Hello.
It's time to gain some horsepower.
Engine is S5 TII, stock ports.
Estimated power will be around 350hp.
Just to notice, all I want is fast spool.
Any advices will be helpful!

 

for a max 350 target the GTx is likely to big for what you want, the size smaller will do it.

Ive got that gtx and its better for 400+ rwhp (14psi at 3000rpm)

 

don't use those ancient Greddy/Mitsubishi turbos.

 

Why not EFR7670?

 

Or airwerks? I dont think the lack of ball bearings or gamma-ti turbine would be any kind of issue at this size on a rotary - the price difference and smaller packaging would make it well worth it over the EFR in my opinion -
https://www.full-race.com/store/borg...00-sxe-7670-1/

 

x2. Absolutely perfect turbo for what you're describing.

I designed that page by the way, so when you go to order something from Full-Race.com, tell them Ryan (Content Creator) sent you.

 

It's really hard to purchase a Borg here in Greece.
Although shipping and customs from overseas will kill me..

 

Understood. So go with the GTX turbo.

But don't use a 20G. They are too old of a design. People use them on other cars now that came with Mitsubishi turbos already, but it is not a good idea to get one now due to part availability.

 

Looks like there are only 2 authorized distributors in Greece:
??????? ???????? - ????????????? - Service ?????????????? ???????
www.turbohellas.gr


Is there a way you can get something that is already in the EU cheaper than the states? Surely you can find one in the EU.

 

shouldnt be to bad. Im from australia and I buy all my parts from the US as it works out cheaper. Shipping isnt that bad. Helps when the exchange rate is ok (but Greece sucks atm)

 

BorgWarner EFR IWG 13B Rotary Turbo System

7670 size

 

If you are going with the Garrett turbo you have a couple choices in the right 350rwhp with great spool size range.

GTX3076R or GTX3576R.

The GT3576R has a larger 68mm exhaust wheel versus a the smaller 60mm exhaust wheel of the GTX3076R and a different though same sized compressor (11 fins versus normal 9).

I would go for the GTX3576R both for the larger exhaust wheel and also because the surge line is slightly better in the low pressure ratios so you will get more boost below 3,000rpm on the rotary.

The GTX3576R can use the larger GTX3582R exhaust housings so it is easier to find T4 divided exhaust housing.

Find a good local fabricator for a divided turbo manifold, big 3.5-4" downpipe for best spool.

I suggest local fabricator instead of a full turbo kit as with current state of your currency your money should go much further getting as many parts done as you can locally.

 

T04E or Gt61 will also do it if you are on a budget. Both can be had under a grand.

 

What about this kit?
1 HR FC V2 87-92 Mazda RX-7 T04E Turbo Kit FC3S [HRV2_T04E] - $2,989.00 : Himni Racing, Turbocharger, Turbo, Garrett, Turbo Kit, GReddy, Mazda RX-7, HKS, Apexi, TiAL, TurboXS, TurboSmart, Flange, Turbonetics, Exhaust, Intercooler, ACT, Intake

 

Placement of the wastegates is very poor in that design and can result in difficulty controlling boost. If you look at the way the runners flow, you are asking the exhaust to make a nearly 180 degree turn to get to the wastegate. It should be a straight shot. A lot of companies think they can weld together a bunch of pipes, polish them up, and them to work great. A lot more goes into designing a proper performing turbo kit. I unfortunately don't currently offer an fc turbo kit as there just hasn't been enough demand. You would be much better off with something from Gleaseman.

 

Have you tested the performance of those manifolds? It's not as simple as saying "oh that's a sharp turn, that manifold is improperly designed."

Zakspeed:


Arrows F1:


Renault F1:


BMW:


Even my HKS manifold WG takeoff is a sharp 90 off the runner but it will hold 6psi to redline if I ask it to.

 

I would trust IRPerformance on that..

 

I've owned a manifold with a design like that and it wouldn't hold boost with a 4" exhaust. Picture (not mine) of the manifold below.

http://i236.photobucket.com/albums/f...torpics005.jpg

I initially tried lopping off the flange and welded on new wastegate runners. Bigger in diameter, shorter, at a much smoother angle and with hardly any turns before the wastegate. Basically straight up with the wastegate next to the turbo and a nice smooth transition. It didn't make any difference! I was really surprised. Ended up going to a 60mm gate which did the trick.

Personally I would still prefer to buy a manifold with good wastegate priority, but it seems like just using a big gate often works regardless?

Edit: Another slightly unrelated thought, F1 might not need very much wastegate flow for the boost pressures they run?

 

My exhaust is 4" for the first 18" dropping to 3.5" no issues with the single HKS 60mm gate. That's the problem with just guessing at manifold design imo, it doesn't always work out the way we think it should. Or to quote IRP:

"A lot of companies think they can weld together a bunch of pipes, polish them up, and them to work great. A lot more goes into designing a proper performing turbo kit."

I've seen manifolds with "bad" WG priority work wonderfully and manifolds with "ideal" placement work poorly. My friend's old full race 2j manifold was so bad that he built significant positive pressure with the wastegate completely removed from the car and a gaping hole in the manifold, hence my question regarding the Himni manifold. I wouldn't be surprised if it creeped, but it seems unfair to poo-poo it in favour of another brand if IRP has no personal experience with it.

Those manifolds aren't just F1, you can end up with wacky manifold configurations anytime you have major space constraints. I can only guess as to what the design considerations were back in the old F1 turbo era but considering that power levels for the BMW (for example) ranged from 800hp-1400hp from race to qualifying, I'd say that effective wastegating is still a concern. Now it looks like they're using Moog E085s for WG actuation which makes packaging and control much easier haha.

 

Yes I have many times. A lot depends on the porting, turbo sizing, and how well the system flows in general but on a rotary it is very common for that style manifold to have difficulty controlling boost. If you want to run 20 lbs regularly its not an issue. But often when trying to dial it back to 12 or even 10 lbs you may not be able to get the boost where you want it. We have replaced many of these style manifolds with better designed pieces to get the boost under control. Piston motors don't seem to care as much with wastegate placement because they don't have the exhaust velocity a rotary produces and generally have more than 2 runners. You can also somewhat get around it by oversizing the wastegate but that can lead to packaging issues.

 

F1 exhaust manifolds are not a good comparison. Those are not running low boost at all, and they generally had HUGE wastegates for the size of the exhaust flow. Ihor's comments are correct.

 

Anyone can identify this turbo?
Owner said came with hks turbo kit.

 

^^
Just to reiterate, in the early years boost was unlimited in F1 and then in 1987 they limited it to ~60psi boost and then down to ~36psi in 1988.

If you look at the later "low boost" F1 engines some have more wastegate priority manifolds.



However, both trains of thought on wastegate priority still exist.

In IndyCar Chevy still uses a 90 to the wastegate off the collector.