I was at a local race shop today and was talking with the tech about my evo 8 (2003 model year). He had good compliments about the engine in the car but said that the real weakness with the 03 model year was the clutch and differentials because they were not helical.

He actually seemed surprised that my diff wasn't broken already (at 17xxx miles!). So my question is, are the 2003 owners driving around in time bombs? If I run this thing on a road course, how much can my diff's take before I see any kind of failure? This guy was saying that he had an evo in his shop with 10 miles on the odometer (with some mods - what I dunno) with a broken diff that mitsu wouldn't warranty. That sounds crazy, has anyone out there had issues with their diffs at all in any manner?

 

I notice people that work in "race shops" like to hype things up and pretend they know what they are talking about even though they've heard things 25th hand and don't really have a clue what they are talking about. Unless I want to plop a fart can on a honda I stick to people in the know. Can you say exaggerate much? I have ~45K miles on my stock diff. Yes the clutches go if you use your car for drag racing...Yes if you get a race clutch and continue to drag race your car something else will give...there is a short list of ZERO cars that could actually put up with that kind of driving. I personally saw an STi with < 8K miles getting towed away from the drag strip because his clutch was gone, it just happens.

Take your car to a road course, drive it like it's supposed to be driven, and you'll be fine.

 

i have been talking extensivley with a friend of mine that is building a drag evo and he told me that the only things i have to upgrade in the driveline are the clutch and the transfer case. i already have a cusco twin plate carbon-carbon clutch and i am going to spend the extra money to get a race spec transfer case so i can easily hold close to the 500 awhp i am going to be pushing. as far as i know the diffs are fine. but i also have an 05 with the acd, and an lsd front and rear. hope this info helps.

 

This guy actually did have surprising knowledge of the evo. He actually rally raced with them in europe before they came stateside, so he did know pretty intimately what changes were made. But I hear what you are saying, he definately isn't seeing evo's day in day out, he's jack of all trades, but I think he's a very smart jack of all trades.

Guess I'll just see how things hold up if I don't end up selling my car (as it's for sale so I can build a house) and takin' to the track!

 

Call Jon at team RIPP in kalamazoo michigan, he will answer every question you have, he is very intellegent and long winded! he goes by the name gears on this site. find him.

 

so are 2004-2006 helicals?

 

No. Only 2005 and up

 

I believe the straight cut gears are inherently stronger. Helical allow for smoother
transition but it is weaker. No matter what the design, if the gears are not toleranced correctly and also the material is not of high quality any gear design would fail with enough load. The evo gear box is most likely not toleranced nor of a higher quality. Mitsubishi doesn't have the quality standard to enforce this.

 

To say the EVO transfer case is a weak link is a fair statement. Jon at Team RIPP is one of the gurus. I don't believe every blown diff is the result of unreasonable abuse. Many are though I'm sure. Big HP racers are doing fine on stock TCs, but most of us probably don't have the skill their drivers do. Whether its operator error or not, most of us wish the Tcase/front diff was tougher. The tcase saga has been beaten to death around here. Search some other threads to hear the drama and make your own conclusions.

 

So what kind of wear does flying around a road course staying in third gear do to the transfer case? Is driving like this something that reeks havoc on the TC?

 

The main reason people blow their front diff is wheel hop!! That is one of the major causes of breaking and hard high rpm clutch drops when launching. I spoke to jon a while ago and he said the Evo TC is actually very strong(ring and pinions), but the front diff is weak.He also said the Evo gearbox is very stron also. Dont know how strong the Helical one is, havent heard anyone brake on yet. If you are worried get upgraded spider gears at TRE which jon says no one has broken yet, and is fairly cheap too. Or if you want even better, get a Quaiffe or Ralliart LSD, but its expensive as a ****

 

i'm selling my stock diff in another thread... and in the pic i posted, you can see that w/25k miles and four track days, it's still perfect. Granted, I use redline and don't drag race. For the road course I don't see durability as a big issue.

 

I dont know what anybody is talking about there diff breaking. I have 59,XXX on my car and I drag race at least once a week and I never have any problems. BUT I know how 2 drive my car. I dont launch above 5500 thats just not smart. U sping like crazy and risk your Xfer case.