Hello all.

I am in the middle of my GT35R build & I ran into a question. I'm shooting for 400whp on a stock port engine with water injection. This should be attainable. I plan to go with a 6 puck later when the engine is rebuilt & ported.

When I bought the car, the owner told me the clutch was replaced when he replaced the engine. It's a ACT Street/Strip with a HD pressure plate... Good for 405 ft/lbs. Currently has roughly 7k miles.

When pulling everything apart I decided to take a look at the clutch to see how things were. Honestly, I don't know much about wear and what it is suppose to look like. It looks thin, as though the allen studs don't have long before they will be coming through & hitting the flywheel. When I went to ACT's website, a brand new disk looks almost identical, so I wasn't sure if this was simply the characteristic of the clutch.

So the questions are....

Is it worn enough to replace?
Can the ACT Street/Strip hold up to 400whp?

It's being built as a fun street car with occasional drag strip usage. Nothing torturous, but I do like to enjoy the car.

Thanks for the help team

Here are some pics....





NEW FROM ACT

 

first of all. You CANNOT look at it and know if it is still good or not. You need a micrometer and measure the thickness compared to factory spec.

Ive got a friend who actually had the GT35r on his FC with ACT S/S and he's telling me that sometime he can feel the clutch slipping. So my guess would be, go with a heavier duty one or get a twin-disc from excedy and not have to worry about a clutch again =]

 

Agreed on the micrometer... I guess I never thought of it. I can go pic one up and give ACT a call to find out its proper specs.

As far as upgrading goes, the FC Street/Strip is rated for 268 ftlbs, and the FD one is 405 as I mentioned. Likely no wonder your friends is slipping.

I've searched and many seem happy with the sprung 6 puck. However, I would rather wait to upgrade the clutch & a light weight flywheel when I rebuild at a later time.... if possible of course.... I hate to delay things any more, if it would handle it.

 

I ran an ACT S/S clutch with HD PP for several thousand miles on my 420hp street port T04R FD. perfectly streetable and held the power just fine. The clutch and pp were even reused from my previous full bolt-on setup. I ended up switching to a sprung 6-puck on my HBP because I was shooting for 500whp.

And like other have said you need to measure the disc's thickness. But I'd bet it's well within spec. Looks alot better than mine when I pulled it out in perfect working condition.

 

The problem with a 6 puck clutch is that they don't last, no matter how easy you drive them. They're designed to grip, they're not designed for longevity. I called up the ACT tech line and spoke to a rep, he warned me about this. The problem with an aftermarket twin disc clutch (some cars have them OEM I believe) is that they are noisy, unless the Exedy is somehow different.

 

^^ I have heard great things about the Exedy.... just not big on their price. If push comes to shove I would buy one, but my power goals should keep me in the moderate clutch range.

Thanks for the info all...

 

i'm making 370whp and 340 ft/lbs on my 35r @15psi.. i have the act street/strip setup and racingbeat l/w flywheel with less than 5k and it's slipping. pedal pressure used to be a little firmer and the engagement used to be quick. i think you will be better off without an organic disc.

 

I got about 10k miles on mine and had 374whp at 15psi and when I jumped back on the dyno a couple weeks ago it slipped at only 13psi. We didn't get in any tuning it slipped on the second pull. I just got the 6 puck put in last week and am getting back on the dyno the 14th. I plan to see what the GT35R can do with preturbo WI and the ported shroud. I'm looking to turn it up to 20+psi. For ~400whp the S/S is gonna be a gamble. I'm hoping to just go with the Exedy once this disc is worn.

 

I've run the ACT SS on two 400+ rwhp FDs now. No issues at all. It's a nice street clutch.