C6 GS 2010, stock : KR

[Brice]

I've tuned 2 Corvette C6 today.

A C6 LS3 2009 and a 2010 Grand Sport.
both 100% stock, Octane 93.

stock 2009 & 2010 stock tune are about the same.
But the GS has 6-7 KR from factory between 4000 and 6500 rpm
with factory tune at wot, the 2009 is 23 degree timing and the GS : 15 degree (KR).

The two owner has previously dynoed the cars (same day, same dyno), the GS is 25rwhp less.
When I substract 3-4 degree timing, KR are still there.

Thoughts ?

[vette_c6]

traction maybe ?
something lose?
try to add some fuel just to rise the octain and see the KR business ,,

[Brice]

I think it's similar to the camaro 2010 SS octane issues...

[Blacker]

That is normal and after dyno tuning 100's of GM Cars/Trucks, it is all in the tuning. GM Tuning needs some work and once the AFR and Timing for in safe ranges, the power will be there.

[vette_c6]

Brice ,,
i saw many Kr from the Octain Issue
good luck ,,, i guess you need C16 Fuel in your dyno :P to use it sometimes in case

better for you ,,, good luck Brice ,, and always keep us update

[MikeOD]

Is the MAF sensor registering a realistic Hz/airflow number?

[Brice]

Is the MAF sensor registering a realistic Hz/airflow number?

damn I haven t Save the logs.
I will tune it on the dyno in 2 weeks.
The car has 10000 miles, I only remember the 6 degrees and 15 degrees at wot. No audible knocks.

[Mep_q8]

I've managed to pull of 21 degrees on a stock Grandsport without de-sensitizing the knock sensors on my loaded dyno. It is as said all in the tune, you gotta make sure you go into WOT with a nice transient to PE and not give it such a shock in timing as to promote burst knock.

[Brice]

Sure I can trick the stock tune.(zéro the afr vs timing table)

My real question is : is the symptom on all the 2010?
Why the hell the 2009 with the same engine/tune doesn t have the same kr?

[Brice]

So it seems I m the only one who has 6-7 kr on stock tune.
I have to check mecanical issues

[IDRIVEAG8GT]

Well.... How many miles/kilometers on the car? Break in period can substantially affect that. Also check for oil in the intake manifold.

[Brice]

Well.... How many miles/kilometers on the car? Break in period can substantially affect that. Also check for oil in the intake manifold.

10 000 miles

[IDRIVEAG8GT]

10 000 miles

Well she's broken in then.... I assume the knock in question is Audible?

[Closer_2001]

So it seems I m the only one who has 6-7 kr on stock tune.
I have to check mecanical issues

Mike at Gforce shared the same thing with me on my 09 CTS-v

Roll into it to avoid burst knock.

I say drop some 100 unleaded race gas and see if it improves.

[vette_c6]

any news brice ?

[Brice]

any news brice ?

I will dyno tune the car in 2 weeks.
I don't have race fuel here in France.

[vette_c6]

there is some small Cans to rise the fuel octain ,, try to find some of them

https://www.google.com.kw/search?hl=...CISBhQegndTtCA

[Brice]

there is some small Cans to rise the fuel octain ,, try to find some of them

https://www.google.com.kw/search?hl=...CISBhQegndTtCA

thanks but the aim is to run with 93 octane. When I ve substracted 6 degree timing, there was still 6 degree KR. I doubt raising the octane on the dyno will solve the problem.

[vette_c6]

well if you confirm that ,,
it will mean you dont have any mechinical issue ,,
if you rise the octane and you still have KR ,, mean something in the engine ,, or its a False Kr :d

good luck bro ,, keep us update ,, and dont forget to log the scanner for us