Jochen

Hi,

i scanned my Stock PCM file for my 97 C5 and saved it to my HD. Then i flashed the PCM with my Hypertech PP III. Then again scanned and saved the PCM file (with the now installed Hypertech file).
It took me a view hours to compare both files, table by table. Beside Fan ON/OFF settings, most changes had been done in the low octan spark table (just a view changes in the high octan table) and in the Power Enrichment (PE) table.
What really confuses me is that the PE settings in the Hypertech tuning had always smaller numbers in the respective cell than the stock tuning (e.g. stock cell is 1.23 which leads to AFR of 11.95:1 - Hypertech in same cell is 1.20 which leads to AFR of 12.25:1) which should mean that with the Hypertech tuning the cars should run more lean than with the stock tuning under WOT. . . So why do i get more HP with the Hypertech installed than without ? (i gained about 18 (DIN) HP with the Hypertech installed compared to Stock PCM programming).

Hope somebody can explain.


Thanks,

Jochen

horist

Lean = power
Too Lean = boom

The leaner you can run w/out detonation/KR the more power you'll make. the HPP3 power tune leans the WOT mixture so assuming no detonation you'll make more power.

Some cars have the opposite affect to HPP3 tuning, especially if they're running an aftermarket MAF that leans the car out already... (reports less airflow) ...

Jochen

Thanks for your very fast answer.
So as long as i dont get any KR, i can try to lean a little more out in the PE table, right ?
Like, changing small numbers, Dyno car, while on dyno log data and check for KR, if no KR try to lean out a little more . . . until KR is present, then step one back and check again KR ?

Sounds like some work, but save . . . ??!!

Thanks,

Jochen

foff667

iTrader: (2)

not necessarily...just because you dont have KR doesnt mean your going to make any more power...generally though, yes.

Phoenix 5.7

iTrader: (7)

changing timing is another option instead of just leaning it out to make more power

luv2spd

iTrader: (1)

Use a wideband to adjust the a/f mixture to 12.8 or so and then mess with the timing to achieve optimum power.

Jochen

How do i find the best timing ? just increase numbers and check for HP and KR ? As soon as no KR and no HP gain stay with the setup ? sounds like a lot of work and time on the dyno . . .

I was (and still am) thinking about the WBo2 thing. However, i have to check first the dyno i alway visit about there capability to deal with WB Sensos . . . I guess its not that common here in "good ol germny"


Thanks,

Jochen

Phoenix 5.7

iTrader: (7)

generally people set the AFR at one value and adjust timing for power, like luv2spd said. yeah u just have to play with it on the dyno. A real tune would be your best bet, but id wait till u have some mods done first. it might be hard to find a tuenr with ls1s over there. if that is your main way of getting power, then you need real parts. its hard to get parts over there, but only so much can be gained by fooling with those 2 variables.

ZL1Killa

iTrader: (17)

Ok, you need to look at the proper numbers for the differnt Air to fuel ratios. First of all look under the file that is in the PCM and tuning category on this site and find the sticky with HOW TO TUNE 101...........in that file you will find this:
AFR Info

Here is a chart that I have that should give you some insight into what standards are for lean cruise etc...

9.0:1 BLACK SMOKE (NO POWER)

11.5:1 RICH BEST TORQUE @ WOT

12.2:1 SAFE BEST POWER @ WOT

13.3:1 LEAN BEST TORQUE @ WOT

14.6:1 STOCHIMETRIC AFR ( CHEMICALLY CORRECT )

15.5:1 LEAN CRUISE

16.5:1 BEST FUEL ECONOMY

18.0:1 CARBURETED LEAN LIMIT

22.0:1 EFI LEAN LIMIT

That explains most of your question, and since the cars run kind of rich from the factory that is why they gain so much power. I will tell you that right now I'm running around a 13 AFR and my car is fine; my dyno is in my sig.

I would much rather learn how to tune and be careful and tune my car and get even more horsepower out of it from using a FULL TUNE from a program such as HP TUNERS OR EFI LIVE V7 and of course use a AFR monitor and other monitors to make sure everything is ok.

Jochen

Thank you guys. I found this link:

http://www.transamws6.net/HPTuners/ls1tuninginfo.doc

Which most of you know already. Just printing it out . . .

Cheers !

Jochen

Jochen

Ok guys, one more question:

i attached a picture where you can see two loggings. The histogram on the left shows a logging run with the MAF connected, the histogram on the right shows another run without MAF.

I want to leave the MAF Sensor connected in the car. So what do you guys recommend: Changing the VE table according the table on the left (with MAF connected), or changing VE table according the histogram on the right (the histogram wich i got when logging without the MAF). Keep in mind, i want to keep the MAF Sensor in the car all the time.

If you guys think its better to run without the MAF - what are the benefits and drawbacks in doing so. I guess when i run the car without MAF, i need to tune using the right histogram . . .

Hope this is not a dumb question, but i was just wondering and dont want to mess the VE table . . .

Thanks for your help

Jochen

Jochen

Nobody ?

Common guys, somebody should know . . .