Thread: Yada yada, more dynos.

Guys just remember HP is just a number. It would suck for a 450 whp to move out on a 550 whp. A lot of people get caught up on the figures.

Exactly, haha people always ask me how my car whoops up on 600 and 700hp cars. Its because power to weight for one but yeah ive seen small turbo cars destroy big turbo cars before. Alot of that again is power to weight but its also response too.

Seriously! 16.0 flat with 3.0 60' times all day long. Nobody asked what the trap speeds were, though

same here. have a t2 gt3071r .86 a/r with asp equal length mani and aem water/meth injection.

I wish I had more experience in higher powered FWD B14s so I could tell from your video if you're making the power that the dyno is showing.
Something tells me a trip to the drag strip could shed a lot of light on this situation.

That looks to be a very potent turbo right there. Flows more than the GT3076r with the .82ar. How laggy is it?

The 1.06 maybe very laggy, but 1.6 & 1.8 honda guys seem to do pretty good on the .82. So it's probably a no-go for the 1.06ar huh?
Its too bad, it looks to flow as much as the SC61 but with smaller wheels.



What is crazy, is this setup seems to hit torque later than my old log manifold. The twin scroll has wicked fast response, but torque doesn't climb as fast as it should.

I really really want a water/meth kit so I can run 20psi all day long on pump.

I should also add that when I had the VE cams in the AFRs and torque started to drop off on the top end again, just like with the log manifold. It seems like it is still getting choked. Not as bad as with the log manifold, when I only made 300whp with the VE cams on 15psi.

The numbers speak for themselves. 350 solid whp with a conservative tune on the log/.63 housing, and only 320whp with VE cams .78 housing and tubular manifold.

Now that the VET cams are back in, I am pretty much at the same power as I was before spending money on the tubular manifold. Possibly less.

I found this dyno graph. 19psi runs on a DET motor. 2871r .64 vs the 3071r .78.


The larger 3071r has a slightly bigger turbine wheel, which flows better. The .78ar prob still flows better than the smaller .64. Not huge, but similar. The gains seen here are likely from an increase in VE from a slightly better turbine flow.

Now the .86 2871r would flow better, and make more power than both of these. Especially if reversion is an issue. But Even with VET cams with little overlap, the .78 hits peak torque 400rpm later than before (regardless of when it boosts). If I laid my graphs out over each other, they would look similar but with opposite results. I bet a .82 would make more power sooner because VE would be improved. But this is just speculation...

tune the car or get somebody to tune it. All that money on a new ex housing would sure be good for a good tune or an aem management

could not agree with this comment more!

not only does it give less backpressure caused from housings etc but it will also aid gasses leaving the restrictive standard ve ex ports.




The t2 3071r is not that good a turbo. Sure it flows quite well, but this is due to a 90trim. The restrictive part of the turbine is the same as the t3 versions, hence it is limited by this. It also has a slighter bigger a/r this is where some of that extra flow comes from as well as the fact the air doesn't have to swell as much before leaving the wheel. This is the problem with your earlier comparisons, you are looking at a bigger wheel with a smaller trim and blaming the housing for being restrictive, Not the restrictive part of the actual turbine wheel.

A t3 gt30 will out spool a t2 version convincingly on a well set up car. There is a reason the WRC cars with there $20k turbos use a 73 or 76trim 60mm ns111 wheel.

True, but the trim is only part of the picture as to why the wheel flows the way it does. Larger wheels in smaller trims can flow just as much or more, and can have higher efficiency.

A 73 or 76 trim NS111 will spool very fast, but won't flow as much as a higher trim wheel. The UHP turbine in the GT30r is 60mm 84 trim. But you can get just about the same flow from from the 64mm 73 trim GT32 wheel.

But overall flow will depend on the number of blades on the wheel as well. Since I don't know the actual blade count on the GT32 wheel, I have to just assume that with the .78 housing it will flow about the same as the .78 on the GT30r. Even though the GT30r has a smaller, higher trim wheel.

The other thing about the larger wheels with smaller trim, is they can flow better at lower pressure ratios when compared to smaller turbines with larger exducers. Of course this makes sense. As the boost turns up the smaller exducer will be a restriction as flow demands get higher.

So we know that the backpressure is going to be an issue with the VE head. It always has been a limiting factor in my setup. The 84 trim 60mm turbine shouldn't be a significant restriction unless the housing chokes flow. I would love it if the GT30r had a larger turbine though.

I think the reason why the t2 GT30r isn't a great turbo is because the turbine wheel is so inefficient. It is kindof a odd turbine, with lower efficiency than I would have expected. But it does flow better in the .86 housing than the .82 60mm does, at least at higher pressure ratios.

So even though the T2 GT3071r may be unresponsive and sluggish, it should still make good power. I will be debating on which route I should go. I could sell the 30r and buy a different turbo. This turbo is expensive, and housings are over $300. I would like to find a S200 or something similar with a T3 flange and a divided 1.22 housing. All I can find is T4 crap, and I don't really want to hack my manifold up.