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I heard today Gibson used to tune their qualifying GTR's to 12.7:1.... but they also had over 1000 degrees exhaust temps and had to make special brackets to hold the exhaust manifold up as it got so hot it started drooping.

In a track car i'd say that its too lean but thats just my opinion and really its up to you, your use of the car and your tuner. If your tuner says its fine, then its fine. If you dont trust your tuner, find a new one. Second guessing them is no good.

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12:1 to 12.5:1 on the road is a ok tune but if on track then need to be alot richer as heat takes over and cause issues as Strik3r mentioned

Sorry to hijack, but how much richer?

I had my GTR tuned for the first time last week, and below are the results. The car spends 25/30 days per month in the garage, but will be doing some track days in it.

post-194-1228864140_thumb.jpg

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i dunno. in my eyes, for a GTR with decent power, if you're going to be punishing it, it's a bit too lean. and their AFR scaling is so wide as to be completely fking useless. so it's hard to tell even from that graph what exact AFR you are running. BUT on the other hand they have tuned and built more GTRs than i've had hot breakfasts so I would like to think they know what works better than I do. if it bothers you talk to them about it. ask them why they tune it to that AFR, and maybe ask can you have a little more fuel for safety.

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Sorry to hijack, but how much richer?

I had my GTR tuned for the first time last week, and below are the results. The car spends 25/30 days per month in the garage, but will be doing some track days in it.

post-194-1228864140_thumb.jpg

That is a totally awesome tune. Probly the first dyno sheet i have seen posted on this site that has had a 100% tune. I was impressed, then i saw the tuner stamp so I am not suprised at all.

That tune is 100% safe and perfect for every day street use and track use. how much did that tune cost you? (just wondering)

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geez, bit hard to say quite how awesome a tune is by looking at AFR. we still need to know timing, boost control etc. but having said all that I reckon my old tune was pretty much spot on. took 3 years of track and street abuse and ran flawlessly and never had any knock to speak of.

it was exactly what I asked for. 11.8:1 dropping to 11.5 right up the top (near limiter for a bit of extra fuel up there, no real loss in doing that as peak power is already past anyway).

0517002ui9.jpg

0517001bo2.jpg

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That is a totally awesome tune. Probly the first dyno sheet i have seen posted on this site that has had a 100% tune. I was impressed, then i saw the tuner stamp so I am not suprised at all.

That tune is 100% safe and perfect for every day street use and track use. how much did that tune cost you? (just wondering)

Thanks mate, it was all the good words about them that i have heard which pushed me to them. And with out doubt the most pleasant dealings I have ever had with a workshop.

All up cost wise was

Nistune ECU - $350

Tune $450

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Beer Baron, what boost control are you using on that second graph? Holds very well.

Anyone who gives an "expert" opinion on a tune after only seeing an AFR graph, isn't an expert.

For example, my car came over with 11.5:1 AFR's, but pinging its ring off because there was over 30deg ignition timing in the top end.

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Beer Baron, what boost control are you using on that second graph? Holds very well.

Anyone who gives an "expert" opinion on a tune after only seeing an AFR graph, isn't an expert.

For example, my car came over with 11.5:1 AFR's, but pinging its ring off because there was over 30deg ignition timing in the top end.

:D

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