Trots*88TII-AE*

iTrader: (11)

On the exhaust side, trim refers to the size of the turbine. A P-Trim wheel has a ~74mm inducer and ~65mm exducer (minor), the O-Trim has the same inducer (major) with a slightly smaller ~58mm exducer.

P-Trim is tried and true on the rotary, and some manufacturers to this day still use them on their latest and greatest.

For the compressor wheel, as Mike said, T04E is only a family, there's a 40 trim, 46 trim, 50 trim, 54 trim, 57 trim and a 60 trim, all flowing anywhere from 280 max WHP to 4xx max WHP on a rotary.

I believe only the 57 and 60 trim were produced by HKS for the rotary. I would go with the 60 trim if possible, as it will still spool quickly and give you over 400 whp.

..13b..

.

fd3s400438

I will tell you about mine . I have the same setup for the last 7 years. HKS T04E 57trim , 0.6 cold side - 1.0A/r hot side. PFC + GREEDY profec b spec 2 . 550cc + 1300cc , blitz front mount + blitz water radiator and lots more

when I was running 1 bar , maybe 1.1 all was fine ... About 410bhp/fly

Last year I started to raise the boost. My max target is 1.55 over coming down to 1.4 constant

Well the car has a mind of its own. I have 80% boost , 16% gain - 0.9bar set gain on the profec and all it does basically is vary the overboost. No mater what I do I CANNOT get more than 1.2 bar contant

The boost gauge hits 1.55 but drops very quickly back to 1.2

So what are the possible solutions , bear in mind that this is a 7 year old setup

1) the wastegate OEM HKS spring ( 0.6 ) is crap anfd will not hold more boost . I have one brand new 1 bar spring going on

2) The is a boost leak which so far I have been unable to find

3) The turbo is not big enough to give me a solid 1.4 bar. I have an aggressive port and since I did 410 @ 1 bar maybe @1.4 I am maxing a small turbo ( HKS T04E ) which should produce max 435 from what I hear

BEST solution ::::: Get a GT 35R or GT3582 or Garrett TD61 full kit with manifold -downpipe etc + bigger 1680cc bosh inj raise the boost to 1.3 and get about 480-490 bhp

Other than that I would kill to find out why the boost drops dead and no matter what I cannot get over 1.2 constant

thats all

Any help-comments welcome

Trots*88TII-AE*

iTrader: (11)

Plain and simple, you've maxed the turbo out. Even if you could get more pressure out of it, you'll be so far out of the efficiency range you won't be able to make any more power. Check it out:

http://www.rbracing-rsr.com/turbo/TurboMaps/t04e-57.gif

These turbos put out 45 lbs/min of air, which would generally max out at approximately 350 rwhp on a rotary, which sounds like you are there and maybe some.

If you really want more power, your best bet would be to sell the kit whole and upgrade to an externally wastegated (if yours isn't) and with the turbos you've already suggested.

fd3s400438

I all ready have a 40mm external wastegate with a 0.6 bar spring as written above. My only concern is that the car used to pull alot stronger at 1.1 bar than what it is pulling now with 1.55 overboost-1.2 constant

furthermore in the last week alone in order to maintain 1.55 in fifth gear i had to rain the pesentage at the profec B from 70% to 81%

Thats why I started thinking there might be a boost leek or the external wastegate spring is coming to the end of its life...

arghx

iTrader: (3)

It could be something as simple as the weather changing, requiring more boost control duty cycle to achieve and maintain boost

fd3s400438

yes I will comment on this. once the weather drops to 5-9 degrees C I can get away with 70-74% duty cycle

The last run was made on a warmer 18 C day . But is it only the weather?

StavFC

As an update to this, I ran consistant 120mph 1/4mile terminals in my FC running the .84 turbine 57 trim HKS T04E.
Running about 20-23psi boost (peaked then falling as revs rose) and pre-compressor water injection.

87GTR

iTrader: (61)

When I had T04E I peaked out at 372rwhp .96 with 57 wheel. it would spool quick but the boost would start dropping past 5500

fd3s400438

87GTR because i am getting similar boost drops can you bee more specific

ie on mine in 4rth gear I get 1.55 right on the gear change but as revs rise I loose pressure fast and it finaly stops round 1.2 bar

is there a way of solving this in order to maintain a healthy 1.3 or 1.4 bar constant? will a stronger external spring work?

