The application is for street/track, there allot of hill races around where i live and want to get involved in that.
The T04Z sounds like it will give me more range for now and the future? seems to be a well priced kit on rtstore as well.
Thank you for the responses.
How hard is it going to be to swap them out, am i under estimating the job?

I would do it right the first time, and not plan to swap them out.

All comes down to boost levels you plan to run, along with power goals.

10-20 psi, 35R, up to 450ish rwhp with 'better' spool
15-25 psi, T04Z up to 550ish rwhp with 'worse' spool

believe it or not, this question has been covered 65 billion times before in the history of this forum..... you're not the first :lol:

What is rtstore?

If you'd like I can point you in the direction of another Aussie who really knows his shit both when it comes to FD's, but also when it comes to turbos. He can be a right cunt to deal with at times, but the mans got solid knowledge and experience..

you could squeeze a p-trim gtx35 (gtx3574, tdx61) hybrid turbo in between there for T04Z power levels at near 35R spool and response.

Welll I absolutely love my GT35R T3 1.06. It has quick spool as I get 10 psi by 3200-3300 rpms and has minimal lag. The guy I bought my kit from made 427 RWHP at 17 psi...

Here is a very crappy video that I took: 12 psi, I WOT at :02 and you can hear the wastegate open at :03

Thanks for the insight. Seems to me the t04e would make a better track car turbo for someone looking for 370-400whp.

fendamonky - yeah by all means point me in the direction of another Aus, likely to be miles away from me though, appreciate all the advice I can get.
I am aware this topic is discussed over and over again, to be truthful it will always be discussed so I won’t be the last to ask the question, the fact I’m discussing what I’m after with people is a lot better than reading old threads, it’s great to hear all your opinions.
I am concerned over the TO4Z having too much lag, my engine is not ported and I wouldn’t go out my way to port unless the I needed a rebuild, another user has mentioned precision 62/66… what are these like.
I would like provision to get 450HP on pump gas – that’s 98 octane here. Summer days are 40+ degrees Celsius though.. if that has an impact.

Garrett GT35R has a 61.4mm compressor inducer..... it also will definitely make more power than stock twins for a given boost level. I think you're selling it a little short

Quite right, I must have confused the trim and compressor inducer dia in my head writing that. My point was just that one had a larger compressor cover/wheel and one had a larger exhaust wheel/housing.

GT35R is about the smallest single turbo you would bother replacing the stock twins with. Very good powerband for the street, but will require higher boost levels to make more power than the stock turbos power potential. Different specs (T3/T4 exhaust housings) are available for this turbo and will effect its performance greatly on a rotary.

Perhaps I am selling GT35R short, but I meant and wrote that you will have to run higher boost levels (my bad its a very relative term- higher than stock twins 10 or 12 psi) on the GT35R to achieve the stock turbos power potential of 350-400RWHP (which would require 12-18psi boost with stock turbos).

I also haven't seen any GT35R charts for 10-12psi where the stock turbos are happiest at but I would expect it would be around 300-340rwhp.

GT35R is about the smallest single turbo you would bother replacing the stock twins with

That does sound negative, maybe I should have said-
The GT35R is the right size single turbo to replace the twins with for good response without sacrificing power at lower boost levels and having the potential for much more power at higher boost levels.

I would like provision to get 450HP on pump gas – that’s 98 octane here. Summer days are 40+ degrees Celsius though.. if that has an impact.

Definitely more T04Z territory than GT35R territory, but it will have the lag.

Aus 98RON is like 94AKI (US octane)- nice.

GT35R would be nice with less lag if you reduce your goal to 400hp on pump and have a race gas map with more boost and 450hp for hillclimbs.

My experience is 400hp RX-7 is really fast, if you don't tell your fellow racers/passengers they will think it is 500hp or more because RX-7s are lighter than most cars that can make that power and the rotary torque doesn't drop off at high rpm like piston engine.

Blue TII - Is there a in between option? when you guys say lag this is in comparison to the GT35 obviously, in reality are talking about lag that would be annoying on the street or not really noticable.

