rfgonzo

I think with that upgrade a reasonable amount of speed should be 3 to 4 mph.

NASCAT

For those of you that have committed to the upgrade do any of you own boats w/ Bravo 3's & the duo prop? I ask b/c I'm wondering whether the upgrade will require more prop in order to optimize. 4- B3 props wouldn't be cheap assuming you had twins.

BrianH244

Are you running the new 8.2? Because the 8.1(496) gets totally different gains.

rfgonzo

I just ordered a set of custom headers today for the 8.2 Mag HO and will be getting the stage 2 from Wipple in a week or two.

NASCAT

Who offers the headers, what do they run & what are they claiming the gain will be? Or you can just quote how many $100's per HP, just curious if you don't mind sharing.

SummerObsession

This is a great question! I have a Formula 400ss with 8.2 HO's that would love more power! I would assume the axis system would be unaffected also?

BrianH244

I called mercury and Dustin at whipple today to try and find out about removing these cats because I want my PCM tuned for no cats. Well neither of them knew anything about it. Mercruiser actually thought I couldn't remove them abd that they were all one piece. Well i said heck with it and tore mine apart today. Just as I thought they slip right out from the bottom of the riser. There was 3 cats on each side. Here is a quick pick I snapped. The exhaust has to flow directly through the honey comb. [IMG][/IMG]

Keith Atlanta

Why couldnt you use conventional CMI's for a 525? Assuming Dustin reprogrammed them for No Cats....

BrianH244

I didn't want to spend the money on a different exhaust if I could just simply remove these cats.

Whipple Charged

525HP EFI has a different bolt pattern at the cylinder head/exhaust flange.

CMI 496 exhaust is a direct bolt on and better than stock. Stock has more tight bends and even without the cat, will not flow as much as the CMI.... Can't tell you the difference in power, we didn't test stock exhaust without cat.