[The Forbidden Supra]

I recently dynoed my car on mostly pump gas and made 575rwhp and 500rwtq with fairly conservative tuning, which I thought was pretty good. That's stock cams, stock intake, etc. Today, I filled my tank with straight 110 leaded Sunoco Turbo blue and even at 28 psi I couldn't make 575 rwhp! Also the turbo was hitting max boost over 700 rpm later!! I increased the timing quite a bit, until the point where the power stopped going up, but the power was still very low. The car appears to be running awesome other than the low power. During the dyno, it didn't knock even once and the EGT's were quite low. I've had the same problem in the past... whenever I ran more than 50% leaded gas the car just felt dead. I assumed it was because I used to run the stock ECU and it was being stupid... but I have full control over timing now with my AEM. I had the a/f up to 12.5:1 and the timing up to 16 degrees at high boost and it wasn't giving me any more power. People are telling me 100% leaded gas should work just fine, but I'm not convinced. Does this gas just suck or what the heck is going on? My compression is precisely perfect.

-Paul

 

[cuemaster]

your numbers really should be higher. lxa and i are going to chitown in the spring for a tunning one weekend care to join in? g

 

[OC]

Could it be something related to the O2 sensor?

-Olivier

 

[Ebanks]

i don't know the cause of your issues, but I can tell you we run straight leaded 116 minimum, and usually 118. I have never had a problem with it not giving me the power I expected, but I also run 20-21 degrees of timing.

-Ethan

 

[The Forbidden Supra]

Strange. It has to just be this one gas I'm using. A few people have told me that Turbo Blue is just no good. Next time I'm going to use some real gas. I'm sure they sell C12 or C16 around here somewhere.

Olivier-
I don't think it could be any O2 related since I didn't even setup my AEM to use the stock o2 sensor nor my wideband! I have o2-feedback off, just using it to log the a/f and that's it.

I just diluted my fuel with 50% 94 octane pump gas and the car DEFINITELY feels faster. At 24 psi, I can't even begin to get traction in 4th... it feels much much stronger than it did earlier when I had it at 28 psi with straight Turbo Blue. The power is just unbelievable. Anyway, I guess that was the problem! But I'm still curious why.

Thanks.

-Paul

 

[The Forbidden Supra]

Ah, I just talked to a guy with a fast grand national who also tried running straight Turbo Blue in his car. He said the same thing happened to him.. lost at least 100 hp!! Then he tried C12 and it ran just fine. And to think, this is the race gas I've been using for over 3 years now! Seems like absolute garbage. At least it's relatively cheap.. =P

 

[OC]

Oops...I was wrong. It simply bad gas!!

-Olivier

 

[emodragracer]

i don't know the cause of your issues, but I can tell you we run straight leaded 116 minimum, and usually 118. I have never had a problem with it not giving me the power I expected, but I also run 20-21 degrees of timing.

-Ethan

are you running 20-21 of timing thru the whole power band? or start lower and then step it up at the end?

 

[Brad Mayo]

My car used to LOVE that stuff on the stock twins. 1/4 tank of 93 and then 5 gallons of Sunoco 110 and it made 430rwhp and 450rwtq at straight BPU. W/o the 110 in it it made 400rwhp and 410rwtq with everything equal, just poured in 5 gallons and reset the ECU and it picked up 30hp and 40ft/lbs..... BUT, it didnt like any more that that exact mix. If I ran out all the pump gas and then put in just that Sunoco 110 it didnt feel as strong and would lose a MPH or 2 in the traps through the 1/8. Get some C16

 

[The Forbidden Supra]

No, I'm not even running 20-21 degrees at all (under boost). When I tuned at the dyno yesterday, I found the car was making no extra power past 18.5 degrees at 18 psi, 17.8 deg at 20 psi, 16.0 deg at 22 psi, 14.6 deg at 24 psi, and 12.9 deg at 26 psi. That's at peak torque. I have the timing flat where the motor is making max torque, roughly, and it's ramping up gradually otherwise. At 8000 rpm I have the timing set about 4 degrees higher than at peak torque, for each boost level. How do those timing figures sound? They sound pretty darn low to me, for race gas... I was expecting to turn up the timing much more, but it just wasn't making more power. It never started to knock even the slightest bit though.

-Paul

 

[The Forbidden Supra]

Good numbers, Brad. Yeah, it seems like that Turbo Blue stuff works just fine unless you use to much. Like I think I mentioned, I used to mix it up to 50/50 all the time and never had any problems. I made up to ~680rwhp with the T66 I used to have using that mix, so it obviously works. Well, C16 is obviously the way to go it seems. Or should I try C12? I hear that would be plenty as good as well, and probably a bit cheaper?

-Paul

 

[Ryan23]

Good numbers, Brad. Yeah, it seems like that Turbo Blue stuff works just fine unless you use to much. Like I think I mentioned, I used to mix it up to 50/50 all the time and never had any problems. I made up to ~680rwhp with the T66 I used to have using that mix, so it obviously works. Well, C16 is obviously the way to go it seems. Or should I try C12? I hear that would be plenty as good as well, and probably a bit cheaper?

-Paul

Paul -
From the people I have spoke to, C12 seems to be fine up to 2 bar. I would run it straight, not diluted (or as straight as you can). Your timing sounds REALLY low though, what did your knock 1&2 raw look like? I'm guessing dead quiet? Did you log timing itself? Did any get pulled? Certainly throw some more timing at it. The other possibility is, are you sure your T-belt is lined up properly? That will throw ignition timing off if it's incorrect. Hell, I'm running 16~17 degrees on pump right now (and I've had an occasional spike to 1.5~1.6 bar during tuning). Even then, knock raw was pretty quiet. I would shoot for 22~25 degrees of advance and see how she does on some good C12.

