battery location in XR

[2fast4mom]

I noticed my XR handled MUCH better with lead shot bags up front. Darris then told me that the whole reason he put the quickrelease front cowl on the XR was so that the battery could be mounted up front. This is where Darrris intended the battery to be, to bring the bow down fast at holeshot.

Glenn Reynolds concurred with this and further advised me to strap the battery down good - so if the unfortunate happens and the boat goes sideways or upside down, I won't be eating the battery. I went to a lot of trouble to do this, installing bronze strap times with stainless bolts thru the kickpanel and front stringer. The battery is mounted in a Gaffrig billet Optima box. Check it out from this cellphone picture:

Today I ran #2 gauge wires to the rear compartment, on the port side, for a net weight gain of 6 lbs. They are on the floor just outside the cockpit, they ran very easily and I tied them to a terminal block I got at Allison last summer.

I was wondering how many of you run your battery up front, or where do you have them mounted?

Thanks

Lou

 

[RedAllison]

GREAT WORK LLDOGGG, I want that beyatch PERFECT when you bring it to me for the TN Rally!!! :beer: :beer:

:big grin :big grin
RA

 

[XXXR2001]

I've never seen one mounted up front. I have my batteries mounted behind the back seat and up against the divider. All the XR2001's I've seen have had the batteries mounted near the divider, either in front or behind. I would think the front hatch was designed so that the boat could be rigged (i.e.: steering, gauges, etc.).
Please let us know how the boat handles with the battery located up front. I'm very interested in hearing how she drives with the weight up there. I've tried putting 25lbs of weight up there before and my boat didn't handle very well but everyones boat is different and it might be the ticket for you.

 

[john4utvols]

My 04 drag has one battery up front and a place for another one, I thought it handled better than any Allison I have ever drove, we got it up to 110, but I have never been in one with the battery in the back. i will take some pics and post later.

 

[2fast4mom]

My boat porpoised terribly with the battery in the back, right behind the dividing bulkhead. When I added 50 # of lead shot to the front, she handled like a dream and the porpoising at high speed went completely away.

That porpoising at high speed was butt-puckering. It would LEAP out of the water at speeds past 70 and no way to control it with trim either up or down. The weight up front cured it.

When I told Darris about the porpoising the first thing he asked me was, "where do you have your battery?" He allowed that it also will help holeshot because when it jumps out of the water the weight in the bow will settle her down faster. We will see.

Now I have the battery up front and have removed, of course, that much weight from right behind the rear bulkhead. I will test her Tuesday morning (before I leave for the WAR) and let yall know what happens!

Thanks

Lou

 

[john4utvols]

Lou here is a pic of mine.

 

[2fast4mom]

Thanks John, that looks purty much exactly where mine is. My box is 4" ahead of the kickboard.

 

[Rocket]

Interesting thread here for sure guys!

FYI,,,,, Our Battery's are mounted in the back almost to the transum,,, and as close to center as they can go,,,,,,,

 

[2fast4mom]

Rocket, where else is the weight distributed in your boat? Obviously the fuel cell is in the rear, do you carry any forward ballast of any kind?

Thanks!

Lou

 

[john4utvols]

I was talking with casey, yesterday and his is behind the passenger seat. Lou how much set back are you running, mine is 9'', and this is why I believe the battery is in front. If I ever swap it to 6'' I will probably have to move my battery back behind the passenger.

 

[2fast4mom]

I am running 6.25" of setback. The propshaft is high at around 7/16" above the pad.

What size fuel cell are you guys running? Mine is large (relatively speaking) at 20 or more gallons. This may be the source of my imbalance. When the tank is full, that is substantially more weight back there than when it's say 1/2 full.

The large tank when full will put lots more weight towards the rear, that maybe is why I have the world's fastest porpoise unless the nose is weighted down with bags of lead shot.

The battery was back with the fuel tank too, now it's up front, I'm going to run her Tuesday morning with a full tank and see how she goes.

When I won the WAR 2005 drag races against Badbait and Pinkie, I was running 50# of lead shot up front PLUS a full tank and battery in the rear. The boat never gave a hint of porpoising when rigged like that. The only other difference now is that I have a Titus 200 case on, and back then I was running a borrowed / modified CLE.

