Exhaust Manifolds for Turbo?

Does any aftermarket company make decent exhaust manifolds for the GTA Turbo? I am starting to assemble my 2975cc motor for my Turbo, and have decided I may spend the extra for a set of exhaust manifolds.

It is of course possible to get custom ones made here, and if I do I will move to an external wastegate type, if possible to fit in, so as to use a GT30 Garrett turbo.

Only custom I'm afraid. Ive designed a system using the 3-1 mandrel bend atmo manifolds, and a link pipe arrangement bringing the two together to a turbo flange, but the turbo is now low down in front of the engine (in front of the main pulley). This system will require relocation of the oil feeds and return (return needs to be tapped into the front of the sump face), and bin the original silencer and have a complete new downpipe and silencer system, but this is designed for a V-Band type 3" outlet, so it would need changing to fit your turbo.

Intercooler piping may need altering to as I designed it to work with a new chargecooler.

No restrictions, 'relatively' inexpensive, only suitable for a 'big' turbo to get the most out of it, but laggy

Has anyone ever looked into a twin turbo set-up? With a completely different exhaust and air intake system? Simualr to the Nissan 300 zx exhaust system.
I know it would be costly, but a set-up like that should give some serious benefits!

Yes, the two manifolds in the system I said above can be used for twin turbos, but its twice the cost, two lots of exhaust systems, two chargecoolers/intercoolers, and really needs a new inlet manifold system to make the most of it.

More power is available using just one decent turbo, and its far simpler.

I am looking to keep the turbo in the same position mostly to make it look standard, and save hassles, and I do like the fan blower system. I would like to run a ball bearing turbo, but there does not seem to be any T3 of suitable size with an internal wastegate, bar an HKS at twice the price of a Garrett.

The turbo facilities I use can supply a roller bearing core to fit standard T3 components, but its very expensive (over £800)

The GT series is the most affordable way, and they still have the same T3 mounting footprint. You will just have to modify the oil feeds and returns slightly, and modify the downpipe flange.

I looked at this when I was sourcing the hybrid for my 3 litre and the verdict was unless your going to run 20psi + all the time there was very little benefit in using a roller bearing turbo. They spin up a little quicker but cost twice as much! If moneys no object then have the best but otherwise something based around a Escort Cossie T34 is a good size. Turbo Technics built me a T38 which is pretty much the biggest T3 based turbo you can buy - uses mostly T04 parts with the lots of machining to fit them. Bolts sraight up but you do need to alter the air inlet and plenum pipes and the heat shields have to be modified to fit

I like the ball bearing centre as it certainly does make the turbo make boost earlier and so much nicer to drive. It also allows you to run bigger A/R and not end up with a lag monster. I am looking at 0.9 Bar boost. This is what I have seen in practice with many Japanese motors,(lower boost, comparitively small turbo) and then others end up running huge turbos that make massive numbers at 5000 rpm that are great on dragstrip and hopeless for anything else.

Tony, what A/R does your turbo have on the turbine and compressor? Is it running yet?

Anyway, at this stage it is all some months away, and I will see what happens when the theories are put into practice.

I know its a .63 housing but I can't remember whether the trim wheel is 55 or 60. Its laggier than standard but comes on boost very smoothly and you can get full boost by 3000 rpm without a problem. If I could sort out an ecu I'd be able to tell you what it went like!

If I could sort out an ecu I'd be able to tell you what it went like!

Come on Dave

Tony has an ECU....he just hasnt got it working yet...come on Tony!!!!

Nobody wants to do it! The fact that its an unknown quantity car wise and that the Adaptronic is not a well known ecu seems to be putting people off. ARR have given up, I may try and source an A610 ECU and then just get it chipped.

Tony, bring it down to me at the new workshop and we'll sort it.

Once its done, you (and everybody else) will be sorted!