[bluedemon_II]

I was tuning my car and I got the timing down but I was wondering what AF ratios do you guys think would be good to have under full load points. I was aiming to hit 12.0:0 or 12.5:0 under full load. and taper to 11.5 or so near redline. My mods are basic Stage 2 with drop in filter and up-pipe plus Meth kit starting to spry at 7 until 20-21. Right now the car runs quite good but by comparing it to other cars with the same mods i think i can do a little better. Logs don't show knock anywhere on WOT so as of now my tune is quite good. Any pointers would be nice. I'm Logging with romraider and LC-1 so the readings are quite accurate.

John.

[reid-o]

Your target A/F will depend on the timing curve you choose to run, so it's hard to give a straight answer on the matter.
I personally shoot for 11.8 or so, but I try to run a more aggressive timing map. (I'll post my timing curve later if i remember)
I also run rather lean on boost onset and have the nozzle spray a bit early. So discussing target A/F with meth/water is difficult without seeing total timing.




I urge you to set your A/F using the dyno software listed somewhere on this site. Picking an arbitrary air/fuel is just that--arbitrary. But you can measure a gain from running a leaner a/f versus a richer one, then at least you're making methodical choices. You may find that running leaner isn't necessarily faster.

[bluedemon_II]

This is a log that I made a few days ago, here you have an idea of total timing. Sorry but this log does not include the a/f readout. Il try to make one today. You have an idea of total timing etc.


Well if i manage to stick the log in this post well you can see it

[reid-o]

What kind of loads are you running? Tuning with meth and extrememly high loads and big turbo versus a stage II type setup is slightly different.


If you're on a big turbo, I would shy away from extremely lean A/Fs and just increase timing and keep a slightly more conventional A/F of 11.8 or 11.5:1.
But then again, if you're running slightly lower load points and lower boost levels, you could try to lean it out with the existing timing or a moderately lean mixture with slightly increased timing.

[bluedemon_II]

Well stock turbo, the highest load point is 3.25 on the average side. So far my timing is 16 to 18 degrees btdc on said load pints which are full boost at 21 psi. I was thinking on changing the meth mixture to 75%- meth 25% water and correcting the A/F to add more detonation suppression to see how much room will that yield.

[renns]

I run 70/30 meth to water at 23 psi on the stock turbo and my AFRs are at 12.0 from 3500 on.

[bluedemon_II]

I'm supposed to be running at 23 also but i want to iron out the meth mixture first and then have a try with going back to 23 psi. What are your load points and what sort of timing are you running up there?