Xb 2003 2.5 280 best set up for top end ?
- Thread starter PaulyB
- Start date
aj06bolt12r
Active Member
An RE4 is not going to be the best prop for top end most likely...
You are going to want a 3 blade for that.
28 or 30 pitch will probably be about right for a 280 if you don't have a bunch of extra weight in the boat. Maybe even a 26p if you are turning some RPM..
A Hoss Triton, ET, RE3 or a cut Chopper are probably going to be your best bet for an all out top end prop.
Prop height depends the condition of the lip on your pad and how much setback you are running.. Assuming the lip is not modified and assuming you are running about 14" of setback like most XB03's you are going to want you prop center line about 1/4" below the pad... You might creep up a little from there as you are getting dialed in and trying for that last few MPH.. This is also a good way to get thrown out of the boat.. Don't know how much experience you have in Allison boats but they will hook and spit you out in the literal blink of an eye.
You are going to want a 3 blade for that.
28 or 30 pitch will probably be about right for a 280 if you don't have a bunch of extra weight in the boat. Maybe even a 26p if you are turning some RPM..
A Hoss Triton, ET, RE3 or a cut Chopper are probably going to be your best bet for an all out top end prop.
Prop height depends the condition of the lip on your pad and how much setback you are running.. Assuming the lip is not modified and assuming you are running about 14" of setback like most XB03's you are going to want you prop center line about 1/4" below the pad... You might creep up a little from there as you are getting dialed in and trying for that last few MPH.. This is also a good way to get thrown out of the boat.. Don't know how much experience you have in Allison boats but they will hook and spit you out in the literal blink of an eye.
Thanks for the info my last boat was a 20xd with 280 then I got allison fever lol. I've been so used to flyin the nose and running alot above the pad in the bullet the allison is a big change. I appreciate the info I started out with a 28p 3 blade big ear chopper and it got a small burr thus the reason running the re4. I ve ran the boat to low 90s several times but been afraid to go any further cause it starts feeling a lil loose
aj06bolt12r
Active Member
I'd send that 28 chopper you have to Billy Eaves and tell him what you have and what you are trying to do.. He will fix you up.. That should be good for low triple digits with that 280. Ive got a 28big ear chopper as well, with a "hoss cut".. Its my favorite prop, drives awesome, very low slip numbers and carries the bow no matter what, but my pad has no lip. People on this board are going to need to know the details on the setup you currently have to help you much more.. Most importantly the condition of the lip, current setback and PTP.. Which LU and if any mods have been done to it.
aj06bolt12r
Active Member
Cool good deal.. The lip is very small even from the factory.. But it makes a huge difference in how the boat reacts to trim and engine height changes and trying to slow down from high speeds.. A lot of people end up with boats with modified or removed lips due to the lip getting damaged or because they want to lessen the effects of the lip. Very hotly debated subject among Allison owners.. Id suggest measuring exactly how much lip you do have.. Will need that info to give you engine height recommendations... If the lip is in fact stock and you are running 1/2" above pad that is considered way too high and you are flirting with blow out and hooking the boat. Might be why it felt so loose once you started getting some good speed up.
You might already know this but I'm going to assume you don't and tell you anyway.
To measure how much lip you have....Take a straight edge and place it on the pad. One end of the straight edge should be on the lip and the other end on the flat part of the pad running parallel with the boat... Then take some feeler gauges or a set of drill bits and a dial caliper if you have a good assortment of small drill bits and measure what the gap is between the straight edge and the pad right up against the lip in the middle of the pad. If its stock it should measure around .060"
To measure engine height... Put a level on the pad of the boat, not on the lip but in front of the lip. Use the trailer jack to get the boat level. Then take the level and put it on top of the flywheel of the engine. Use your trim switch to level the engine.. You are now at neutral trim.. Might want to take note of where that is on your trim gauge and mark it with a sharpie or something just for reference while you are driving.. With the boat and the engine level take a self leveling lazer level and put it on a floor jack.. Jack it up until the lazer light is hitting dead center on the back of your prop shaft... Then take a tape measure and see how far above or below pad the lazer light is pointing.. That is your prop to pad engine height.
Let us know!
PS.. I'm not an expert... I've never been over 93 in my boat myself, hopefully that will change this spring... I just read a lot...
You might already know this but I'm going to assume you don't and tell you anyway.
To measure how much lip you have....Take a straight edge and place it on the pad. One end of the straight edge should be on the lip and the other end on the flat part of the pad running parallel with the boat... Then take some feeler gauges or a set of drill bits and a dial caliper if you have a good assortment of small drill bits and measure what the gap is between the straight edge and the pad right up against the lip in the middle of the pad. If its stock it should measure around .060"
To measure engine height... Put a level on the pad of the boat, not on the lip but in front of the lip. Use the trailer jack to get the boat level. Then take the level and put it on top of the flywheel of the engine. Use your trim switch to level the engine.. You are now at neutral trim.. Might want to take note of where that is on your trim gauge and mark it with a sharpie or something just for reference while you are driving.. With the boat and the engine level take a self leveling lazer level and put it on a floor jack.. Jack it up until the lazer light is hitting dead center on the back of your prop shaft... Then take a tape measure and see how far above or below pad the lazer light is pointing.. That is your prop to pad engine height.
Let us know!
PS.. I'm not an expert... I've never been over 93 in my boat myself, hopefully that will change this spring... I just read a lot...
whipper
Well-Known Member
30 is going to be fastest but top end will be probably more than you want yet. A 28 drag 3 is a very nice prop on an 03 with a 2 stroke.
Eaves cuts a mean chopper for Allisons and over the counter stock performance 28 DR3 are great also some like to add a tiny bit of cup to them. i like mine stock. 1/4 to 1/8th below as mentioned is always good. The higher ya go the faster ya go until it blows out. haha So always make sure every bump you gain rpm. Because if you dont above 85 your going to need to bump back were ya did. :]
Eaves cuts a mean chopper for Allisons and over the counter stock performance 28 DR3 are great also some like to add a tiny bit of cup to them. i like mine stock. 1/4 to 1/8th below as mentioned is always good. The higher ya go the faster ya go until it blows out. haha So always make sure every bump you gain rpm. Because if you dont above 85 your going to need to bump back were ya did. :]
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aj06bolt12r
Active Member
Whipper has been around a while and he knows whats up! I probably read 1000 Whipper posts on Allison setup, props, driving ect...
Glad your still on here posting and keeping this forum alive!
whipper
Well-Known Member
HaHa Thanks. Every time I think I need a bigger boat im reminded on those days your the only one on the lake and that feeling of speed on water and how ya got there in an Allison. Since they are guaranteed for life and will never rot its hard to settle for less or a boat this size thats needs more power to be not as quick. haha Other than needing new seat covers she is still mint after 24 years. :]
aj06bolt12r
Active Member
Thats awesome Whipper! You still running that same Promax?
The only thing I know of that could tempt me away from an Allison might be a Tuff 24... But they are $$ and I dont want to give up the ability to fish out of mine.. My buddy and I just fished a tournament out of my old XB03 a couple of weeks ago.
whipper
Well-Known Member
Yep still the same 225 pm. lol :]