1976/1996 Polaris Ultra Custom

What was your intended objective when you started the build?

Build something cheap and different that would get into the 12’s, Its actually at 11.61 @ 106 mph right now. Plenty to improve on

What motivated you to start your project?

Tired of grass drag and ice races that always fell apart here. Went to asphalt. Track is open 6 days a week, 9 months of the year. 45 min. from my door

What was the most unique and creative thing you did to the sled?

I have a 81 SRV trail sled with a 90 HP engine. It weighs in at 470 lbs. I wanted something lighter. This one started with an Ultra chassis that we cut off everything forward of the ft bulkhead. Made a Yamaha style front axle out of Alum to look like SRV them fabricated some very small struts that used Pri clutch springs to again appear Yamaha and fit correctly in the Yamie hood. Everything not needed was removed. End result, it weighs 358 LBS.We then made mounts to put on all the 86 SRV body work handle bar pads, gas tank cover seat etc. Honestly with the hood closed almost no one knows its not a stock SRV.

What are you most proud of?

Getting it done LOL

What do other people say about your sled?

They seem to like it mostly because its different from everything else out there.

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Submitted by: Bob V

Specifics

Make, Model & Year: 1976/1996 Polaris Ultra Custom

Fondly known as: Spare Parts

Time spent: 3 months, mostly full time

Sled cost: Nothing

Money spent: I honestly have $800. in actual cash

Engine: It honestly started as a fan cooled 535 SRV engine. Everything in it has been modified. It has SkiDoo 670 pistons and is now 617 cc's. Cyls have been welded solid, big V Force 3 reed cages welded on. Rear transfers open into the reed cages. Cases milled down and a 1/2 in spacer plate made to ease the flow into the cyls. Ports were all welded up and reconfigured. It now dynos at 117. This engine was originally made for a USSA oval class called Pro Sprint 600. Rules called for Fan cooled, 600cc's, single pipe, with stock 34 mm carbs to keep speed down. My kid won at Eagle River in 2013 with this engine in a Champ chassis. Engine was built around 10 years ago.

Intake: It still has the stock 34 mm carbs on it now. For bracket racing the small carbs are very consistent. I might move to a set of 39.5 taper bores which is what my other sleds run. One of my concerns was keeping it cool when running rounds in summer bracket racing. I didn't finish it until fall, and so far not a problem. If it does start to get hot, I will switch over to alcohol as fuel.

Exhaust: Custom made single race pipe

Drivetrain: Pol. primary, A/C roller sec. 10.5 x 121 rubber asphalt track.

Tunnel/Chassis Modifications: Actual rear tunnel is Pol. Ultra. Skid is laser cut, custom with all wheels.

Suspension: Everything is custom made

Brakes: Pol. hyd

Finish - Paint: I spent 30 years as a air brush artist doing custom paint full time. Oddly ( all my other sleds are full custom paint), this on only has the faded red/orange/yellow background out of paint. I designed the logos on a computer and printed them on Carbon fiber looking vinyl. That and all lettering is under the final clear coats. It also has our company logo computer stitched into the seat, which my wife made.

Accessories: AIM/MyChron, EVO4, 20 channel data system with GPS. It records rpm, egt, a/f, head temps, GPS speed, jackshaft speed, and carb intake temps. All this is Wifi fed to a computer in the trailer and can be displayed as graphs including over lays of previous runs. It also has a tri axle accelerometer, which reads out G force down the track

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