i have a 2003 evo 8 recently when uget on the gas the boost just goes straight on 2 20psi but the car doesnt catch up till 1-3 sec. later all u hear is boost what wrong??? plz help thanks 4 the advice..

 

check for boost leaks

 

like manifold maybe

 

slipping clutch

 

How many miles are on the current clutch? When you do the simulation above, do the rpms raise and mph not raise, and no power is made until a couple seconds later?

^^If so, your clutch is slipping.

 

im thimkin the boost goes up rpms go up mph goes up slowly i did notice a little bit of oil comin out of the middle bolt on the head.but it shifts fine smooth as ever it s just like the boost spoils and the motor lags but it finally catches when get on the gas stiil not sure what itcould be though.

 

Try this...

Put the car in 5th gear, and then repeat the following in 4th gear, going like 30-40 mph and give it 100% throttle and see what happens.

Usually the clutch slips in higher gears first, such as in the process I just described for you to try.

Monitor the rpms and mph and boost guage. If rpms go up and boost gauge goes up, but the mphs does not go up, it is a pretty good indicator that your clutch is slipping.

 

This! If you are building boost... most likely the clutch.

 

Unfortunately that sounds like a bad slipping clutch, try the old trick and throw it in 5th!!

 

thanks 4 all the advice in fact it was my clutch.So now i have to buy a clutch kit.. and my valve cover seal is busted also.