The V8 Owners Forum -

Even saying Garret T3 or T4...that could cover 50, 60 different units.

Whether you can get anything custom to fit in your existing housings...no idea. It would be a case of shopping around. Although custom units could get expensive.

I have seen places in the past sell on centre housings....but they would be really old and not common these days. Whether they would allow fitment of anything modern or could be modified...no idea.

Could your manifold not be adapted to move the turbo to a better position or something and then allow something more modern ?

Taken from Garratt's website:

On-Center Turbine Housings
On-center turbine housings refer to an outdated style of turbine housing with a centered turbine inlet pad. The inlet pad is centered on the turbo's axis of rotation instead of being tangentially located. Using an on-center housing will significantly lower the turbine's efficiency. This results in increased turbo lag, more backpressure, lower engine volumetric efficiency, and less overall engine power. No Garrett OEM's use on-center housings.

So from reading the above I would say that the issue with efficiency is also with the housings, not just the turbine/compressor wheels.

Tom.

This is why no other type of turbine housing will work ,I'm thinking im going to have to work with what got , I've only got about 10mm space
either side, 10mm between turbo and rocker covers and 10mm between turbo and suspension turret











As you can see if I used the other type the turbo would hit the suspension turret or the rocker cover depending on what side it's on.
I did think about making a wedge shape adaptor but it would make the flow even worse and the turbo would end up way to high prob hitting the bonnet or very nearly

Just make a wedge shaped adaptor for the new turbo.

I'm not seeing any major issues ?

stevieturbo wrote:Just make a wedge shaped adaptor for the new turbo.

I'm not seeing any major issues ?

Stevieturbo your right , I'm just to bloody sentimental about my crapy old roto masters I'm clutching at straws to try and keep them LOL !!!
I think I'm just hoping someone agrees with me and says have them re built and try it , I've had these turbos about 15 Years now, they came with a old sd1 janspeed kit I bought , ive been dreaming of getting my tr7v8 running with these on for years, I just wanted to keep the old roto masters because the janspeed tr8 had them and I liked the period look ,
Was hoping to get 300hp with them on my 3.9 with injection and stand alone ecu and intercooler

If you want to retain them, then retain them. But if they do need fully rebuilt...there will just be far far better options out there.

But as said, make enquiries with a few turbo builders and see if they can make something work with the housings you have.

stevieturbo wrote:If you want to retain them, then retain them. But if they do need fully rebuilt...there will just be far far better options out there.

But as said, make enquiries with a few turbo builders and see if they can make something work with the housings you have.

Ok well I'm pretty sure the roto masters are the same as garret t04b turbos .60 ar compressor .40ar turbine side I've pulled them apart wheels look ok , they measure compressor inducer 43.7 xducer 70.0mm and if my maths is correct trim 39 , turbine 72 inducer 52 xducer , I've spoken to midland turbos they say they can refurb for £180+ vat so will give it a go ,

They are from a sd1 janspeed kit ,according to a old road test I've read in April 1979 Motorsport magazine where the sd1 with the identical janspeed kit I've got is reviewed "boost comes In progressively from 1800rpm reaching it's maximum as the needle rises to 2500rpm"
So doesn't sound like to much lag ? Assuming my turbos are the same spec ?

Not sure if they will choke the engine at maximum rpm ? As i said before I would be happy with 300hp with efi etc and intercooler but that's not a deal breaker , I would be interested to know if my roto masters are the same spec that chodjinn from this parish had on his old engine ??

I guess only thing to do is get them fixed up and get it running.

Any turbos will be better than none ! lol