Thanks for your reply Yello EVO 2003. I would believe there are many more than two. I live in a small town. The first EVO to put an ugraded clutch in here blew his gears out after a week. All he was running was a MBC. I am sure he abused his car, but don't we all abuse it sometimes? This leads to the question of does it break because of abuse over time, or a single high pressure moment.

I would love to think I could put in more clutch so I could lauch with burning the stock clutch. I am not going to go the track every weekend, maybe 3 or 4 times a year. I also will be doing some track days on Roebleing road and Road Atlanta. I am just not convinced yet that the differentials or gears won't be sacraficed if I do the mod. I still pick up the kids in the EVO.

Again I would like to shine as many opinions on the subject as possible.

 

I don't think you really appreciate how much the driver affects the longevity. I have owned a WRX before with nigh on 350 whp (a lot for a stock powertrain) and had it for over 30k miles without breakage of the motor, trans, diffs or clutch. All stock. Some poor fools break their trans within a month on a stock WRX. The same can happen on an EVO. I could break a bone stock EVO in one day if I wanted to.
The purpose of an upgraded clutch is to hold more power. If you buy it to decrease your quarter mile time, your trans (or something) will probably end up breaking soon. Spend the money on more power and stop trying to shave a few tenths by beating the crap out of the car in the 60 foot.


Mark
www.Quantum-Racing.com

 

well put - driver has more to do with longevity than anything else. The stock clutch does appear to be a weak point for some...but not everyone drives their car at the lvel required to reach that point on the stock setup.

Conversely, some owners have had slipping clutches very early on, and decided to replace it once and forget it. Assuming you know how to drive a 5 speed properly, upgrding to one of the aftermarket units could be a great choice and eliminates a potentially weak link (agaon, depending on usage).

I would not go so far as to say the only people who need to think about an upgrade are those that drag race or road race, though those are excellent candidates. Some people are building or have built some pretty high hp street cars, and are simply using the car daily, but do not want to deal with the stock unit. For many of them, upgrading simply gets rid of a "what if".

Adam

 

Hmm.. This sounds vaguely familiar.. I think I've said this many times in the past! I really rather make up my time with the power than make a high-RPM launch... If I chose to drag race, which I don't do very often at all.. Most people end up doing the rolling grudge with some jackass on the street anyway.. I really have had very few problems with my car. like Mark said, most problems with these cars can be directly attributed to the driver. I can reiterate that more.. Be it inexperience or abuse.. Even the highest performance cars will tear up a clutch in no time if you abuse the crap out of it.

 

Ah yes. Regarding just draggers and road racers, I was simply referring to the style of car they have built and the type of street driving they do. For instance, some ppl like to launch from stoplights; I like to go out into the country and enjoy the corners and curves. I agree; many street EVOs could definitely benefit from a clutch.

 

I like to beat the **** out of my car and hope it stays together.

I tracked my car 3 times so far...
Clutch smelled on every run.
One time I slipped it to much and had to let of the gas to.
Haven't been able to hit a 1.7 60 on the stock.

So I figured better be safe than sorry, I purchased the Cusco twin-plate from Adam. The inspection of my cstock lutch showed it had some life left, probably 2 more track days. But it is better to be safe than sorry.

My cusco feels good. I've taken it easy, acouple time WOT. Probably not as easy as I should have, but it seems to be ok.

Irregardless of the clutch life... The Cusco rev's much quicker. Probably gives acouple horsepower also.

Now, I'm going to E-town this weekend. I'm probably going to take it easy, because I don't have the money to pay for a new transmission or transfercase.

 

Mark, I really do appreciate how much a drive affects the longevity. First things first, I am 36 years old, two kids. I have had three different BMW M cars, GT stangs, 5 Vetts, s2000, trucks, and raced motorcycles on road courses for 2 years. I know the stresses and strains on machines.

What I have not had is an AWD car. I am trying to figure out if putting more stress on the drive train is a smart thing to do. If the twin carbon, ceramic, or organic material will slip close to the same ratio as the stock unit when engaged then hold more Tq, then I am sold. But my car does not have gobs of Tq. If an aftermarket clutch slams closed then the driveline is going to get stressed. I like to drive hard, but I don't drive like a 16 year old (no offence to anyone) with daddy's car when he is out of town.

Top fuel drag cars have multi plate disc to slip so they won't spit transmissions on the track and will allow the tires to hook up. Part of the science is to dial in the clutch slip in drag racing.

