Garrett T04z - .84 or 1.00 A/R?
 

I've decided that the t04z is the turbo for me, now I just need help deciding on an A/R size. The motor is a Pineapple Racing streetport (largest sp they do), 3mm seals, and unfortunately S4 rotors. The motor was built for someone else who couldn't pay for it, so I picked it up at a steal of a price. Anyways, I'm going to be shooting for just over 500whp (yes, I know the other supporting mods required to achieve this power figure, please do not turn this into one of those threads), and I'd like to know whether or not the experts think the .84A/R housing will get me there. I think that with the large streetport I might be flowing too much exhaust for the .84 at that power level (especially since I'll have to run more boost than most due to the S4 rotors), but the car will be used for a decent amount of street driving with its secondary purpose being road-course racing, and a little bit of drag thrown in every now and then, so I'd be happy to have whatever extra spool I could get my hands on with the .84. Lemmie know what you guys think.

Id say go for atleast the 1.00 housing. I think u will see backpressure with the .84 housing, and the rotary wants bigger exhaust housings then a piston engine.

Im running a 1.32 housing on my T04Z and im seeing 15 psi at 3000 rpm. This is though with a Bridge Port and E85. But i still think u will se quite good spoolup with the 1.00 housing. Maybe a 1000 rpm later then me to 15 psi or so.

JT

Go with the 1.00 it will still spool up quickly, the .84 will run out of breath at the higher RPMs.

1.0 at least. I have aggressive sp, T04z with .96 hotside and I made 424whp on 92 octane @15psi.

A friend of mine at Gotham Racing strongly believes that any mild-aggressive street port is at home with a 1.0 A/R.

I'm trying to do the same as you. I'm looking for a T04Z with a 1.0 A/R.

I have the hks t04z with 0.81 AR and looking for 1.00 AR but it is discontinued from hks..so I was wondering if garrett 's 1.00 AR turbine housing is a proper fit for my hks t04z.
Thanks
George

Garrett has discontinued the 1.0 P trim turbine housings. It would need to be clearanced for a BB turbo if you found a used, or old stock one. So short answer is no.

i had a t04z BB CHRA with t04s 60-1 kompressor and a 1.0 ptrim turbine with v-band outlet, the company still have a few of those turbine housing on the shelf (in sweden) and they a cheap!
allthou ther recimmended a 1.15 or larger if streetported (mine where stock port)
407rwhp @17 psi but with the t04s 60-1 compressor. Never tried the t04z one, still have it at home thou

@rx7jocke what's the price of these units?
@turblown I found a new stock one. They told me that the 65mm P-Trim 1.00A/R turbine housing fits perfect either the Garrett TO4Z BB or the HKS TO4Z unit since the have the same CHRA and specs. I know nothing about these things..
HKS TO4Z specs:
COMPRESSOR:
-Wheel: 63 Trim, 66.7mm Inducer/ 84mm Major
-Housing: Ported Anti-Surge 4.00" (100mm) Inlet / 2.75" (70mm) Outlet,
-A/R: .70
TURBINE:
-Wheel: 76 Trim - 74.2mm Major / 64.7mm Exducer
-Housing: T4 Divided Inlet / 99.1mm V-Band downpipe discharge
-A/R: .61, .81 or 1.00

Garrett TO4Z
Compressor wheel diameter is 84mm exd. / 66.7mm ind. (63trim) Compressor housing is .70 A/R has a 4" inlet and 2.5" outlet slip on connection. Turbine Wheel: 74.2mm w/ 76 trim,Available Divided T4 Housing A/R, .70, .84, 1.00, 1.15

HKS offers 0.61 and 0.81. Is it possible that only the 1.00 A/R fits perfect both units without any clearing to be done?

thanks,
George

I just bought a "knock off" T04Z that has a 1.00 housing.(China.)
The wheel specs are the same what you just posted Black7Conv.
So even if the turbo starts to go,I got a good 1.00 housing!(it's just temporary anyways!)

Oh the Chra will fit the exhaust housing,no problem.(can swap garrett chra and chinese chra onto the exhaust housing)
The front plate though wont allow the Garrett compressor housing to fit onto the chinese chra as it is too thick.The plate sticks up above the housing where the bolts go.It doesn't sit in flush.

If its a bb chra, which to4z are, you have to clearance that turbine housing. Yes it will fit without for mockup, but will rub when running.

Definitely 1.0. A.84 will have slightly better spool but you will be choking the motor at the 500 hp level.

Thanks a lot for the replies guys!

I have a 1.15 on my car, its a bit lagy but leaves more room to breath when I go high hp.