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Frozen Lake Driver
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Discussion Starter · #1 ·
Hey guys, been a long ass time since I posted but seeing as I'm playing with things only you guys may appreciate I thought I'd go for it.

A while back we decided to push our shop car a bit which at the time was a stock 86.5 GE auto car. It is now an R154 GE-T with some mild work (studs, shimmed pump, MHG, injectors, etc) and a haltech elite 2000.

We wanted to push 600whp from a factory bottom end but thought, hey no one plays with the ct26 anymore, let's get one shove a big ass wheel in it and see what we can do. So here we are now, with a China made 57 trim billet wheel and a few hours on the dyno. Putting down 390ish HP/TQ. Throwing some E content at it next to try and break 400whp.

What's the most your guys have pushed through one of these baby turbos?

Ps: numbers from a dyno jet
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I made 399.2 whp and 428.8wtq @ 21psi falling to 18psi by redline. Drove the car like that from 2004-2006 or so. Dynojet 248.

7M-GTE, 62-1 compressor wheel + hogged out cover in a rebuilt CT-26, Divorced external dump downpipe & 3in exhaust, HKS VPC/SAFC combo, 550cc injectors, TT Supra pump, some homebrew IC piping replacement.
With the stock IC, it'd make that kind of HP for one 4th gear pull, the next pull on the dyno it'd make the same boost but lose about 30hp and 30-40 ft lbs from heat soak and get progressively worse. A proper intercooler would have made a big difference.
Try as I might on different dyno days, It'd consistently hit 385-395whp but I never once broke 400whp.

I never dynoed it on Trick 101 octane, but it made significantly better torque as the turbo spooled but it still fell off at high RPM, which between that and the loss of boost at high RPM led me to believe I was at the limit of the CT-26 exhaust housing and/or the cams. Later I'd learn more, and I knew it was the exhaust housing that was the biggest restriction there and camshafts wouldn't have made any difference.
 

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what compressor are you guys running ?

also what PSI ?

that e85 and GE compression is great I bet. But your going to saturate the exhaust side of the turbo before gas would because there is physically more mass flowing (because more fuel on e85)

I rebuilt mine with this one (below), stock exhaust turbine. pretty much same setup as wreckless mentions, but I have fmic. this thread makes me want to get on a dyno so bad, tnx for posting

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Frozen Lake Driver
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Discussion Starter · #5 ·
what compressor are you guys running ?

also what PSI ?

that e85 and GE compression is great I bet. But your going to saturate the exhaust side of the turbo before gas would because there is physically more mass flowing (because more fuel on e85)

I rebuilt mine with this one (below), stock exhaust turbine. pretty much same setup as wreckless mentions, but I have fmic. this thread makes me want to get on a dyno so bad, tnx for posting

View attachment 265758
I do believe that is actually the wheel we are running. We managed to pull a bit more power at 19psi (408whp/370ft lbs, I'll post the graph for anyone interested). We didn't get to full E85 though as our flex fuel here sucks. With a half tank of 93 (best pump gas we can get in Canada) and a half tank of our E85 (more like E60 from the pump) we had about 30% e content and man did it make a difference.

This head has also been shaved right down so compression is up there although I've never done the math to know what it is or a comp test to guess.

We literally assembled this engine, ran it for about 20 mins on the dyno doing 2000-5000rpm light pulls and engine braking before sending it on the dyno.

Oh I also forgot to mention we did actually build our own custom trigger setup for this as well, HUGE improvement over running the stock CPS.
 

Frozen Lake Driver
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Discussion Starter · #6 · (Edited)
I made 399.2 whp and 428.8wtq @ 21psi falling to 18psi by redline. Drove the car like that from 2004-2006 or so. Dynojet 248.

7M-GTE, 62-1 compressor wheel + hogged out cover in a rebuilt CT-26, Divorced external dump downpipe & 3in exhaust, HKS VPC/SAFC combo, 550cc injectors, TT Supra pump, some homebrew IC piping replacement. With the stock IC, it'd make that kind of HP for one 4th gear pull, the next pull on the dyno it'd make the same boost but lose about 30hp and 30-40 ft lbs from heat soak and get progressively worse. A proper intercooler would have made a big difference.
Try as I might on different dyno days, It'd consistently hit 385-395whp but I never once broke 400whp.

