wanna kick it up a notch

[patches]

Laser injection is the type of injection unit your motor has on it from the factory. The other type of Mercury injection is horn injection that comes on the 260's/280's/drag's

7000 would be fine with the 40 amp stuff since the factory rev limit is already at 6750. Another 250 rpm's would be fine

The idea behind the 1" spacer is to allow the air to have a straighter shot into the motor therefore cutting down on turbulence and increasing airflow speed.

I still think the for the average fishermen using these motors that a little compression bump to make the most of 93 octane and the Brucato ACU are good upgrades for the 225 Promax without going broke. You'll probably get better fuel mileage too. If you wanna turn enough rpm's to need lighter flywheels and different bearings then maybe you should be looking at a 280 instead of the 225 Promax.

 

[Allyfishing]

Thanks patches. I always wondered what that big "horn" was on some engines I have seen on the different boards. I did not know it was fuel injection. I thought it was some sort of air ram for carbs. I'm not a mechanic but am thirsty to learn all this stuff.

I don't mean to infringe on boater777777 questions and post but am curious also since I am having a Promax built and want the most bang for the buck without getting crazy. I have received good advice from here and other boards but keep options open for other interesting add-ons. Since I already have a Brucato SVS/ACU would it be advisable or not to have the 1" spacer put on?

Hoping some of my questions are OK with you boater777777?
Thanks, Craig :beer:

 

[catfish123]

I don't believe the "horn" on 280's has anything to do with fuel injection..........it has to do with air intake. If I'm wrong, I'll stand corrected.

 

[patches]

I just call it horn injection. It's actually just air coming in the front and through the reeds before the fuel is injected in. This is called a dry reed system because there's no fuel in the intake charge when it passes through the reeds. The Laser injection is a wet reed with the injectors in front of the reeds. As far as the 1" spacer on an SVS I can't answer that. In just about all matters Brucato I would punt to Tony Brucato. Great service!!!

 

[Allyfishing]

Gotcha!! Thanks

 

[hullbilly]

Allyfishing,

With the promax, I really think it all depends on what your goals are? A bone stock promax (stock ingnition, stock intake, stock compression, stock side pinned pistons, stock plastic cage bearings, and stock 40amp flywheel) but a well tuned ECU and a TON of setup time can be a potent combination.

It's going to be hard to take advantage of any mods without dealing with the pesky rev limiter. You can prop your boat for the stock limiter, but you're probably looking at a 30p prop. If you want to have a snappy holeshot or possibly do any racing, this is not an option.

I have no experience with the aftermarket add-ons and ecus. I can tell you that my boat had to weigh 2050 lbs with a bone stock promax. The motor turned 8600 rpms all season with a 22p propeller in the 1/4 mile.

Here's a pass at the DSRA World Championship race.

http://s388.photobucket.com/albums/oo325/hullbilly1/?action=view&current=20091003_06.flv

Good Luck!

 

[boater777777]

Can I just get the limiter changed on mine?
Alleyfish ,not a problem you are hinking thing tht help me too

 

[hullbilly]

Can I just get the limiter changed on mine?
Alleyfish ,not a problem you are hinking thing tht help me too

Yep!

Rapair Electronics - Talk to Sean Hill and tell him Mark Screen sent you his way. He's the guy that worked my boxes. He's got a lot of experience with the promax engines/ecus.

I think simon motorsports does promaxes too, although he couldn't a year ago when I was interested.

 

[boater777777]

I just tried the prop slip calclator for hoots. is 3 percent a reasonable entry for slip to estimate speed xpected at 6750 rpm and say 7000?
would 7000 rpm be an expectation to raise mine to?

 

[hullbilly]

I just tried the prop slip calclator for hoots. is 3 percent a reasonable entry for slip to estimate speed xpected at 6750 rpm and say 7000?
would 7000 rpm be an expectation to raise mine to?

3% is low on a heavy boat, although my race setup would get close to that. For recreational purposes, most people use about 6 to 10% slip.

As far as the rev limiter goes, it just all depends on what you want to do.

 

[Allyfishing]

hullbilly, thanks for the advice and the response! Your photobucket album is really cool..Congrats on the wins!

