Mod motors

[big_G]

Every day in my business I run into guys with Cobras and other Mustangs running Kenne Bell superchargers. What I have a hard time grasping is how they are getting 650 to 800 RWHP out of 281 c.i. Now I feel a little depressed that my 383 sbc with a D1SC at 15+ lbs. of boost is only 550-600 RWHP. Is it the heads?..If so, what heads will at least come close to that hp/ci ratio?....Maybe LS series heads? Chime in, dudes!

[DeltaT]

What heads do you have? A 383 with modern CNC heads, like an AFR 220 would hit the 650rwhp mark easily with the right cam, IC and supporting bits.

My 383 hit 632rwhp with ported Edelbrock E-Tec 200 heads at ~12# on a Vortech T-trim which is pretty similar to the D1SC.

Jim

[big_G]

I am running Vic. Jr. heads (215cc). The best so far is 555rwhp with a 230/236/114* solid roller. Currently at 15 lbs. boost. I have since switched to a 244/248/114* cam, and will dyno in a few weeks. Needless to say, I was hoping to be in the high 600's to low 700's. Any insight you can provide is appreciated. Back to the mod motors...I'm guessing their claim to fame is the cam and heads. Must really pack the cylinders well.

[MrForce]

Are you intercooled and/or running water injection? It can make a big difference. And yes, most of those mod motors are intercooled.

Rob

[big_G]

Are you intercooled and/or running water injection? It can make a big difference. And yes, most of those mod motors are intercooled.

Rob
ProCharger 3 inch core intercooler. No water or meth. 8.3:1 scr.
Last dyno. for reference:
https://static1.pt-content.com/images/pt/2009/04/dyno0423-1.jpg

[greygoose006]

the power is in the heads IMO.
DOHC with a supercharger is a good combo

[big_G]

Well, the latest dyno pull yielded 625 rwhp, with the drag radials spinning (smoking) on the rollers at about 5,900. I think the heads are the limiting factor. Disregard the a/f graph.
https://static1.pt-content.com/images/pt/2010/05/dyno05081001-1.jpg

[DeltaT]

That's more like it! And you didn't seem to lose any lowend torque or anything. Strap that thing down better, put a couple big boys in the trunk and spin it until the HP starts to drop - I bet she has more in her.

Jim

[big_G]

Thanks, Jim. The engine obviously liked the bigger cam. I like how the bigger cam not only gave up nothing, but 500 rwtq came in 500 rpm earlier, and held on forever. I think the dyno drum is too smooth, we tried tieing it down tighter and dropping tire pressure, to no avail.
https://static1.pt-content.com/images/pt/2010/05/th_dyno050910-1.jpg (http://s19.photobucket.com/albums/b156/big_G1/supercharger/?action=view&current=dyno050910.flv)

[DeltaT]

You need studded snow tires for the next run :)

Jim