Don't know if this has been posted here before.

SVTPerformance - View Single Post - 03 Cobra vs 09 T/C Cobalt SS

 

lol smoking while racing, that's aggressive.

 

He seemed butt hurt about doing a roll race. C'mon... FWD vs. RWD. Unless he SUCKED he should have the dig race. That's a no brainer.

 

giving the car credit over there.

of course you'll have a couple people who hate on them, but it's expected

 

There's a little left in that Cobalts tune. My balt was pulling away from my Cobra when the Cobra was still stock.

 

I was thinking the same thing.

 

Then again it's probably a Trifecta tune car

 

lol I got a kick out of that , dudes like screw you muh fuka big old smoke puffin away .


Good **** LOL

 

they werent even going fast..i woulda kept going lol...idk if there was traffic tho lol

 

I know both of these owners.. 2 good friends of mine. The TC has a mildly safe HP tune, no KR anywhere and a little richer than what most people here run. Also only like 22psi. The cobra nowadays is stupid on a KB.

I pulled the TC a little on spray.

 

So do these 2 live in SoCal?

 

Sounds exactly like my car..same tune...22 lbs Max..tuned a little rich ( AFR 11.7-12.3 range).

 

That is more than a little rich for this motor, on gasoline anyway.

 

that cobra didn't have a blower, you counldn't hear the whine.

 

wow 40 in first that's fast.

 

Stock Cobra=55 MPH in first.

 

52 actually running it to 7k. Stock redline is 6500, roughly 46.

 

AFR was I believe in the .81-.83 range last time I logged it.

 

I know..you may have seen this before....
Well, here is Tune chart of AFRs before and after. Note the coresponding changes in torque
and HP.
+20 HP and +30ft lbs torque at 3500RPM. +15 HP and +20Ft Lbs at 4000RPM.
BTW, the motor was detonating on full boost at the original AFR. Timing was also backed off a tad. I don't think I'm pig rich here...just wana be on the safe side. I run 22 MPG ave and I drive it HARD..How rich can I be?

 

It is strange that the car shows gains going that rich (must have been the elimination of the KR). My car made 25 whp more at 13.0 A/F than it did at 12.4 A/F (stock timing on both runs). Richening my car does not help with KR on my car. I can run the same amount of timing at 13.0 A/F vs 12.4 A/F. I have 93 octane gas but even on 91 I still run them lean but with less timing.

 

cali has oxygenated fuel, add about 6% more fuel to the mix to be safe.

 

The WB on the car picks up the extra O2 and will richen it back to the commanded lambda value (LNF is always in closeed loop) so on the E-15 I think they have. I still use the same PE Lambda value but stoich for E-15 is ~13.85 so 0.883 PE lambda for E-15 is ~12.23 A/F I forget those dyno WBs read in A/F not lambda because I so used to reading my scanner data in lambda.

 

makes sense, never tuned an LNF, but wouldn't that throw off the fuel trims?

 

Yes it does but I always fix them. Cannot adjust stoich on the LNFs with HP Tuners so the only way to fix the fuel trims is to adjust the MAF tables. I have done 6 LNFs so far on a 50/50 mix of E-85 and gasoline so I know the drill.

 

Interesting...never thought of that.
Sean Church of Church Automotive is a tunning *guru* out here in so cal and is highly regarded. He's tunned thousands of cars over the years.... really knows his **** and takes his tunning seriously. His concern was being *safe*. Like I said, according to my overall gas milage (@22MPG), I can't be running that rich! I guess the best way to find out would be OA for fuel dilution.