Asphalt Drag Tips

[SnoDmon]

I just wanted to start a thread where people can share info and tips on asphalt drags. Can people start giving tips and asking questions? I have had a sled set up for 4-5 years now and just sort of ran it how it was, and I know there is a lot of room for improvement. Start firing guys!

Should I start with some of my findings?

-I geared to the top of a Polaris chart - dropped about .5

-I put on 9 or 10 tooth drivers - dropped about another .5

-I don't have an air dam, but I hear they help a lot

-I also heard dual angle and triple angle helix's help on the top end

Now for two of my questions:

-Does lowering the sled help at all?

-What have you guys done for clutching and what has worked?

Thanx, and I hope we can start a great thread!

 

[NROBISON]

I am in the finishing processes of buildin me an asphalt sled right now, just got the seat done last night, motors set, clutch covers built, gearing is done, tank mounted, need to wire it, run cooling lines and finish adding wheels to the rear skid. I went to some drags at the first of the this summer and before i did i was plannin on a hood, bellypan, regular tank and regular seat. When i returned home i changed ideas. Took hood and bellypan off, cut the seat down three inches, mounted a one gallon aluminum tank behind the chaincase and cut my stearing post down 8 inches so now its more of a lay down position. Thats how those guys ran theres and said you dont gain a whole lot unless you are doin competative racing. I already had dropped my suspension 3 inches in the front and rear. Should be ready to roll down the road for tuning in in a week or so. Am runnin a 121x15 track with 21 39 gearing and 8 inch drivers, with a 925 triple polaris motor

 

[snowx22]

asphalt sled

Been Running my 800 polaris here for a little while here, not an expert by any means but can share what I've learned. Gearing and Clutching are going to be dependent on whether your running 1/8th mile or 1/4 mile, and whether your going for all out fastest time or bracket racing. I am running 1/4 miles and bracket racing so consistency is key.

- I lowered my sled with the wahl brothers rear suspension, then lowered the front to match and give a correct angle seemed to pick up some time but maybe only 5 hundreths to a tenth and that wasn't on the same day so not sure if the air was the same
- Air dam in the front- I have run with and without and it doesn't seem to make much difference in the times but on a windy day it seems to go straighter at the top end of the track
- I kept the stock seat shape but lightweight, stock gas tank, stock hood but lightweight with no front vents cut in it. According to the NHRA rulebook sleds are suppose to maintain stock appearance but I'm not sure if anyone really follows that or not.
- I am running 24-35 gearing (9 tooth drivers) and that puts me at about 117-118 at the top end, I am not running over 120 mph, because I don't have full leather suit
-When I first started I found my lauch rpm, and then added weight to the clutch weights until the sled quit going faster, adjusting the clutch spring accordingly to maintain top rpm and what I wanted for engagement.
- I think the straight cut helixes (run a 50 straight on mine) are quite a bit more consistent but maybe don't give you the absolute best et
- I used a car radiator with fan on it, and a bilge pump to cool my sled at the end of the track? not sure if there is a better way but that seems to get the job done

 

[SnoDmon]

Cooling wasn't a big issue for me. I race at a small track where it haas time to cool down. When I first started doing it I would buy two big blocks of ice at any gas station and set those on the running boards once I got to my trailer. I don't think it did much but I had the guys running the staging lanes look at it a couple times, but I explained it was only water and I always have rags in the trunk.

If cooling is a problem: People run quick connectors to a cooler. To set it up, put a quick connector (sorry but I don't know what type) on your main coolant line. Than get another quick connector for your cooler. Run two hoses out of it so they will reach the sled. Drill the cooler out and hook these hoses to a coiled copper tube in the cooler. Seal up the cooler with silicon. Fill the cooler's lines with anti freeze and pack extra in case of spills. Pack your cooler with ice cubes and even your favorite beverages beer and/or lunch. You then have the slickest most efficient way of cooling your sled. Just hook it up and let it run for a few.

Also one thing I have found out is that on a black Cobra windshield, you CANNOT remove shoepolish! After ruining the look of two windshields, I use red electrical tape. Just as easy and way flashier in your choice of a corresponding color. Just dont forget a knife or razor blade on race day.

Happy Racing!

 

[fatguy1]

I am running a 121" X 15" track also and I have always wondered how much MPH I would pick running a 10 5/8", based on the fact it's weight is a lot less?

Deep thoughts by Fatguy1

 

[pstock800]

cool down

easy cool down cart.
take a snowmobile heat exchanger in the bottonm of a cooler. with a pump. '
the quick connectors are made by CPC. you can get them from HPI. i raced on the grass for a few years and it was a quick way to cool the sled down. bags of ice in the cooler. works good

 

[pstock800]

track

smaller track is not always better. more apt to break away. its like running on a motocycle tire. it is easer to keep the sled straight with a 15w track

 

[SnoDmon]

I like that pump idea. How big of one does a guy need? Also the snowmobile cooler seems simpler than coiling up your own copper tubing.