I never dynoed it on Trick 101 octane, but it made significantly better torque as the turbo spooled but it still fell off at high RPM, which between that and the loss of boost at high RPM led me to believe I was at the limit of the CT-26 exhaust housing and/or the cams. Later I'd learn more, and I knew it was the exhaust housing that was the biggest restriction there and camshafts wouldn't have made any difference.
No matter what were running out of peak power at 5600rpm. From your experience this is from the hot side of the turbo?

From what I'm seeing in the graph I was assuming cams to be our limit but I didn't consider the small hot side of the turbo. Small hot side kind rocks though, were making almost 300ft lbs before 3000rpm.

This test was literally just to see it run on the ct26 and if we could break the 380whp goal at had. We do have a 6266 to go on it next for bigger numbers. I can't believe how fast this little CT26 spools though.

Edit: I notice you're making a tonne more torque which leaves me to think I've still got more room on the table timing wise. You don't happen to have an old dyno graph for comparison do you?
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No matter what were running out of peak power at 5600rpm. From your experience this is from the hot side of the turbo?

From what I'm seeing in the graph I was assuming cams to be our limit but I didn't consider the small hot side of the turbo. Small hot side kind rocks though, were making almost 300ft lbs before 3000rpm.

This test was literally just to see it run on the ct26 and if we could break the 380whp goal at had. We do have a 6266 to go on it next for bigger numbers. I can't believe how fast this little CT26 spools though.

Edit: I notice you're making a tonne more torque which leaves me to think I've still got more room on the table timing wise. You don't happen to have an old dyno graph for comparison do you?
Yes, absolutely it's the hot side of the turbo. Back in the days of the old SOGI email list, etc, there was a lot of smack talk about how HKS cams were worthless for the 7M-GTE, because they could 'move the power around' but not make any more HP. With very few exceptions, built 7M's in the US back then were using some kind of bolt-on CT upgrade and not running T4 manifolds because everyone was terrified of turbo lag, and everyone wanted everything to spool and act like a V8. Putting 2 and 2 together, HKS cams made no improvements because the hotsides were totally choked out. The biggest improvement in top end came from a 10-12* turbine wheel clip when going to a 60-1 or larger rebuild of a CT26, but that also added lag and didn't really solve the problem of the limited turbine housing size.

My dynos all nosed over around 5600-5700rpm as well, and running the stock ECU it was 'spicy' on the timing advance of course but I couldn't tell you exactly how much timing was in it at peak torque. I do know that I ran things 10.7-11.2:1 just to try to keep it as fat as possible to mitigate detonation, and thereby keep the timing advance. I'll dig around for those old dyno sheets, since they were back in 2004-2006ish I'm not even sure any ever got scanned in.

Since you're running an E mix I'd expect the CT26 hotside to be even more restrictive, as the additional exhaust mass from running a high ethanol percentage will cause that little hotside to max out that much sooner. You'll be able to make a ton more torque but it'll still nose over on HP and peak HP will be largely unchanged.
I've seen this happen with E85 on SR20DET builds w/stock turbos and similarly super-small upgrades like the old HKS GT2510.
 

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did you guys see mamba also makes a higher flow turbine ?

mamba should send you one so you could post a back to back dyno pull and see what happens. that would be so interesting.

with what your posting (aka awesome results) it could possibly make 450 wheel / friggen 500 at the crank on a CT frame wtf !?!?!?!#$#!!


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did you guys see mamba also makes a higher flow turbine ?

mamba should send you one so you could post a back to back dyno pull and see what happens. that would be so interesting.

with what your posting (aka awesome results) it could possibly make 450 wheel / friggen 500 at the crank on a CT frame wtf !?!?!?!#$#!!


View attachment 265794
A higher flowing turbine usually comes at the expense of turbine efficiency, and it doesn't solve the problem of the physically small exhaust housing. So more peak HP might be possible, but at the expense of lag with none of the other benefits of a larger turbine housing, like lower EGT's/better VE.
 
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