I have a 2013 Formula with twin 377-320hp. The engines of course have CAT exhaust.

I am interested in reprogramming my ECM to help the boat along. I do not have plans to build the motor. However if there are small modifications that produce HP, I'm in.
I have read about whipple's Up Grade and others that preform the same service with Big blocks.

• Does anyone have experience with/and or running an Up Grade with a Small Block?
• Does the Up Grade block the Oxygen sensors for the CAT exhaust? If so, how does this affect the Injectors?
• Do I need a different valve train for the extra 400 rpm? Stock is 4800-5200
• What exhaust would be needed if any?
• can the stock throttle body be modified for better air flow?
• Is there a Taller element aftermarket Flame Arrester for my application? I'm sure the 3/4-1 inch FA is a choke point for air.
• Should my Props be fine, or an up grade would be needed?

If I left anything out, please chine in. And thank you for your response.
Dave..........

Lots of questions there but lets put it this way.. You will gain nothing but Headaches.

Chris

Which one is the headache Chris? And your reasoning please.

Call and talk to Dustin at Whipple. My guess is he will want you to remove the CAT's and go with aftermarket manifolds or headers. By the time you purchase those and possibly have to have tails made along with the price of the reflashes you are probably better off building 383's. You will have a ton invested in those stock 6.2's with probably less than desirable results and still have weak links in the engines.

So. Your answer is 383's? Remans go anywhere between 11-$12,000 each , plus shipping . Then there's between $5000-$10000 to R&R the engines. I guess I could put a different crank, forged pistons, rods and injectors in mine. Do a valve job, put new Springs in it while I'm at it. Even though the engines have 80 hours on them. Probably cost just as much.

I called Whipple. The gentleman that answered the phone said I could use my same exhaust because he takes the oxygen sensors out of the loop.

​​​​​​​And what's the weak link(s)?

Well I just answered three of my questions. 5 more to go.

Whipple did the 8.3 with Cat and sensor.
Whipple Offers PCM Upgrades for Mercury 8.2 Engines

I dont know why they dont take the Cats out - maybe a machine shop could put them in a fixture and get them out with a Bridgeport or similar.

But the root of the question is Whipple did do it on an engine with Cats....

Keith, thanks for the link. Read it all. The big blocks seem to improve with the PCM Flash. But that was stage 2, not 1. I didn't see anyone with SB. One took the Cats out of the manifolds and used the same manifolds. That's an Idea. Anything to take the restriction out and make the engine breath better.... Thanks

That is typical...usually just me and the dog.

Right^^^ LMAO.. My Lab, gal and I will celebrate Christmas weekend on the water.

Stage 1, Stage 2, Stage 3.... Its all relative. At the end of the day you dont need Super Unleaded 93 till stage 3. But the smallblocks may be different. You need to talk to Dustin and discuss what he can do.