Source...

http://www.sdsefi.com/meltdown.htm

I think after reading this you will know the results and FACTS about going with 11:1 Compression.

Choose your CP choose your FATE all i have to say on this..

 

That is not 100% true. If you utilize the correct parts, correct fuels or additives, and correct tuning methods, you should be just fine.

I would not suggest utilizing 10-11.0 compression on pump gas, but if you add meth or race gas 108-116 octane, you could have some good times..

 

Depends what HP you are looking for. With 8.8:1 on 93 octane, we pulled my timing back to around 10 deg. or so between 3500 and 5000 rpm to get to 600 rwhp without pinging. With 11:1 compression, we would never have been able to get to 600 rwhp on 93 octane.

If money is no object and you never venture too far from home, sure, run your car on C16 at roughly $10/gallon. Meth injection also will help, but make sure you have a large meth tank. Otherwise, you will have to turn down your boost each time you have to fill up on pump gas. That's now fun.

 

Well, I'm looking for 100whp less and I would be willing to run high octane fuel to get it. On pump I would like 400whp. I think I'm sticking to stock compression to have a happy medium.

 

If you want 500's whp then 11's are just to damn high. The highest I will go is stock compression but you will need to run race gas to achieve that power and still be on the safe side. It dont matter if you have all forge internal, no forge internal can withstand serious detonation. I think 9:0 or even 9:5 is a good safe bet for pump gas and psi between 15-18psi. We dont have a 4banger that need high boost to achieve big power, you can get 600whp easy at only 16-17psi with Twins.

 

my car is not a daily driver so good gas or meth is not a big deal to me. I plan on running 12 psi on the street with 93+meth and shooting for 20psi on C16.

I am one of the few guys to have run 24 psi on an opened deck VQ motor with great success. When I took apart my motor last time, the pistons were 100% fine and zero signs of detonation. My bearings were a bit worn due to debris from my turbos when they went, getting into the motor...The contamination was the reason the motor came apart.

Good fuel and keeping down the knock is key to survival.

One thing I dont like about pump gas, is that you never know from tank to tank what your going to get. From my learnings over the past few years, I no longer feel comfortable tuning pump gas for more than 500whp, even if you surrpress the knock initially, eventually the odds will catch up.

 

Need...more....info!

 

What info do you need?

 

Your car.

 

Just finished the meth install..Gonna do some preliminary road tunes tonight. I plan on running about 12-13 psi on 93+meth. Race gas will be a different tune with no meth..

 

What compression?

 

Thats a common number on 7psi with a stock block and twin turbos. I won't say high compression won't work or can't work. I have often thought why not leave the compression at stock 10:1 and used forged internals. I guess most people building are planning/hoping for big boost so they drop the compression. With your goal why not stock compression and forged internals it should work fine.

 

I'm thinking the same thing...

 

/\ + here read up.. I had this debate with the guys in MY350Z regarding running high compression piston. I just dont see why we need to run 8:1 because there are only a handful that run high 600whp and even with that power you can reach it with just 17-19psi.

http://my350z.com/forum/forced-induc...rbo-build.html

 

What ecu program you plan on using? I'd think a full standalone or a reflash like Uprev would be in order. IMHO, you'd need closed and open loop alterations running this config.

I'd guess that long duration cams would help lower your dynamic compression a bit.