Race Fuel and Ignition Timing

[6cylindakilla]

I know this isn't exactly the right place to post this question, but I couldn't find anything more appropriate. 

I have a NA 16V that is I'm tuning with DTA SEM.  Does anybody have any idea of a ball park estimate for how much additional ignition timing when using proper race fuel.  I have been and will be using 110 octane fuel for track days, and want to get an idea of where to start.  I know dyno tuning is the answer, but I just want to get close.



Thanks!

- Dave.

 

[bobqzzi]

What kind of compression are you running? 

[6cylindakilla]

Oh yeah.
Statically I've calculated to be somewhere between the high 10s and low/mid 11s.  Cams are Schrick 276 hydro w/ about 4* retard on the belt sprocket, with stock inter-cam sprockets.

- Dave.

[enginerd]

Here are some logs with different octanes.

GT2871R ~22 - 23 psi of boost.
You can obviously run more timing without boost, but it gives an idea of the delta between 91 - 93 and
100 oct.



You should really be tuning for mean best torque though. You can advance to the point where it doesn't make any more power. If you road tune the AFR the timing should be pretty quick to dyno tune.

[bobqzzi]

You needn't worry about detonation with that compression and race gas (or probably pump gas either).  You really need to dyno to see what makes the best power.  More is not neccessarily better.  If I had to guess I'd say you end up somewhere around 26 degrees for best power- but that is a guess- it has been quite a while since I dynoed a 16V.

[6cylindakilla]

Thanks guys.  I'm road tuning for AFR, but DTA loves to crash, so it can be time consuming.  I'm intending to dyno tune after I'm close with the fuel, but I'm not sure when that will be as I'm pretty busy with work right now.

Thanks for feedback guys.

- Dave.