Inliners International
Posted By: dodgycanuck compression question - 03/31/10 12:44 PM
What if I were to use factory compression and 5lbs of boost? Would that yield about the same power as, say, 8:1 and 10lbs?

Just a thought.
Posted By: CNC-Dude #5585 Re: compression question - 03/31/10 12:49 PM
What's the factory compression?
Posted By: dodgycanuck Re: compression question - 03/31/10 04:21 PM
That, I am not sure. The engine is a '76ish 250. It will have a 194 head with some work. I would think about 9-9.25:1?!
Posted By: Turbo-6 Re: compression question - 03/31/10 09:17 PM
More boost means more air is being forced into the engine which makes more power. The higher boost makes more cylinder pressure which is why you need to be careful on how much compression you run, or else you will have to kill the ignition advance to make it live.
This is why a better flowing head will make more power at lower boost, higher compression, and more ignition advance.

Harry
Posted By: Turbo-6 Re: compression question - 03/31/10 11:19 PM
More boost alone will not nessarly make more power if you don't have enough fuel to go with it, this becomes the biggest problem how to get enough fuel to keep the engine from detonation and melting parts.

With siamesed bump ports, to get better air flow, the easy way is to use fuel injection with methanol it can be run extermely rich, almost like a Top Fuel car, the cylinders run cooler won't lean out as easy and melt parts. otherwise keep under 400 HP

With the 12 port Sissel Kirby head (the best flow )you can you can make more power with an intercooled, injected or carb set up on gas.

Harry
Posted By: 56er Re: compression question - 04/03/10 04:56 PM
More compression with less boost gives more around driveability. Less compression with more boost will give more peak power. It depends on what your goals are.
Posted By: Turbo-6 Re: compression question - 04/04/10 12:57 AM
This is true, but why turbo a car if you want driveability.

A Hot Rod is a mean, nasty, scary thrill to drive.


Harry
Posted By: 56er Re: compression question - 04/04/10 04:33 PM
You and I are on the same page for sure, Harry. Driveable cars are boring!
I think a streetable car is running 3600 RPM stall,use a trans brake @ see 4000-4100.

A 4l85E trans that wont over heat @ take long trips to the track, no trailer for my Car. But that's just part of my idea of a street car.



MBHD
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