A forum such as this is the best place to get statistical data... so here's what I'd like to do:

Get compression-data (all cylinders) for cars with the S/C - doesn't matter if its auto or 6-spd. Another key parameter will be mileage driven while being FI.

The first candidate for this should be cls6sp03 as he has the most mileage with the Comptech S/C.

This could be a slight pain for some folks, but a compression-tester is like $45 and all you have to do is unplug the coils and replace one spark-plug at a time with the tester and then crank the motor.

For convention, let the cylinder #'s be as follows:

6 4 2
5 3 1 (TB--->)

(Looking from the front of the car)

Interesting data will be comrpession differences between cylinder(s) 1-2 and 5-6.

Hope you guys are interested in doing this; will be good data for everyone involved!

Ex. data:

Mileage: 10K
Cyl #1: 220psi
Cyl #2: 217psi
Cyl #3: 220psi
Cyl #4: 212psi
Cyl #5: 214psi
Cyl #6: 218psi

 

Are those your compression figures? Healthy! I know they can last. I know of several (Like 100 or more) '92-'94 Audi S4s with the 5cyl that are running 25+ PSI on 9.8:1 compression with 150k-250k miles. Never heard of a major engine failure on one.

 

I think Eric (types1976) has the most miles on his S/Cer.

and how do you expect to pull the coils off and test when the S/C'er shaft prevents you from removing them?

 

Eh? Hmmm... forgot about that one! I guess do the rear three cylinders!

 

Generally you do not want more than a 10% difference in compression between any of the cyl's. Your at a 18PSI difference between CYL3 and CYL4. Very close to 10%.

 

Remember. Do it when the car is cold and push the gas pedal all the way down.(floor it) Top PSI should be at about the 5-6th compression stroke.

 

No that difference is 8 PSI.

 

this would be interesting to do..

 

Oh ya, by bad. I should go back to sleep today thats only a 4% variance. Sorry running on only a few hours of sleep for the past few days. Dunno why I was thinking 18PSI, lol. I am truely useless without sleep.

 

Thanks for volunteering me. It is a great idea though. But I'm not too kean on removing the blower until it's time to change the plugs out. But I will definitely remember to have each cylinder compression checked when the time comes.

Thanks for that suggestiong...