micahmiles what power and drive setup are you running?

Mine is a 2003 33ZX Daytona with factory 575sci and XR ITS (integrated transom system). I've recently upgraded the blowers to TBS billet 8-71's but still only running around 4 lbs if boost which is factory, but it does force more volume than stock.

BTW, I've recently listed it for sale if anyone is interested. http://www.powerboatlistings.com/view/34166

I just alerted buddy who is running Whipples on his 33ZX. He should chime in at some point.

One of my favorite 33 Daytona's right there. Nice boat man! How did it run with stock 575's? They seem like a good upgrade option from my 500's if I can find a set at the right price...... Just out of curiosity why did you go to the 8-71's at 250 hrs and leave the boost at 4.5 psi?

Thanks, I've really enjoyed her.

With stock blower setup she would run mid-80's in fresh water in hot and humid weather. The 575SCi motor is bullet proof and a great motor with one exception, the factory Holley/Weiand/B&M "250" frankenblower is the only weak spot as it requires frequent rebuilding and maintenence to be reliable. I would take mine off about every 60-70 hours and send to Darren Meyer Performance Engineering (DMPE) to replace bearings, retime, I added teflon strips to the rotors, hard coated the rotors, etc... The Blower Shop billet 8-71 is a superior product with much more performance upside with a rebuild time in the 400-500 hours. As well, it's turning much slower to make the same boost which helps keep the intake charge cooler. Swap the blower pulley's and it'll double the boost to 8 psi. Super easy to add about 100hp per motor - just swap pulley's and reset AFR. The 8-71 also pushes more volume and you can really feel the difference in power even at the same boost.

The reason I've kept it around 4 psi is, some people have had bad luck with higher boost and stock head gaskets, some 575SCi's have Cometic gaskets and they can handle the boost, I don't think mine does, but have not been able to verify. I've I were to keep the boat I was going to add roller cams before 300 hours (I have 240 now) and at that time replace with a top quality Cometic gasket and then turn the boost up to 8 psi. I have a friend with the same setup in a single engine Nordic and it runs great. But, as I mentioned, I have it for sale as I think I'm going to have to get a more family friendly towing / watersports boat for the next few years.

I do love the boat and the power package, cranks right up, sounds awesome, runs great and never had a single problem with any of it.

I just happen to have a 1999 Donzi 3250 SS for sale.... 11 foot beam 6'7" head room in cabin and still runs 55

micahmiles pm sent

I have to jump in this thread, cuz i am the "kid" from Germany who bought the big NA Cobra Engines...

I have set them with -2" Stelling Boxes and XR Upper with - 2" Imco Sc Lower - so far so good - but as micahmiles said, the boat starts to jump up and down and you have pull back the throttles. I played with props:
31 Maximus, 34 Bravo 4 Blade and 32 Bravo 4 Blade, but all with the same result wether spinning in or out. The X Dimension was set to 4,5" and i can't go higher, but to lower is possible...

The boat don't like to trim very much and it runs best with a set to Close to 3 (indicator). Are your boats running with the same trim and has anyone a Suggestion what to try next to eliminate this dam jumping?

The boat wants to run faster, but i can't pass the 90 without to start jumping...