avbiro

Does anyone on the forum have any experience with a 575sci and a Superchiller? I am in the process of rebuilding my 575 and I am at a fork in the road whether I should put a new supercharger & intercooler on it or not. At this point I am putting in a new bottom end and top end . Only thing original will be the Block, Crank, Rods, heads and exhaust. Everything thing else will be new. Since this rebuild is costing me about 8k the only horse power gain is about 50hp with the Roller Cam. Maybe another 20hp by boring it out to 509 with JE Pistons. At first I wanted to keep it about the same as stock but after seeing how much I am spending I would really like to get 100hp or more.

Bob from Marine Kinetics is setting me up with the cam but I am at a fork in the road. If I choice to keep the 575 stock then the cam will only get me about 50hp . However if I decide to increase the supercharger boost Bob will set me up with a different grind and I will get hopefully get about 100hp between the cam grind and boost increase. But to keep my pistons from getting to hot I know I have to consider a Intercooler or a larger blower that maybe more efficient. I really like the Blowershop 250 replacement ($2,800) and the Superchiller for another 2k. To help offset my costs, I will sell my Weiand so hopefully I am only out the cost the Intercooler.

So I guess I will get to my questions.
One, will the Intercooler with the stock 250 supercharger fit under my engine hatch on my 29 Nu Era?
Two, what kind of HP increase has anyone seen or estimate with the Intercooler and running about 7lbs of boost?

I see online that the Superchiller with pulley, larger fuel pump and ECU change should get me about 100hp. Add the new cam for another 70hp and 20hp for slightly bigger pistons for a total of 190hp. Does this sound right?

Currently I am spinning a 28p Lab Bravo prop and I can get 76mph in Long Beach behind the breakwall. What size prop do you think I can spin and what kind of MPH increase do you think I should see after the rebuild and upgrades?

I would appreciate anyone's input or constructive comments.

Uncle Dave

Jimmy,

I wouldn't do the chiller for the HP gain, but for extra protection against detonation when you are boating in the desert.

I wouldn't put any kind of contact lobe type blower onto a boat without a chiller. A whipple maybe, but not a classic roots blower.

110 degree intake air on Havasu combined with blower heating up the air is a killer on a marginal tank of gas you may pick up at the back end of a big lake. What if you can only get 87 at a marina? Your current rig is 92 only.

If I were you and was doing a rebuild anyway Id go the other direction and punch the thing out as big as you can maybe put a bigger stroke in it -
Go NA and live with what you can get with a new top end kit. Your drive with thank you....

If you punch it to a 496 add new heads a cam a Madera combo will likely easily make more HP than your 575 SC did.

F- that windmill BS. Not worth it in the long run.

Don't know if it would fit or not.

UD

avbiro

Thanks Dave but the pistons have been delivered and the bottom end is ready to be assembled. I just need to figure out the Cam grind at this point.

Uncle Dave

Then find a way to make a chiller work so you get as long a life as possible.

As tempting as it is to go find more power with the chiller I would avoid that temptation.

See you on the water !

UD

avbiro

Agree, adding a chiller without more boost will probably decrease my current boost which is only about 4 lbs stock.

Uncle Dave

Make sure you get the cupronickel (salt water ) version as the freshwater one will die an early death in the ocean..

UD

SB

iTrader: (1)

Have you measured your IAT's with the old motor ?

The 575 uses thropttle bodies with injectors, therefore your SC system is 'wet' which does keep intake ir temps down more than if 'dry.'

avbiro

SB,
I did not check the Intake Ambient temperature because I wasn't thinking about increasing the Boost. Thank you for the suggestion.

Schweeng

Hi,
I had a 29 with a HP 500efi... can't give you much input of motor stuff......not a gear guy. But I did put a Whipple on it which was said to boost HP to 700 or 720 with 7lbs of boost. That fit but I think a roots is taller...
Not sure it was worth the money- gained maybe 7- 8mph on a great day..... The bottom of the 29 is so excellent in rough conditions, disorganized waters, tight swells but it is not a "efficient " or speed bottom like a Fountain lets say. If you're looking for much more speed from the increase in HP, not sure you'll get it.

That is one thing I would not do again.... Hope this opinion helps.

lavey jr

Looks like most questions have been answered. I'll answer one that's been left out, yes the 575 with superchiller will fit under the engine hatch.