So, Mark are you saying with your opinion that this is the same principle with the aftermarket clutch. They are there so they won't slip in the power band if you have 400-500 hp. But there is no cure for an AWD launch?

This is my point of the orginal post. Why, unless you have some ultra powerful EVO is the point of an upgrade. The stock unit holds fine and does not jepordize the driveline. The mods on my car are very basic, the route most people will take. EBC or MBC, Exhaust, SAFC, intake. It may produce 280 to 320 at the wheels.

I truly think if someone puts an ugraded clutch in thier EVO so they won't slip when they launch, well you know what is going to happen. This is my entire point of the post.

 

I guess based on your discussion so far, there would be no chance of you breaking anything with a dual clutch. If you are not going to do 5000rpm launches, it should not be a problem anyway. I don't think anything you could do in a roadrace scenario would be anywhere near the breaking point of any of the drivetrain parts. It sounds like you are approaching analysis paralysis. The stock clutch is fine for amateur road racing and even an occasional rolling stoplight run. Have fun and enjoy the EVO. It is a great car.

 

By the way, Evolutionist, I know there have been more than 2 diffs go down. What I said was ON THIS BOARD I have only seen discussions on two that broke. There may have been more, but I have read this board every night for months and have only seen the two. Nobody on this board seems to be bashful about complaining about a problem so with only two reported differential destructions in at least several hundred EVO's represented by the people on this board that comes out to less than 0.1% of the observed population. I would guess that is no worse than Camaro differential, tranmission or damaged engines experiences. I personally know of a Z28 that trashed its engine, transmission and differential in the first month the driver had it. In that case, it was defintely driver error. Performance cars will break more often than the go to market Malibu's because of how they were designed to be driven and the general nature of the people who buy them. As other writers have pointed out driver ability is of course an issue too.

 

OK, I see where you are coming from. An EVO with mild upgrades will eventually finish the clutch off; it isn't a Honda; the clutch will go; I expect it to start slipping in 20k with my own mods. I recently pulled it off and it had looked like it slipped a little bit but nothing bad. It has about 75%+ life on it from 12k miles yet. The point of the clutch is so it won't slip when on power. The point of using a sprung hub twin plate is to hold lots of power (so you don't have to worry about replacing it soon) while still being a bit slippable.
BTW, a clutch can't add torque or horsepower. Like anything that can lighten a car or reduce rotational inertia, it makes the car accelerate faster.

Mark
www.Quantum-Racing.com

 

Now, I will buy it for that!!! I am sold!

 

I've heard people explain that AWD transmissions are weak, but I have a hard time understanding why. Where is the weak link? I've gone to "www.howstuffworks.com" and read all about them there, and I understand how they work, but I would think that distributing the power to 4 wheels as opposed to two would actually decrease the stress on the transmission. Any opinions on this?

 

It can be likened to "give". Compare the transfer of forces to punching things. 2WD is like punching a mattress. AWD is like punching a brick wall.
AWD cars are not weak they just don't have anything to lessen the stresses or give like 2WD. Lightening the car yields a greater chance of spinning tires on launch which gets you back to the "mattress" concept a little.
AWD might be called a skilled driver's setup. It will provide greater performance but you have to be aware of what you are doing as you are more likely to break something; depending on the system.
Not all AWD systems are weak. They come in weak and strong variants (and everything in between) just like 2WD systems.
The EVO setup is quite good. It isn't the best, but is much better than most. Go check out the ATESSA ETS drivetrain. Now that's an amazing system. Getrag are know for building some great stuff.

Mark
www.Quantum-Racing.com

 

Umm...Why wouldn't the Cusco or Exedy give more HP? (all of these clutches are packaged units w/ flywheel) Correct me if I'm wrong (I'm not ) but the lighter weight flywheel puts less mass for the crankshaft to turn. Thus boosting HP; similar to a balance shaft removal. I'm not talking 20Hp, but 3-5 is realistic.

 

I have replaced my own clutch once already. Not only do I own an EVO but I know the exact problem and the cause of it.

The driver is the greatest factor.
People are blowing out the clutches trying to acheive the 13.0 second 1/4 mile times.

In order to do these times you must launch.

If your a daily driver you do not need a new clutch. You can race on the stock clutch once in a while. As long as you learn to launch properly.

If you are not a serious drag racer you do not need a strong clutch. Also, in general the stronger clutches are harder to drive in daily driving.

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