Tooter is building my 225 Promax for me and is leaving it basically stock except for the obvious....oil injection gone, steel cage bearings, vertex pistons, 2 black boxes gone... and putting in a high performance tuner. I think that is it. I was advised by others as well as Tony to leave the 40 amp system on. Tony can set his ACU at whatever I want it. Probably at 7000. I'll call him and find out if he recommends the 1" spacer for his SVS.

I think what boater777777 was saying before is that his Promax is a 2000 year model? Is it a 200 or 225 Promax? Are you having it refreshed or is it still together and running?

Great advice here and great conversation. So you guys recommend he up the rev limiter if his engine still has the oil injection on? Boater777777 do you plan on having it tore down and refresh it? things to think about.

 

[hullbilly]

Failed to mention that my oil injection was removed and I mixed 32:1 when racing. Sorry!

Allyfishing,,,sounds like you're going to have a great engine!

 

[boater777777]

yes mine is a 2000 year 225 PM Still together and running great I just want to get alittle more

 

[F2008]

You can prop your boat for the stock limiter, but you're probably looking at a 30p prop.

If you want to have a snappy holeshot or possibly do any racing, this is not an option.

Uh oh, ... sounds like multiple prop purchases on the horizon. Let me help. I'll help find 'em, you buy 'em. :big grin.

 

[Allyfishing]

LOL....well I hope its not a 30P prop. I already bought a 27P TXP 3 blade. I know hullbilly knows his stuff but I don't have a light XB03. I'm a foot longer and if I am not mistaken 300#'s heavier.

Well Don...start lookin'!! Deal!!

 

[Allyfishing]

yes mine is a 2000 year 225 PM Still together and running great I just want to get alittle more

I am by no means an authority and don't know any more than what I have been told or read but I think the general consensus is when the Promax's are revved too high with all stock internals and oil injection is when trouble starts.

What do you think hullbilly? You said when you race yours is stock and you turn it over 8G. Is that with the stock pistons and plastics cage bearings? I know you said you removed the oil injection.

 

[RedAllison]

I wouldn't worry about building it with 7k-7500 in mind, if you were going to put that motor on a XB02-03 then yeah. But not on the 21 barge. Torque moves this hull when you add the kitchen sink and family, not horsepower. No need in turning it much over 6500, I'd think you would need 24-25" wheels with 1.87s to get it near 7k if you were lucky. Back years ago when I had just gotten my 225SS and the SVS was relatively new I called Tony and asked him if I changed nothing else and just bolted it on what would I gain? He said nothing in outright topend but the midrange and general acceleration would be noticably better. That alone would be something useful on a smallblock powered XB21!

Don't think turbo 4cylinder in a lightweight, think turbo DIESEL in a heavyweight! :at the bar
RA

 

[hullbilly]

I am by no means an authority and don't know any more than what I have been told or read but I think the general consensus is when the Promax's are revved too high with all stock internals and oil injection is when trouble starts.

What do you think hullbilly? You said when you race yours is stock and you turn it over 8G. Is that with the stock pistons and plastics cage bearings? I know you said you removed the oil injection.

Yep, I posted that in post #26.....stock side-pinned pistons, stock plastic cage bearings, stock 40 amp flywheel, stock heads, stock intake & injection system.

Now, I'm not saying metal cage bearings and top pinned pistons won't buy you great insurance, cause they definitely will. I'm just saying that I raced mine completely stock an entire season with a lot of testing at 8600 rpm with no failures. The stock oil injection was removed. Mixed 32:1 with Klotz R-50 (required by racing organization).

I just noticed you have the xb-21. I have no experience with that hull, so please take that into account when considering my data. However, I had to add 180 lbs to my boat for the class I raced in. My boat had to weigh a minimum of 2050 on the scale. I was routinely over 2060. That's pretty darn heavy.

 

[F2008]

You know we're going to try it, my 30 T4X that is, but I agree with Red. I think your motor would have to be pretty stout to spin a 30 on that hull. Maybe, .... we'll have to see.

 

[hullbilly]

You know we're going to try it, my 30 T4X that is, but I agree with Red. I think your motor would have to be pretty stout to spin a 30 on that hull. Maybe, .... we'll have to see.

My comment on a 30p wheel, was based on my experience with the xb2003 and a stock promax, not the xb-21. Sorry.