Ryan

 

[The Forbidden Supra]

Yeah, I thought the timing was low too, not REALLY low, but low. The knock data was dead quiet. The higher the boost was, the less noise the engine was making. Strange? My car seems to make the most noise around 18 psi. The a/f is exactly the same at every boost level, about 12.3 right now and the timing decreases about 1.5 degrees every 2 psi. Like I mentioned, I just kept increasing timing until it didn't want to make any more power. I especially didn't want to go nuts increasing timing b/c I was starting to think my motor was screwed up. Timing didn't get pulled even once. The knock data I logged was waaayyy below the knock table I set in general. Probably because the explosions were so slow and wimpy. Normally, the knock data was up around 3.75-4.2 volts under boost at high rpms, but with straight Turbo Blue it decreased as much as 1.0 volt across the board. The car even sounded quieter than normal I think. I'm pretty certain my timing belt is lined up right. It was off once in the past and it was very very obvious. The whole drivetrain was clanking and the motor sounded horrible. The car runs awesome since I diluted the gas with pump gas. Thanks for the help, everyone.

-Paul

 

[65vette396]

12.3 AFR is a little lean, especially on the dyno. You should shoot closer to 11.0 to 11.5 on the dyno that way on the street you are at your 12.0-12.3 range. Drew

 

[bad94sup]

12.3 AFR is a little lean, especially on the dyno. You should shoot closer to 11.0 to 11.5 on the dyno that way on the street you are at your 12.0-12.3 range. Drew

Although I myself have not seen a full AFR point varience from dyno--->street, I would certainly tune for at least 11.5's up top on the dyno....I usually see around 11.9-12.1 on the street on a dyno tuned 11.5-11.6...

Just my opinions/observations..

Andrew

 

[Evil_TT]

I recently dynoed my car on mostly pump gas and made 575rwhp and 500rwtq with fairly conservative tuning, which I thought was pretty good. That's stock cams, stock intake, etc. Today, I filled my tank with straight 110 leaded Sunoco Turbo blue and even at 28 psi I couldn't make 575 rwhp! Also the turbo was hitting max boost over 700 rpm later!! I increased the timing quite a bit, until the point where the power stopped going up, but the power was still very low. The car appears to be running awesome other than the low power. During the dyno, it didn't knock even once and the EGT's were quite low. I've had the same problem in the past... whenever I ran more than 50% leaded gas the car just felt dead. I assumed it was because I used to run the stock ECU and it was being stupid... but I have full control over timing now with my AEM. I had the a/f up to 12.5:1 and the timing up to 16 degrees at high boost and it wasn't giving me any more power. People are telling me 100% leaded gas should work just fine, but I'm not convinced. Does this gas just suck or what the heck is going on? My compression is precisely perfect.

-Paul

Where are you getting sunoco turbo blue 110? Sunocos 110 is acctually purple, and is not designated as a Turbo fuel. I run sunoco racing 112 which is by far the best fuel i can find based on the data available on the website.

But here is the question after comparing VP110 and Sunoco 110 i see a variation fo 2 octane points in the motor octane (107 for vp comapred to 105 for Sunoco).
any way i dont see any 110 blue fuel on either site, so i would check with yoru source, and verify that its a real sunoco racing fuel and not some aviation fuel or something

Both VP and Sunoco are purple for 110, dark blue for 112, and light blue for GT unleaded (100 and 104)

 

[MK4LIFE]

I have been using the 110 blue/purple this whole summer and after reading this and what my buddy has logged, i will be switching to 112 the next drum.

My buddy used 10 gallons of my 110 and went out and did some datalogging on his DSM. with the 110 he was getting unusual counts of knock. He could not understand it. He used up all the gas and threw in some 100 octane and instantly the car had no knock.

I always use 118 at the track, so im good there, but im switching to 112 for the street.

 

[The Forbidden Supra]

65vette396-
I generally tune my a/f with my FJO wideband that is in the car. I've found that my afr really doesn't change much at all on the street vs. the dyno. Not more than .1-.2 (I was surprised). This was in the 0-125 mph range, not crazy speeds. I like to keep my afr around 11.8 all the time (pump gas), except past 6500 rpm I like to bring it back down to 11.5 or so. My EGT's have been staying incredibly low lately. I added a bunch of timing (closely watching knock) and now my EGTs are only going to 1575 F or so instead or 1650-1750 like they used to.

With 33% race fuel I've been keeping my afr at about 12.1-12.2 and with 50-100% race fuel I keep my a/f close to 12.5. Seems to work fine.

 

[neonafk]

wow im glad to know that this gas sucks!

Im never buying this again, im going for 112 or 116 now,

guys, C-12 is how much octane?

Brett

 

[The Forbidden Supra]

Well, I wouldn't say anyone should never buy it again just b/c of my bad experience with it. Try it yourself. Just keep in mind what happened with my car in case you get strange results. It seems to work fine as long as you don't use more than ~50%. The fact that using straight turbo blue works so poorly implies to me it's just not a good fuel to use for our application, and maybe even at 50% I'm losing a lot of power, who knows. Perhaps too much lead or something. I've been told 116 is around ~$8.25 and 112 is a bit less.