StavFC

As title really.

Got a HKS T04E on my car at the moment, T4 divided, .84 a/r 74mm P trim wheel, and T04E 57trim comp wheel.

Its got a fair bit of play (up/down not in/out), run 1.5bar, I inject lots of water pre turbo, and it ran filterless before I got it, so I expect its only a matter of time until its dead.

Despite having positive boost by 2k I wouldnt say its fast till at least 4k, and thats fine by me, it spends its time at 5k+ anyhow, but its the throttle response in the powerband I do like, its pretty good.

Are there any newer more modern turbos that would be at least as powerful but even more responsive (not worried about boost threshold as long as it ok from 4k, jus care about the response when in it), or should I just get this one repaired to the same spec if/when it craps itself and dies?

Thanks

Turblown

iTrader: (12)

A 3076R would be your best bet, however its not available in a T4 turbine housing. You would have to move to a Gt35R. Another option would be a BB version of your current turbo.

StavFC

With a turbine wheel about 15mm smaller, even if a T4 turbine was in existance I dont think a 3076 would be a good upgrade as its the turbine side I'd expect is choking it as it is.

RedBaronII

iTrader: (4)

I had the HKS TO4E and now, this past January, I switched to the GT35R from A-spec.
The response is the same, if not better being a BB turbo, plus the power delivery is insanely quick.
This is the perfect turbo for the street and track for the FD.
I do more track, than street driving and it is awesome!!!!!

turbotoaster

i wouldnt touch a BB turbo on a rotary engine myself because of 2 reasons.

Stav, are you saying the turbine wheel on your t04e is 75mm? as i could only find ones up to 65mm

If so then id go with BW S300S.

79mm turbine wheel, flows max of 64lbs and should be comparable with your turbo.

its around a gt35 sized but probably cheaper, plus with ETT it will give you great numbers

if your saying you want a bigger turbine wheel you normally need to look at bigger turbos im afraid.


you know you want a s475 really though......with the 0.90 rear housing it will hit 1bar at 4k and do 400whp at that boost with ease

RedBaronII

iTrader: (4)

I don't know where you get your info, but if you read Howard Coleman on the GT35R, I don't thing you can beat it for response and power.

Howard Coleman

iTrader: (6)

"i wouldn't touch a BB turbo on a rotary engine myself because of 2 reasons."

o k i'll bite, what are the 2 reasons? probably 75% of all the singles running on rotaries are BB so we are all interested. this is not to say, BTW, that journal bearing turbos are necessarily inferior. i actually like journal bearing turbos... but am curious to know why BBs don't work.


"are you saying the turbine wheel on your t04e is 75mm?" since the P Trim is 56.6 X 74.9 call it 75 probably yes.

"you know you want a s475 really though"

uh, probably not. the S475 at 9.456 sq inches of compressor area, larger than a GT4294 at 8.384, doesn't really seem to fit his objectives. i don't get the feel that he is looking to make a zillion hp.

he is swinging 5.369 sq inches currently which is actually less area than the stock twins at 5.972.

probably take a step up to a couple of Garretts or a BorgWarner.

look at either the GT3582r BB w the Garrett shrouded cover
or the GT3574 journal bearing w the Garrett shrouded cover (cheaper, w a larger rotor friendly hotside). 6.386 compressor

or

a BorgWarner S300SX 60 X 83 comp 6.383 journal bearing
75 mm turbine 10 blade inconel T4 rear 1.0. need to mod to V band i believe.

or

you could just fix your turbo. it will make 360 rw rotary hp at 22 psi and does have a P trim rear. call Majestic to get it fixed.. or any other good rep turbo rebuilder.

good luck,

hc

StavFC

Great info Howard, really appreciate it

I did 119.5mph in the quarter with it running about 22psi dropping to 19 or so at the top end (running a lot of pre-comp water inj), dont know what sort of power that relates to?

I would like more power though tbh, I just dont want to lose any of the pretty instant throttle response above 4.5k or so. Dont get me wrong, id love to see 140 in the quarter, lol, but I want the response still. Not fussed about low down power, but throttle response, yes.

turbotoaster

Well the problem in my opinion is bb is not that theres anything wrong with them actually, just there applications on rotarys.

1. If you blow your engine...which is alot easier to do than a pistion engine equivanlent them there is a change that the remains of an apex seal will go through your turbocharger damaging it.

Now having a journel doesnt save you from this fate but when you then have to fix it you find you almost have to replace the entire turbo which costs a fortune.

2. For example on a gt42 turbo, a bb is twice the price, im sorry but i dont think you can justify doubling the price just for it to be ball bearing, i think thats to dear....but then that is my opinion on that.

