C5 Dyno (408ci, Twin T66, AEM EMS)
03-10-2004, 02:51 PM
#42
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I've seen the car.
Those are some AWESOME numbers, be cool to see what it does at the track. Car went 9.9x at the Supra Event last year I think.
And that was with the following...
"MTI re-sleeved aluminum 422ci stroker, MTI stage 3 LS6 heads, MTI custom solid roller camshaft, TNT 150 hp nitrous system. 530 rwhp / 500 ft-lbs on motor, 720 rwhp Nitrous"
I'll take two...and a large diet coke.
Those are some AWESOME numbers, be cool to see what it does at the track. Car went 9.9x at the Supra Event last year I think.
And that was with the following...
"MTI re-sleeved aluminum 422ci stroker, MTI stage 3 LS6 heads, MTI custom solid roller camshaft, TNT 150 hp nitrous system. 530 rwhp / 500 ft-lbs on motor, 720 rwhp Nitrous"
I'll take two...and a large diet coke.
03-10-2004, 03:39 PM
#46
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Congrats on the serious numbers. I think there are still a few videos floating around of two years ago with the vette dominated the event. 
That car may have to run in it's own class this year.
Rick
That car may have to run in it's own class this year. Rick
03-10-2004, 03:42 PM
#47
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Truely fricken sick! Congrats!
For your lack of boost, is it possible that the turbos are creating an excessively low pressure area between the compressor inlets thats preventing them from getting enough air to make more boost?
Regardless, 1khp with anything less than 20psi? SICK!! Good luck with it; I can't wait to see this on the road.
For your lack of boost, is it possible that the turbos are creating an excessively low pressure area between the compressor inlets thats preventing them from getting enough air to make more boost?
Regardless, 1khp with anything less than 20psi? SICK!! Good luck with it; I can't wait to see this on the road.
03-10-2004, 03:55 PM
#48
The problem with boost increase is most likely inlet depression and choke on the turbos.
That powerlevel through a C5 IRS is pretty damn close to 1200 flywheel. You're really working a pair of 66's pretty hard at that level. If memory serves, they flow high 60's lb/min each. It was just a hair under 70 i do believe.
What A/R on the hot side? or DP size? You might be corking it on the exit side
That powerlevel through a C5 IRS is pretty damn close to 1200 flywheel. You're really working a pair of 66's pretty hard at that level. If memory serves, they flow high 60's lb/min each. It was just a hair under 70 i do believe.
What A/R on the hot side? or DP size? You might be corking it on the exit side
03-10-2004, 04:03 PM
#49
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Its got .81 exhaust housings with 3" downpipes. My Supra made 647RWHP with a single T-66 and I've seen several others approach 700 with a single T-66. Exhaust is 3" straight out the bottom of the car (turndowns just before the diff).
If we are indeed out of turbo, its time for bigger ones.
But seriously, I think we aren't getting enough air to them. We even put all the boost pressure to the Wastegate to hold it closed (no pressure on the front side) and it still didn't go higher than 13PSI, although there was a slight peak that hit nearly 14.5PSI from what I remember. We'd make attempts to fix it, but at this point, the car needs to be cleaned up and loaded by Tues for its trek to Texas.
I'm pretty sure that after Texas we are going back to the Dyno and attempt the 1200RWHP mark (maxing out the dyno reading).
If we are indeed out of turbo, its time for bigger ones.
But seriously, I think we aren't getting enough air to them. We even put all the boost pressure to the Wastegate to hold it closed (no pressure on the front side) and it still didn't go higher than 13PSI, although there was a slight peak that hit nearly 14.5PSI from what I remember. We'd make attempts to fix it, but at this point, the car needs to be cleaned up and loaded by Tues for its trek to Texas.
I'm pretty sure that after Texas we are going back to the Dyno and attempt the 1200RWHP mark (maxing out the dyno reading).
