Yo dudes, sooo...I've been swooning over my Apexi(/IHI) RX6 Turbo for a minute meow, but finding flanges/gaskets/**** for it has been a royal pain. I JUST finished up getting the turbo manifold and downpipe for it all done up to, but this dude is hollering at me at a straight trade for an HKS T04R setup. Everything's going on a 13BREW.

So...

Apexi (/IHI) RX6 "Isamu" TCW15 P27
Brand new
Dual Ball Bearing
Stainless Steel Housing...super light
Oil cooled only, won't tax my cooling system
Supposedly spools 800rpms quicker than a GT35R
Custom Turbo Manifold and Downpipe
Would need wastegate, oil feed line, drain flange and line fabbed up.
No base map tune available... anywhere.

VS.

HKS T04R Full Kit .70trim .96A/R
2000 miles on it
Journal Bearing(?)
Comes with HKS cast turbo manifold, HKS 50mm Wastegate and Downpipe
Already comes with all oil and coolant lines and is essentially bolt-on
I have a sneaking suspicion that my PowerFC already has a tune for this turbo kit from the previous owner, and I'm betting the hotside pipe for my FMIC kit is already made for it.


Supporting mods are:

- Apexi PowerFC and Commander
- Greddy FMIC Kit
- Greddy BOV
- Stock 550cc Primaries and Injector Dynamics 2000cc Secondaries
- Injector Dynamics Secondary Rail
- Fuel Lab MiniFPR


Shooting for 350-400rwhp, so both will work. Now, it's just a matter of being lazy on my part.

Real world experience and input would be most appreciated.

Thnx

 

TO4R, easier to get parts for, more room to grow in the future power wise noticeably laggier than a RX6. Also allows for more turbo options in the future.

RX6, responsive fun 400whp turbo, parts are a pain to source if needed. More expensive to operate in the long run, less power potential than the TO4R.

If all you'll ever want is 400whp and no future plans down the road the RX6 is a good turbo and better choice for 400whp, that said...

Having personally owned and tuned both what now seems like decades ago. I'd sell both and get a newer turbo if that is a option. It's up to you but that is it broken down as simple as it gets.

~S~

 

Sean is on the money and i will just add a bit.

the RX6 is a neat small turbo and i speak from experience. it will be a major challenge if anything needs replacement.

the reason it spools early is that it has a tiny turbine. tiny as in retaining more heat in your engine. not good.

comparing turbo turbine areas:

RX6 4.31 sq inches

stock OE twins 5.25

GT3582r 5.17

Borg Warner GT35 type 6.31

bigger is better

howard

 

How did you come up with this number?

Something tells me that you just took both measurements and added them together. In which case I've got this nagging feeling that it's wrong. Wrong in the same sense that twin 2.5" exhaust pipes won't flow the same as a single 5" exhaust pipe.

Please educate me in how the stock FD twins have a larger turbine potential (which would theoretically equate to more lag and higher power??) than a GT3582r.

 

FOCUS!!! Lol, let's try and stay on track dudes!!!

Honestly, my main reason in even considering the trade, is the availability for rebuild components with the T04R, as well as the good chance that I will need minimal tuning because I'm pretty sure the used PowerFC I have already has a tune for it.

Sooo..what I'm asking is if I should do the trade to save time/money/tuning?

 

A) I would consider this one, both for parts availability and for interchangeability.

B) All tuners are NOT created equal. Keeping a map built for another vehicle isn't the best idea, as most vehicles are unique. Pay for the time to have your vehicle tuned properly and you'll appreciate it in the long run.

 

"How did you come up with this number?"

i suggest you read my sticky thread entitled "Turbo Comparison"

the hotside wheels are 42 X 50.5

that's 2.625 average area times two. DTM

as far as equating this to flow, i sort of figured that everybody on the board would know that the manifold is a deal breaker.

 

I concur with Howards' assessment. I ran one for 18 months and enjoyed it on the street, around 400 max and high egt's. Dual ball bearings??

Pureturbos.com, they have a replacement cartridge for the IHI RHC7.

