Why has no one mentioned getting a stock set of heads and having them worked by a good Cylinder head company like WCCH? He could get better flowing heads, and his CR wouldn't increase that way he could safely keep the blower. Add the headers, cutouts on the exhaust before the merge on the Corsa and a blower spec cam. He could get the DMH cutouts that allow you to adjust from fully closed to 1/4 1/2 3/4 and fully open to adjust the sound. Going on a long trip? Close the cutout, have a headache? Close the cutout, have a pesky Mustang at the light? Open the cutout and bust their ***. I think if the heads are worked with what you have in mind, teamed up with a boost spec cam and the exhaust there is a good bit to gain. I know some of the Cobra/Lightning guys would port their blower or the inlet/outlet side. Would that be an option to flow more are and increase the displacement of the blower? Another thing that was mentioned is with the blower you are moving the air of a 10.4 liter motor, any restrition on the intake or exhaust side that you can remove would benefit you greatly. If the air has a great deal of restriction it would generate heat, which would cause detonation. I think with what I sugguested your setup would be safer. Just my .02

 

You may be right....i was considering the fact that the heads came ready to bolt on CNC'd with stainless roller rockers, valves. double springs...etc. They are aluminum as well which drops about 112lbs from the weight of the engine. They have said they will replace thier BCK105 cam with one of thier blower cams if i wanted to go that route. Honestly with the amount of boost i will be generating after the heads, LT's, and exhaust work.....i cant see this 2.3L blower pushing more than a 4 or 5 pounds which is still extremely safe but still good for another 75-100rwhp. I have never considered cutouts.....I dont know why, but now that you bring it up.....that may be a pretty simple solution to reworking the whole exhaust. Thanks for the info SkyHigh, i have my mind made up on the LT's, but still very open to ideas about the blower, heads, and cam situation. Do you think with that little boost (4-5lbs), running a blower cam is necassary? What makes a blower cam different?

 

I am not 100% sure but I would think the overlap and etc would be different on a blower cam. If you keep the stock heads with the LTs, and the other mods with the blower get a custom cam. Have one specd by someone that has a clue and knows your setup. An off the shelf grind will be a waste. Don't call Comp either they have always been ultra conservative for my goals and setups.

 

Would it not be possible once the motor is running so much more effeciently to change the pulley and get more boost? Right now you are forcing boost to an ineffecient motor. If you make the motor more effecient and able to move more air more effectively would it not make sence that a pulley swap would allow the blower to spin faster since there would be less restiction since the air would be moving more freely? Or is the problem that the blower simply can't move any more volume?

 

Precisely. This 2.3L compressor will just not get the job done. I am already running a 2.5" pulley and am only seeing 145kPa peak pressure (usually consistant around 136kPa). I realize once i remove the restrictions, i will be seeing even less, but this truck loves boost and responds well to it. I can realistically see a gain of at least 80-100rwhp from this blower after the other stuff is installed even with boost in 5psi range. I dyno'd stock at about 255rwhp. After the blower and intercooler install (no corsa or injectors at the time) i dyno'd 415rwhp at 6.5psi. So considering keeping the blower will cost me nothing, it seems senseless not to use it unless i was going to sell it to help make some money for the other mods. I am getting estimates of being able to add another 100rwhp to my setup by adding the heads, cam, and LT's.....and getting a lot of that new hp in the RPM ranges where its really needed. If that is close to real world numbers, then i would be in the 500rwhp and 600rwtq range with significantly better HP in the higher RPM range (3600 - 5000 with the 8.1L). This thing is a monster off the line, but afterthe 1/8 mile it starts falling flat because of the contrictive heads, exhaust manifolds, and small cam.