03-10-2004, 04:11 PM
#50
The .81 A/R explains the "lazy" spool/torque rise for sure. My .69's come on alot sooner than that with less cubes. But i'm running 3.5" DP's that dump infront of the motor, maybe 18" long
We sized the turbos/IC's for about 1400 at the flywheel on a 348 motor, so i could see you getting close to the limit.
I nice pair of 70's would do ok
On center or tang housings?
We sized the turbos/IC's for about 1400 at the flywheel on a 348 motor, so i could see you getting close to the limit.
I nice pair of 70's would do ok
On center or tang housings?
03-10-2004, 04:13 PM
#52
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I've built a few T66s for supras going over the 600hp mark so I don't think it's a problem. If there is enough room (and there never is) try even just attaching a 1/2 a u bend to the compressor inlet to open up the airspace the turbos are pulling from. If even sticking up in the air on the dyno, it will tell you if that is definately your problem. If you don't have enough room, even a simple barrier in between them will break the low pressure area up if even just enough to gain 2psi.
Last edited by Speed; 03-10-2004 at 04:21 PM.
03-10-2004, 04:27 PM
#53
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We wanted to pull the whole thing (intake system) out at the dyno, but it requires unbolting one of the Turbos. Definately a project for after the Texas meet. I still think that a smaller (.69) hot housing would probably be OK and not really limit the power (and spool a HELL of a lot faster). Unfortunately, I'm not sure that opinion is shared amongst the group of us.
03-10-2004, 04:30 PM
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Originally Posted by cr133r
We wanted to pull the whole thing (intake system) out at the dyno, but it requires unbolting one of the Turbos. Definately a project for after the Texas meet. I still think that a smaller (.69) hot housing would probably be OK and not really limit the power (and spool a HELL of a lot faster). Unfortunately, I'm not sure that opinion is shared amongst the group of us.
03-10-2004, 04:38 PM
#55
Originally Posted by Speed
I ran a .69 on the T72 I built for the LT1 described in my sig. Spooled super fast. Obviously two different animals but I would honestly consider something as small as a .58 hot side then let your wastegates make up for the restriction.
if you choke it off with a small turbine housing, the waste gate will be closed anyway.
03-10-2004, 04:45 PM
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Originally Posted by VINCE
Very impressive. I never thought you could use AEM ECU.. That is amazing.
On an F-body, it would have been a LOT easier.I could build an adapter harness if only I could find the ECU plug (apparantly you can get the harness pins/connector through GM but I have yet to confirm this).
03-10-2004, 04:46 PM
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Originally Posted by y2khawk
if you choke it off with a small turbine housing, the waste gate will be closed anyway.
A smaller turbine housing won't stop the turbo from making boost, it will cause it to make it sooner. With only 204cubes spinning 8k max into a .58 A/R turbine housing on a T66, I don't think the .58s even would be terrible once the gates are open. That will cause it to reach peak boost sooner and open the wastegates. If it were just a matter of the turbos being too small, it would make a ton more boost then suck it back down when it gets up in RPM.
I think his fears of the smaller turbine housings are that they will restrict top end but the wastegates will dump some of that pressure anyway. I've done it before, just build a dump tube and allow the gate to dump to atmosphere. Works awesome!
03-10-2004, 04:47 PM
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Originally Posted by Speed
I ran a .69 on the T72 I built for the LT1 described in my sig. Spooled super fast. Obviously two different animals but I would honestly consider something as small as a .58 hot side then let your wastegates make up for the restriction.
03-10-2004, 04:51 PM
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Originally Posted by eviltwins
.58's are gonna be too small for a 408 inch motor. I tried .58's on my 377, and I had 13 pounds of boost by 3000, but it was starting to fall off by redline (6500). The .69's work great on my car, boost is rock steady but it still spools quick.
That's wild. My LT1 has a single T72 with a .69 on it and it spools hard and holds it. My experience has been that too small of a turbine housing combine with not enough wastegate will cause it to creap up not down. The never ending world of possibilities in building cars
