Has anyone used one of these? I am asking because I want to swap one of these in for the factory twins and am aiming for 500HP. Needless to say basically everything else will also be modified, but how is the kit rx7store.net sells?

 

I have a ball bearing T04R (aka T04Z) from Phoenix Turbo and love it. On my old FD I had this identical turbo (.84 A/R, Divided T4 housing, etc) except non-ball bearing and it got full 14 psi boost by 4200-4400 rpm. When I installed the new ball bearing turbo on my old stock port motor. I was seeing a full 12psi by 3500rpm (14psi would have been about the same, but I was just running wastegate pressure). The only other factor that would decrease the spool time is the fact that now I am running a full 4" exhaust and my old car had a 3" exhaust.

I still don't have the car fully tuned, so we will see if the .84 A/R turbine housing is too small and falls off at high rpms.

 

Old and somewhat outdated turbo, much better options out there. But, it is a solid reliable power making turbo.

 

I'm not doubting your knowledge here one bit, but I wouldn't be so quick to discredit it. Comparing it to a newer GT4088 ( I know, smaller inducer, larger exducer ) it puts out about the same flow, however at 2.5 PR and 65 lbs/min, which is around where a "typical" rotary will make 500whp, the T04Z is in a higher efficiency range...

 

I have never seen a real compressor map for a Garrett/HKS T04R/T04Z/T67. Do you have one you can post?

 

T04Z is a great 500HP turbo that spools fast. I sell a lot of them in kits and just the turbo by itself for other projects.

 

 

the TO4 compressor, 66.7 X 84 is one of the best options for someone looking past the GT35r but not wanting a turbo as big as their shortblock

efficiency is the key. note the map's smallest efficiency is 70%!

there's "Gross Air", that's the number on the X line and then there's what counts, "Net Air." (my labels.)

it is all about oxygen molecules per volume.

a turbo flowing 70 pounds at 60% efficiency delivers 42 pounds net air.

a turbo flowing 70 pounds at 70% (like the TO4) flows 49 pounds.

16.6% more oxygen.

love this turbo.

howard coleman

 

my A-Spec 500R is similar (has an identical compressor wheel) and I've been very happy with it thus far. Great spool and transient response, and pulls very hard at 15-20 psi

 

It is a good solid turbo, but like I said, there are better options. The billet 6765 is one example. Same size compressor and turbine, but much more efficient and will flow more air. 920whp in an Evo, 850whp in a Supra, numbers that a T04Z will never produce.

The 4094 is more comparable in size. At 2.5/60lb per min, the T04Z is less efficient. The 4094 isnt that great of a turbo(GT42 compressor cut down) but its still more efficient.


Howard, mass flow(lb/min) is a measurement of oxygen molecules, CFM is a measure of volume(mass vs temperature). 70lb/min @ 60% efficiency is still 70lb/min or air, but the temperature is higher than 70lb/min @ 70% eff.

 

The HP6765 from Turbonetics will flow ~ the same as the Billet 6765 from PTE and is a little cheaper as well. Same basic CHRA with same turbine wheel. Comp wheel is the only difference.

 

And the 4088 is even worse, efficiency is awful across the map. But I agree, there are better choices. I'll be trying the 6768 shortly. I really wish PTE would release some maps on their newly developed wheels.



But at less efficiency your 70 lb/min is of lower CFM due to temperature is it not? Is volume not more directly linked to producing power?

 

The 4088 is actually very efficient, it just isnt great for big power on a rotary. I agree, maps would be nice. You dont always need them though, but they help.

Nope, lower efficiency @ 70lb/min means a higher CFM due to heat. When mass remains the same and heat goes up, volume goes up. Its not the volume of air that makes heat but the mass. That why you use an intercooler, you lower the temp which makes the air a lower volume/temp, which means more molecules fit into a cylinder.

 

And which turboes would those be? I do need them to be ball bearing, or dual ball bearing for sure. I want this thing to be very near bulletproof. I'm no expert on turboes and really need to sit down and study how to read a chart because all I know to consider is what kind of horsepower they can support.

 

Get a billet 6765 ball bearing. They are very solid and make loads of power, I know guys who beat the crap out of theirs with no problems so far. How much power are you trying to make? Enough guys here can help you pick a turbo that will suit your need.

 

Thanks, it seems like common sense now, I wasn't thinking about it properly. It would be nice to have a map just to see if the changes they are making to the aero are beneficial across the board, not just in higher PR like most have been saying.


I agree about the Billet DBB 6765, you will have the same response or better as a regular T04Z, but with the billet aero, you have the ability to run more boost and more power if you decide you want more.

 

Is the cost about the same? does anyone make 6765 kits?

 

I saw the guys at Turblown building a Precision Billet turbo setup the other day, shoot them an email; www.turblown.net

 

The 6765 is a few hundred more than a T04Z, but its definitely worth the money. No point in buying a 15+ year old turbo when you can buy the updated version.

 

I need more info on the billet turboes. what do i do for a wastegate? who's running these in a setup could you lend me some specs?

 

I have read a few forums (buicks) where they said it spooled slower than a T04R. In my mind the jury is still out till someone with a rotary actually runs one on a dyno and posts some facts for comparison.

Scorpion do you sell Precision turbos?

 

I have a funny feeling the billet turbos are just as happy with a normal WG as non-billet turbos are

 

I don't want to get into a billet turbo debate, because I always seem to get shouted down... but no compressor maps and some dyno sheets from 4 cylinders still puts them in the "internet forum hype" category at this point--especially when they have the same nominal measurements as stuff that's been out a long time

 

well I'll be getting one installed on a SP'ed S4 engine, as soon as I can get dyno sheets I'll be posting them. As far as I'm concerned, if they can match the curves of a regular T04R even at lower boost, then it's pretty much settled. They've already proved on 4 cylinders that they will outperform a standard T04R by significant amounts on the top end. Power is power, regardless if it's rotary or piston.

Again I don't want to turn this into another debate, but have you ever seen a standard T04R net over 900whp on any engine/vehicle?

 

I probably should do some searching on this, but are you saying that even though garrett claims the T04Z/T04R will flow up to around 750hp (compressor maps confirm this too) that if you had a billet turbo with the same dimensions, it would have more flow capability ?