I'm looking at a boat with twin 502 EFI's. Can you add more power to these engines or is it best to leave them along?

...better know what your get'n into...if ya want to mod them out??....then go with carbs....actually go bid on boat on ebay with 500+hp's

http://cgi.ebay.com/ebaymotors/ws/eB...ADME:B:LC:MT:1

I personally think there the best for adding a Procharger or whipple too. They have very good internals such as forged J&E pistons Steel cranks ect... and to top it off they have a low compresion ratio of 8.75:1, which is what you want for super charging. The only week part is the cheap head gaskets. but thats an easy fix to have a reliable engine. I have over 190 procharged hrs. on mine running at 5-6 lbs of boost.
Have fun

in a single or twin application...the weight of the boat does matter! what prop???

In a 31' Warlock SXT cat. Twins with 30p Bravo 1 props. I installed Whipples on carbed 454 mags. I understand the EFI's are harder to do. I just wanted to be sure the 502 EFI's could take more HP. If I do get this boat, it will be some time before I could afford more HP.

Thanks Roger

hummm,,, cats, big props, and bravos=big budget!...i guess if your in smaller lakes it would not be as bad

OK Audacity
What do want to say. I know you are selling a Active Thunder and they are great in the rough stuff but your Active Thunder will not run 95 MPH with the same power. To get that kind of speed out of a Active Thunder you would probabley need 525SC's or better. The HP 500's won't make it. I'm sure you know better than me what you would need to make a Active Thunder run 95. If I put Whipples on the 502's, I think 115 MPH or 120 MPH may be reached. What would you need to make your Active Thunder run 115 MPH?
Yes, the Active Thunder will handle 4'+ waves better than the cat but if its that rough come over to my place and we can party on the dock.

don't get me wrong i LOVE cats...6 months ago i had plans myself of buying one....but a cat w/o #6's or better was not a parameter. i'm about reliability and go'n boating every weekend.

I'm runnig a 502 mag efi with a stage 1 Procharger and Stainless Marine exhaust. It makes aprox 620hp with 5 lbs of boost and has been very reliable. Had a little problem with vapor lock in very hot weather, 98 deg plus range other than that no problems. If you exceed 5lbs you should consider head work.

I saw the boat this weekend and the motors are 502 Mag MPI's. Is that the same as 502 EFI's?

Joey, I see what you mean. If I add as much power as Mate 229 has it will probably distroy the Bravo 1 drives. Domino effect.

Mate 229, what drive do you have?