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Thread: Another dyno session tomorrow

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Posts: 31-40 of 47
2010-03-06 21:23:14
Meeee Tooooo!
2010-03-06 22:15:43
Well leaning it out did some good, but it's still nowhere near what I want.

At 19psi of boost I managed 411 uncorrected whp and 298ftlbs torque. Since the correction factors wouldn't have made much difference due to the temps and whatnot.

I definitely need to bump timing up since I'm only at 17 degrees at WOT. The tune's AFR is solid at 11.5, so more timing and/or boost is in order.
2010-03-06 22:16:15
Graph to follow.
2010-03-07 00:40:28

Lower numbers are from the first dyno session that I had at the last dyno day, a couple of months ago.

I'll post these in the other thread temporarily until I can scan a decent copy of the sheet.
2010-03-07 02:32:45
Just for comparison... I made 396whp on 19psi. Corrected. With a 13% correction factor. So your uncorrected numbers are amazingly higher than mine. 344whp vs 411. You've got a winner there.

Good numbers tekkie. I would love to feel what 500whp uncorrected would be like in a little car like ours. I bet it is insane. We run different dynos, but mine seemed to boost a lot sooner than yours... .82 housing the culprit? You hit 200whp around 5K, and I did the same at 4100-4300rpm. That's a lot of area under the curve.

Is this because of the larger housing? You can def tell it is helping you out though, you need some more boost or more revs to really wake that thing up! 7700rpm is 500rpm more than mine and you are still building power. a 9K redline would show pretty amazing power I think. Hard to do in a DE? Still impressive nonetheless.
2010-03-07 02:34:39
BTW I think I was at 21* advance on my tune. So you get away with a lot more power with less timing. Just take it easy, your BMEP is likely much higher than mine. Don't want to hurt your baby.
2010-03-07 03:52:01
Too much to quote on phone

.63 would spool faster definitely but wouldn't make peak as shown with your setup. The motor is built to withstand 8500rpm but I had revcut at 8k, and the dyno correction for RPM saw it as 7780 or thereabouts.

Remember that the correction factor with 52 degree temps and barometric pressure at labratory spec will in essence cancel itself out. Technically, if you ran a correction factor today you'd see no real world differences due to weather conditions we had.

What I actually want to do is dial the cams down and bring the powerband lower. The peak power should come lower with the torque being able to hold longer. I honestly feel that the torque shouldn't have fallen off like it did, but I'll need to do more studying on that subject.

Raising timing a few degrees and then adding back in some fuel should make more power, I think. The dyno tech that also happens to be a Nissan head pointed out a few sections of other graphs that show where I'm experiencing slight break up. Some are apparent on the graphs I posted. I plan to do another session in a couple weeks in Connecticut. I should have the ultra blues by then, and I'll throw new plugs in and check other ignition components.

Anyhow, thanks for the comments/compliments .
2010-03-07 08:58:04
I saw a recent dyno where cam timing on the intake was increased by a lot and it moved the graph forward a lot. With hardly any top end loss. Wierd, DSM.

Just don't get that turbo spooling before 3500rpm and you will be fine. I was boosting so early I was getting some pretty crazy surge on high boost.

My Atmospheric pressure where I live rarely sees over the 12.5psi mark. So we always have correction factors on. 24psi of boost up here performs more like 20-21psi at sea level. Loss of adiabatic efficiency and more pumping losses from the higher pressure ratio the compressor has to run.
2010-03-08 13:45:31
I brought my dynosheet in to work today, and promptly spilled coffee on it

It's still legible, though.
2010-03-08 23:17:47
lol @ the coffee spill!!

good numbers man, congrats!
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