Any hop up tips for a 98 Pro Max SS

[Larry33kc]

I have a 98 Allison with a 98 Pro Max SS turning a 30" chopperI was told that it was a 260 horse when I bought it and that it had some special heads on it but can't remember the guy's name. But any way I was wanting to know if there is any free or some what cheap hop up tips that I can do to go faster and get a better hole shot. TIA

[StratosVT]

Get rid of the chopper prop, buy a real Yamaha Drag (26pitch or smaller), and get rid of your rev limiter (reprogram ecu). With the prop change alone, it should run like a different boat. But, you'll need to rev it a little higher to get some speed out of it.

[HighVelocity]

Just look out for the ECU police, I heard there checking ECU's. LOL, LOL right.

What a joke.

[TheRickster]

If your ProMax still has the oil injection in place you might consider removing it first of all for a little insurance..

Rick

[David]

Yes, get rid of the 30" chopper. If it is a small ear, send it my way. I know my holeshot would be lousy but that's OK.

[Larry33kc]

I don't have oil injection and it iss a large ear Chopper. Also how will not having a rev limiter make it run better. I am a little nervous about twisting it tighter than the 6300 RPM it is doing now

[ChrisXS2003]

I don't see where you mention what Allison model you have, but any '98 Allison/225PM rig should spin a 30" chopper at or near the rev limiter when light. That's 6800 RPM or so.

If you're only spinning 6300, your poor holeshot is likely related.

Do a compression and leak down test on the motor and tell us about your setup.

Something is wrong

Chris

[props4u2]

Agree withg Chrisxb2003, even on a heaver prosport you should be turning a 30" prop atleast 6500 with 2 people and tourney load with a 225 ss unless someone has installed 1.75 gears in place of 1.87's.


Lee

[THE FAST ONE]

<TABLE id=HB_Mail_Container height="100%" cellSpacing=0 cellPadding=0 width="100%" border=0 UNSELECTABLE="on"><TBODY><TR height="100%" UNSELECTABLE="on" width="100%"><TD id=HB_Focus_Element vAlign=top width="100%" background="" height=250 UNSELECTABLE="off">HEY LARRY,I THINK THE BIG EAR PROP IS THE WRONG CHOICE FOR YOUR ALLISON.JUST MY .O2--ED</TD></TR><TR UNSELECTABLE="on" hb_tag="1"><TD style="FONT-SIZE: 1pt" height=1 UNSELECTABLE="on">
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I don't have oil injection and it iss a large ear Chopper. Also how will not having a rev limiter make it run better. I am a little nervous about twisting it tighter than the 6300 RPM it is doing now

[The Big Al]

Take the advice about the prop change.
Also you can send the ECU to Brucato to get reprogramed and remover ev limiter.

www.brucatosvs.com (http://www.brucatosvs.com)

[Larry33kc]

I have a xb2003T, I have done a compression check and all cyl. were #155 but one and it was #152

[StratosVT]

I have a xb2003T, I have done a compression check and all cyl. were #155 but one and it was #152

That's a lot of compression if you're running pump gas. At that compression I hope you're running a splash of race fuel or some octane booster because you're right at the limit of safely running 93 octane pump gas.

You said this motor is a Promax SS. Is it a 225, 200, or 150 horsepower? I know they made the SS in a 150 & 225 model; not sure about 200hp. If you have a 225, as I believe everyone has assumed, the rev limiter should be at 6750 rpms (give or take a little as they seem to vary slightly). I don't think you could hit the limiter with the 30" chopper. Maybe, but I doubt it given the weight of your boat. I run a 29" SRX on my XR2001 and I have a stock 1998 225 Promax SS with the limiter removed and a stock fuel curve. I can turn the SRX appoximately 7200 rpms when I string it out. I'd guess that I could turn a 30" chopper about 68-6900 rpm, but my (bare hull) is probably 200 or 300 lbs lighter than yours and my running weight is probably more like 500lbs less. Given those numbers, I don't think you're that far off if you're turning the 30 chopper 6300 rpm.

The thing is that those large pitch props are only good for running high speed after you string it out. Holeshot sucks, mid-range sucks, and on a bass boat it's even worse because of the weight. Get a smaller prop and you'll be happy. Yes, higher rpms are tougher on the motor, but as long as you're not stringing it out at 8000+ all day long, it shouldn't be a problem.

[Larry33kc]

Its a 225 PM. Sorry about that