HKS GTxx vs Trust T67 turbo comparison

[RS500]

HI folks,

As i'll be looking for a turbo (streetable although with ability to produce ~250rwkw) for my Sierra Cosworth, i was just wondering if anyone has done a comparison (practical/theoretical) between any of the Trust T67 and the equivalent HKS GTxx turbos?

i know that the HKS turbos have the advantage of the ball-bearing cartiridges and the 'new' design wheels/housings, although, not many people talk about the trust range of turbos even though most of the big hp GTRs and Supras in Japan run single Trust turbos.

Does anyone know the actual hp the T67 can support?

anyway, thanks in advance for your help.

cheers, RS500.

[RS500]

come guys, surely someone knows something about Trust turbos.

[Merli]

Perhaps the following chart will help you:

Groups in order(top to bottom): HKS, Trust, Apexi, Sard & Blitz, Power Enterprise

[RS500]

Thanks for that Merli.

The reason i ask is that i was thinking of going for the Trust T67-25G (8cm exhaust housing) on my 2L and was wondering if it will be streetable and at the same time be able to produce reasonable and streetable hp.

[Merli]

Streetable is a very subjective term... Some people love cars that don't spool up until 5000rpm, others want as much low down grunt as possible so they can be heros at the traffic light grand prixs...

I've got an HKS GT3040 on a 2.5L, and it's got a ball bearing core.. It makes 1 bar by just under 4000rpm...

The T67 is slightly larger (albeit with the small 8cm2 housing you want), it's non-ball bearing, and you're running it on a 2L... I can forsee it to be quite laggy...

[Merli]

BTW, if you only wanted 250kw @ wheels, you don't need to go anywhere NEAR as big as the T67... That will put out approximately 350kw @ wheels...

Look for a 400-450hp rated turbo...

[RS500]

streetable to me is not having full boost at 5000rpm. i'd like to have a nice spread of torque/power throughout the mid-range rpm.

which exhaust housing do you have on your GT3040?

[Merli]

I have a 0.87 A/R Exhaust housing... I'm not sure how that translates into cm2, but it's a very small exhaust housing.

[Merli]

For comparison's sake, my HKS GT3040 is rated to about 500hp.

It makes 280rwkw @ 1.2 bar, and is rated upto 1.8 bar (should be around 320-330rwkw)

The Trust T67 is rated at 550hp, so it would make around 350rwkw like I said before...

[EVOIV]

I used to run my HKS GT3037S turbo on a 2L and I can tell you that it is quite laggy. Not much boost was made until after 3500rpm. The turbo is quite "smallish" in that it has a 0.6A/R compressor housing and a small 0.73A/R exhaust housing. Which is on the smaller scale of the GT3037S turbos. They can go over 1.0 A/R for the exhaust housing. The power was good though, making 206kW@four wheels at 1.2bar. This was on my EVO4. For street use, I wouldn't go any larger than the GT3037S.

Remember that the TRUST turbos are normal bearing and so will have more lag than the equivalent HKS turbo. I think the GT3240 is the largest BB turbo HKS makes? The larger turbos are all normal bearing like the TRUST ones.

[RS500]

thanks for your reply EVOIV.

did u get max. boost at 3500rpm or is that when boost starting coming in?

what other mods were done to the engine?

[EVOIV]

Hehe...no, that is when the car started boosting. I might not be accurate, but boost probably came on a little earlier than 3500rpm. You could probably hit 1bar boost around 4000rpm, maybe just after.

No internal mods were done to the engine. But if you had the $$$, you could buy longer duration and higher lift cams and cam gears and that would make the car make boost a little earlier. Really, if you want the best out of a big turbo you should run highish boost. Although HKS and Garrett turbos are similar, it's been stated that Garrett turbos are more efficient at lower boost (under 1bar), whereas HKS turbos are most efficient at high boost (1.5bar). So it's best doing internals when making the most out of an HKS (or any other large) turbo.

[RS500]

thanks for that EVOIV.

btw, have you read your PM's yet??

[Merli]

Originally posted by EVOIV

I think the GT3240 is the largest BB turbo HKS makes? The larger turbos are all normal bearing like the TRUST ones.

This used to be true up till about a year or two ago when HKS released an updated T51R range (KAI and SPL) with ball bearing cores