Re: Total compression
 

Jay...I like your setup!
What is your total timing?
Im @ 8:1 looking at finishing up with 7# and 30* total.
This is non innercooled with alum. heads.

Mcollinston,

Yes you're correct. If you open the throttles at 3000 RPM or really any RPM above idle, the Whipples boost will go to MAX. I wouldn't do it in my boat, as the parts and pieces from the drives would make a mess of the water :(, but when we dyno these we pull boost from the mid 2000 rpm all the way to WOT, on power pulls. Alternatively, make it an easy run up and the boost doesn't come into play until the 4,000 or so range.

If you're ever in the South Florida area, give a call and we'll take the boat out.

Take care,

Steve

I also really don't get into the boost with my Whipple setup until 4000 rpm's. It's not that the blowers can't do it… it’s more of, they don't need to.

Even if I’m cruising at 3000 – 3200, as soon as I stab the throttle, the motors will almost instantly tach up to at least 4000 rpm’s where I will see about 5 psi of boost. I guess it’s more engine load than rpm’s that use boost. I can cruise all day long at 4000 rpm’s and see 0 vacuum or boost on the gauges. However, I did try one “burst” from 2600 rpm before and I did see about 4 – 5 psi by 3200 – 3300 rpm’s.

Also, the boost on any positive displacement blower (like Whipple) isn’t as constant as people say. I would bet that there is about 2 psi less boost at 3000 rpm WOT (I’ll never see it) than WOT at 5000 rpm. I’ve attached the dyno sheet from a run I did this past winter.

-Bayley

Interesting... the 530hp is a lot less than the 590hp they advertise for the 454mag efi.

"the 530hp is a lot less than the 590hp they advertise for the 454mag efi."

...Isn't it?

I've talked to Dustin in great detail about these results. We both agreed that the water temperature was too high for the intercooler (150 F). It should have been done around 110 F, where I normally run. Also, the run up on the dyno was pretty quick. Dustin thought that this system needed time to "stabilize" in order to make peak HP. Don't get me wrong, he was just as surprised as I was.

550 HP seems about right to me. I'm about 2 - 3 mph faster than the exact same boat with HP500's. However, I do have significantly more acceleration.

Hey Back4more :)

Nice chart-helpful. What happened with your drive? I hope it was somthing simple....

SteveDavid
 

how much mechanical cr are you running in your tipples with those whipples?

Back4more
 

Yep, thats pretty close to mine. 502 with Dart 360cc aluminum heads bowl ported intake and exhaust and the combustion chamber is ported and polished 124cc. I used the 168771 Crane cam (gen6 block) B&M 250 non intercooled supercharger. I bought new Holley supercharger carbs, 750's. 30* total timing and it made 700.0 hp at 5700, 697hp at 5800 and at 4300 it made 667 ft lb torque. at 5700 it made 644.9 ft lb. Jay

Yep, just a couple of gears.:rolleyes:
I thought there things where built better!?!?

Speedmaster project this winter??? :D