From the experience with my S4 (a 400hp B5 S4) I'd say this problem is down to the gas your running and I'll agree with previous post that you may want to get Betim to re-tune your ECU for pump gas.

 

Also, be careful with your estimate of octane when mixing the "race" fuel with 91 octane fuel. Alot of those higher octane mixtures have other components like ethanol (sometimes up to 10%) which on our tuned ECU's aren't equivalent, so your figure of 100 is more likely 95 to 98-although just using the c----- 91 alone recently is likely your culprit for the pinging. Ideally, you would have a 91 program and a 93+ program or, as suggested, a program that automatically adjusts from feedback from the knock sensors-ala the EVOMSit.

 

What octane is it programmed to run on?

 

I thought it had both programs.

 

Perfect storm right there. Extra load (you+passenger) on a hot day. By the time you've got to 5k rpm in 5th, you've been under load for a while, running lower octane fuel than you're mapped for. To be honest, it's a testament to the way the car's tuned that you didn't get knocking until all those conditions were met. Either way, the ECU sensed the knock, and did what it was programmed to do to protect the engine.

Add in the race gas, wait til it cools off, take her out again by yourself, and make sure you don't get the same behavior. You should be fine. These aren't unsophisticated engines, and the better tuners know how to keep the factory safeguards in place.

 

Barrister,

I agree with everyone here. There should be ZERO damage to your engine at this point.
Fuel is definitely the culprit. Talk to BBI about it as you likely have an aggressive tune not meant for pump gas.

Easy fix is to detune or to stop being lazy ass LOL

Best of luck!

 

I would suggest adjusting the tune down to be able to run on pump gas. Sooner or later you will find yourself in the same situation and will always have it in the back of your mind. It is too much of a pain to be mixing fuel, especially since it a DD. Either that or try to have a switchable map that can be switched for pump or race tune. It is what I have on my 997TT.

 

Dana,

I agree with everyone that the engine should be fine. If you are experiencing detontation with 100 octane, your timing and boost is probably set very high. The guys at BBI told me that your car pulled like a rocket ship. Have them detune the ECU a bit if you want to run on 91 octane.

 

are you sure you are describing what you heard properly?
Under heavy load on a hot day with the sudden lift off the gas pedal you'll her the exhaust release the boost pressure, its not a ping. It sounds more like a blast.
It happened to me yesterday, I was cut off WOT, 95 degrees.

 

eee