Can you post a website as to where to purchase those connectors? I don't know what HPI is...

Keep 'em comin'!

 

[snowx22]

asphalt

You can get the quick connects from Wahl Brothers Racing in Northern MN too, www.wahlracing.com They are the same CPC ones, and are about 30 bucks a set and you will need two sets, one for the sled and one for the cooler set-up. They seem expensive but if you try to go cheaper and use garden hose quick connects, they just don't last. Spend the money up front and get the good quick connects and they will last a long time and are less of a mess. Buy some extra O-rings for them though, I seem to go through an o-ring every couple races.

What I am running is a car radiator with a fan and marine bilge pump (25 bucks at the local hardware store) all set up on a little red wagon. Then hoses that come out of the radiator with quick connects that connect to the rear cooler lines on my sled. Hook the pump and fan together and then to your pick-up battery with alligator clips and away you go. It works good, cools the sled in 5-6 mins and you never have to buy ice or worry about how long your ice is going to last if you get a hot day and start going a lot of rounds.

 

[maluchm]

A cool down cart is a good idea so you don't heat soak the motor. Even a fan on the clutches to cool them between runs. My cool down cart was a cheap tool cart on wheels that had a radiator with a fan, small pump and a deep cycle battery. It worked great and it didn't create a drastic temperature change like the ice might. The pump you can use a Harbor Freight pump or even a good RV style pump. If you are using the stock suspension I'd strap it down front and back. As for the track I'd suggest the 10.625 x 128. Not many people use the 15 wide anymore. Air damn is really necessary if you're just going out to have fun. Also, soak down the track with WD40 to soften it up for a better bit or get some VHT if you can.

Do you have access to a track dyno?

 

[XLR8ER]

go to
us plastics .com for your connectors-way less expensive

 

[NROBISON]

Just finished the drag sled build. Hopin to get it out today and tune it somewhat. I cant wait to ride sleds again. Its been far to long since i quit, memorial day was my last ride this year.

 

[NROBISON]

Got the drag sled goin last night and took it out for its first run up the road. Need to get the rear skid to transfer some more but other than that it ran fantastic. It was nice to beable to get on a sled in july. All the work i did to get it goin finally paid off. The hookup, the pull and the speed are all worth the work. If anyone ever asked if its worth buildin one, i would say totally worth it

 

[SnoDmon]

That sled is low man! Is that like right out in front of your house in town?? I at least took mine to a quiet highway a couple miles outta town to test things out. LOL

 

[NROBISON]

Ok, now i have a question. I moved the rear mounting bolt in the rear skid forward about 3/4 of an inch and tightened up my rear springs and now it packs the skis about 8 inches off the ground but seems to transfer to much cause it bobbles about 4 times before it finally sticks and hookes up 100 percent. I thought what i did was a small adjustment but its night and day difference. So my question is, should i move my bolts back to the origional possition or loosin my springs. Im lookin for a gradual pull up of the front end, not a fast pull up so hard i loose traction and it bobbles.

 

[SnoDmon]

Was that a MTN sled to begin with. If so find out what the bolt spacing should be on the 121" skid and drill 'em to that. I have had mine in so many places, its ridiculous. The first year it was solid, but now I have it transfering about right. If I want to jump on the back it will drag the bumper

 

[SnoDmon]

Oh YA! DRAG RACES IN LEWISTOWN, MT THIS WEEKEND - JULY 11th & 12th

Big Buck Shoutout on Sunday.

Bring your drag sleds!!!

 

[maluchm]

Ok, now i have a question. I moved the rear mounting bolt in the rear skid forward about 3/4 of an inch and tightened up my rear springs and now it packs the skis about 8 inches off the ground but seems to transfer to much cause it bobbles about 4 times before it finally sticks and hookes up 100 percent. I thought what i did was a small adjustment but its night and day difference. So my question is, should i move my bolts back to the origional possition or loosin my springs. Im lookin for a gradual pull up of the front end, not a fast pull up so hard i loose traction and it bobbles.

You don't want the sled to porpoise off the line, that will kill your 60ft.

 

[NROBISON]

Thanks fellas. I got lookin and my front limiter strap was tight when the skid was out of the sled but when it was in with someone on it it wasnt so i tightened it up and now it works perfect. Ya its a 96 polaris ultra 680 mtn chassis. I just ride it out in front of my house, i have tried to think of a place to test and tune it but cant come up with anywhere so i only ride it up and down the road two or three times. Its unbeliveable the feeling i get, it just ****s and gets.

 

[NROBISON]

How high is everyones skies comin up when they stab it from a dead stop? And for how long untill they drop all the way down to the pavement?