Re: Dyno vs Actual Exhaust
 

Your hitting the torque plateau of the engine for the way it is cammed. I preach small cams but what you have is very little for what you want to do. Something in the 220ish @ .050" range should get you the R's you want to turn.

Now the truest test for any engine is when she comes off the dyno with numbers and those numbers are verified when put in the boat, car, truck, whatever. You may want to go to another shop for a 2nd oppinion.

Chris

Re: Dyno vs Actual Exhaust
 

Good point Chris! Not all dyno calibrations are created equal. Also if the 24 Pantera really does 90 with 600 ish HP I would be very inpressed with the efficiency of the hull. There are comparable sized cats that won't run that good with 600. :cool:

Re: Dyno vs Actual Exhaust
 

You should change the piping from the IC to your Intake. You'll Gain 2 mph!! If you switch to a 504IC you'll gain 4-6 mph. I swiched from a 324IC with piping like yours to 504IC and cleaned up the piping and gained 170hp (on a custom small block with a M3 Procharger) same dyno same day no other changes but needed to increase fuel pressure. Look at the picture of my freinds 454 with the 504 IC much cleaner and less restrictive then the 324IC set up.

Re: Dyno vs Actual Exhaust
 

I'm running the aw504 innercooler,i offset it on helm side of motor,their was not enough room between back seat. I did some pressure drop testing in the fall and with my elbows i'm loosing less than 1.5 psi from innercooler and piping,Smitty

Re: Dyno vs Actual Exhaust
 

My 24 excalibur, which is about the same dimensions, ran about 80 with less than 500hp, so it wouldn't surprise me. I'm not so sure hull efficiency has as much to do with it as drive height, because there is only about a foot or two of the hull in the water at that speed....................The Ex did have a 4" pad it would ride on though...................

Re: Dyno vs Actual Exhaust
 

Thanks for the input...great answers and alot of good ideas.

I just pulled the boat out of storage, so I'll look into the pulleys and belt.

Smitty -

I'm going to have my guys fabricate a new supply manifold from the intercooler to the intake manifold from polished OD/ID SS tube, hope to eliminate soem of the drop and get beeter flow with the smooth ss and orbitally welded joints.

Re: Dyno vs Actual Exhaust
 

Sorry if this seems too simple... are the butterflys on the carbs opeening all the way? Possible that the throttle cable is not adjusted correctly to allow for max travel?

Zack

Re: Dyno vs Actual Exhaust
 

They open all the way. Good idea though, it's happened to many people.

Re: Dyno vs Actual Exhaust
 

Here's where I am in my 28.

24P Bravo 1 Prop.

4000 RPM - 50 MPH

5000 RPM - 63 MPH

I have adjusted fuel pressure up and down, minimal effect.

I think a new cam is in order. What are you guys running? I have a 502 Intake and I'm going to get 50 PSI injectors and have the ECU reprogrammed. Now I need a cam...

Re: Dyno vs Actual Exhaust
 

Its between the Crane cams below:

731 : 226/234 .587/.610" lift

741 : 234/242 .610/.632" lift

How do I know if my spirngs are up to the challenge?

I run ISKY 9265 Springs.

Hopefully a cam change, injector change and a reprogramming will get me through the year . . . . . . . . . . then I'll build a 540 short deck for next year, close to 900 HP.