Next question, say both are setup with 12psi boost no more no less, at which RPM does each one of them hit full boost....

sorry one other thing, if it is a case of of only 500 rpm difference then i could live with it, if its 2k rpm thn hell No. (hell no for me that is)

If the supporting mods (exhaust/intake/boost control) are the same the stock sequentials hit 10-14psi full boost at 2,000rpm and as you read above the GT35R will probably get 10-14 psi full boost after 3,000rpm.

NO SINGLE TURBO will come close to the response of a working sequential system with full supporting mods.

The smallest Apex RX6 single turbo talked about previously in this thread would be the closest single turbo, but in reality people make more power on the stock sequentials than the small RX6 is capable of.

My FC has a T04B hybrid that makes ~3psi at 2,000rpm, ~8psi by 2,500rpm, over 10psi by 3,000rpm and full boost (12-17psi) before 3,500rpm and makes 340Rwhp at 12psi and 380Rwhp at 14psi. In other words less lag than most GT35R set ups.

It feels really laggy compared to my FD sequential with exhaust only. You don't notice when doing a hillclimb as rpm don't drop below 4,000rpm- but you really notice it around town, on country roads or auto-x.

For my FD I will follow the path of keeping the stock twins as people easily make 350RWHP with them and as much as 425RWHP.

But... I don't track my FD. The twins are fine for short sprint events like auto-x or hillclimbs, but for continued lapping on a track they will be too much restriction on the exhaust side and subject the motor to too much heat load. I would say the GT35 would be as bad in this case though, you need something with a really big exhaust side and low boost.

If you are not super mechanically inclined and into tinkering and still putting the kit on yourself I would stay away from any of the kits us Americans offer as you will always have fitment issues, need more parts and have no/poor instructions. Spend the money and go with HKS or GReddy to save headaches.

If i had a coice sequential would be on the cards but the previous owner stripped it out, when i bought the car 8 years ago i thought sweet non sequential most be mentally fast lol how i was young and stupid then. putting it back in is out of the question as it would be cheaper to buy another rx and sell mine (which i would never do im too attached to it), still not convinced either way with the turbo choices...
The GT35 on RX7 store has a high flow option?... will this get me 400hp

if get the greed for more power i could increase the boost and add water injection..

im pretty logical and methodical thats why i feel like taking it on myself, plus i dont mind taking my time i have a clean garage and plenty of room to work in.

On the RX7store there are allot more options for sale, are these basicly not an option to me? like the TO4S and the TD06

Just read another thread on this option, it read like the best setup.. but people are talking about 30PSI!!! what would an engine need to withstand that kind of pressure

You can get bnrs and a custom solenoid rack and a 99 y pipe for 3k all new.

sThat's the cheap part the expensive part is all the fab work, coolers etc... to make it work properly when pounded on the track. Add another 10k for that hehe ;)

Forget thinking about any power level over 400 for road racing unless you plan on upgrading the diff and the trans and replacing engines on a regular basis etc...etc...

The stock drive line is only good for 375 max and even then you'll absolutely need a trans and diff oil cooler if you don't like replacing them often. The motor is good for 400 BUT you are on the ragged edge and it won't last long so 350 is the ideal/max power level and when set up right there's no reason you shouldn't get 10k track miles and I'm talking the full gas driving style variety or very few sections where you are modulating power and this alone typically takes years of seat time to develop with just 350 rwhp much less 400 plus.

My favorite turbo is the t04e (1.06 hot side) which is cheap and durable, spools fast enough and makes the perfect power band/curve for smooth full gas acceleration.

Here's a vid from last year with GPS showing speeds etc.... My car isn't making more than 350 in this vid and trust me I don't want to go any faster (in other words don't want more power) other than better driving etc....... The car has plenty of time in it with just a better setup and my driving improving at its current power level.


