Anyone Good that races i mxr 450 i have??'s

[hein886]

Would you go wider?(axle/A-arms)
Did you go wider?
What kind of pipe do you have?
Handle bar riser or new steering stem?

And any tips would be nice




These questions are for a Experienced racer that owns a mxr 450 not a 525. I don't need someone telling me what works if they only ride trails...

Thanks

[Colby@C&DRacing]

I have a mxr450 and race XC. The 450 need to be narrowed up for XC racing. If you only race MX the stock width will work really well once you lower the quad. The factory shocks are to long and need to be shorten for proper performance. I am using am HMF elliptical slipon. The 450 made 32 HP stock on our dyno and 37 HP with the slipon and the proper jetting.

[hein886]

Do you use JD jet kits, someone else, or your own jetting.

[Polaris 450MXR]

Anything to post would be great. I would like some info on this as well. I am running the Prod B class in NEATV-MX and need to keep shocks stock but can make any other mod to engine internals. Stock airbox and Exhaust. Sag info would be great. i think i vave read someware that front should be like 90%and Back like 80% ? Does this sound right? Riding mine i feal like it has a very high center of gravity but flies very nimble(easy to manouver). Any Ideas how to make the setup better for racing would be great. I am contimplateing going full bore mods (a-arms-Axel-Front air shocks and exhaust) Love to see how other MX Outlaws are dealing with some of the above issues.

[baldwinmx450r]

A full report on my outlaw will be done here shortly. I'll be contesting the WPSA A, 16-24 and select Pro Am events on my factory backed outlaw 450 this year (I received a factory sponsorship :-)

We headed over to TC Racing to start on the motor. And got hooked up with a exhaust system. We modified the current airbox to allow more airflow and jetted accordingly. We were going with a clamp on filter style, but decided to mod the stock box, this way we can tape it up if we encounter a muddy race.

We are going wide with this bike, out to the 50" legal limit. Lone Star Racing has Supplied me with an adjustable Excalibur axle, The stock alum hubs are great so are running them. LSR has also set set me up with a stock length steering stem set up with a set of Flexx Bars. I will also be bolting on a Lone Star Racing DC4 Long Travel Front End.

The suspension will be handled by PEP PB1's on the front and rear. At the moment I am running my ride height at about 6.5 inches, Which is close to what I will run with the PEP's as well. The stock shocks are very good, with thier ZPS Setup.

We are running the bike with a stock motor for the ballance GNC. We are going to see where we stand in the power department. If I feel we need a bit more. Tom will head back in and start on porting

If you have anymore motocross spcific quesitons feel free to ask. I was skeptical when I first got the machine. but after working on it and riding it, i am confident that this is a podium capable machine.

Also you need to make some sort of rear fender braces. the fenders will crack under extreme MX riding. LSR will be making some this season, but they are still in testing stages.

[baldwinmx450r]

One more thing you must add a PRECISION STEERING STABILIZER!! the front ends are super nimble and a quality stabilizer is a must

[525 Outlaw Dude]

One thing i've custom done to my 525irs (shear i'd work on the 450's) is take a K&N Outer Wear cover and cut clean squars on the side's, back, and bottom of the air box and take a good heavy-Duty adhesive and cut the Outer Wear to fit the squars, But make shear that the outer wear is atleast 1/4 inch past the squars corners so its a strong hold!!! free's up some usable Hp and another is the EHS Racing lid (it helps for Hp too)

http://www.ehsracing.com/catalog/product_info.php?cPath=21_27&products_id=248

[azza450]

This is my first post on the forum, it's good to share info with other Polaris owners, some good tips and tricks on here.

I race ATV MX at pro level in Australia, for a two man team with backing from Polaris Australia, Luke Beechey Motorsports and various other sponsors.

I've been riding my MXR 450 for a around 6 weeks now and have found it to be a pretty impressive machine, but have encountered a few small issues. As far as mods go for MX I'd be happy to add my 2 cents, would modify the following.

Rear rims struggle especially at 9 inches, lasted two rides, upgraded to 8 inch Douglas beadlockers and have had no problems. Front rims seem good. Bar risers and Pro Tapers have set the steering at a perfect height for me. I run a HMF slipon pipe with modified airbox, jetted accordingly which really woke the motor up. Rear fender braces are a must, mine are just made out of steel, nothing special. Also trim the front plastics before they crack on the inside of the front gaurds.

The stock front shocks are awesome but be careful when introducing sag into the front end, make sure there isn't any spring float with the front wheels off the ground or the spacer between the two springs can smash, then the lower spring saddle will dislodge, I found this out the hard way. The stock rear shock rezzie is too close to the exhaust which causes some overheating problems in long motos, 15 mins plus.

My race bike was first set up with stock shocks (now PB1's), Rath A-arms and Excalibur axle. The front shocks were more plush and worked heaps better on the Rath arms. The bike was much more predictable, stock width feels nervous when pushed hard, but keeps you on your toes and heaps of fun!!

I have smashed two of the rear aluminium hubs on rough hard packed tracks, something I'm a little concerned about, I'd highly recommend Lonestar hubs.

I can't really help you out in the motor department, your US motors are a lot more highly tuned and use race fuel, but our capacity limits are higher, my race bike is a 540.

Hope this helps.

[baldwinmx450r]

Lone star is not making rear hubs, only front hubs

[Polaris 450MXR]

Just set my quad with 80% sag in the rear and 90% in the front that still leaves me about 9" under the front of the motor. You had mentioned 6" how do you get that low? When I first got my bike last year it seamed very good but a little high so I set my springs to the lowest setting but seemed to bottom out a lot so I have reset to the 80/90 split but I would really like to be lower but do not see how and still maintaining the travel that is available. I also saw some ware here that with the side mount exhaust it is possible to modify the rear shock to reduce height by an inch and gain an inch of travel. Is this a simple revalve?

[baldwinmx450r]

You are prolly measuring at the wrong location. you take two measurments. one where the frame flattens out, usually by the front motor. and at the rear of the frame, your measurements should be very close to the 6 and 7 inch mark. to adjust the ride height you must change the preload on your shocks. You shoulden't have to move the pipe to alter the shock. Any suspension builder should be able to shorten the rear shock. You would most likley have to install a smaller shaft and smaller springs

[Colby@C&DRacing]

To achieve the proper ride height with the stock shocks the bodies must be cut, they are to long from the factory and are limiting the performance of this atv. My 450 with XC tires on it is 7.5" off the ground and still have more travel than stock after we modified the shaft travel. We also converted teh front shocks to a triple rate and the resprung the rear shock. I agree with the fender bracket this is a must my fenders braoke after the first ride. I am using and HMF slipon with no lid and re jetted the carb std jets. Our 450 gained 5 peak HP on our dyno with these mods. Once our full XC build is done on this atv there will be an article on the home page.

[outlaw450mxr]

how much would it be to do that stuff to the shocks but not for xc for mx?