If you boost, you are pushing compressed air into the motor, then on the compression stroke, you are now compressing the compressed air, as well as the fuel...octane is the compressibility of the fuel, if compression is too high for given volume of air/fuel you get knock, which is when the fuel ignites spontaneously due to compression and temperature rather than spark. If you reduce the compression ratio, or lower the compression, you have the possibility of running more boost, or using lower octane fuel, i.e. pump gas, or both. You can tune out knock to a certain extent, but at some point you will have to increase octane, or lower compression, as well, you can cool the intake charged air by intercooler, and also you can use water/meth injection post intercooler for additional intake air cooling, which reduces the likely hood of knock.

hope that makes sense.

so therefore the knock at some point would whip out your engine sooner or later am i correct?? But yes that does make sence thank you for sharing

yes, boost pressure doesn't kill motors, knock kills motors.

knock aka detonation, out of sync combustion puts a fair bit of stress on the crank, and other internal moving parts.

allright, so lets say at some point in the near future i wanna start a build on my RA to be as fast as can be N/A but end goal would be to be boosted. Thats all when finace is all in the right place what do you think would be the best route to go.. from my understanding to be running pretty good N/A you would try to raise comprassion and flow through the engine but on the other hand to be boosted. i would have to try to lower compresion and have better cooling in order to run a good amount of boost ( 7-12 psi) and not to stress the engine too much. key words their are TOO MUCH

You would be better of leaving the internals stock while your n/a , then building the motor up solely for boost when the time is right. Unless you have the money/time to burn on high compression pistons, rods, rings,headstuds, and piggy/reflash for a good tune. Only to take it all out one day ,to install the lower compression pistons etc.

Let's try and keep this thread on topic

Update,

Heard back from Cometic yesterday, gasket has been analyzed by their Engineering dept. and I'm now working out final specs with them. Stay tuned.

Gents,

I'm officially running a group buy for these on Club 4G. Please PM for details.

PM Sent! Can you link to the club 4g post? Can't seem to find it.

what if i want lower compression

Lol, take your boost elsewhere!! Any updates on this? I'm really interested..

Bueller...bueller..

it's bueller's day off

Wonder what happened to this

Cometic has pulled all both the 4g69 and 4g64 gaskets from it's catalog. I have had conversations with a new custom gasket maker and working out pricing and technical details. I may just have Lanzer pull this thread and start a whole new one.

So cometic took my oem head gasket contribution too ?