Need help with high compression test readings
05-19-2010, 04:12 PM
#1
Teching In
Thread Starter
Join Date: Jan 2006
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Need help with high compression test readings I was wondering if someone could shed some light on this for me.
My setup is as follows...LS1 with Scat 383 stroker rotating assembly, heads milled .040" & ported, GM MLS head gaskets, TSP 228R cam, stock intake manifold (for now), Sanderson shorty headers with 2 1/2 collectors. Engine management is a Haltech E11v2 with full sequential injection and waste spark ignition. If you need any more details just ask.
Engine was recently built by me, I've got roughly 1500 miles on it now and decided to do a compression test. My highest readings were 215, with the throttle fully open and all other spark plugs kept in the engine. After talking to my machinist, I was warned that my DCR is too high and power & durability will suffer as I will need to pull more than optimum timing to keep det away on pump gas (91 octane here in Cali). Right now I'm running 25 degrees max under WOT.
I really like the throttle response of the setup and its hard to tell if its optimized or not as its in a '92 Mazda Miata. The car is incredibly fast, about on par with my other weekend warrior, a '93 Mazda RX-7 at just shy of 500 wheel HP on a ported 13B. In either case I'd really like to keep the smaller cam, I don't want anything north of 450 at the wheels cause it will be completely unmanageable in this car. But at the same time, if the consensus is that the smaller cam will cause me issues down the road, I will change it.
Opinions? Thanks in advance!
My setup is as follows...LS1 with Scat 383 stroker rotating assembly, heads milled .040" & ported, GM MLS head gaskets, TSP 228R cam, stock intake manifold (for now), Sanderson shorty headers with 2 1/2 collectors. Engine management is a Haltech E11v2 with full sequential injection and waste spark ignition. If you need any more details just ask.
Engine was recently built by me, I've got roughly 1500 miles on it now and decided to do a compression test. My highest readings were 215, with the throttle fully open and all other spark plugs kept in the engine. After talking to my machinist, I was warned that my DCR is too high and power & durability will suffer as I will need to pull more than optimum timing to keep det away on pump gas (91 octane here in Cali). Right now I'm running 25 degrees max under WOT.
I really like the throttle response of the setup and its hard to tell if its optimized or not as its in a '92 Mazda Miata. The car is incredibly fast, about on par with my other weekend warrior, a '93 Mazda RX-7 at just shy of 500 wheel HP on a ported 13B. In either case I'd really like to keep the smaller cam, I don't want anything north of 450 at the wheels cause it will be completely unmanageable in this car. But at the same time, if the consensus is that the smaller cam will cause me issues down the road, I will change it.
Opinions? Thanks in advance!
05-19-2010, 11:27 PM
#4
TECH Regular
iTrader: (21)
Join Date: Mar 2005
Location: butler, pa
Posts: 435
Likes: 0
Received 0 Likes
on
0 Posts
you should be fine.. my compression test was burying the gauge at 250-260psi.. the machine shop didnt like it, but i was told it was ok by the guys that made the cam, i dynoed it last week. it runs good
