30 hp is a better way of measruing it than new 1/4 vs old 1/4 because of the many variables that can take place.

 

No one should be running a turbo car with less than 93 octane on 18-19psi of boost. Let alone trying to tune with anything less than 93 Detonation will occur and the ecu will retard timing thus slowing you down before you blow up the engine.
on that note...

DO NOT START PLAYING ON AN AFC WITHOUT A DYNO AND/OR A WIDEBAND O2 SENSOR. You will blow stuff up. Namely your engine. A/F tuning is not as simple as buying an AFC at your local tuner shop, slapping it on, setting points and your done. Its a methodology.

Having a wideband O2 sensor in the car is a great tool to have. A couple of companies the Supra folks have found to be good are FJO and www.WideBandO2.com

 

A better measurement would be AF readings, SAFC settings, dyno charts, EGT temps.

As Turbonium stated, drag racing involves too many variables. You might see a mph difference of 1 or 2mph through the traps.

But then again, this goes back to my whole gripe about people trying to drag race a car that was never set up to drag race but rather set up as a road course/rally car. Both of which have nothing in common with drag racing.

 

dmora, would that wideband 02 in your link work on the Evo??

 

its a device that works with either stand alone ecu, or as a piggyback system. Should be fairly generic. Call them up and ask for more info. I'm sure they would love to get popularity in the Evo market since not everyone has access to an AWD dyno and wideband equipment.

 

Funny that. I have never used a dyno or a wideband O2 sensor, and in 4 years of tuning my car with an AFC and similar setups, I have never blown up an engine.

Why do you make such statements?

I use a datalogger. With an OBDII datalogger, you can log O2 voltage (very coarse, just to give you an idea of where you are), ignition timing (if it drops, then you are getting knock), and RPM.

With the datalogger I have, you can also datalog knock, knock retard, boost, etc...

Just watch your gauges and datalogger. Tune slowly. Change only one thing at a time. Be methodical. Soon you will get a feel for what your car likes and how to tune it.

Sure, a dyno and a wideband O2 sensor can help. But you can get along very well without either, if you know what you are doing. If you feel that you absolutely can't tune without either of those, then I'd say you don't know what you are doing.

 

Tune? Yes. Tune well? Unlikely.

Shiv

 

Tuning is a matter of trial and error, regardless of the tools one uses.. I'd definitely be concerned about damaging my engine without using at least an a/f meter and an accurate O2 sensor.. But My experience with an OBD-II data logger is you can gather much of the same information you would need.. Track/dyno testing is essential to gauge your improvements though..

 

Well enough to get 112mph out of my car with a small 16G. Tuning on the spot will always yield better results than tuning for the lowest common denominator. And you can't tune on the spot with a dyno.