I am confused as to why I can go 85.5 mph turning a 27 tempest @ 6400 rpms with a TM case 1:75 gears, .5" below pad, and others on here are going 82-84 mph with same set up but a different prop and only turning 56-5800 rpms.
My boat is a 21xd with a 250xb modded, 14" setback.
This is tourney load 1 guy and 1/2 tank of fuel.
I also have a 27 PT TRO4 which runs only 83 mph @ 6300 rpms.
Why am I not going allot faster if I am turning allot more rpms. I need help.
Um...Slippage? Need more cup? Not really a 27? Tach needs to be calibrated? Just my 2 cents. My wife says I have none. "Cents" that is.
Jas 4:8 Draw nigh to God, and he will draw nigh to you.....
All good questions but I don't know. What does your run
What has been modded/done to the XB? Those numbers sound a little off to me
cowl mod, 300 pm heads, and ecu, poppet valve, hydrotech tuner, lightweight flywheel
One thing is your running 1.75 gears and a 27 in prop.
I run 26,to 28 (according to which prop)on mine with 1.62 gears.
Do they have rehab for this addiction,cause I need to go!!!!!!!!!!!
What is your rev limiter set at now after the HT mods??
I would have to think you can turn a 29 or 30 pitch prop to 6300 with the XB and 1.75 gears
Do you have a bud around there that has a few taller wheels you can try??
Are your speeds consistant??
Do you have most of the weight to the back of the boat (not much tackle up front)
Is the boat balanced out when your in the drivers seat?
i have a buddy that had the same setup with close to the same mods. the boat would run 80mph with him driving. 78-79 2 people fishing load. i'm sure he will chime in. he had the same questions as you.
20XRD COMP/300X
26 or 27 hydromotive was the best running prop on is rig
20XRD COMP/300X
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by bayoubullet »</td></tr><tr><td class="quote">26 or 27 hydromotive was the best running prop on is rig</td></tr></table>
I had that same set up. Minus the flywheel and the heads, with 15" of setback instead of 14
The best I ever ran was 84.2 by myself with a fishing load and about 1/4 fuel, no watr in the wells.. That was with a worked 26 Trophy at a little over 6300 R's That was a one time number. The motor was to high and wouldn't hold the nose very well in turns with this prop. I would never run another trophy on any of my set ups cause they sling ears
My best fishing prop was a 27 Hydromotive. It had amazing lift an awesome holeshot and would hold the boat up at the same height the trophy was at no matter what. The best number with it was 83.8 and that was with bayoubullet running it by himself with full livewells and full gas with fishing load. I turned it to a little over 82 by myself with the same load(I weigh 350lbs) add another person in the boat same load and I could run 80 any given day and on occasion 81-82. I believe I was turning it a little over 6000 it has been a while since I ran it.
I would have to agree with Lou on the 29 Hydro with the heads and the flywheel you should have enough grunt to turn a big wheel. I was also told that the XB makes it's peak power between 6100-6300 r's
Don't beat yourself up over some of the numbers you see here. I found alot of the numbers flying around were one time numbers and not fishing loaded.
Hope this helps a little
SUSHII
21XRS/SHO
Thats a 90mph boat with the right set up. Nose cone and 1.75 gears I would be looking for a 28/29 Bravo dual PVS holes re raked and re pitched.
Put all your lead and heavy plastics in the back of the boat. Keep all your crank baits and misc lighter stuff in the front of the boat. Make sure the boat is balanced from side to side while up and running.
Then move onto motor height.
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Hydrilla »</td></tr><tr><td class="quote">Thats a 90mph boat with the right set up. </td></tr></table>
to fish or top end #?
SUSHII
21XRS/SHO
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by SUSHII »</td></tr><tr><td class="quote">
to fish or top end #?
</td></tr></table>
87/89 with fishing load 90+ light.
That motor I believe makes 272.014636 hp Stock and with those mods I should put him at 305-310.255432 if he has a strong one.
I called a friend of mine to check my thinking. He had a stock 21xd/250xb that would run 86 light. He feels the same and is the one who knows about those mods on XB.
I believe Paul ran a 21xdc/250xb all stock to 90.?? with a 29"
yeah I wasn't doubting it. Was just wondering. I know they pump some power, and with the mods he has done I know that bad boy is putting out some power. I wish I would have had more time and moola to mess with mine.
you didn't have to pull out the "phone a friend" option on me
SUSHII
21XRS/SHO
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by SUSHII »</td></tr><tr><td class="quote">yeah I wasn't doubting it. Was just wondering. I know they pump some power, and with the mods he has done I know that bad boy is putting out some power. I wish I would have had more time and moola to mess with mine.
you didn't have to pull out the "phone a friend" option on me
Your XB sounded nasty in that vid for sure
Don't forget this is just my opinion. This particular boat may never see over 86. Its just one of those things...
Lou I have no one around turning a prop that big, my rev limiter is set at 6450 as this is the promax 300 ecu limit or so I am told.
Ran tourney loaded 2 guys full tank of gas yesterday it fluctuated between 80.5 and 82.5 seemed to jump up and down, I think I have alot of prop slip but can't figure out to to fix it, more cup in the prop ??
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by bass bullet »</td></tr><tr><td class="quote">All good questions but I don't know. What does your run </td></tr></table>
The best I've done in mine was just over 85 with a 28 Pro ET. The norm for mine with 2 peeps and a fishing load is right at 80. You might want to try a lil more cup (sounds like) These fellers know more than me though.
Jas 4:8 Draw nigh to God, and he will draw nigh to you.....
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by bass bullet »</td></tr><tr><td class="quote">
Ran tourney loaded 2 guys full tank of gas yesterday it fluctuated between 80.5 and 82.5 seemed to jump up and down, I think I have alot of prop slip but can't figure out to to fix it, more cup in the prop ??</td></tr></table>
Where you running the TXP OT4 when this happened.. That is a lot of up and down speed varience, did it pick up in speed when air got under the hull (wind).. Or were you hitting the limiter and didn't know it??
I'm just thinking that the prop you ran with the load may need to droped 1/4" on the plate for better bite, tip cupping will also help you may need to go up one pitch as well.. Also some boats do need a little more set back then others..
Use the prop calculator pinned up top to ck your slip..
I was running my A45 tempest 27 pitch at .5" below pad, 14" of setback. It was flat calm so when I did hit a little ripple it helped, I was also running about a half mile behind another boat, so I was running in his water as well, so maybe that was a bit dirty and not good bite.
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