z28hokie

What's the max compression people are running on 93 octane pump gas (assuming crappy 93 octane- so probably closer to 92-91)?

Reckless

iTrader: (9)

About 11:1 with 26-28 degrees timing You can always tune with less timing if the CR is higher.

z28hokie

Ok, thanks, I figured around 11:1 was pretty reasonable...

Phil99vette

iTrader: (11)

It depends on the cam...the more overlap you have the more compression you can run. I am running roughly 12.2:1 with a big cam and have gone 10.7 on pump gas and a mild tune.
Phillip

Phil99vette

iTrader: (11)

BTW I drive it everyday...

z28hokie

Heh...neat. Unfortunately I can't run a crazy cam thanks to emissions inspection...

Fireball

iTrader: (21)

I'm running ~11.8:1 with 232/232 112 cam

Mean Machine

where is ashburn located? are you near blacksburg or in nova? we don't have testing down here in richmond. yet.

99 Black Bird T/A

iTrader: (4)

My custom 224 XE-R on a 113 LSA is spec'd to pass emissions sniffer etc and my car has ~ 11 to 1 compression. 93 octane has been fine even in the middle of summer.

The LSA is very important in passing sniffer related tests. Emissions tunes can also be created to pass sniffer too.

As for OBD-II scans as long as the computers says everything is good..it is regardless of cam installed with correct tuning.

It might be possible to get a 226 to 228 by emissions sniffer testing in some cases if the LSA was 114 to 115 to reduce over lap with careful selection of valve timing.

Damian

iTrader: (89)

You can run 13:1 compression on 93 if tuned properly. The tune itself will decide how much compression you can run without detonation. However for the everyday street car, 11:1 compression works the best IMO...

FWIW, my car is @ 11.3:1 compression, 26 degrees timing, and 93 pump works..

josh

Scalpel

iTrader: (4)

I run 11.25:1 compression on pump gas.