Ok so I've done multiple searches and as yet nothing. Feel free to point me in the right direction if I'm missing something. The GtIII 4R is apparently the new T04Z however I can't find much info about it or reviews. The kit is why I'm interested as I have limited choices locally and its not too excessive. I cannot find a compressor map for it. If any one has any info or opinion I'm all ears. My goal is around 400 hp quick spool minimal lag flat torque. Preparing for an annual tarmac rally and some local time attack.

 

It's going to be a big, laggy turbo with old technology.

If you can get your hands on a Borg Warner EFR 8374 setup, do so. Spools as fast as twin turbos but makes an easy 400+ HP. It's such a game changer turbo for the RX-7.

Dale

 

Thanks Dale, do you know if I could use the hks kit for everything else other than the turbo, manifold pipes etc? And use the efr turbo. I believe it's a t4 flange. It's the only off the shelf I can find that is really complete. I've been told the iwg has boost creep issues at low boost wish this ewg kit would avoid.

 

You're probably best posting and reading up on the single turbo forum. I don't have as much first-hand experience.

My friend Stephen did that turbo setup on his car -

https://www.rx7club.com/build-thread...-base-1140779/

and I drove it a few months back at Deal's Gap. I was AMAZED with how well it drove - the power was instantaneous and pulled like a freight train to redline.

I don't think the boost creep is enough of an issue to warrant not using the internal waste gate. External waste gates are nothing BUT problems and having a nice turbo with an IWG is very appealing.

There are some nice plug and play kits out there - IRP has a great kit, as does Turblown. They can typically ship world wide too.

Dale

 

Thanks Dale, I will search along those lines, appreciate the input.

 

The efr8374 will not clear the intake manifold with the hks manifold
but +1 on the efr8374 being a phenomenal turbo!!

I was using the efr8374 ewg for several years and i have been very very happy with it

 

Thanks. Did you do a custom set up to run ewg? Any opinion on iwg/ewg for these? I note the a/r seems preferable from what I've read here. Probably not an issue for me in that regard.
excellent to know the hks kit is a dead end.

 

i had used a greddy t78 manifold and i made a 20mm spacer to go between the manifold and the block. 20mm is much thicker than what you actually need but i wanted to space the turbo as further away from the intake manifold as possible. Other than that and a custom downpipe, nothing else was needed to make it work

I had then experimented with the hks t51r and the t04z manifolds in the same way (spacers etc) but the t51r, which was my "weapon of choice" due to the larger runners, did not clear at all due to the angle that the turbo is placed on the manifold.

while i had no issues with the ewg if i were to do it over again i would have gone with the iwg for the sake of simplicity.
There are plenty of good manifolds out there. IRP is a solid option. Full race makes a real nice one for the iwg option( i cant say i like their ewg system) .
You can mix and match stuff but theres always a good chance that you will have to get creative to make things work as they should

I do have the t04z t51r and t88 manifolds sitting on my shelf.

 

Thanks, sounds like the IWG concern is not much of a concern.

 

HKS has i think discontinued the turbo kits, what they have, is a manifold and wastegate kit, and then a "turbo set up kit" which is the turbo kit without the turbo.
i think the cast manifold got a redesign too, its got a new part number and the old one is NLA.

i'm not sure what is easier for you to get the GTIII 4R does look kind of laggy though

 

Thats the kit, I like the look of it and it's complete however as above, the efr doesnt fit on it so I/m less keen on it. if the internal wastegate is not a problem I think I'll go with one of the kits suggested above. The GTIII is meant to be an improvement over the older HKS ones but I take your point. Lag is not what I'm looking for. I guess I was looking around for EFR alternatives as I am worried about putting a seal through the exhaust housing since they are not rebuildable. I'm in Australia and these turbos cost alot more here so a full replacement is a bit of a worry but I think I will bite the bullet.

 

I would look at Pulsar G35-1050 (they are about 1/3 the price of Garrett G series or Borg Warner EFR), have a look at Australian workshops who make manifolds or consider getting one fabricated.

That HKS setup looks a bit compromised.

 

That is a significant cost difference, whats the catch? how do these perform comparitively, compressor maps available?
Edit: I see these are a chinese knock off, to be honest I am not going to support china ripping of companies P.I, they have no regard for patent law and are screwing companines that do the R and D. I will just pay the price for genuine as I dont support that type of thing. That is the politest way I can put my opinion on Chinese trade practices. Thanks for the suggestion though.

 

Installed one on a mostly stock 93 earlier this year, very nice setup and nowhere near as laggy as the engine dyno would lead you to believe. The install was dead simple, customer supplied the full kit (turbo + set up kit combo). Power builds from just after 3k on the road. 91 octane, Stock MAP, PFC, SMIC, 70mm exhaust, stock ports, throttle, etc. 300 wtq from 4500 to 6500, 325wtq at 5500 on a hub dyno sweep. Peak power was made from 6800-7200RPM as expected from HKS's published EMAP and dyno data, and imo is pretty ideal for a stock port engine. The wastegate recirc was a great touch, no creep. No lag between shifts at all, full boost builds in first gear.


"It's going to be a big, laggy turbo with old technology."

Definitely not the case It is a new MHI turbo with a billet compressor wheel and lightweight billet turbine wheel. Interestingly, MHI have been using TiAl turbine wheels for over 20 years now, so does that make EFR "old technology" ?. Compressor housing has a TSS provision cast in. The cast manifold was revised and while HKS don't publish compressor maps, they do publish power, boost, and exhaust pressure numbers for a given application which imo is far more relevant for most people imo.

 

A little data to show that the 4R is not as laggy as the dyno would indicate:



Supernow fitted a 4R to their stock FD after the factory turbos ate it. The owner made a post about his first outing at Nikko Circuit which is comparable to a larger autoX course. Blue trace is stock twins, red trace is 4R. The arrows on the data trace point at wheelspin, the owner had yet to divine if the spin was due to the condition of the tires (10 heat cycles on 4R lap vs new for stock), or if the tire width was insufficient for the increase in torque. Either way, the acceleration from as low as 60kph is quite comparable between the two setups.

Here is an in-car video:

 

Nice, thanks.

 

just to update, the two graphs from HKS come from two different engines.
exhaust manifold kind of looks like the older ones, but has been revised







spec for the turbo looks pretty conventional, in the USA its a lot more expensive than anything else, so probably going to be really rare

 

I wouldn’t touch one of those chinese copy cat turbos with a 10 foot pole in one hand and your wallet in the other.