Hi everyone, i just recently purchased a 92 Evo GSR from Japan, it's been modified. From what i can tell, it has an apex-i acr boost controller, aftermarket exhaust, cusco full customizable suspension, brembo big brakes up front, 17 rims, momo steering wheel, aftermarket front bumper, and strut tower bars all around. I have no idea what has been done to the motor, but it seems safe to run 1.2 bar boost. But i have a problem.
When i start my car and head to work in the morning, the car runs fine, until i boost hard. It's starts to 'hop' and 'clunk' when i make corners to change streets, it doesn't do it on wide corners. It only comes from the front end, and ceases when i apply the clutch (roll through a corner). It doesn't go away until i parked the car for like 4 hours or more. Any ideas?

 

probably has an uprated lsd fr diff , like kazz/cusco ,always clunky on slow cornering .

 

but like i said, it drives normally until i boost. Than it seems 'stuck' in full lock? is this how it works?

 

shouldnt be try an oil change see if it improves it ,might be sticky plates , there are 1way 1.5way and 2 way fr diffs cant remember which isthe most severe use silkolene boa ls 90 oil or similar.

 

i was thinking that, but i've never owned a awd drive car, always had american crap, new to all this. But i noticed that it will 'disengage' more quickly in colder temperatures (it was like -4 celcuis last few weeks, today it's -20, and i parked the car for 1 1/2 hours and it unlocked) The car only has 65,000 kms on it, but i have no idea of it's history, on clues....it has racing decals all over it, and knee/legs braces in the cockpit, and a couple scuffs along rear bumper sides and dings in rear fender wheel wells. Thankx for the info.

 

it seems to be coming from the rear too, could in be transfer case?

 

It sounds like the center diff. The EVO1-3s are just like DSMs where the Transfer case is just a 90* hypoid gear. The front and center diff are both inside the trans. THe EVO 4-9 have the center diff are in the trans and the front in the transfer case. I would say if it normals if it has a welded center diff or a broken spider gear in that diff its not welded.

 

so what are you saying, the diff is broken?

 

anyone?

 

He wrote broken or welded. Welded is a modification where the center diff is locked on purpose by the owner. If welded it would be that way all of the time.

My guess is that the viscous coupling, if that is what it still has, is defective.

I suggest you take it to a shop that works on DSM's. They, most likely, can tell you what is wrong.

 

if it doesn't get fixed soon, will it create more damages?

 

I broke a center diff spider gear in my 93 and was able to still drive the car on the trailer and to it. driving straight the car was fine. It felt like it was hopping when you turned the wheel real sharp tho. I got home and drained the fluid and actually found 3 gear teeth in the drain pan. They where straight cut and definitly a diff gear. I just tore the trans down 2 weeeks ago to find the teeth were from the center diff. I would say talk to TRE, SHEP, of Jackstrans.com

 

I just reread ur orginal post and the boosting part makes no sense to me. I hope we are talking about the same thing.

 

also it kinda goes away when i'm not accelerating through a turn (ie, gliding through an intersection onto another street) I haven't really driven the car without boosting (i love it) so can't really say if the boosting really causes it, but i does start immediately after boosting, but like i said when it was really cold out (-15 celcuis) a short boost around town about 10 km it started, parked for an hour or more, and it was gone again vs on a warmer 0 - 5 degree day it takes several hours to go away. It has my mind boggled, but i'm getting my oil change this weekend, so i'll have the lube tech check my diffs, and look for peices on metal on the plug.

 

how do these diffs work? are they of fluid type?