T
The Forbidden Supra
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Well, I did a few quick dyno pulls yesterday at 18-20 psi with my new T72 .81 Q-trim. I went there with a bunch of race fuel in my tank b/c I was planning on turning up the boost a lot more... but I didn't like the dyno or the people that worked there so I cut it short. My friend put his bpu supra on the dyno and all of a sudden it was popping and gurgling and didn't seem to run right, then I put my car on and it was doing the same thing. I have no idea what the deal was, but our cars weren't doing that on the way there. This was on a DynoPack chassis dyno, which I have never used/seen before. Two devices are used that bolt onto both rear wheel hubs. The owners claimed this type of dyno was much better than either dynojet or mustang dynos, and the numbers it reads are quite a bit lower than dynojet, but usually higher than a mustang dyno.
I think I tuned the timing fairly conservative and the a/f is very flat but quite rich, I think. The a/f meter at at the dyno was reading 12.5:1 and my brand new FJO was reading 11.8-12.0:1. They were arguing with me saying my FJO was a POS and theirs was 10x more accurate, but I thought they were full of crap, so I tuned according to my FJO. On the dyno, I remember my FJO reading about 12.1:1 which I thought was good and safe, but looking at the data I logged it's showing <1.6 volts from the o2 sensor... which was 11.5:1 or not even the last time I checked, so I really have no idea where my a/f is/was... somewhere between 11.5-12.5:1, and quite flat as you can tell by the graph. My fuel octane was about 105 octane, which consisted of 50% leaded gas and 50% unleaded. What a/f should be I tuning for with this fuel? 12.5:1? Or is that too lean? What about with a 50/50 mix of 93 unleaded and 110 leaded? (That's what I usually run)
Anyway, I dyno'd about 575 rwhp and 500 rwtq at 20 psi. I thought that was pretty decent but some people didn't. Want do you think? It looks to me like some cams would really help! The hp and torque especially fall off pretty fast. I didn't do a lot of tuning. I think I tuned the timing fairly conservative and the a/f was quite rich I believe. Please take a look at my timing map (if you know anything about timing that is) and tell me what you think. Specifically, I was wondering if it might be safe to increase the timing near redline, especially since the torque isn't very high there... my egt's were getting quite high after 6000 rpm, 1700 F by 7000 rpm. If you could help me optimize my timing and air/fuel for a 50/50 mix of 93/110 leaded and/or a 50/50 mix of 104 unleaded/110 leaded I'd really appreciate it. I also posted my knock data from the final run, which looked pretty much identical to every other run I did, so I don't think I really had any knock... maybe a tiny bit while the turbo was spooling. I'd like to tune the car for 22, 24, and 26 asap, but I want to make sure I'm on the right track before I do something stupid.
UPDATE: I totally forgot to mention, all of my dyno pulls were done at only 92% throttle. The guy dynoing my car didn't even press the pedal all the way down!! What happened is... I have this little button under the gas pedal that used to trip my nitrous when I had it... so you gotta push down just a tiny bit extra.. hardly more than the weight of your shoe. I really don't know how it's possible to not push the pedal down all the way. The guy dynoing my car must drive like a freakin' pussy. I just noticed that while looking over the data I logged...
-Paul
I think I tuned the timing fairly conservative and the a/f is very flat but quite rich, I think. The a/f meter at at the dyno was reading 12.5:1 and my brand new FJO was reading 11.8-12.0:1. They were arguing with me saying my FJO was a POS and theirs was 10x more accurate, but I thought they were full of crap, so I tuned according to my FJO. On the dyno, I remember my FJO reading about 12.1:1 which I thought was good and safe, but looking at the data I logged it's showing <1.6 volts from the o2 sensor... which was 11.5:1 or not even the last time I checked, so I really have no idea where my a/f is/was... somewhere between 11.5-12.5:1, and quite flat as you can tell by the graph. My fuel octane was about 105 octane, which consisted of 50% leaded gas and 50% unleaded. What a/f should be I tuning for with this fuel? 12.5:1? Or is that too lean? What about with a 50/50 mix of 93 unleaded and 110 leaded? (That's what I usually run)
Anyway, I dyno'd about 575 rwhp and 500 rwtq at 20 psi. I thought that was pretty decent but some people didn't. Want do you think? It looks to me like some cams would really help! The hp and torque especially fall off pretty fast. I didn't do a lot of tuning. I think I tuned the timing fairly conservative and the a/f was quite rich I believe. Please take a look at my timing map (if you know anything about timing that is) and tell me what you think. Specifically, I was wondering if it might be safe to increase the timing near redline, especially since the torque isn't very high there... my egt's were getting quite high after 6000 rpm, 1700 F by 7000 rpm. If you could help me optimize my timing and air/fuel for a 50/50 mix of 93/110 leaded and/or a 50/50 mix of 104 unleaded/110 leaded I'd really appreciate it. I also posted my knock data from the final run, which looked pretty much identical to every other run I did, so I don't think I really had any knock... maybe a tiny bit while the turbo was spooling. I'd like to tune the car for 22, 24, and 26 asap, but I want to make sure I'm on the right track before I do something stupid.
UPDATE: I totally forgot to mention, all of my dyno pulls were done at only 92% throttle. The guy dynoing my car didn't even press the pedal all the way down!! What happened is... I have this little button under the gas pedal that used to trip my nitrous when I had it... so you gotta push down just a tiny bit extra.. hardly more than the weight of your shoe. I really don't know how it's possible to not push the pedal down all the way. The guy dynoing my car must drive like a freakin' pussy. I just noticed that while looking over the data I logged...




-Paul