do I get it so I can set tables beyond the stock limits to accommodate this 2.5 bar TMAP sensor ?

thank you !

[kiwiracer]

Ok, I have re-read the articles.. Like you do on a Saturday morning. I dont need to go beyond the limits, It looks like I just set them at the maximums..

It did give me another idea thou, has anyone used any MAP sensor regulators/adjustors to map 2.5 bar values back into 1 bar voltage ranges ?. It seems you could do this and keep the resolution,

[cobaltssoverbooster]

cavalier is alpha-n it only uses the map at idle and cruise. changing the bar of map doesnt effect your performance.
alpha-n is tps by rpm.

*edit: you can technically run 2 bar but i believe it requires a dealer reflash??

i didnt want my post to sound like a complete shut down so i found you this read that should help you out with your SC setup:
http://www.ecotecforum.com/forums/sh...C-Fake-2-5-Bar

[kiwiracer]

Thanks for the feedback, that's right, Fuel @ Idle is MAP based and with us using this for road racing only then the TPS should be good for High RPM.. It's the Spark where it uses the MAP values, for the advance/etc.. But I think I can get this sorted by following the process in the forum post I referenced.

I am still fairly new to tuning, this is a personal race car (miata, with L61 now with supercharger :-)), endurance racing..

I did not think there was a factory reflash for the 2003 cavalier ECU (What I have) ? I will look around..

btw: I had not seen these guides in your signature, it looks like some great reading

Cheers !!

[cobaltssoverbooster]

gm offered a reflash a while ago.. im not 100% sure if it is still available but i do remember people having trouble reading it with hpt. i would check the repository to see if the gm flash ecu's have been read and saved. it would mention a gm flash in the file notes as its a special file.


i wanted to put a turbo 2.2 motor in a miata so bad but never pulled the trigger. nice to know someone out there is making it happen.

[JMHZ2401]

I recommend running the 1 bar map sensor on the M62 in a Ecotec Cavalier.

[Dr. Nopps]

I downloaded the GM reflash from the HPT repository years ago just to research it & still have it on my laptop that is currently fried, but yeah it was basicly just a factory version of a fake 2 BAR tune w/ larger injectors. It would be kind of handy however if you decide to go the fake 2 BAR route as the values along the rows & columns of the VE tables are already correctly re-labled for you and the timing tables looked normal, as long as you stick with a 2 BAR MAP sensor of course. I hate to disagree with anybody on here especially cobaltssoverboostet as he knows more about tuning than I probably ever will, but I'm sure those Cavaliers run both MAP and Alpha-N. Those early Cavaliers are a funny little animal indeed but I've studied their habbits quite well and would swear that by playing with the different modes the PCM would go into: Alpha-N was being used at idle and also when in open loop and even still when below 1% throttle and when not in PE which while running in this format would constantly fluctuate the commanded AFR in direct relation to TPS. However when the car was in closed loop and in PE mode with at least 1% throttle applied and no DTC's or open/disconnected sensor circuits present, I would swear it was commanding a constant AFR and using it's MAP and it's VE tables to control fueling allowing for some fueling tunability, at least where you would see most of your boost. Unfortunately because of all the above you have to leave your o2's plugged in and trims active while tuning but I believe people used filters while logging their scans to help with that and they now have widebands with programmable outputs to simulate factory o2 signals making this a little easier still. Funny little PCM but simple and very few tables, only the bare basics of what you really need to fuel inject a car or even most motorcycles! It's the reason I fell in love with that style (MAF-less Cavalier/Sunfire) PCM & operating system and plan on running a much newer block using it. I know it sounds crazy, but it should be unique and fun and I'm really serious about trying it out. And to help clear up the confusion for the OP they don't actually max out the values when generating a fake 2 BAR tune, they multiply the values in their VE tables, their injector constant, and their timing tables by 2 and by 0.5 or by 2.5 and 0.4 for a fake 2.5 BAR tune then adjust the part at the bottom of the table for VE Offset. This fools the PCM into thinking it still has the 1 BAR sensor. No type of regulator could really expand the resolution because ultimately in the tune you still have only ten MAP columns to control 200KPa at the end of the day. You could design a conversion module for it to read properly range wise, but I think just doing that without fudging the rest of the data would just essentially convert the 2 BAR sensor back down into a 1 BAR sensor. It would have to "convert" 100KPa from the 2 BAR sensor from 2.5 to 5 volts which is the maximum value for the sensors table reading leaving the upper range of the sensor itself useless. Hence why some guy one day came up with the idea of a "Fake 2 BAR" tune.