This is from a Stage2 running a 2.8 pulley:


as you can see there is 100% duty at 6300rpm and 90% occurs at 5800rpm.

as for meth/water injection, on my car I removed fuel up top because the car would go rich when the meth would kick in. This would help lower duty cycle top end.

as for knock, meth injection would raise your octane to help remove knock top end.

These are just from what I've seen logging cobalts/redlines.

Oh btw. anyone running an aftermarket intake might have a problem with their IAT1 sensor. As you can see here the IAT1 is incorrect (way too high). I've seen this on another with an intake.

31.7psi absolute pressure off the MAP = 17psi boost

 

*sigh* alot of conflicting reports.
looks like a car by car thing to me.

 

This is what I was trying to tell you guys. I have seen at least 3 screen shots like that and all say the same thing. So I have never seen proof that a 2.8" pulley with 42lb injectors is safe. All I have seen is that it's not and proof is what matters.

Like I said guys, I recomend no bigger than a 2.85 or even a 2.9 to be safest. It's all in the proof.

 

You are at 6000ft of elevation. This will change the mass air flow and thereby the fuel flow will be less. If you were at sea level you would see 100% IDC's.

Pierre

 

See with just the 3 in my IDC hits a max a 64 so droppping .2 inch pulley would bring that up to 90+%

 

it seems your IDC is not setup correctly, you should be getting higher numbers specially if you are running the stock injectors. In HPT, under custom PIDs the formular for duty should be [SENS.112]*[SENS.70]/1200 also your TPS% is not correct as it should read 100% during WOT. I can send you my cgf file if you PM me your email.

 

PM Sent

 

Mase,
i got the config u sent me but something seems wrong with it. No way on Stock GM stage 2 i am getting 130+% Inj duty.

 

It looks like it really might be 1/2 of that. Not 130% but 65%

That would make more sense. I may be wrong.....

 

On the config i had before i was 64 around 6900 and was trying to understand that a .2 drop would casue 26% rise in my inj duty. I really dont know that much so that why i am wondering ?

 

I was actually thinking about this. Most of the 2.8 guys up here only see 14.5-15.5 psi. Well within safe limits but at sea level 17-18 might be more accurate. This being the case, our 2.8's work just fine with the 42's while others may not.

Also, another thing I was thinking about. The Gm Stage 3, when it is released, could have a smaller pulley and other things but I havent heard if it will have different injectors. If the pulley is close to 2.8 but no bigger injectors than what does this say about the IDC's? All things to think about.

 

How much difference in boost is there between a 2.8 and a 2.85? 2.8 and a 2.9?

 

in theory 2.9 -> 2.8 1lb 2.8 --> 2.85 maybe a 1/2 lb thats all in theory though

 

uh ohhhh more conflicting reports

 

the formula from WOP (if you know who he is) is [rpm x inj pulse (INJ B1)]/1200

try it, you will get 130%, there's something definitly wrong with your tune. I get max. 80% with 60lbs with the exact config file. I log my buddy's and his are in the 100% with 42lbs and 2.8.

Do a run in 3rd from 3000rpm with trottle 100% all the time, in the above log you only when WOT in the very end.

 

OK i can try that but I am not doubting you man but i have the preatty much STOCK Stage 2 tune the only thing i edited about it was the MAF failure and i have my fans turn on sooner if you want ill be more then happy to email you my tune maybe there is something wrong would you take a look at it just to make sure and any help you could be would be great!!!

 

Well, after my trip to Atlanta this past week and driving in the much cooler weather, I have gone ahead and ordered the 60# injectors. I doubt it helped any that my car was custom tuned with a 98F shop temperature, either, but I am most definately running lean up top. At only 4k rpm I am seeing about 3-4 kr and at 6k rpm about 5. I haven't run it any higher than 6k rpm ever since because it sputtered and back fired on that one run right at 6k rpm, also threw a P103 code. Injectors and a new tune FTW.

I know at least one person on these boards actually suggested running HOTTER plugs for the winter, anyone else have an opinion on whether this will help?

 

Interesting questions...

Could anything bad happen while running a step colder plugs in the winter?

-Rich

 

one of the cars that levi has a scan from is mine I have run 3 different tunes to deal with KR and each one no matter what i do the highest IDC i see is 85%