trafficking coke works real well

 

I thought you might also be interested to see what borg warner is doing..



btw ALL borg warner turbos are twinscroll...

 

WTF is that electrical thingy on the compressor outlet???

 

It's the flux-capacitor. Once that baby reaches 88 MPH your going to see some serious sh*t.

 

like from back to the future?

 

lmao

 

ahahahahahahahaha i will never tire of that line

 

Electronic diverter valve.

 

Geoff et all,
I've seen several posts lately saying that long runners on exhaust manifolds are superior. Why is that?

 

Geoff are there any turbos by Borg Warner that are comparable to the gt35r and gt40r?

 

First is to use a manifold with sufficiently large internal volume that the exhaust output pulses of each cylinder are damped and a more or less constant pressure is available to the turbine. The internal volume of the manifold sufficient to obtain this pulse dampening can be 1.4 – 6 times the swept volume of the engine. That rules out pretty well all long runner exhaust manifolds, although a log-type one of the sort suggest by Allard may fit into the bottom end of this scale, and the current fashion in the US for mounting the turbo at the back of the car (in a car with a front engine!) would also conform to this approach.

The second approach is a pulse system, where the exhaust pulses provide additional short-term energy to the turbine. In a pulse-type manifold, Humphries suggests that the pipe runners should have a “cross-sectional area....not significantly greater than the geometric valve area at full lift [and] these connections should be kept short and free of sharp bends”.

He says the reflection of pulses within the system will be determined by pipe length, exhaust temperature and the status (ie open, closed or partially open) of the exhaust valves. In addition, at pipe junctions the exhaust pulses will split, with smaller magnitude exhaust pulses travelling down each pipe. “The overall pressure wave system that occurs in such a manifold will be very complex, with pulses propagating from each cylinder, pulse division at each junction, total or partial reflection at an exhaust valve...and reflection from the turbine.”

In order to take advantage of this pulse flow, “narrow pipes from several cylinders can be connected through a single branched manifold to one turbine....a four stroke engine which can have its cylinders grouped into threes is particularly attractive.” This is because “the opening periods of the exhaust valves follow successively every 240 degrees with very little overlap between them.... thus a sequence of pressure pulses arrives at the turbine...”

-jacked from a turbo performance book.

Ted also I feel that any restriction in the runner is energy that doesn't make it to the turbine. You need the manifold to be as big as possible before you start losing heat/velocity due to the pipe causing the gasses to cool off/slow down. I couldn't guess how you get the exact size, but I am almost positive thats why all the VERY FAST turbo cars usually use a long header.

Scorke

 

Not really, Borg's aftermarket devision isn't even really alive yet, they make some crazy stuff for porsche/diesel (kubota/ford f250/john deere) applications like the variable vane turbos, they have the technology just haven't decided the market is there......yet. Supposedly it might be in the works, my old roomate SoloEvo co-ops there...

Scorke

 

That would be sick if we could get one of their turbos in a gt35r, gt37r or gt40r variation.

 

To be honest I am not sure how much sicker they would be than the Garret CHRA, the twin scroll housings are the only real advantage, if what Full-Race and others are doing I'd love to see TiAl making custom nice V band twin scroll housings.

Scorke

 

Ditto... their stainless steel housings are very nice (and pretty light ) pieces. Would love to have a .9-1.1 AR twinscroll, t3 variant for a gt35.