2.9 Twin turbo project - Turbo choice?

[Capri_Andy]

Help! ive seen this on ebay! http://cgi.ebay.co.uk/T25-T28-Hybrid...QQcmdZViewItem
Should i use them on my engine or not?

Im stuggling to decide what spec turbos i need, but i was thinking along the lines of a pair of T25s from saabs. I know quite abit about turbos, but nothing about how to decide what spec i need.

The engine im working on is a 2.9 12v in my capri. It will be running standard efi with 7th/8th injectors and 7psi to start off with on a std bottom end, so it will be around 220bhp.

What i want to avoid is choosing a pair of turbos that are too large and dont come on boost early enough, or have bad lag. Can someone with more knowledge give me some advice and tell me if that turbo on ebay will cause any bad effects or is it ideally suited?

Cheers.

[david_white]

Help! ive seen this on ebay! http://cgi.ebay.co.uk/T25-T28-Hybrid...QQcmdZViewItem
Should i use them on my engine or not?

Im stuggling to decide what spec turbos i need, but i was thinking along the lines of a pair of T25s from saabs. I know quite abit about turbos, but nothing about how to decide what spec i need.

The engine im working on is a 2.9 12v in my capri. It will be running standard efi with 7th/8th injectors and 7psi to start off with on a std bottom end, so it will be around 220bhp.

What i want to avoid is choosing a pair of turbos that are too large and dont come on boost early enough, or have bad lag. Can someone with more knowledge give me some advice and tell me if that turbo on ebay will cause any bad effects or is it ideally suited?

Cheers.

You may be in luck, I happen to have to hand a pair of reworked 2.9 heads with manifolds and matched turbos. They belong to a workmate so I'll try to badger him for a price if you're interested.
I bought other bits off him and everything was like new.
All from an abandoned xr4x4 TT project

[therealpinto]

I usually recommend Mitsubishi TD04-15Ts off Saab or Volvo turbos. I have been involved in a twin turbo 2.8 Capri with those and they worked beautifully. The Mitsubishi is a really nice turbo that has good spool and supports a lot of power.

At "only" 220 bhp you could go even smaller, 13T. A pair of T25/28 hybrids may feel a bit big.

Regards

Gustaf

[Capri_Andy]

Thats great if you can find out and PM me David, im interested. Find out what turbos they are and whats been done to the heads. I wont be needing manifolds though. Custom manifolds are in development to locate the turbos to fit a capri engine bay.

Thanks Gustaf, thats what i needed to know. Theres a big saab breakers near me so anything that comes from saabs would be very handy.

[sierra3dr]

What i want to avoid is choosing a pair of turbos that are too large and dont come on boost early enough, or have bad lag.

I'll give you my pennies worth. I'm not fully sure if you have the manifold already,you may consider in getting a twin scroll or divided inlet turbo,these illiminate turbo lag,have a look here
http://www.nissanperformancemag.com/march06/nerds/

[therealpinto]

But a V6 using twin turbos already have a very good pulse spread and a twin scroll/twin inlet turbo will be a little bit hard to set up when you have 3 cylinders feeding each turbo.

I can vouch for that using 15Ts on a 2.8/2.9 there is no need for a divided inlet, they spool quick enough. That said, a programmable management system like Megasquirt together with a mild tuning cam does wonders for the engine.

Gustaf

[sierra3dr]

Clearly Custaf,you are alot more knowledgeable than I. I'm still learning and I have on my XR4i a T04 twin scroll turbo on it. I have learnt that the turbo is from a Leyland bus according to BTN turbo. The turbo kit is from Eichberg,and originally the turbo that should be on the XR4i is a KKK 3LKZ,which was used on a DAF engine,which I presume was twin scroll because the original Eichberg turbo manifold was this

I am just trying to evaluate the possibilites with a V6. But,as the Cologne has two ports per bank,this is no use to Andy. I suppose the T15s would deem better

[Capri_Andy]

Interesting looking manifold. Is that for single turbo, where one bank is fed through one scoll and then the link pipe going into the other scroll? Just curious.

My cologne has 3 ports yes, and will be a turbo per bank, so no way to plumb it in really.

[sierra3dr]

Interesting looking manifold. Is that for single turbo, where one bank is fed through one scoll and then the link pipe going into the other scroll? Just curious.

Yes that's correct

My cologne has 3 ports yes, and will be a turbo per bank, so no way to plumb it in really.

So what do you have,the 2,8 EFI? I've been trying to establish which cylinders on a V6 would be on the exhaust stroke simultaneously...hmm

[therealpinto]

If you're going single turbo a twin inlet turbo is nice to have. I think Andy's using a 2.9, hence the three ports.

Regards

Gustaf

[mihakrapez]

My friend used Dodge Stealth V6 biturbo turbos.

Or Maybe couple of Fiat UNO Turbos.

But I think that there is better to use only one and slightly bigger.

[FLD]

c

[FLD]

Single turbo systems do have the advantage of costing less and having less plumbing to do. Why not consider a single T3? These are everywhere so cost very little, they produce good boost and are available in a range of trims. This manifold is also available in cast iron (better than any tubular manifold). There is however the trap of "whats better than one turbo....two of course"! But then thats for you to decide isn't it.

FLD

[Capri_Andy]

This project for me is not so much what works best, or the easiest way to get power. a 24v would be an instant 200bhp. Im trying something a little unique and interesting, and if i can get it right, it might be the start of a new cost effective way to make power from an engine that will supersede the 2.8 when replacement engines for capris and mk2 granadas are harder to come by (Like in poland already , see how many 2.9 conversion they have done, loads!). Either way, its for fun, and to make it look good.

The thing is with the 2.9, its like 2 seperate engines, 2 exhaust manifolds, and a dual intake plenum chamber. A link pipe would be needed (if designed incorectly this is liable to cause poor turbo lag). Also an aftermarket engine management system would be a must unless you run the 2 air flow meters into one turbo which would be undesireable. And then after the intercooler the pipe would have to split into 2 again into the throttle housing, unless a custom single throttle housing is made.

Twin turbos in a good sized engine bay could actualy make pluming a little simpler, and it will look the dogs danglies!!!

[FLD]

Aye, I see where your coming from, and yes it would look rather nice I was just making sure you'd considered all options. WRT single turbo conversions the janspeed one is a drawthrough system (throttle pre-turbo) and uses the original ecu. A link pipe would be needed but with a small turbo running say 7psi you'd have very little lag, boost from around 2K. A nice twin GT22 would be good or you could consider VNT's for boost from idle.

[therealpinto]

It's no real problem running the 2.8/2.9 EFI system with twin AFMs on a single turbo, the first engine we built for the Capri V6 turbo had that setup. It worked reasonably well.

But IMO a T3 turbo is way too small for a 2.8 to give good power and a power band that suits a sports car like a Capri. It tends to run out of breath quite early. We used a Holset HX35 turbo and even though the wastegate setup was far from ideal there were no real problems with lag. But still, twin turbo was better...but it does get cramped!

Gustaf

[Stevie]

the original tt car's like the one i have run t2's

[BRIGSPORT]

Single turbo systems do have the advantage of costing less and having less plumbing to do. Why not consider a single T3? These are everywhere so cost very little, they produce good boost and are available in a range of trims. This manifold is also available in cast iron (better than any tubular manifold). There is however the trap of "whats better than one turbo....two of course"! But then thats for you to decide isn't it.

FLD

Who produces this manifold,and how much is it?

[FLD]

I produce it! Probably looking between 100 and 150 for a bare casting depending on the current iron price.