Compression #'s for a DET??? [Archive] - SR20 Forum

: Compression #'s for a DET???


blackb13
07-11-2002, 09:20 PM
Paul P and myelf just tested compression for my DET. The only thing I forgot was to hold the throttle open (oops). Here's what the numbers were. 150, 145, 145, 147. Are these within spec for a DET? Any comments?

paNX2K&SE-R
07-12-2002, 02:36 AM
Well, on one hand the numbers are good b/c the are all pretty close to each other. On the other hand they don't mean much more than that b/c you didn't do them at wot. Try it again at wot and see what they are. Hopefully they will all be close again but at higher numbers.

paul p
07-12-2002, 09:23 AM
Steve,
I dunno if you got a chance but there was some info in the se-r mailing list archives. I was feeling a little masochistic yesterday and decided to pop over there for both yer issue and my emmisions (search function is WAY clunky). Specifics are kinda thin and unfortunately no definitive answers. From what i could gather 145-155psi are reasonable #s for the DET. The fact that the values were even across the engine is a very good sign.
Also interesting to find was the effect of no throttle vs WOT while cranking and measuring. I have to dissagree w/ paNX2K that not doin it WOT invalidates results. On a N/A motor the closed throttle values were consistently 20psi lower than at WOT (1 post specificaly compared the #s of the 2 methods back to back). For the DET the gap was smaller, more like 10-15psi, prolly because even when at WOT you have the turbo still blocking both manifolds. It's just that the published values used for comparison are generated one way, if you are comparing values generated using the other method they have to be adjusted.
Then again, come on by, check it again the 'right' way and maybe we'll have enough time for a spin. Liz obviously wanted to get outta there, get that movie and get back home. Maybe next time ya'll could pop in for a drink or hang for dinner.
I'm gonna chuck a banana or two here and say i think yer engine is OK.
Now bout that loud exhaust. =P

RySE-R 1
07-13-2002, 08:01 PM
Awww, man! The exhaust is the best part!!! BTW, Steve, have you broke your clutch in yet and taken some WOT runs with it?