briana

After 1 year with my 90mph plus 32 fever, I sold it to a guy in orlando, It was running perfect when I sold it.

My new project is a single step 35 lightning 98 hull with stock 502mpi. Here is the question?

What performance should I expect out of these upgrades to the 502's:

dart ss heads with roller rockers
upgraded cams (mild)
cmi exhaust
new pulleys
remapped ecm's by asm
msd ignition,with hotter wire upgrade

the block is in good condition (fresh water boat for 5 years)
240 hours on the blocks.

current performance # are 72mph gps full fuel 2 people

asm says 525hp at the crank.

all input is appreciated.

jryan26

Random bumped up his hp500s to 600hp in his 98, and I believe he is running around 85? Faster than that with shorties.

Beak Boater

72- 74 was about the norm for MPI 502 boats. 35's with 500 hp's were running from 81-84 mph some faster. I think they rated the 500 hp's at 470 hp, at the prop shaft. Not sure what it was at the crank. Sounds like a solid motor, your MPI fuel injection will restrict what you can do for more HP. It doesnt flow enough air. Good luck.

Ran-Dom 32

96-99 hull had a lower X (16 3/4) - you can safely gain 3-5 by going with a a -2 inch shortie lower. The set up you mentioned along with a set of shorties should put you in the low to mid 80's

briana

sounds like the #'s I was thinking of, now here comes the question?

does anyone have reasonably priced low hour shorties out there for sale?

does the ratio matter?

i have seen some on classified but not a set of 2.

briana

If i put shorties with the motor upgrades what type of props are people running with this set up


2 525hp w/shortie drives.

jryan26

I would say most of us are looking for some low hour reasonably priced shorties!

briana

ok high priced high hour

jryan26

I've got a set with 6000hrs I'll let go for 3k each!

Fanatic

What did the early 90's "35" non step hulls run with the 525 Merc's?