Could you please specify at what boost you got 370 WBHP and after the boost dropped what was your constant pressure?

thanks

arghx

iTrader: (3)

how do you have the boost controller hooked up? Is it connected to the top port on the wastegate? There are alternate plumbing configurations you can try.

fd3s400438

i did it exactly as shown on the GREEDY manual . and then double checked it again. I have seen many comments on this post that are similar. it seems that the HKS TO4E seems to stop producing power after 7000rpm and seems to drop boost pressure after 5500rpm. Not only on my car but on others as well

SO :

1) Do we all have a boost leak?
2)Is the HKS 40mm external spring not strong enough
3)Is the unit too small to maintain 1.4 bar of constant boost on a ported engine?

Ideas?

arghx

iTrader: (3)

Usually the HKS 40mm is actually too small. I had boost control problems with an HKS 40mm. There is a reason why few people run 38mm/40mm class gates on rotaries. You probably have maxed out the turbo.

fd3s400438

Ok latest update. I fitted today a brand new HKS 1 bar spring. On the way to the garage with the Greedy set at 82% I saw 1.41 bar over boost in 4rth gear

We fitted the spring and changed a cracked vaccum pipe going on one of the two OEM fuel pressure regulators

Going back on the road I reduced the Greedy setting from 82% to 65% and saw 1.66 bar at witch point I him my max boost cut off limiter. I reduced it to 60% and got 1.45 bar and will have to do a few more test runs and set the boost between 60% and 65% to achieve 1.55 over with a constant boost close to 1.35 bar all the way to the limiter

So the 1 bar spring gave me almost 0.2 - 0.3 bar all through the rev range with a more aggressive turbo kick in and also I redused the Greddy settings by 20%

Not bad for a 20$$ spring

Also the weather was very warm ( 35-38 C intake compared to older 22C runs ) so on a cold night run I may have to reduce the Greedy settings even more...

fd3s400438

Forgot to mention that the spring removed was a 0.6 bar OEM HKS item that came with the kit almost 7 years ago...

s1mpsons

iTrader: (5)

given your success, I will try bumping up my spring to a 10lbs spring.

fd3s400438

I am not used to american units so what does 10lbs equal to in bar or psi . Also I would like to add that it looks like the whole HKS T04E kit was designed for a mild tuned Rx7 with boost pressures not more than 1 bar

My engine has less compression using lower compression rotors and aggressive porting and can take probably close to 25psi of boost

What I am trying to say is that instead of running a T04E ***** out and having power loss issues at 7000rmp and boost drops at 5000rpm it might be wiser to move up to the Rx7 store

GT3582 kit with 44mm external , upgrade to 1680cc secondaries with the Aeromotive Fuel Reg
and probably get 50-80 BHP crank more than I have now at less boost

I believe the Gt35 should give a healthy 480-490 fly round about 1.3 bar = 19psi

If only I had 3000$ to spend for both turbo and fuel upgrade...

s1mpsons

iTrader: (5)

"lbs" is an abbreviation for pounds per square inch (or PSI). Same thing.

Trots*88TII-AE*

iTrader: (11)

Or, in the case of compressor maps (flow), it's lbs/min of air. Just so you aren't confused.

fd3s400438

Last night I raced a 430bhp Subaru Impreza Sti and after the race on my way back home after hard acceleration in third gear I managed to destroy completely the rear diff with its case.

This was a very unpleasent experience because the car was doing over 100mph and when the rear diff broke , the right wheel locked up completely until the car came to a full stop. I left a massive tyre mark on the road for over 300 yards and was lucky that the car did not skid and no other cars hit me while it was decelarating

So be ware. Over 400bhp the rear diff may fail and lock one or both wheels. Also the massive 275/40 rear nitto Nt05 tyres and double HKS cluch made things worse cause all the stress goes to other parts of the trany like the rear diff

s1mpsons

iTrader: (5)

Switched to a 10.5lbs spring. At 85% duty the car hit 20-21psi on the dyno. Worked like a charm. 400whp now. http://hamfistracing.blogspot.com/20...1-dynojet.html