some pics for you to see if you havent already of my setup

injection

turbo manifold

intercooler

the old a-12 tt carby setup

Quote:

what?, is there a typo or missing word or something, please clarify thanks

NO BOOST is low compression lower emisions, the higher the octane the more C/R u need to stop it predettarnating {pingging} and the higher the emisions.When you boost air in you must add more fuel too so it dont lean out that takes the top of pistons off.I will look in this book for more info it has been a while since i read it

finally found thread again sorry RC I took a wrong turn somewhere
The open chamber and close chamebr head is found on pulsars but the low comp one is when the chassis plate doesnt display the "S" option. I found one of these heads and went crazy when I saw that the ports where as big as the gx head I had at the time and a worked close chamber a15 head.
Then spoke to Gerald at mammi motors and he said that this head would make a perfect high boost turbo head for the "a" cause of its hemi like chamber dome shape.
After all in theory it would provide an even burn toward the piston in a turbo setup as opposed the closed chamber kidney shape.
removing piston material on cast ones for turbo is not considered safe for strength.
Unless tried though its all theory whether its the wrong path or not.
So the question is which setup would work best at 7.8 to 1... a dished piston or open head resembling a dome a-la hemi style?
The other thing if it is by piston that the compression is going to be lowered then angle shaving the head to have the valves parallel to the pistons would be ideal for extra squish, as long as the pushrod dont become a problem.

Not wanting to hijack completely but...
From your experience which head would modify best for a N/A race a series? I have an A14(S) head in my Pulsar and 2 or 3 different A15 heads on the floor as well. Which would be best to modify? Originally I've always thought the A15 was best choice but the info on the A14(S) has me thinking...
Thanks all.

The A15 head is the best one for non-turbo engines, the A14 head is better for turbouse when you need a lower cr!! Still I use the A15 head on my turboengine cause I don

hey rc just a thought......In my home town here there is a bloke who has a turboed 250 crossflow, the internals are standard and it has a good intercooler and turbo on it.
This thing flys.but my point is he had it dynoed and after drpoing the boost from 15psi to 12psi and bumping up the comp ratio he ganed an extra 40hp at the rear wheels he got 440hp at 12 psi and it runs low 11's in an old zepher wagon...lol
complete with bench seat
also it was more driveable off boost aswell

this thing is a complete sleeper

any way you really want to talk to someone in the know(not saying that you guys dont know) about comp ratios.as much as lower is better it can also be a killer to go to low

also one other point I was under the impression that shims or copper gaskets upset the squelch area by shifting it into the cylinder and not up in the combustion chamber where it needs to be to work effectivley.......just my thought