Jump to content
SAU Community

Recommended Posts

I posted this over at gtr.co.uk, but haven't got any responses really, maybe you guys can help me out...

I have been searching for info on this for a while now. I would truly like to buy a GT4088R and be done with it, but right now money is tight and I'm not sure I can afford a ball bearing turbo when the time comes.

So what I am looking for is anyone's input on spool time for decently sized journal bearing turbos on a stock displacement motor with stock heads. My goals are between 550-600 whp. I have a pretty good knowledge of turbos and choosing the right turbo, but some first hand RB26 specific info would be great. Specifically these are the turbos that I am looking at mostly...but if anyone has any other suggestions definitely don't hesitate to voice you're opinion. Some specs were hard to find.

Also I must state, that this will be in a LHD Z33 and I really do not want to deal with the hassle of twin turbos and downpipe routing around the steering shaft, so twins are pretty much out. My hp goals are in the 550-600 whp on pump gas. The motor has CP pistons and stock rods with arp rod bolts...fyi.

Garrett TO4R

compressor: TO4S

.70 a/r

66.5mm inducer

84 trim

flow: 75 lbs/min 960cfm

360* thrust bearing standard

turbine: T4

.96a/r divided

P trim wheel

flow: 75 lbs/min 960cfm

360* thrust bearing

wet center section

Garret GT4088

compressor

.72 A/R

88mm 54 trim

turbine: T4

1.06 A/R Divided

77mm 84 trim

PT66

Compressor:

66mm inducer

52 trim

Turbine: T4

.96 A/R Divided

P-Trim Wheel

76 Trim

360* Race bearing

We reparied and highflowed a HKS T04S on a Tommy Kiara R33 GTR

All the important bits putting out 685rwhp hitting 1.5 bar at just after 5000rpm.

This is with HKS 272 degree inlet and exhast cam shafts on a near standard displacement engine (2.645) 87mm pistons built at Signal in Japan.

Most big horsepower singles are Journal :laugh:

I would have thought a ball bearing TO4Z would not be the end of the world these days depending where you got it from . If you know someone who can strip BB turbos a cheap way to build a TO4Z is to buy a Garrett T3/T4R , one of them is a TO4 P trim/60-1 hybrid (cartridge or CHRA no 757179-0001) and that compressor can be flicked for the TO4R compressor that TO4Z turbos use . Some machine work is required because often bush bearing compressors use different back spacing to ball bearing ones .

HKS's TO4R is just the same P trim turbine /TO4R compressor with a slightly cropped turbine in bush bearings .

The part nos for the wheel , housing and backplate are 451470-0001 , 409722-0023 , and 408997-0018 in bush bearing TO4S outline form - according to my data . It shows the wheel as BCI-8D family .

Cheers A .

So any other experiences with spoolup time and journal bearing turbo's like these?

discopotato: Is that to make a T3 based TO4Z?...because my manifold will be T4 divided.

Edited by 002-M-P

plain journal GT4088 1.34 rear housing on my stock headed 25/30 was on full boost around 4500 in 2nd gear, earlier in higher gears. they're a good thing i reckon with a smaller exhaust housing than mine. they have a HUGE compressor cover so watch your clearance to the strut tower etc. TA45 split pulse flange on em i believe.

TO4Z's are really easy with turbine housings , ANY TO4 P trim turbine housing bolts up to them in a myriad of A/R sizes , and single/split T3 flange or single/split T4 flange or single/split TA45 flange which is sometimes called T4 International . The only thing to watch using Diesel spec turbine housings is that they sometimes develop cracks over time because the material spec was intended for the Diesel engines lower exhaust gas temperatures .

Garretts GT40 range of bush bearing turbos are more modern designs than their TO4S and TA 45 ranges . Better cartridge and wheel technology though not right up with the BB GT4088R . This ones a ball tearer depending on the airflow required and even has the high temp spec turbine and housings for petrol performance apps . The down side is a retail price of someting like $2750 . With our rising dollar and sales competition it may get better .

Cheers A .

