454 Mag MPI Hop-Ups
 

For those of you with experience, what should my next move be on my 1998 Gen VI 454 Mag MPI motor? So far, I've done:

1. Gil wet exhaust
2. Vortech flame arrestor
3. ECU reprogrammed by Arizona Speed & Marine
4. Adj. Fuel Pressure Regulator (set at 48 psi)

So far, my results have been zero at WOT. The engine runs great, but no more power.

Where should I spend the next chunk of my life savings?

The following are not options:

1. Supercharger (maybe later)
2. Dry exhaust

Thanks,

perf
 

Push your timing up about 3 deg.

Hot boat has done that on every EFI test they have published. You want your WOT timing around 36 deg BTDC - maybe a little more if you run good gas. Also, IF your system is working as it should - if you have too much timing - your ECU should bake your excessive timing back - if you experience any preignition KNOCK.

My 502 seem lame last year, and in the fall I pushed the timing up the 3 deg. and this past season the boat ran better than ever before.

Good luck

MAV

Gotta Have It,

My ECU has already been remapped by ASM, so I'm not sure I'm safe increasing timing. They told me the remap is calibrated to work off of stock timing. I'm not sure I have much comfort in the knock sensor . . . they sure as hell don't work in any of the American cars I've owned.

Mav,

I'm running at 5000 - 5050 with a 1.5 gear and 23P Mirage Plus. My reprogrammed ECU increased the rev limiter, so that is not the problem. I tried running a 25P Mirage Plus but gained no speed and lost too much acceleration.

Anyone have other suggestions?

That's what I figured. A cam swap does not seem to be an effective way to go at this point.

A Procharger will work wonders on a mag engine. Just keep it at a reasonable boost, 5lbs or less. My 502 puts out 620hp with similar mods to yours and a stage 1 Procharger. There were some good deals on them in the classified section.

Scarab22 look at this one.

Re: 454 Mag MPI Hop-Ups
 

I have a 454 in my 96 27' Power Quest its heavy modded with the following

Conversion to carburetor

Dart Alumn. Cyl heads
Dart Intake manifold (hi riser)
Holly Carb
JE pistons 9:6:1 Compression
Cranks Cam Hydrolic camshaft
Hydrolic rollers and lifters
new valve covers
blue printed and balanced

Dyno at 514hp :) hehe

If you want to see pics of the engine, you can check out the pics on my website

[IMG]www.customtints.com/454/done1.JPG[/IMG]

www.customtints.com/454.done2.JPG

Re: 454 Mag MPI Hop-Ups
 

It will not allow me to edit the top message those URLS again are

www.customtints.com/454/done1.JPG

and

www.customtints.com/454/done2.JPG

hehe

Re: 454 Mag MPI Hop-Ups
 

Modifying a fuely motor has not worked too well for me.
I changed the cam, exhaust, and had some head work done.
AZ Speed re-calibrated 3 times for me and still didn't get it right.
I have been using the stock calibration and have gained about 300rpm and 4mph with the same prop. So what is that? 40-50HP?

If you want real gains N/A, modify and use a carb.
or
Buy a blower...

Good Luck,

Re: 454 Mag MPI Hop-Ups
 

I gave up on my 454 Magnum. I am building a 540 carb motor.
At least I will be able to tune this motor myself.