The V8 Owners Forum -

hi i have a friend whos into his nissan 300zx's and he thinks a pair of 300zx z32 garrett t25 would be a nice match for the 3.9 v8 im currently building, (instead of the 30 year old rotormasters from a old janspeed kit i was going to fit) ,i wont be exeding 7psi as only on normal slotted 3.9 cast pistons my goal is 300hp so not looking for mega power the turbos look quite compact , and he can put his hands on some quite easly the 300zx is 3L v6 what do you lot think ?

Only one way to find out. Pop them in and run it.
Post a video for us to see, please.

I had Garrett T3's on mine ( Cossie type) and they were Goldilocks.
T25's may limit the top end gas flow but lag will probably not be a problem.

DEVONMAN wrote:I had Garrett T3's on mine ( Cossie type) and they were Goldilocks.
T25's may limit the top end gas flow but lag will probably not be a problem.

Which Cossie type mate, Two door Cossie ( T3-55) Saphir Cossie ( T3-60 ) Escort Cossie T3-4 or later Escort Cossie T25 ??

Initially I put 2wd sapphire turbos on but later changed them to the 4wd sapphire type. The 4wd type have slightly larger compressor wheels and I noticed a small increase in lag but no noticeable improvement at the top end. Hard to tell without a rolling road test.

JP. wrote:

DEVONMAN wrote:I had Garrett T3's on mine ( Cossie type) and they were Goldilocks.
T25's may limit the top end gas flow but lag will probably not be a problem.

Which Cossie type mate, Two door Cossie ( T3-55) Saphir Cossie ( T3-60 ) Escort Cossie T3-4 or later Escort Cossie T25 ??

I'm running a pair of Genuine T3-4's on my 5.7 chevy!

Found the specs for stock turbos

Definitely throw them on and try it if you can get them cheap.

Although really if you were to take a pair from most modern 1.8 or so 4cyl turbo engines, they'd work fairly well too.

stevieturbo wrote:Definitely throw them on and try it if you can get them cheap.

Although really if you were to take a pair from most modern 1.8 or so 4cyl turbo engines, they'd work fairly well too.

Out of curiosity would turbos off 1.8 diesel be equally suited or
Would it have to be petrol 1.8 car ?

Twinturbotr7 wrote:

stevieturbo wrote:Definitely throw them on and try it if you can get them cheap.

Although really if you were to take a pair from most modern 1.8 or so 4cyl turbo engines, they'd work fairly well too.

Out of curiosity would turbos off 1.8 diesel be equally suited or
Would it have to be petrol 1.8 car ?

Depends how much power they were to supply.

Ultimately the turbos only move air, but you would expect a modern 1.8 petrol to be around the 200hp ish mark.
A 1.8 diesel....not so much.

I read this somewhere on the 'net so it could well be wrong but is it right that oil can get sucked past diesel turbo bearings when used on a petrol engine, something to do with high manifold vacuum when the throttle is closed at high revs on a petrol engine?

ratwing wrote:I read this somewhere on the 'net so it could well be wrong but is it right that oil can get sucked past diesel turbo bearings when used on a petrol engine, something to do with high manifold vacuum when the throttle is closed at high revs on a petrol engine?

On a blow through installation, there would never be vacuum anywhere to do that.

Maybe ancient suck through or something.

Ok so I thought 300 zx turbos might be. A good idea but unfortunately there is not enough room in engine comp ,I'm using boost prerfomance manifolds , one side is to close to rocker cover, on the other side to close to suspension turret So what to do next ? My original turbos old rotamasters are what I have learned off the net are what is called ( on center turbos ) they fit ok but need refurbing but are old technology ,I need to find some other turbos that fit that are also on centre design or get my original turbos refurbed poss have some hybrid wheels put it to make them better?? , ive already bought my intercoolers etc and have made other modifications so don't want to deviate from the twin turbo route , and don't want to have to make custom manifolds .
refurb for the rotomaster Is about £200 each or could strech to upto about £800 for something else but this must include refurbing costs ,I don't want to just slap on some old turbos and take the chance (I only want to do this once lol) so refurb or new is must , any advise will be greatly received

You can buy some on centre housings for Garrett stuff.

IMO you'd probably be better off just making manifolds to fit some modern turbos. They'll be miles better than any of that ancient junk.

stevieturbo wrote:You can buy some on centre housings for Garrett stuff.

IMO you'd probably be better off just making manifolds to fit some modern turbos. They'll be miles better than any of that ancient junk.

Hi stevieturbo
I tried making my own manifolds befor its a very tight fit it drove me round the bend , I gave up and the project stalled for a long time
That's why I bit the bullet and bought the boost performance manifolds ,

From what I've read off the net my roto masters are essentially garret t3 /t4 and apparently are comparable with garret And the chra could be swapped to a more modern one with minimal work, but keeping the external appearance and size the same as the old ones that fit (but only just ), would this then be an ok turbo ? or Is there anything inherently wrong with the turbine housings or compressor housings ? I do like the idea of keeping the period looking roto masters compressor housing , with more modern internals that might spool faster? , Maybee buy a smaller garret on center turbine housing to reduce the lag ?