Clutch and Hp

aakrusen · 02-07-2008, 11:57 AM

How much power can the stock clutch hold reliably? Sure it could hold 500 hp if you baby it, but hoenstly, how much is too much?

What clutch is recommended for 400-450 crank hp?

polyol · 02-07-2008, 01:27 PM

Well clutches are rated on how much torque they can hold. Not hp. Also, its hard to say how much the stocker can hold really, some people cant get it to hold at stock power levels. Other put near 400wtq and it holds for them. So it really is all in how you drive it and what you expect it to do day in day out.

I would personally go twin plate if I was pushing the 400+ mark.

ChristianCGM · 02-08-2008, 04:30 AM

I am going to back up what polyol said. Typically if you have 400-450 chp you will probably have a 20g, a 49 lb/min turbo or a gt30r, which means that your torque will be around the +/- 400 wtq mark. Generally an sprung clutch disk with a strong pressure plate will be good around that mark, and would be the most forgiving for a daily driver. However if you want to be absolutely sure that it will hold a sprung puck clutch will definitely do the job. Puck clutches do not last as long as disk clutches because there is less surface area to wear. This is good and bad. Good because the puck pads cool down faster enabling them to grip better and prevents the clutch from slipping at WOT as a disk would since it would cool down slower. Bad because they will wear faster since there is less surface area to wear. I have no experience with the twin disk clutches, but every so often I read reviews where people love them or dislike some aspect of them being too harsh in daily circumstances. The best thing to do is to go to the clutch manufacturers website and look at the specifications on the clutches; and to search for reviews of clutches. Some of the brands that people stick with are RPS, ACT, SPEC, and Exedy.

PS - (general blanket statement) The more power you make the more has to be held. To hold that power will require a stronger pressure plate and a better disk. The stronger the pressure plate, the more power it will hold, the stiffer the clutch pedal will feel and the more uncomfortable it will be to drive compared to stock.

Flycaster · 02-08-2008, 07:36 AM

Just bear in mind that clutches are rated in foot pounds, at the crank. They clamp to the flywheel, not to the ground, so if you 're putting down close to 400# at the wheels, you need a 500# clutch. FWIW, the stock clutch seems to OK with up to 400#, though Exedy does not publish torque ratings for their clutches.

aakrusen · 02-08-2008, 11:52 AM

Quote:

Originally Posted by Flycaster

FWIW, the stock clutch seems to OK with up to 400#, though Exedy does not publish torque ratings for their clutches.

Are you saying the stock clutch is an Exedy unit? If so, should I use that brand since they are familiar with our car?

What about the ACT street racer (I think that's what it's called) clutch? It says it's rated for 515ft/lb tq. Is that pushing it too close?

**Turninconcepts.com** · 02-08-2008, 12:45 PM

Quote:

Originally Posted by aakrusen

Are you saying the stock clutch is an Exedy unit? If so, should I use that brand since they are familiar with our car?

What about the ACT street racer (I think that's what it's called) clutch? It says it's rated for 515ft/lb tq. Is that pushing it too close?

The stock one is an exedy unit. That does not mean you have to stick with that.

We have been using an ACT street clutch in our STI for a bit over a year or so and have had no problems with it.

Tony

aakrusen · 02-09-2008, 12:50 PM

So if I get a Protune and I make somewhere around 300whp/350wtq, will the stock clutch hold?

Flycaster · 02-09-2008, 03:24 PM

There are lots of guys here with that power and the stock clutch. Some have tons of miles with zero problems; others have had to replace them fairly quickly. I think it boils down to how you drive, but I'd stick with the stocker until it goes and get the free miles.

02-07-2008, 11:57 AM	#1
aakrusen Junior STI Driver Car: 05 STI Fav Mod: Covering those ugly stock fog lights! Location: Waiting for UPS Posts: 99 Join Date: Oct 2006 Trader Rating: (0)	Clutch and Hp How much power can the stock clutch hold reliably? Sure it could hold 500 hp if you baby it, but hoenstly, how much is too much? What clutch is recommended for 400-450 crank hp? This ad is not endorsed by this member. Please register or login to hide this ad.

02-07-2008, 01:27 PM	#2
polyol Spec C Club Car: 04 STi Fav Mod: Motor Mounts Location: Eugene Posts: 2,263 Join Date: Oct 2004 Trader Rating: (0)	Re: Clutch and Hp Well clutches are rated on how much torque they can hold. Not hp. Also, its hard to say how much the stocker can hold really, some people cant get it to hold at stock power levels. Other put near 400wtq and it holds for them. So it really is all in how you drive it and what you expect it to do day in day out. I would personally go twin plate if I was pushing the 400+ mark.

02-08-2008, 04:30 AM	#3
ChristianCGM Grassroots STI Racer Car: 05 STi CGM Fav Mod: whiskey tango Posts: 580 Join Date: Oct 2005 Trader Rating: (2)	Re: Clutch and Hp I am going to back up what polyol said. Typically if you have 400-450 chp you will probably have a 20g, a 49 lb/min turbo or a gt30r, which means that your torque will be around the +/- 400 wtq mark. Generally an sprung clutch disk with a strong pressure plate will be good around that mark, and would be the most forgiving for a daily driver. However if you want to be absolutely sure that it will hold a sprung puck clutch will definitely do the job. Puck clutches do not last as long as disk clutches because there is less surface area to wear. This is good and bad. Good because the puck pads cool down faster enabling them to grip better and prevents the clutch from slipping at WOT as a disk would since it would cool down slower. Bad because they will wear faster since there is less surface area to wear. I have no experience with the twin disk clutches, but every so often I read reviews where people love them or dislike some aspect of them being too harsh in daily circumstances. The best thing to do is to go to the clutch manufacturers website and look at the specifications on the clutches; and to search for reviews of clutches. Some of the brands that people stick with are RPS, ACT, SPEC, and Exedy. PS - (general blanket statement) The more power you make the more has to be held. To hold that power will require a stronger pressure plate and a better disk. The stronger the pressure plate, the more power it will hold, the stiffer the clutch pedal will feel and the more uncomfortable it will be to drive compared to stock. Last edited by ChristianCGM : 02-08-2008 at 05:02 AM.

02-08-2008, 07:36 AM	#4
Flycaster S204 Racer Posts: 3,008 Join Date: Apr 2004 Trader Rating: (0)	Re: Clutch and Hp Just bear in mind that clutches are rated in foot pounds, at the crank. They clamp to the flywheel, not to the ground, so if you 're putting down close to 400# at the wheels, you need a 500# clutch. FWIW, the stock clutch seems to OK with up to 400#, though Exedy does not publish torque ratings for their clutches.

02-09-2008, 12:50 PM	#7
aakrusen Junior STI Driver Car: 05 STI Fav Mod: Covering those ugly stock fog lights! Location: Waiting for UPS Posts: 99 Join Date: Oct 2006 Trader Rating: (0)	Re: Clutch and Hp So if I get a Protune and I make somewhere around 300whp/350wtq, will the stock clutch hold?

02-09-2008, 03:24 PM	#8
Flycaster S204 Racer Posts: 3,008 Join Date: Apr 2004 Trader Rating: (0)	Re: Clutch and Hp There are lots of guys here with that power and the stock clutch. Some have tons of miles with zero problems; others have had to replace them fairly quickly. I think it boils down to how you drive, but I'd stick with the stocker until it goes and get the free miles. This ad is not endorsed by this member. Please register or login to hide this ad.