Rb 2860-5 Highest Hp?

[Dose Pipe Sutututu]

Ok, so the turbos glowed and the boost dropped off...

Turbos glowing - excessive egt.... why?

Boost falls off - Compressor cant keep up (out of flow). Not related to exhaust housing restriction. If anything boost would remain at targeted level because the gases cant escape the engine quickly enough.

let's play a game of broscience.. if your housings are too small and you can't get enough exhaust gases out of the motor to spin up the turbines how will the compressor keep working?

Say you can only get X amount of exhaust gas into the tiny housings and only X amount of exhaust can get out.. well that's only Y amount of kinetic energy to move the compressor.

Like I said, not rocket science.

[Jc052685]

So you are saying that the exhaust housing is incapable of flowing enough air through it to spool the turbo its self?


So in your theory you seam to think we dont know what the exhaust housing will flow..... well we do

[Ben C34]

This thread rules

[mr skidz]

we do know they work well up to 550 600 whp thats all that matters.

Amazingly the front wheel and the rear wheel run out of steam at the same Point which makes it a nicely balanced turbo but it has limits.

Like anything

Edited April 28, 2016 by mr skidz

[XKLABA]

Lets just pour some fuel on this one lol

The tail end isn't restricted in -5s, the compressor is out of flow, my RSs with the same rear hold 28psi flat to 8500 on a 3.0 though the power does start to fall away but that might have been the old cams as well

And the boost v backpressure on these things is garbage

[mr skidz]

Lets just pour some fuel on this one lol

The tail end isn't restricted in -5s, the compressor is out of flow, my RSs with the same rear hold 28psi flat to 8500 on a 3.0 though the power does start to fall away but that might have been the old cams as well

And the boost v backpressure on these things is garbage

What do you mean the tail end isn't restrictive?

You mean exhaust housing?

And what do you mean boost vs back pressure is garbage back pressure where in your turbine or in your exhaust?

Have you measured it?

We all really need to be more specific including myself with our typing as everything will be taken out of context and waste probably 10 pages of this thread and half our lives trying to clear things up[emoji85]

Edited April 28, 2016 by mr skidz

[XGTRX]

The best way to do it is have the dumps straight out of the bonnet and boost it till it blows.

Any volunteers?

[XKLABA]

What do you mean the tail end isn't restrictive?

You mean exhaust housing?

And what do you mean boost vs back pressure is garbage back pressure where in your turbine or in your exhaust?

Have you measured it?

We all really need to be more specific including myself with our typing as everything will be taken out of context and waste probably 10 pages of this thread and half our lives trying to clear things up[emoji85]

I mean the exhaust side of a -5 can out flow what ever the compressor side can send it

I mean exhaust housing and turbine wheel, the more variation in pressure from pre and post turbine the better the turbo can work, just to spell it out the lower the pressure in the exhaust post turbine compaired to the pressure in the manifold/exhaust housing the better the turbo will work

Boost v backpressure in this instance is obvious but I will spell it out also for the knowledge lacking few, the backpressure pre turbine v how much boost the compressor is making

We measured it in the BSM GTR time attack/ sports sedan when it was running -10s and ended up controlling boost according to exhaust manifold pressure

if everyone had to explain everything that is posted this thread would be a fark load longer, certain things just need to be expected to be common knowledge, if there is something someone doesn't know they should ask a specific question

[mr skidz]

Did you find boost pressure and manifold pressure to equalize at 28psi?

Were they N1 or std ported ones?

My manifold is threaded and I'll be measuring the difference at some stage.

Edited April 28, 2016 by mr skidz

[GTSBoy]

Did you find boost pressure and manifold pressure to equalize at 28psi?

Equalise? I think you will find that any turbo set up to provide any sort of response at all will have more ex manifold pressure than boost. Often as much as 2:1.

[XKLABA]

Did you find boost pressure and manifold pressure to equalize at 28psi?

Were they N1 or std ported ones?

My manifold is threaded and I'll be measuring the difference at some stage.

We didn't test mine, I don't have that capability setup on mine but we set the BSM GTR to about 1.8-2:1 back pressure to boost iirc, that was a long time ago now

BSM had Tomei manifolds mine a ported std

At a certain boost level the manifold pressure escalated which is why the boost was set that way

[Piggaz]

Got any idea what boost pressure that was, Micky?

[XKLABA]

Nah man not exactly, it was up their though, high 20s I think

I do remember when it was in IP with the restrictors on the intake it would get to 26-27psi before the restrictors took the fun away from around 5500rpm

[sneakey pete]

Hey ID anyone thinks the rears are tok small feel free to buy my tomei turbos and put a gtx3071 in or something

[XKLABA]

Hey ID anyone thinks the rears are tok small feel free to buy my tomei turbos and put a gtx3071 in or something

.

Which ones are they ?

[sneakey pete]

The arms m7655, the smaller of the two in terms of wheel size. The housings are a big chunk bigger than -5.-10 housings, I'll try dig up a comparison photo when i get home thisarvo

[Piggaz]

When will you have your gtx frankenstiens up and running Pete?

[bigmikespec]

We didn't test mine, I don't have that capability setup on mine but we set the BSM GTR to about 1.8-2:1 back pressure to boost iirc, that was a long time ago now

BSM had Tomei manifolds mine a ported std

At a certain boost level the manifold pressure escalated which is why the boost was set that way

Wow that is average for a race car... but was that built to class rules?

[sneakey pete]

Shop building the engine placed an order for the stroker at the begging of match but the pistons still haven't arrived yet apparently. So I dunno, august at this rate between me putting it back in when its done and my site roster.

[Piggaz]

What stroker did you end up going?