575 SCI upgrades
 

I just picked up a new to me boat with a 30hr 575 in it. Looking at Whipple's website, I see that they offer a kit to take it to 700hp. Consists of an intake with a chiller and a smaller blower pulley, belt and tune. Has anyone tried it and how did it work out? Still looking for dependability. Seems a bit pricey for basically a manifold and pulley. Is there a better bolt on option? Anyone have a used setup that they removed when going bigger?

Thanks

Its a manifold, cupronickel IC (over 3 times more expensive then aluminum but will never corrode), IC fittings, billet adapter, thermostat adapter, belt, pulley, tune, fittings, hoses, mounting hardware.....

Yes, I have the WC-9062B Hi-Performance 575 SCI Performance Kit with a 3" pulley. Do I think I'm getting 700HP...no. When I did the conversion, I had 200 hours on the engines. I did see a fairly large improvement on hot and humid days, 75-76 GPS vs. 80-81 GPS. There are so many variables involved, that it is "exactly" hard to gauge the "top end" improvement. Would I purchase the kit again ...yes, as there is a noticeable improvement in all around performance.

This was prior to my Arneson conversion.

You might want to think about swapping out the old flat tappet cam and going through the heads first....both are weak points of 575's and can cause costly issues later on down the line. Buy a decent set of Brodix aluminum heads and a hydraulic roller cam. That, with the right tune and a pulley swap will probably get you close to 650hp..plus you will be increasing reliability.

We are finishing mine up right now. Before adding any more boost I would check head gaskets. I went back with Fel Pro MLS. Those or Cometics would be my choice. I also added ARP head studs for additional insurance. I also upgraded to hydraulic roller cams. Will see what dyno says.

I will do the cam, head upgrades at rebuild time. But this is a 30hr engine and I am not ready to pull it out just yet with summer fast approaching. I am interested in a proven package that won't have to go to the dyno.

I did the Superchiller. It came with a 3.5" pulley and no ECM mods. It works great. Head gasket blew 50hours later. Fixed that, on both engines, and a cam busted shortly after. Rebuilt both engines. Went roller cam, .030, and head and block clean up for minimal more compression. Still no ECM changes. They've run great the last 200+ hours. If you do the pulley, DO the head gaskets!!! Take care of the blower bearings too!!! I change the oil every 25 hours and change the bearings at 100. They've always looked great.

I have been running Amsoil marine gear lube in my drives. Is this OK in the blower? I think it calls for Merc HP drive lube.

The blowers call for the Merc gear lube, which I use. I'm sure the Amsoil would be fine, maybe better, but I know the Merc stuff works.

On the 250/256 blowers gas dilution can be an issue so check and change often. They are not real picky on what gear oil you use in them. With 30hrs I would check it and change it with what you have on hand. The rear bearings are sealed on later models with the only maintenance being done at rebuild time (wouldnt run them more than a max of 200hrs before rebuild). The head gaskets are only good for about 200hrs as well.

My 2001 575 was very rich out of the box. I ran a 3.5" pulley and a 120* thermostat with quite noticeable gains and did not remap...BTW, I have a 3.5" that I will sell you...they are getting hard to find.

As far as an the whipple kit you still should check and see how much hatch clearance you have as hatch modification adds even more cost. You may want to consider upgrading the whole blower package as the low hour blower you have is in quite high demand for guys that have to replace one and want it to match their other motor. It would sell for a premium. This is the route I took after replacing the 256 once and then the rotors touched on the second one. I was able to rebuild and sell the second one. I did end up going with a whipple lowpro innercooler and an 871 littlefield on top of that utilizing the stock fuel injection. I had an ECM mapped by EB marine in Tennessee copying a guy who had about the same setup. I also added an adjustable fuel pressure regulator so I could bump the fuel pressure up if needed. I am now running 9lbs of boost with the 871 slightly overdriven. I have also upgraded my headgaskets .

If you have any questions let me know

I've been running Amsoil drive oil in my blowers
going on 7 years now, with no problem.

check with arizona speed, website, they have a great upgrade kit for $995, 70-80 hp gain, have twin 575's on a cat it made a huge difference, in fact had to go from a 32 bravo1 to a 34 " prop

Snap proceed with caution though.
http://www.offshoreonly.com/forums/b...ed-marine.html

guess I was one of the few lucky ones, just bought the kits, installed everything myself and and had the computers reflashed by my local performance shop but we run a little rich, nice black exhaust pipes and perfect water and oil temp

Yes, I know all about ASM. That is like a 4 letter word on here.

Just looked at the ASM 575sc kit and have to ask. Why would you put a MSD box on this engine?

I am in the process of doing some work to mine. Getting Brodix heads and all new hardware, head studs, new cometic gaskets, custom cams (get rid of the flat tappet ASAP!) Should be done sometime after Memorial Day... Eddie Young has them right now. He is going to do a tune on them once installed also. No superchillers, I can't take the fact of cutting a hole in the hatches...The whipple chillers are awesome and low pro. Running stock ignition...ignition isn't the weak point the injectors are...

I am doing the same thing except I ported the stock heads. I had SPR Performance go through the throttle bodies. Injectors are not a problem. Throttle body flow probably is. There are larger injectors available. This is his website http://www.tbiparts.com/. Let me know how yours turns out. I hope to dyno in the next 2 weeks.

Here is a ported dart head and cam swap that JimV did last winter. This is with the addition of Teflon strips to the 256 no intercoolers. And pulley'd up to 6PSI. Tyler did the tune on his dyno.

You dont need to. The stock iginition should hold 800hp. Waste of money if you ask me.

Thanks everyone for the input. At rebuild time, I will go all out with a Whipple chiller, roller cam and good heads. For now, gonna put on a smaller pulley and run it this summer like it is.

Have the Whipple intercooler, Dart Pro1 heads and hyd. roller cam. Great set-up. 703hp 738 lbft torque on the dyno by Tyler Crockett. Turn key deal. Don't forget a real good sea strainer/filter for the intercooler, mine has a good stainless mesh filter type.

what did he do to your throttle bodies?

What size heads and cam did you use? that is a lot of power...

The cam is similar maybe a little more aggressive than the 741.

The heads are a JimV's own hand port design head that Dart cast for him using their base 345 Pro1's. I believe they are about 330cc intake runners. I also run these on my NA 454's and will be adding B&M 250's next winter. Here are some pics of when Jim and I went to the foundry the day they cast them. It was a neat experience, something you don't get to do every day.

He had the injectors cleaned, flowed, and made sure all were equal. Rebushed throttle shafts. Narrowed throttle shafts to flow more CFM. Tack welded blade screws. We could have went farther with the bodies and ported them but felt we would see how this worked.

Sean did the throttle bodies on my 575's too. Great guy to work with & does an awesome job. I know this is an old thread, but I had to give a thumbs up to Sean & SPR. Great experience!