siguy2k

iTrader: (3)

Well I have a s5 turbo vert with RA apex seals and street ported and did a compression test today. I thought it was pretty decent. It pulls anywhere from 15-28 vacume at idle. Why would it fluxuate so much sometimes? Anyway the #'s were 100-102front and 94-96rear. What do you think? Thanks

By the way this was on a piston compression checker, dont know how much of a difference it makes.

SpeedOfLife

iTrader: (16)

How many miles are on the rebuild?

texFCturboII

iTrader: (17)

Yea maybe the rebuild is still breaking in? But 90's on the rear rotor is going to need another one in a year or so.... depnds on how often / how hard you drive it.

I hear the flames coming from a mile away.......

alexdimen

iTrader: (13)

You pull 28 inches of mercury at idle with 95 psi compression? Somethings off... probably the vacuum.

Why did you use RA seals? Yes, they last forever, but I've heard they tear up your housings.

From what I understand, they're designed to be used in aircraft engines, which are routinely rebuilt with new housings... hence the lack of regard for long term effects on the trochoid surface.

siguy2k

iTrader: (3)

There are about 5000 on it now. I broke it in real nice and it runs real strong. Never boosted at all until about 1500 and i have never taken it past 8lbs because i need to get my injectors in. Would the piston checker make a difference? Why would the vacume differ so much? Some times its alot and then sometimes its at like 14? WTF

Also there was one new housing so that was probly the front. I thought that anything above 90 was good?

siguy2k

iTrader: (3)

I used RA because thats what my builder(The Rotary Doctor) recommened in the turbo motor. He has been using them for along time with good results. Also we have all heard they tear up housings but all you can really find is chattered and in most those cases they used the RA springs and not the Mazda ones.

rx7vadim

the tester maybe off a lil, did u do cold test? after warm up then test on the hot engine, the numbers go down. 10 psi in my case. i managed a woping 85 psi hot. But still not accurate.

siguy2k

iTrader: (3)

No i did it after a good long drive. I think it is fine. The car pulls really strong on 5-6lbs i a cant wait to see 15lbs?

alexdimen

iTrader: (13)

Your vacuum sounds really odd. 28 inches is ridiculously high and the fluctuation on top of that is really weird. Try a different vac gauge.