Were those T3 or T4?

I did ~600whp on a baby cam 4.8 with a pair of 5056 turbos in .63 A/R T3 on a heartbreaker dyno at 17 PSI.
Backpressure wasn't an issue, power was still climbing but didn't rev it out too far.

 

What car is it? I didn't see one referenced.

 

they are more like a t3 I think. It’s v band in and out.

it could be the higher compression on the flat top pistons and the stage one cam pushing more air. I’m not too sure.

 

it’s a BMW Z3 coupe

 

Ahh very cool!

 

here is the dyno graph. The blue line is the first pull we did with really low timing.

 

Is it just me or does it look like that power curve just hits a wall at 5,500ish rpm?
Looks like it continues to climb afterwards?
Nice install of that LS too bud, very clean.

 

yeah it had a lump in it. We didn’t spend much time on trying to get the timing just right. Kinda shut down after we felt the housings were not flowing enough.

 

just in case you guys have never seen these precision v band in and out housings. They are really small

 

Holy **** those are tiny!
I'm no expert but I think that might be an issue.
I think it would be in your benefit to install some sort of way of monitoring back pressure, even if you did it on only one.
Can you swap to a different turbine housing?

 

LOL yeah I posted pictures so people would get the point of how small these housings are I had them for a different project, but they ended up on this LS

you can get them in 64 82 or 105

The 105s are a bit fancier in stainless but that’s the ones I’m going to order.

the same turbos on a few set ups make 800 to 1000 hp pretty easily but they’re probably running the bigger housings

 

Betting back pressure is so angry with those turbines. I like stuff that lights off quick but dang that is small! 😆

 

WOW, how do the exhaust gasses even flow through those micro housings? That might be a "small" problem.

 

I’m excited to see how much power it will picked up from the bigger housings.

I know a pair of 6262’s can make over 1000whp on a LS. And I have seen a L33 make 725whp at 17psi. Don’t know what housings he was using.

 

I made 600whp with those exact same housings and backpressure wasn't a factor. Could've made more power with more boost.
It ran mid 10s banging gears at ~3500 lbs.
Could very well be your cam's response to them.

 

Clean setup. Any idea what boost control pressure is to make 15psi?

 

Guy I know makes nearly 600 wheel on a audi 2.7t v6 on a single 6062 with .64 v band in the 30 psi range. Granted that would be more based on ethanol fuel but I believe his backpressure was in check. Different engine but still seems clear you should be ok, but testing is better than guessing.

I have turbonetics old cast wheel 6265 in the .82 dual v band housings and made 1000 at 19psi with ethanol but that’s on a 6.3 10.2:1 engine with porting and cam. I wouldn’t change them out yet, but if you do I can’t see the need to jump to the 1.02 housings on a 5.3. I guess it depends on your goals.

 

It might be the camera but it doesn't sound happy in the dyno video. Is it hitting on all 8?

 

I think it’s just the wastegates. Pretty sure it’s firing on all 8. I have two wide bands they didn’t show anything.

 

I just have it in a 3 port Mac valve controlling two Tial 38mm wastegates. It’s at 22% duty cycle