tune with pump gas or VP c16?

[turbocolt2.4L]

need some advise pros and cons

[Shel-Game]

Tune with the one you plan to run.

The biggest difference will, of course, be octane rating. And, therefore, spark tuning.

But just as important is the specific gravity. The SG of C16 is 0.735, the SG of pump gas is usually > 0.76. That's ~ 5% difference. Not a big deal for the street, but if you tune on pump gas, you'll be 5% leaner when you switch to C16. Just something to keep in mind.

[Turbo Joe]

hi tony, i think i now what you mean..just basic tuning run pump gas on low
boost and slowly work up the rpm's.. just to get the a/f and egt's straight then worry about making numbers.. when you get everything looking good then switch over to c16 and adjust your settings. thats what i do cause c16
is like 10.50 a gallon around here so basic tuning with that is a waist of money.if you already have basic tuning done but want to start making big numbers then yes c16 is what you should be using.

[turbocolt2.4L]

thanx so if i tune with c16 and race with c16 than the car will be rich with 94 for the street correct?guess i could do a mix for the street for the amount of driving i'll be doing ....

[Shel-Game]

Quote:

Originally Posted by turbocolt2.4L thanx so if i tune with c16 and race with c16 than the car will be rich with 94 for the street correct?guess i could do a mix for the street for the amount of driving i'll be doing ....

Well, it'll be rich at WOT on the street. At part throttle, the adaptives are more than capable of adjusting for the ~5% change.