MazdaEbrahimi

hey all,
I'm putting a tII in an MGB... no room for the turbo in the stock location. I'm playing with various ideas on what to do with it. I've come up with a location that's about 12" away in exhaust piping. Several questions:

1- from a performance standpoint, how sensitive is the setup to distance from the manifold? i know you want to get it there as soon as possible to use the heat energy. Assuming i heat tape it, how bad is it.
2- I have to use a n/a manifold at the engine. does anyone have pics of n/a manifolds that fit the 13B? I need the tightest one, as space is very limited near the exhaust ports.
3- The exhaust inlet of the turbo is shaped to match the tII exhaust manifold. Since i'm putting it remotely, that won't work. Any suggestions on what housing to swap to?

Thanks

BLUE TII

iTrader: (9)

Closer is better, but there are many instances when turbos are farther away from the engine and still work. Huge turbos almost always have to be fitted forward of original position w/ a turbular SS manifold. The Subaru Impreza has a flat 4 and single turbo so it has long exhaust manifolds- heck the newest one even has a catylitic before the turbo. Since you don't seen to have much choice at least you know it works in other cars... You can try to reduce the loss of thermal energy w/ "header wrap" on the manifold. The stock RX-7s (especially 87-88) have a real problem w/ excessive ehaust energy leading to boost creep spikes anyways once they have a straight through exhaust so maybe this will even help w/ that?
NA manifold? Do you mean the tubular manifolds for exhaust instead of cast iron? Not sure what you are refering to.
As far as the divided flange the turbo itself; that is because it is a dual scroll design in which there are two angles the exhaust strikes the turbine blades. In 87-88 a flapper in the mani. closed one off for quick spool, in 89+ each rotor had its own scroll and the manifold was much more direct. Keep your custom tubular mani. divided or use undivided mani. and reduce (grind) the space between the two runners on the turbo. Dual scroll turbo housing is fine.
Are you already informed on overboost fuel cut and all? Hope that helped a little, Ian.

MazdaEbrahimi

I've turbo'ed a few cars before, but not well versed in details of the rotary turbo yet.
My problem with the existing manifold is that the 'bowl' for the turbo points right at the frame. I thought if i used a manifold that would just point the exhaust back, i could then take a pipe up to the turbo and connect it there. I would have to adapt the pipe into the turbo at that point.
The explanation for why they divided flange makes sense. Thanks.
On the fuel cut stuff... I haven't gotten that far yet. Still trying to fit the engine. I've found alot of useful info on the forum, which i'll be refering back to as i get to the fuel / ignition system.
Mazda

BLUE TII

iTrader: (9)

OK, so when you said NA manifold you were speaking of using a manifold/header designed for an NA RX-7 and modding it to work w/ turbo? Not sure if back is going to work. The rear of the turbo is even w/ the rear of the engine in the TII so thats pretty far back to begin w/. Also note the exhaust inlet is 90 deg to the outlet that could make things tricky. If you were thinking the long headers NA RX-7s use that would put the turbo way back and low I think you would have very long oil and water lines and red hot turbo could crack easily from having water splash it; plus intake air has to be piped to and from the turbo.
I think a custom welded mani. that places the turbo up and forward may be the best for the narrow confines of the MGB. But of course, I am not there- able to see the engine in the car.