F242: How FAST with <insert config here>?
 

I'm always trying to figure out how to go a little faster and what changes will help the most on a 242. There is a lot of great info on this site, but sometimes hard to find, so.... I scraped some 242 speed data from several threads and put it all together (not without some abuse from my wife that I was wasting my time and had a million better things to do).

Yellow in the MPH column means the speed was not specified as GPS. This bitmap is hard to read, so I included a pdf. The source thread is included if you want to read about a specific entry.

The WINNER is..... (for now anyway) a tie:

mikemracing @ 75 MPH
86242ls @ 75 MPH

That's fast for this boat! :boat:

cool you put some time into that:grinser010:

Good work. Out of curiosity...what is your RPM at top speed with your set up and what props are you running? Also...what is yout "sweet spot" cruise speed and RPM?

I think thats a good catagory, that is RPM @ top speed.
On my 242 LS its 64.5 with a Mirage (non-plus) 21 pitch @ 5800 rpms. I've done a few mods as well as a new 21 Mirage Plus this winter so I'll soon see if that helped my speed.

I need mine updated
Lightning Headers, Upgraded cam and intake on my 502 and added a -2" shortie
Best of 73.4 mph

Cool notes!

I've been thinking about adding a shorty on my boat. What kind of gains did you get vs standard lower...

The boat rode much flatter with the shortie, didn't take as much trim to get up to max RPMs. Speed gain was 1-2 mph, but it was consistanly faster. Didn't have the "on a good day it ran 71+, we would run over 71 almost any day. Didn't need the perfect conditions anymore.

Thanks - I think it was around 4700-4800 RPM. I cruise at about 3200 RPM. Isn't optimal cruise about 75% of WOT? That should be ~3600 for me.

I hope to post all new numbers this summer. I'm in the middle of replacing the stock intakes and 2 barrel carbs with Edelbrock Performer intakes and Edelbrock 1409 4-barrel carbs (600 CFM). Trying to get to 60 MPH!

Suggest you consider the Holley 4150 600 CFM Marine "Double Pumpers" as replacement carbs....you totally control the secondary opening and throttle response is instant.

I might be a little faster this year I will find out tomorrow, taking it out for a shake down!!!!!!!! trying out a few different props