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I had absolutely no symptoms whatsoever that anything was wrong.... I'm very happy it was all spotto'd and re-bled and re-torqued and aligned though. Will be picking it up tomorrow and undoubtedly be like "Oh, that clunk is gone" "Oh, the car really wants to drive straight" "Oh, that pedal feels better" "Oh, it feels like I've gained 25hp" "Oh, the handbrake works now" It should have been a sign that the new Project Mu shoes had 3mm of pad depth on them out of the box, and the OEM ones from 25 years ago that we took out also had 3mm of pad depth, implying the issue was not, and never was the shoes, but we put that down to it not being adjusted correctly. It wasn't, but it wasn't even adjustable at all given one side was boned and the T Junction of the cables was on a 45 degree angle, the non-working side being the one on the massive angle. Obviously when I had adjusted it and reset it and re-tensioned it I had either got it stuck or something along those lines. Oh well. Live and learn and absolutely could have been catastrophically worse so I'm rationalizing it as a win, kinda. I also got the chance to measure the distance between rear rim and the suspension arm/shocks and found a 30mm rubber block only just doesn't fit there. Which is great to know before ordering wheels, when I assumed 30mm was easy. The man with the Porsche adapters has rims that use 23.9mm of that space, so it's safe to assume I have between 23.9 and 29.9mm of space there to play with on the inside. The wheels looked pretty stupidly pokey with the 20mm spacers on the rear, only for me to find that the studs come out another 12mm and the wheel doesn't actually sit flush with the hub because you're supposed to cut your original studs. The wheels do have cutouts that kinda accomodate it, but not fully. So my 20mm spacer was anywhere between 25mm and 35mm. ~25mm and send it will determine on where the wheels sit with the spacers on. When I put the pads in for the track day I will mess around with spacers (with wheels that do not clear studs properly when mounted to spacers) and do more math, for the last time, for the 7th time.
    • Lucky pick up Best to find these things before something horrible happened to the yoke flange thingies I would hate to think what would happen if it dropped the tailshaft  Hopefully the holes are not flogged out in the yokes and it was just the bolts that got munted  As for the hand brake.....ouch, look like the disc got rather hot, and I assume smokey, I recall when I had a front caliper seize on the Commodore, there was lots of smoke and the disc was glowing cherry red when I was able to eventually stop and have a look, and stopping a big heavy car, going down a big hill with some rather high RPM down shifts and some hand brake action is something that makes you think hard about life
    • One of the things that never seemed right was the handbrake. Put in some nice new Project Mu shoes. We figured the rears were out, so why not. We're right there. My handbrake never worked well anyway. Well, this is them, 15km later. 67fdcf94-9763-4522-97a4-8f04b2ad0826.mp4 Keen eyes would note the difference in this picture too:   And this picture: Also, this was my Tailshaft bolts: 4ad3c7dd-51d0-4577-8e72-ba8bc82f6e87.mp4 It turns out my suspicions that one side of the handbrake cable was stretched all along were pretty accurate, as was my intuition that I didn't want to drop the tailshaft to swap them on jack stands and wasn't entirely sure about bolt torque. I have since bought the handbrake cables which have gone in. I'm very glad that I went to my mechanic friend who owns an alignment machine to get an alignment before the track day, because his eyes spotted these various levels of "WHAT THE f**k IS GOING ON HERE?". Turns out the alignment wasn't that bad, considering we changed the adjustable castor arms out for un-adjustable castor arms, and messed with the heights. Car drove pretty good with one side of the handbrake stuck on, unbleedable rear brakes, alignment screwy, and the tailshaft about to go flying and generally being a death trap waiting to happen! (I did have covid) (I maintain I adjusted the handbrake correctly, but movement caused shennanigans and/or I dislodged the spring on the problem side somewhat, or god knows what). G R E G G E D
    • Very interesting, im not sure how all those complications fit in to running a haltech instead of a stock ecu but I'm starting to think I'm a bit out of my league.
    • I just put 2 and 2 together. This is a Neo converted R32. The Neo ECU (in concert with the R34's AC controller) runs the AC quite differently to how the R32 ECU and AC controller do it. If you just drop it all in, it won't work. There is some tricky wiring required, including changing to the pressure switch that the Neo controllers want to see. I don't know what it is, because mine was done by a guru. It was a year or so after I did that transplant before he worked out what needed to be done.
×
×
  • Create New...