TO4Z turbo results

[BlakeNZ]

This may interest some of you. My mates car is a Z32 300zx V6 3 litre manual with a zed link computer, 720cc injectors,mild cam upgrade,built motor,mild head port.
The radiator has been replaced with a smaller thicker one, further forward, on a angle, to allow the fitting of a single garrett TO4z (between motor and radiator) A 2" steam pipe comes forward from each bank of exhaust ports(after the 3 cylinders exhaust flow has merged together) and merge into the collector. 48 or 50mm turbosmart w/gate. 22psi.

The first exhaust housing was single entry .96, got about 390rwkw(hub dyno) but car was laggy, used to bog in first and second gear at drags, so changed to a .7 twin entry exhaust housing. Lost 50 horsepower, spool up did not improve.
Tried .8 single entry housing , for same result, still down the 50 horsepower, still no better at spooling up.
went back to original .96 housing, regained the 50 horsepower, but still had the bogging.

A chance conversation at the drags with forum member LITH, got him thinking about the benefits of a twin entry turbo, which Lith reckoned was ideal for 6 cylinder motors(and also really suits the two cylinder banks of a V- motor.) So he got a twin entry housing, which was a 1.00( virtually identical in a/r to his .96) and made a new collector that suited the twin entry housing.
He drove the car before getting a retune, and said it felt like it was spooling up 700rpm earlier. had it tuned and dynoed yesterday, and dyno graph showed it spooled up about 300rpm earlier, but at 4500rpm, it has 30% more torque(650Nm compared to 500) and with no timing added, yielded 405-410rwkw at peak.

the tuner found that it could take much more timing, and added up to 7 degrees at top end !!! which yielded 429rwkw and was still climbing when they hit the rev limit(set too low). Timing was then taken out to reduce power back to low 400s, because (i think) the early links don't have temperature compensation.

Overall the tuner felt the car was much more happy, loved the new combination of twin entry housing and twin entry manifold.
It was a surprise to find that the engine became more efficient - producing more power per unit of fuel.More power using less fuel.
Hope this info helps someone, without going through the massive effort and expense that my legend mate did.

[wishihadaTE27]

OMG WALL OF TEXT ! LRN2PARAGRAPH

[Bling]

That was my thoughts too, I read half a line then gave up as I knew I wouldn't be able to break the wall down

[Lith]

Awesome, thanks for sharing- Blake

[Bazda]

I've been telling eveyrone to go for twin scroll turbos and correct manifolds for over 2 years now. My old man felt the benefits from twin scroll turbos int he 1980s on his turbo escort back in the days running in the Tranzam series. Loved those cars!

[Lith]

I've been telling eveyrone to go for twin scroll turbos and correct manifolds for over 2 years now. My old man felt the benefits from twin scroll turbos int he 1980s on his turbo escort back in the days running in the Tranzam series. Loved those cars!

Yeah its definitely not ground breaking stuff but nonetheless a lot of people seem to miss the fact, and its not helped by the fact that most of the aftermarket stuff out there seems to be single scroll based.

The spool advantage in the case of parallel twin turbo setups like on the RB26DETT and 1JZGTE is frequently misinterpreted as being due to having two small turbos as opposed to the truth of the matter which is that the exhaust flow is able to be nicely divided from 6 pulses into pairs of 3 which are fed through very short direct paths to the turbines meaning they are nicely distributed and holding heaps of energy still.

A lot of the really fussy folks will keep the two scrolls exhaust feeds completely pure by running a separate wastegate for each one to avoid any contamination between cylinders 1 2 3 and 4 5 6.

[Bazda]

Thats correct.
As why i run 2 wastegates, on the 4 cyl its keeping 1-4 seperate to 2-3.

Alot of people still run the 1 wastegate but use a divider plate where the 2 gates join. THe divider plate goes all the way to the bottom of the wastegate valve.

[Lith]

Ahh nice, I guess I'm going to have to read up some more on this car - sounds like its got a few things going on I didn't know about haha.