3. Ive seen alot of people saying that bb turbos struggle with massive EGT temps that rotarys put out when being driven to the limit, now alot of that is hearsay and a few people have been told by a turbo company they have problems with the shafts getting to hot.......just seems a risk i wouldnt be willing to take.

If this was a piston engine id say if you have the spare money to go for it, but on a rotary i cant see the benefits outweigh the cost/risk.


On the thoughts on power Howard, i know stav, he loves massive power and even if he doesnt admit it, he secretly wants more go, alot more go, we have been chatting about gt42 sized turbos recently lol

Hence i mentioned the s475 as he says his t04e powered fc doesnt seem to be moving until 5krpm onwards hence with a 0.90 s475 hitting 1bar at 4k, then it should really move from that point at least matching the feel of his old turbo.

Im not sure how the response will be ill hold me hands up but i think if you offer stav 500bhp+ he will take it.

He also mentioned he wanted a bigger turbine wheel......i dont think thats whats holding his turbo back, just the comp wheel and turbine housing.


I might be completely wrong and he calls me a pratt when he reads this but i have a feeling 400bhp wont be enough to last him forever

StavFC

TBH, you are pretty right about me mate, and thats a big dilemma with me.

At least three people who know me have said to me so far once I told them the engine has to come out- "Put the engine back in with 600bhp otherwise you will be bored in no time" as they know what sort of speed I need to keep me entertained.
No idea what power I have now or what I'd need, but I did 119.5 in the quarter with this turbo, and TBH I reckon itd need to be more like 140 to keep me enterained for long. Only car ive ever driven on the road that I felt would never bore me did 160 in the quarter. That was an RX too though.

You are also right about where I want the power. I may have positive boost by 2k and full by about 3k, but even running 20psi its not what id call quick till a good 4.5k, probably due to the ports, but nice and torquey from then on- At low boost its not what id call quick till at least 5k.
I dont mind not having power till 4.5-5k at all, im never under there when drifting or going fast anywhere, but i DO want really fast throttle response above there.

Trouble is, I use the car for all sorts, from straight line street fun to drift and sprint stuff on fairly tight courses. The most accesable and common fun for me is racing supercars and bikes on the street, they're everywhere round here, but big power and big response I like for the twisty stuff dont generally go hand in hand.
I dont know for sure as I havent enough experience of rotarys to know, but I get the feeling I cant have it all, and whatever power would be needed to keep me happy plus the response above 5k to keep me happy probably doesnt happen with one engine/turbo combo. Hmm.

Probably the best middle ground would be the S300SX 83/75 turbo, ie the S360.

turbotoaster

well like you say there needs to be a compromise somewhere.

Your car is very light, probably 150kg lighter than mine with makes a big difference, look how slow most fc&fds are in the uk for the power they put out, if we told the people in US/OZ/NZ the times we run they would laugh there heads off.

We really need to establish what boost your prepared to run, we know how effective pre turbo w/i is from the results you got.

So lets assume you are gonna run 1.5bar in the future, going off that ill say 550bhp in 1000kg should keep you happy, will terminal over 130mph and keep your response.

Now if you were a proper bumlicker and only wanted to run 1.2bar then you want a gt4294 sized turbo, which is fine but you wont have full boost till 5k and your torque wont be outstanding.

If you want to match that power with better spool, more torque and better response then at 1.5bar id go with a gt3574 sized turbo, should hit 1.5bar no later than 4k and good for 550bhp at that level, would that be enough?

I think those from aspec are about $800, or like you say, pick a s360, or s366 if you fancy a bit more on top.

that would probably give you a bit of everything.

the issue we need to get to next is what your gonna do with your engine, now your gonna need some replacement housings, i think tim at rxmotors should have some second hand ones in, or that guy(steve) i gave you the number about, he says he has a couple spare.

The bigger the port we go the earlier the spool(within theory) you only use it for fun so its not a daily driver, if you can live with had fuel consumption and that stupid brap noise they make then maybe going half bridge will help, will help spool a turbo much earlier

Trots*88TII-AE*

iTrader: (11)

Depending on your budget, you can consider a Precision Billet 6265, which has an "updated" version of the p-trim, with a GT35R-sized compressor wheel in billet, which apparently will put out some amount more than the regular 35R, so you can expect over 500whp capability with this turbo. Available in BB ($$$!!!) or journal. FWIW, a standards T3 35R can do 130mph in the quarter.

Are you sure the wheel on your HKS T04E is a p-trim? Only reason I ask is that I had an older HKS T04E 57 from an FC kit, and it had an o-trim wheel, 0.84 A/R T4 divided, same inducer size as p-trim, but smaller exducer.