 

The standard twins have an exhaust flow capability up there with a 0.84 P-trim. Obviously the standard manifold ruins that, as does both turbine outlets firing into a right angle that merges and then another right angle to get the pipe pointing towards the back of the car.

Go compare the wheel sizes to a GT28, there is a flow map available for the 0.63A/R GT28 turbo which is very close to the hot side of a FD3S Hitachis

 

Sourcing YOURSELF isn't valid. Gimme something real, not just another copy/pasta post or thread going back to something that you've written.

(You didn't invent engineering, physics, or fluid dynamics... Quoting yourself to confirm something you've stated doesn't work. I don't have a degree in Mechanical Engineering, but I'm betting neither do you. Source some FACTS to support your assumption, because I think you're posting up some bullshit FICTION to support inaccuracies because the practice here disproves your theory.)

 

further info re the RX6...

four compressor sizes:

TCW 77 61 X 82 6.356 sq inch av area

TCW 76 56 X 82 6.03 sq in

TCW 10 59 X 78 5.63 sq in

TCW 17 54 X 78 5.29 sq in

all RX6 turbos have the same (tiny) turbine

57 X 62 4.31 sq in

as you can see you are being offered the smallest of the (small) RX6 variants.

since the compressor is 83% of the GT35 i would expect 370 tops. weighing against that number is the restrictive, especially for the rotary, 4.315 turbine wheel which is 17% smaller than the GT35... and the GT35's most significant drawback is an undersized turbine wheel...

i would be concerned re higher EGTs and what they might do to my apex seals. my friend ran the RX6 77 with good results so w proper tuning and support it would work but you are swimming upstream w the choice.

howard

 

Coming from the real world; all single turbos are a PIA so if you don't want more than 400 rwhp and it's a street car stick with the twins. If you're worried about solenoids and boost issues etc... just get the upgraded solenoids and go simple sequential.

I would NEVER put a single turbo on a street FD. 300 sequential rwhp is awesome Peter Hahn's car w/99 twins is making a legit 395 (awesomeness squared) and boost is instant.

 

I'm running a T04R after running twins and then a T04S, and I would never go back to the twins.

Everyone exaggerates the lag. Its not bad at all. The turbo doesnt make my full 22psi until around 5k, however, I'm around 7-10psi by 3500rpm which is plenty of low end. Power delivery is smooth and pulls like a beast up top.

With 400-500hp in an fd, the lag almost helps you keep it driveable lol. You will smoke everything when the turbo comes online and completely forget about how much you like that quick reacting primary.

If you feel like lag is an issue, simply drop a gear. Why do you need to go WOT at 3000 rpms anyhow.

Compared to my friends T67 RB25 skyline, the fd spools the 67mm light years smoother and faster.

 

^ what kind of porting do you have?

 

I have the RX6 and am very happy with it. It spools (almost) as quickly as the stock twins and made 380rwhp on 91 octane gas at 1kg of boost which is more than enough for the street or even occasional track days.

As an aside you will probably need to add an ignition amplifier and fuel pump to your supporting mods.

 

RX6 is a very good turbo if it's a TCW77 compressor. Anything else is waste of time IMHO.
However, given the fact the RX6 is difficult to rebuild and expansive to get, a T04S will give you somehow the same end- results for less. You will just need to wait about 1500PRM longer for the kick from T04S compared to the RX6.

just my 2p.

 

To answer someone above, I have a steetport.

Iv never met anyone who sold their turbo for a smaller one.

 

A bit late reply about the turbine size on the apexi turbos but..
you cant just look at the wheel size. the turbine housing size matters just as much.
Whats great with the ihi rhx6 turbo is that you can swap turbine housings as you want without changing the turbine wheel/shaft. Ive gone from a P18 to a P20 and now to a P22 (not on a rotary) and ive as expected noticed slightly slower spool with the housing changes but also less back pressure.
A small P16 housing basically forces all exhausts out in one place of the wheel, spools fast but becomes a bottleneck at high flow, the larges P27 housing does the opposite, more even distribution of the gases around the wheel but slightly less spool.

ps. if anyone has a broken rx6 turbo with a P25 housing or just a P25 housing, please contact me!