My r53 has a Alta 15% pulley ,m7 crank pulley , headers , ddm cai just installed a valeo clutch kit .
On hard accel I hear a whine from passenger side and acts like the clutch is slipping ....it had the same issue before I installed the clutch .
Any info or suggestion would help me out
thanks

 

forgot to mention the sc is rebuilt with new water pump , new idler pulley , ac compressor and new shorter belt .

 

Your belt is likly slipping ....
A "535 or even a 532 length belt is best...
Folks sometimes reuse the stock belt or use a JCW belt...they kinda work till they stretch a bit and wear...
that is if it's a belt squeel...
When you say it acts like a slipping clutch...
Explain....
Just a loss of power?

 

i did install a 535 belt
Engine revs faster than usual when accelerating, in a given gear. In other words, the engine speed goes up faster than the vehicle speed typically would (for a given gear).
thanks ZippyNh

 

^ I would say either belt slip or possibly crank pulley or SC pulley slipping on the shafts.

What "shorter" belt are you running? And what size crank pulley?

 

i do have the Alta adjustable belt tensioner , Gates/ K60535 belt brand new
2% alta crank pulley .

 

That's your problem ...
The Alta tensioner ....it does NOT have a spring...it is fixed. About a 30 year step backwards technology wise....

 

you think I should go back to the OEM tensioner?

 

You can try to tighten it up....the issue with tensioners that don't have springs are they must be baby sat...
Put on a new belt... adjust it... belt stretches... adjust.... stretches... adjust... etc...
You are hearing it squeel cause it's slipping..
That is the most benign explanation of your issue...
Some folks do install their pullies FAR TOO LOOSE....they fail to tq the bolts down and maybe add some lock tight...and it can slip and tear up the sc shaft...
Similarly the crank damper must be installed right...usually heated. Done wrong, it slips, and damages the end if the crank...
The explanation that it feels like a slipping clutch is puzzling...
A decrease in acceleration yes...
A slipping clutch is characterised by increasing engine rpm and DECREASING OR FIXED road speed...if the clutch is engaged, the motor and the road a tied at a FIXED RATIO.

 

A slipping clutch is characterised by increasing engine rpm and DECREASING OR FIXED road speed...if the clutch is engaged, the motor and the road a tied at a FIXED RATIO.
That is what it feels like.....rpms go up but car doesnt go !
thats what got me confused

 

How many miles on the car?

 

So under slow accel, you get X MPH @ Y RPM, under hard accel you get to Y RPM before X MPH?

Welp, only one place in the car where the engine can turn but the wheels not. Bad seal leaking oil on the clutch, bad springs on the hub, something binding the plunger on the slave cylinder...just the first few things that come to mind to check. Unfortunate.

 

Hard acceleration on a new clutch is kind of risky too.

Some get away with it and others have to put a new one in before it's even broken in