[Guest]

Well, last friday, white lightening (95TT) was strapped down for her virgin
dyno experience. all in all it was a good one, i have no complaints.
I've been meaning to get to a dyno in awhile, just to see if my pathetic
trapspeeds and et's at the track could be attributed to the car but for the
most part I found that the low traps could be blamed on only one factor...
my piss poor driving. My car is straight bpu, so there isn't much to
tune. All the runs were done with the ecu fuse pulled between runs and with
about 2 gallons of race gas in the tank mixed with some pump gas, yielding
about a 96-97 octane rating.

Run #1
Uncorrected: 396.4hp & 414.0tq
ttc, street setting, 19psi

Run #2 **BEST RUN**
Uncorrected: 400.1hp & 424.6tq
Corrected: 383.6hp & 407.1tq
ttc, track setting, tried for 21psi but only managed about 19.5psi

Run #3
Uncorrected: 398.2hp & 420.5tq
sequential, track setting, tried for 21psi but only got 18psi

The corrected numbers were corrected to SAE parameters so you guys could
compare them. The uncorrected numbers are "just for show", since they look
a little better.

All the runs looked pretty good and were pretty consistent and
reproduceable. my only problem was that i couldn't hold boost at all. the
boost would peak to 19.5psi but would fall to about 17psi by redline and it
would fall fast. as you can see by the dynocharts the power peaks at
4500rpm and falls to about 340hp by 6000rpm. Is there anything I can do to
flatten out my power curve? my tq curve looks ok but my power curve seems
pretty pathetic especially at the top end.

The two most relevant dynosheets are at http://www.geocities.com/bigles_va/dynocharts.html

All in all a good day, now if i could just find the reason for the loss of
power as i approach redline i'll be really happy!

 

[Guest]

nice #! can you list the modes you've done top your car?

 

[Guest]

MODS:
N1 exhaust
Airinx Intake
AAM Downpipe
AVCR
Lil' HKS FMIC

 

[Rviscosi]

Lester, my car has always done the same as yours boost wise. In 4th I can see up to 19psi for about a second and then the gauge snaps back down to 16 psi. I always here of stock twin cars holding 20 psi to redline in 4th and can't understand it. I don't think it matters much as the efficiency of our little twins go's away after 15-16 psi anyway.

 

[Guest]

Originally posted by Rviscosi:
<STRONG>Lester, my car has always done the same as yours boost wise. In 4th I can see up to 19psi for about a second and then the gauge snaps back down to 16 psi. I always here of stock twin cars holding 20 psi to redline in 4th and can't understand it. I don't think it matters much as the efficiency of our little twins go's away after 15-16 psi anyway.</STRONG>

i think its my aftermarket bov, i could hold 20psi before but after i put the bov on i can't anymore. i'm gonna try a couple pulls on the street and see what happens, i know the dyno doesn't have the loading capabilities to sustain boost near redline. if i can't hold boost on the street either i'll just tighten the bov down a bit and see if that helps.

 

[Guest]

dont you just love what BPU power output can be?

 

[Guest]

haven't looked at the sheet and don't own a Supra ( ) but from what I've seen, it's because of retarded timing ... you need some kind of BCC

either that or you need to run race gas or ice your intercoolers to cool the "charge"

 

[Steve Jarvis]

Basically the power on a BPU falls off because

1. The stock turbos can't hold more than 17psi (Approx.)of boost to redline

2. The stock fuel maps get very rich

3. The stock intercooler get heat soaked by the end of the run.

You have already addressed point 3. by installing an upgraded intercooler. You can help point 2. by installing an Apexi Super AFC and point number 1. is fixed with an SP63 or T66

We actually have almost identical corrected peak dyno #'s. I made 381rwhp and 413rwtq. The difference is that I have a SAFC and stock intercooler. Even though our peak #'s are almost the same I make 15 more rwhp and rwtq at 6,800 rpm. Typically an SAFC equiped Supra will make 50 more rwhp and 50 rwtq (@ 6800rpm) than a Supra without the SAFC so your front mount is definitely helping reduce the heat-soak. I bet you will be able to pick up 30 to 50 rwhp @ 6800rpm with the addition of a SAFC. I bet your peak number will also improve a little. You can see my dyno chart at www.geocities.com/steve_jarvis_me/Dynosmal.jpg As you can see I maintain a flat hp curve from 4600 to 6800rpm. I wish I had a flat torque curve but hey you take what you can get.