Here's another vid of a heavily modded c6 (atleast 500 rwhp). Notice he kills me down the straights but it doesn't take long before I'm pestering him again. Now just imagine if I was driving on race slicks vs the hankook c51s I'm on. If I wanted to lower my lap times the tires would cost a hell of lot less than trying to maintain a 400 plus rwhp FD. Depending upon my schedule etc... I may run it some this year in TTU (car has run sporadically over the last 7 years or so in TTS and done ok) with NASA and it will likely have 1/3 less power than most of the other cars but I don't think I'll get run over too badly.


In case it hasn't dawned on anyone yet the point I'm trying to make is this car is FAST enough at 350 rwhp and requires a gifted amateur driver to come close to getting its full potential so you don't need power you just need prep and seat time.

PS My car weights approx 2800 with me in the seat (I'm 150). I could take out another 50 lbs pretty easy.

If i had a coice sequential would be on the cards but the previous owner stripped it out

You are in luck! Since you haven't experienced a properly working set of sequentials just about ANY single turbo you choose is going to feel very responsive and spool faster.

Any version of the GT35R will get you 400RWHP at some boost level. If you get the GT3582R with a larger A/R T4 exhaust housing it will be at a lower boost level than other versions- between 14psi and 17psi I would say.

I would stay far away from the RX-7Store, but do your own research and decide.

T04Z will spool as fast or a little faster than the parallel twins and make great power.

There are many turbos in between.
T04S is basically the ball bearing version of the old T04E/B that fit the rotary very well for 400RWHP ~14psi boost, but won't have quite the gains of the GT line when you increase the boost.

TD06- Greddy uses modified Mitsubishi turbos which tend to be more laggy and make more power at higher boost levels.

If you don't mind figuring out your own intake to the turbo, sourcing your own gaskets and fittings here and there, figuring out which intercooler solution to use and how to pipe it, minor relocation, notching, bending and cursing- then one of the US kits would work fine. They usually include more options and more cutting edge turbos.

If you want to be able to open the box the mailman brought you in the garage and complete the installation without having to leave, though paying a lot more- then you want an HKS or Greddy kit.

Fritz has got you covered information for continued lapping on a road course!

On our local hillclimb (avg 11% grade, 1160ft elevation rise over 2.2miles) my 2600lb 380RWHP FC feels like it could use some more power, but from what I have seen European hillclimbs aren't usually so steep, IDK about Australian ones.

Even on a 5 lap sprints on a kart track I wouldn't mind more power.

it's the same compressor wheel as a gt or gtx 35r, it'll work at similar boost levels than a 35r but has the power potential of a to4z at higher boost levels. You don't need 30psi.

Turbo choice really depends on which track you are using. I have road coursed several Rx-7s above 500rwhp, and it takes some serious footwork to be hooking, but definitely nice for the really long straight-a ways.

I used to recommend the To4E a lot, but not precision has a 5862, or 5865 that are a lot better with similar pricing. The 5862 is basically a To4E compressor section( but billet and higher flowing) with a GT35R turbine wheel. Very fast spooling 350-400rwhp turbo. The 5865 is the same, but a P trim size turbine wheel. Slower spool, but less exhaust back pressure( better for the 15+psi range).

Precision PT5862 CEA

If you're looking for the ultimate 4 to 550rwhp turbo its our TDX61R;

Garrett TDX61R - Turblown Engineering

This turbo provides a wide flat torque curve which is the most important part to having a fast car on the track.

We will soon having other variants to compete with the Precision lines...

Thanks guys.

Yo mention the US kits will take some fabrication to fit, this will be now good for me specially if it gets to complicated.

Turblown - Does your kit require modification to fit?

That depends on your definition of "modification to fit". With our turbo systems and most you still need to mate the turbo to your inter-cooler. All necessary hardware comes with out turbo kits, no major modifications are required. A filter will bolt onto the front of the turbo.

Just an update on where i am at, TDX61R is my choice, i will be in touch with Turblown in the coming days to place an order, there are a few parts im going fit at the same time so still more shopping around to do.

Thank you everyone for the advice, i will let you know how i get on with it