Yuccaf

hello everybody
i own a evo 7 and evo 5
both my cars are stock , i recently got my clutch replaced , now its not performing the same its used, the drive feels heavier, when i launch the car it boggles down , theres a slight vibration in the higher rpms overall the car is slower ,my evolution 7 was faster than my 5 but now its much slower than it
what can be the possible issues

BluEVOIX

iTrader: (69)

When you change the clutch you need to disconnect a lot things that includes the upper intercooler pipe etc.. Have you made sure all the couplers are tightened down well and there are not any boost leaks?

Yuccaf

Ill check that tomorrow , any other possible reasons , there is no error on my car

BluEVOIX

iTrader: (69)

There really shouldn't be anything else. To do a clutch job to remove the transmission basically here are the following that gets uninstalled:

Drain drivetrain fluids (tcase and trans)
Intercooler Pipes (Upper, Lower , to the turbo etc.)
Battery and tray
Unbolt clutch cylinder thing from transmission
Front motor mount with bar
Eventually the two trans mounts (side and rear)
Lower two tie bars or what ever their called
Downpipe
Wheels and axles
Pull out shafts from trans
Unplug speed sensor from trans
Remove shifter cables
Remove trans /tcase bolts (ACD lines if you have)
Use long screw driver to help release clutch bearing to c clip
Pull apart and wiggle away the trans from engine

There might be some small things I missed, just visualizing the task when I did about 4 clutch changes in the past . It's been about 7 years! I think lower radiator pipe might sometimes be removed depending on preference.

So since now you know what's involved listed above , there is not much than boost leak that can happen. Unless maf is not plugged in but that will throw a CEL I think.

Make sure to check all the intercooler pipes including J pipe on turbo. And there should be a nipple on the j pipe that vacuum/boost line connects to he oem boost controller. Etc.. While your doing all that although they should not have touched the turbo , check the wastegate actuator spring tension. Should have some preload. Like 3 millimeters if I remember correctly .

Pal215

iTrader: (12)

I agree with BluEVOIX,

This sounds like an intercooler pipe popped off or was never reinstalled properly. The bogging down could be the engine running super rich from having an intercooler pipe disconnected. There is no air pressure to compensate for the extra fuel being dumped into each cylinder.

Do you hear the turbo spooling? Check the wastegate as well.

Bladey

Since you have a 7, the SAS valve could be unplugged/not hooked up right when you take the UICP off. That would explain the bogging down too.

I'd make sure you don't have a boost leak and no error codes first

Yuccaf

Checked everything , all intact and perfect , found out the clutch is gone again .

BluEVOIX

iTrader: (69)

Your newly replaced clutch is bad ? What makes your think that? How many miles did you put the new clutch ? Was there clutch slippage (rpms rise but mph not increasing adjecentaly ) ?

barneyb

You might want to check for oil in the gear boxes. No lubrication could equal sluggish.