Hope this helps, Steve

 

[$upraMan]

Originally posted by Rviscosi:
<STRONG>Lester, my car has always done the same as yours boost wise. In 4th I can see up to 19psi for about a second and then the gauge snaps back down to 16 psi. I always here of stock twin cars holding 20 psi to redline in 4th and can't understand it. I don't think it matters much as the efficiency of our little twins go's away after 15-16 psi anyway.</STRONG>

My old car would get 23+ psi in 4th all the way to the redline (race gas). I had big exhaust and low miles, I don't know if that makes a difference.

 

[Guest]

Originally posted by Steve Jarvis:
<STRONG>Basically the power on a BPU falls off because

1. The stock turbos can't hold more than 17psi (Approx.)of boost to redline

2. The stock fuel maps get very rich

3. The stock intercooler get heat soaked by the end of the run.

You have already addressed point 3. by installing an upgraded intercooler. You can help point 2. by installing an Apexi Super AFC and point number 1. is fixed with an SP63 or T66

We actually have almost identical corrected peak dyno #'s. I made 381rwhp and 413rwtq. The difference is that I have a SAFC and stock intercooler. Even though our peak #'s are almost the same I make 15 more rwhp and rwtq at 6,800 rpm. Typically an SAFC equiped Supra will make 50 more rwhp and 50 rwtq (@ 6800rpm) than a Supra without the SAFC so your front mount is definitely helping reduce the heat-soak. I bet you will be able to pick up 30 to 50 rwhp @ 6800rpm with the addition of a SAFC. I bet your peak number will also improve a little. You can see my dyno chart at www.geocities.com/steve_jarvis_me/Dynosmal.jpg As you can see I maintain a flat hp curve from 4600 to 6800rpm. I wish I had a flat torque curve but hey you take what you can get.

Hope this helps, Steve</STRONG>

steve, thanks for the input. i'm probably getting a fuel controller next and do a little fuel tuning to see if i can help out my top end a bit. I also was told an exhaust side cam gear would help, so i may put one of those on too. hopefully it'll give me some more power up top because as it sits now, a civic could probably pull me on the top end.

on your a/f ratio chart what did you tune your car to? it looks like you tuned it to 13:1?

 

[iturk]

Lester,

Congrats on your dyno. I am saving up some $ for JE pistons and crower rods for an engine rebuild since my compression was real low...I hope to get > 400 rwhp one day

We still need to meet up!

Isaac

 

[Guest]

Steve, you've got bigger balls then i do! i probably won't tune it above 11.5:1, do you have a fuel curve without any tuning? i'm curious what it looks like and how rich it gets up top. Also, which fuel controller do you have?

Isaac, yeah, we definitely need to meet up, just drop me a line anytime!

 

[Steve Jarvis]

Actually about 12.5:1. I have since richened it up to 12.0:1. I haven't dynoed at the richer mixture but at the dragstrip I have tried both setting and couldn't tell any difference. You would probably want to tune for 11.5:1 or 12.0:1 for pump gas.

Later, Steve

 

[Steve Jarvis]

I actually ran it on a roadcourse for about 100 miles at 12.5:1 (on pump gas). I forgot to richen the mixture back up before I started that session. Needless to say I was horrified when I realized what I had done. I actually didn't notice any detonation and I was running 17psi. I wouldn't recommend this and I'm sure my exhaust temps were very high. It's nice to have a car that you can be an idiot in and not have to pay for it.

I didn't make any runs without the SAFC. I use the old style Apexi Super AFC (with 5 knobs on the front).

Later, Steve