I have a question about using C16 racing fuel. Does anyone have any experience running C16 and having their O2 sensor crap out because of the high lead content?

 

Of course! You cannot run a cat or an o2 sensor with C16.

 

Some types of O2 sensors will hold up for a little while even with the use of leaded fuel. But I only mean a LITTLE WHILE. They'll still die on you pretty fast. What do you need an 02 sensor for anyway? If you're using C16 you're probably using the car for racing and shouldn't care about the low boost, low rpm, low throttle situations in which the ECU uses 02 sensor input.

 

what about a wideband O2 sensor? Will C16 kill it too?

 

If you wanna run race fuel and still use your stock O2 sensor, run Sunoco's 100 Unleaded. Plus, it's 100% street legal, so no containers necessary. You can pump it right into your tank. http://www.racegas.com/gt100locals/default.asp

 

A good wideband sensor should last a while, but it's life will definitely be shortened by the leaded fuel.

 

I run race fuel whenever I can afford it. My O2 sensor? Well I run closed loop on my Microtech.

 

well I have a PFC so I'm not sure if i can go totaly without an O2 sensor. I am mixing C16 with 92 octane at about a 50:50 mixture for high boost runs. Im actually taking the car down to Rx7store today for my final tune and dyno run with that fuel trim. Since the car gets about 2-3K of miles per year I was just wonder how fast the O2 would go with the C16. I'm thinking maybe 5-10K miles? Any ideas.....

 

oh yeah also its not the stock O2 its whatever kind comes with the Greddy t-78 kit..never really paid close attention if they use a different type than stock

 

No, you don't need an oxygen sensor with the PFC, you can disable your O2 feedback and just run off the vacuum maps for cruise.

 

I'm working from memory here but if I remember right I've read a datasheet on the Bosch wideband and it showed that the sensor stays relatively accurate for 1/7th the normal time (in hours) when subjected to leaded fuel with 0.6 grams of lead per liter. C16 is like 0.56 g/L.

BTW...C16 is awesome. No other fuel ($$ except VP Import $$) even comes close. It's transparent around town but has HUGE power capability. If you run a leaded fuel for track trips don't bother with anything other than C16. The rest is a waste of time.

 

That's only if you tune accordingly for it, correct? Because if I understand correctly, the burning characteristics of race (higher octane) fuels are diff than the pump gas, so if you don't tune accordingly (change your timing) you can actually make LESS power on race fuel, but just run safer at high boost. Yes/no?

 

i use it when i need to tune my car

 

The burn characteristics between unleaded pump gas and leaded racing fuels are different, but it's mostly taking advantage of racing fuel's anti-knock capabilities by increasing compression in normally-aspirated engines or increasing boost in forced-induction engines where the change in ignition timing will need to be made to assist in increasing power. He did state "capability"; you can't just dump racing fuel into an engine that runs fine on and is made for pump gas and reap extra power.
While VP fuels are excellent performers, I wouldn't go that far. There are plenty of other manufacturers that produce superb racing fuels at similar prices.

 

I posted this on a different board a while ago. It's alot easier to cut and paste than re-type out the same thing.

Sooo...I've been running different race fuels for a while now. Tried all kinds of stuff. All different variations of leaded and unleaded and mixes. I'm just posting to tell you guys if you're gonna do it...do it to it. Pure 100% C16 all the way. Drain the tank...do it up right. Around town and on the highway its transparent. I've put some 106-114 leaded fuels in the car and actually felt it "lay down" around town. I'm talking about Trick brand fuel, Sunoco, 76, and other VP formulations...usually the generic stuff that most of the big V-8 trailered cars run while bracket racing. Although I've never turned up the wick as hot as I did a few weeks ago the 106-114 leadeds I used to run made the car feel a little less powerful under medium boost too (17-21 psi). C16 doesn't. It works just great. Now I understand that you don't want to over-octane a car. I always figured I was over-octaning the car when I ran the other leaded fuels and it felt sluggish. With C16 even at 18 psi with alcohol on it feels no different than 94 octane. Still has 100% pep. And the power making capability? Holy crap! There's nothing like being able to turn the boost up thru the roof without being scared of knock. WHOO! Hell...first pass I made the other Friday night I was running around 13.5:1 a/f's at 24-25 psi. No knock...EGT's were pretty low. Just a really healthy surging in 3rd gear. Whoops! :p Added some fuel across the board and all was well.

I think it has to be the particular formulation of the C16 compared to other leadeds. I thought it wouldn't make much of a diference and that them saying its "formulated for turbo cars" was just hype. Well...its not. Whatever is in it the stuff is GOOD!

Like I said...if you're commited to running a leaded fuel during your track trip find some C16. Beg, borrow, or steal! You're handicapping yourself with any other types of fuel. It doesn't have much (if any) of a negative effect on power output that I've noticed as long as you're pushing 17-18 psi or so.

Of course all this relates to max-effort trips to the track. Don't run a leaded fuel unless you need it and even then run it for minimum time. Your O2's will pay the price. Definitely don't run leaded fuel if you still have cats.

That's all based on my experience with my Stealth but it should expand on my previous blurb. Run a generic leaded made for large displacement low RPM motors then switch to pure C16 on a car that has the ability to take advantage of it...then come back and talk to me.

 

I've run a few drums of C16 through my car - so far my FJO wideband sensor is still kicking.... so is the stock O2 sensor.

I agree - if you're going to run race fuel - run pure race fuel. It's very addicting though so be warned.

You will become friends with your local VP dealer too. haha

 

yeah i tuned with a 50:50 mix of C16 and 93. layed down 440@ 16psi and planned on running and tuning at about 20psi on the 50:50 mix but my new AVC-R wouldnt hold above 16 psi it would hit like 18psi then fall to 16psi and stay there, so its either my avc-r or the spring in the wastegate. But yeah even with the 50:50 mix it just pulled so hard on the dyno and the a/f's where still mildly rich and no signs of ignition breakup at all. might even run full c16 and go for 23+psi.

 

has anyone tried VP import fuel? and is it even that much better than C16 if only runing 25psi and under

 

I have, don't really care for it, C16-to 93 pump gas doesn't really take any altering of "out of power" fuel maps to make the car run right. (just trim up the power range a little bit and your good to go) VP Import.... car would barely start without altering the fuel maps. I am sure it good fuel, but its very expensive and is not the fuel for the person who likes to run 93 during the week and swap to C16 on the weekend.

I was told by the VP rep, that fuel was designed for small flame front engines, which we know the rotary is not.

 

thanks for the info..I was kind of thinking it would be a waste since c16 so far has been great even though @ $50 for 5 gallons it is slightly pricy.