These XR boats are extremely weight sensitive and not only side to side but front to rear too, I am convinced.

Lou

 

[badbait]

Lou, if your boat doesn't already have foam in the tank you should consider putting it in. This will really help with the sloshing back and forth and side to side with that size tank. It's a special foam, open cell I beleave that's made for that. I have some I was going to put in the White SS tank but sold the boat before getting the job done. It cuts down on the capacity a little but that won't be a problem for your application.

 

[2fast4mom]

Thanks Bill that's a good idea.

 

[2fast4mom]

Well the porpoising problem was pretty much completely eliminated by moving the battery up front. Today I took her out despite some awful wind at the lake and at first with a 26ET she behaved completely different than last time, the boat had real good manners and drove like you would expect, lean to left when under trimmed and trimming up until the horizon of the lake was level with the cockpit the boat showed no desire to leap uncontrollably out of the water.

I then went back to the ramp and switched out to the Hoss Triton 24 and went over to Spanish Flat where the water was calmer and ticked off this in around a quarter mile:

This was at 9000-9200 rpm so right at around 7-8% prop slip I figure?

 

[Rocket]

Rocket, where else is the weight distributed in your boat? Obviously the fuel cell is in the rear, do you carry any forward ballast of any kind?

Thanks!

Lou

Just my BIG BUTT! :laughing

No really, We have nothing in front of the Fuel cell except me, Everything is in the Back,,,,,, Heck, I'm lucky if Jim lets me carry a water bottle in front with me! :laughing

 

[Casey G]

here's how my boat is set-up. my trim pump is bolted on the center port stringer about six inches forward of the transom and the fuel pump and filter are directly across from it on the starboard stringer. my 12 gal fuel cell is mounted up against the rear bulkhead and my 3 Odyssey's(one 1200 and two 680's) are mounted right in front of the rear bulkhead. for pro gas I place four 25# bags of lead next to the batteries, but still behind the rear seat.

 

[Larry D]

My boat is set up to run modified production and prostock. I don't change the set up from one class to the other. Trim pump is bolted to the transom, 8 gal fuel cell behind the bulk head. 2 1000 cc bateries in front the bulk head, 80lbs of weight, 40 on each side as close to the transom as possible. nothing in the front except me. Just lucky i guess no problems what so ever. later Larry D

 

[jim brinkley]

Weight distribution in an XR is very critical. Hell, I go into the boat and find bottles of water half full and throw them out. LOL It also depends on what prop you are trying to run. Most all of us are running Yamaha or Yamaha type props. Props make a difference also. Everyone on here that has tried to answer your question are running very hard and competive in their classes. Balance is the most important thing. I don't even want Rocket to eat before a race. LOL Just kidding.

Jim

 

[Waterdigger]

Ive watched Rocket's,Casey and Larry D. race their xr's with no handling
problems.....they go down the track on a STRING!

mike

 

[2fast4mom]

Well guys I had my arse handed to me by Bill Smith's STV at the WAR this weekend running idle start 1,000 foot track. I have serious room for improvement - my main problem is consistency. I am looking for any help I can get from the experienced XR2001 runners.

My main / ONLY problem is at holeshot. She jumps and dives and repeats that process twice before I get her up and hauling. After that nothing can stop her trimmed up - pulls MEAN through the midrange and finish and nothing can catch me there...well, not in this class anyway....but Badbait got me on the holeshot and maintained a 1 to 1.5 boat length lead to the finish.

I know there is room for improvement with this boat and as usual, the main problem is the "nut behind the wheel". :idiot

The day after I practiced many runs and found that the best trim "launch" position was NOT full tuck but just slightly under level trim (just slightly negative). This seemed to reduce the "jump, dive" problem. Am I on the right track?

Bill beat me fair and square so it's now time for me to get to work for next year!! banghead

PS, yall have talked abut the only weight up front is yourselves, but having never met most of you I have no idea what kind of weights we are talking about, it would be helpful if we posted driver weights. I am about 215, 6'1".