Calling turbo experts - Rover V8

[300bhp/ton]

As my TR7 V8 should be on the road again soon. I'm thinking of messing about with a home built turbo setup.

I need HELP (well that's what people tell me... )


What would be a good sized turbo to run on a 3.5 Rover V8. CR is around 9.35:1 I think. Looking at a single turbo setup and not loads of boost, just a mild setup.

Ideally I'd like to source the turbo from a breakers, so what car would make a good donor (any of the turbo diesel turbo's??)

Other help:

The car has a weber 500 carb and offy manifold. How do I go about sealing these for use with a turbo?

What BOV would be be suitable?

Thanks.

[Boosted LS1]

Something like this will seal the carb.



As for low boost, a t3 may be to small but maybe you can find a t4 or similar from a cosworth. In the 'old days' a single rotomaster would do the job and there are still a few of those kicking about.

[300bhp/ton]

Boosted LS1 said:

Something like this will seal the carb.

Cool, where can I get something like that?? Do you have any?

Ta

Boosted LS1 said:

As for low boost, a t3 may be to small but maybe you can find a t4 or similar from a cosworth. In the 'old days' a single rotomaster would do the job and there are still a few of those kicking about.

T4, ok I'll have a look.

How would any of the turbochargers off of diesel 4x4's be?? Some of them run 3.0 litre motors, would these work?

[Roop]

For light boost a T3 should be adequate. T3/04 on my RS500 is very laggy but it's only being blown round by a 2 litre.

AFAIK you have to be careful using turbos for diesels on petrol cars as the EGT is much higher on the latter and can melt stuff.

[300bhp/ton]

Thanks for the warning. I'll have a mouch round and see what I can find.

BTW - what turbo's did the old Supra 3.0 litre run?? They where single turbo weren't they. Would one of those be any good?

These ones:

[stevieturbo]

A turbo from a Supra would probably do fine...although be ready for oddball flanges, with it not being a Garret unit.

As for the carb box.....you need to be sure there arent any air bleeds or orifices outside any boost box, in order for it to have any chance of working.

[300bhp/ton]

stevieturbo said:

A turbo from a Supra would probably do fine...although be ready for oddball flanges, with it not being a Garret unit.

As for the carb box.....you need to be sure there arent any air bleeds or orifices outside any boost box, in order for it to have any chance of working.

Thanks Stevie.

I guess it'd be sensible to run two boost gages, one from the turbo and one on the carb box to see the actual boost being retained and keep and eye out for leaks.

Any idea where I can get something like the item pictured above?? It's beyond my fabbing skills.

Thanks.

[stevieturbo]

2 boost gauges are pointless.

You need to inspect the carb for any potential leaks, and suitability when using a boost box like the above.

IMO, something like a cheapy 2 barrel Holley, or Weber could be handier. When blowing through, you do not need a big carb...smaller ones will work better.

Problem is.....carbs these days can be tricky, as not too many guys know what they are doing with them. Add boost...and you throw a further spanner in the works.

[eliot]

Some info on my site showing you how to use Eric's turbo calculator to work out what turbos will work:
http://mez.co.uk/forum/viewtopic.php?t=436

[BB-Q]

Roop said:

AFAIK you have to be careful using turbos for diesels on petrol cars as the EGT is much higher on the latter and can melt stuff.

A myth perpetuated by Holset as they don't want anything to do with the aftermarket.

If it were true then the turbine in a diesel would be running within about 100C of it's failure point. You'll find that the material properties of a metal like that makes this virtually impossible, as it would lose it's strucural integrity at this point.
There's thousands of petrol cars using turbos from diesels- just look over the other side of the pond for proof.

A Holset HX35 should be good for 450hp and has a T3 (divided) flange. Try and find one with a 12cm2 turbine. If you find a 15cm2 turbine housing (or an HX40)I'll swap you.:wink:

[eliot]

BB-Q said:

A Holset HX35 should be good for 450hp and has a T3 (divided) flange. Try and find one with a 12cm2 turbine. If you find a 15cm2 turbine housing (or an HX40)I'll swap you.:wink:

Here's a plot I did for a HX35 a while ago:

Edited by eliot on Saturday 11th October 17:50

[BB-Q]

PR of 3.0 would be 2 bar boost, IIRC?

[eliot]

yes.
Basicly subtract "1" from the PR to arrive at bar of boost (give or take)

[minimatt1967]

Would you be able to use any parts from an MG Metro Turbo be of any use for this project, as they use an S.U carb 1.75" and a garret turbo? Just a thought might reduce costs and developement time.....possibly twin turbo's

[stevieturbo]

Yes, a pair of turbo SU's would be perfectly usable.

[300bhp/ton]

minimatt1967 said:

Would you be able to use any parts from an MG Metro Turbo be of any use for this project, as they use an S.U carb 1.75" and a garret turbo? Just a thought might reduce costs and developement time.....possibly twin turbo's

I was planning on keeping it a single turbo for fitment reasons.

[gmtech]

Hi there

Stop messing about with turbo's on V8ts, what you need is a supercharger for that engine.

Turbo's on V8ts are useless, load pressure on lower revs are for a V8 and that is what a supercharger provides, forget that turbo spend your dosh on a supercharger and get some grunt out of it.

Trust me, I know.

GMTECH

[Boosted LS1]

^ But a zillion other people choose to use turbo's, some with excellent results. I think it's an individual thing.

[gmtech]

You will find yourself in error there, turbo's are better suited for high revving engines, V8 engines suit superchargers much better (for useful power) then turbo's.

I can only tell you what I know, what other people do buggering about with turbo's on V8ts I can only guess what goes through their minds.

I have worked on V8ts and I know supercharged is the way to go if you want some grunt out of your engine.

It's elementary my dear Boosted LS1.

Whatever you decide I hope you enjoy doing it.

GMTECH

[Boosted LS1]

Why, thank you so much my good man.