m.tsang

Hi Guys, i'm a newbie to your fab site. I've got a bit of a prob with my 97 993 silver C2 cab with about 55k on the clock... i stuck the car on a rolling road the other day and found i'm only making 247bhp at the crank and the power curve was very 'wobbly' towards the top of the run! i found a vacuum leak on the actuator to the left of the fan in the engine bay that controls the air for the heating system but fixing that produces the same results... i can just about see 3 actuators (is there any more?) for the varioram system and these appear to work when i rev the engine above 6000rpm... could my cat be blocked or something similar???

Toga

Hi m.Tsang,

check this thread. I don't know if it could affect the power the way you describe it, but that an easy check to do anyway:

Varioram

aubrey993

not sure how you would measure the crank output without removing the engine. If you are actually reading the 247 bhp at the rear wheels, i would say you have an engine functioning very well. Varioram performance should show up on your dyno results beginning at about 4500 rpm. good luck.

m.tsang

hi aubrey993, i checked on the rolling road gadget and i have just 195 bhp at the wheels and 247 at the crank!!! not good!!! and the bloke had just run an old 928 that had 291bhp... not bad for a 22 year old motor... good news ive just checked my fresh air/engine air vaccum actuator and adjacent solenoid and one had a leak and the other didnt respond to the electric signals... so there maybe a happy ending!!!

maurice97C2S

[QUOTE=m.tsang]Hi Guys, i'm a newbie to your fab site. QUOTE]

Where have you been, Mark ? I thought everyone knew about Rennlist !

cheers, Maurice

TheOtherEric

M-
Certainly 195 hp is very low, and it sounds like you have a problem. (As a side note, "247 at the crank" is only somebody's guesstimate; there's a good chance that it's actually more like 230. This is why we most people around here speak in terms of wheel hp.)

A LOT of people would be VERY appreciative if you could post details on your investigation. Can you post pics of the parts you described as malfunctioning? This is a frequent question, and one that has never been thoroughly addressed; i.e. what parts should be periodically checked to insure my engine is performing properly.

Thanks for any info you can provide!

flatair

First of all, what kind of 'rolling road gadget' are ya talkin' about? Are you sure about it's accuracy?

Dr. No

How about this test: accellerate as quickly as possible to 60 mph and see how long it takes. Repeat.