traction aid

[67Dart383]

Last night we ran our 2nd quickest time 12.90 at 107 mph, we know it'll go faster but we working on driving skills and 60ft times which was 2.08 on that run . our best time is 12.82 and best 60ft was 2.00. We are traction limited by BFG's 225/60/15 , just trying to find a sweetspot with what we got. Last night we had rear tires  at 20 lbs and airshocks at 35. Car does not seem to transfer wt properly. Body does not squat when launching or rise up much in front. Any tips on what we can do to improve 60ft without going to drag radials or slicks.We want to get it to hook the best it can with real street tires. The car has a rake,  behind front tire 91/2" and in front tire 11" between body and ground.      Thanks

[Capt Jack]

first things that come to mind are

1) shed some weight or at least relocate it to the rear wheels. 
2) you can go up a little on the front tire pressure to reduce rolling resistance, but the gains from that will be minor at best.  usually shows up more on the high end
3) be careful going too low pressure on the rear street tires.  it can decrease the footprint and actually reduce traction in some cases and with some tires
4) might try skipping the bleach box.  just burn em enough to dry the tires real good and go.  not all street tires react well to being overheated although from what Ive heard the BFG's are pretty forgiving in that depending on which ones they are.  treaded tires also tend to hold onto the water from the box fouling a hookup.  Ive seen some tires with low tread height (worn tire) hook up far better than a newer one of the same type because the tread is stiffer and more uniform.
5) spring clamps on the front half of the rear springs and flatten the cars stance slightly.
6) did I mention shedding some weight?  back seat for starters.  relocated battery and glass hood couldnt hurt either.  varying the amount of fuel in the tank sometimes works a little as well.

bottom line is all cars are dfferent and like different things.  especially on street based cars that vary far more than carefully crafted race cars.  sometimes things that work on one really suck on another.
finding the combo is half the fun   


yeah yeah I know.   

have fun 

edit: and Id personally lose the air shocks.  go get some good KYB's or the like. 

[67Dart383]

Ayah Sir!  Thanks for those tips!   

[moparrr07]

my advice if you want to run the 225 on the street is to buy a set of beater rims and put some bigger tires on, you should be able to fit a 275 in the rear wheel well,

i agree with everything jack said, especially skipping the burn out, just give it a kwik blip to get the stones off

[illfish]

dry hops only decrease traction

[bOb shingler]

dry hops only decrease traction

  yes but only with slicks, with a purely street tire one dry hop to clean the dirt off and your ready to go.

[guzzimike]

 
Keep in mind that a  BFG 275 is Not gonna fit a stock wheelwell, unless you fit rims with the correct backspacing (5" or so), hammer away the inner fender lip AND you retrofit some offset spring mounts...

[67Dart383]

THanks  Everyone!!

[illfish]

If you "blip" a tire, you are only cleaning a small section of the total diameter of the tire. 

[cu440da]

Body does not squat when launching or rise up much in front.

Thats good, you don't want it to squat. The rear of the car should rise on launch (2-3"), planting the tires. Squat reduces traction.

Try a pinion snubber if you don't have one.

[flyboy01]

First of all, stop smaking that stuff, 225 radial tires are not going to ever give you any traction. You are absolutely wasting you time trying to avoid "slicks" and experimenting with traction aids. You just don't have enough tire to give you traction.

The first thing to do is get a set of Drag radials, that is the only way you are going to get traction. You can get small 235 or 255 size DR's that will greatly improve your ET's and still be drivable on the street. Look at the MT or M&H.

[67Dart383]

Alot of people come up to us asking are we using drag radials or slicks just to get it into the 12's. We say look up under the car and you see some little treaded street tire. We want to go as fast as we can with the taller tire, then we are going to put on some drag radials on and see how much it improved. I get what you all are saying that we need to forget about runing with street tires. There are alot of people that thinks that they can beat us becuase we have some little street tires, I have proved one person wrong already. I raced a 70 model Cutlas he had some Drag radials under his car, yea he red lighted becasue he thought he had me, but i passed him in the 60ft mark.

thanks for everyhting guys.    383KIDD

[Jim13]

On my Dart for street tires I have 275/60/15's.  Stock wheelwells and I have not moved my springs.  With the proper backspacing,  they will fit fine.

For the strip I have 235/60/15 MT Street ET's,  Comp 3 way shocks, and SS springs with the rear leaves clamped.  Best 60 so far is 1.81.  If you get it to hook like this, you will be flying.

[67Dart383]

Thanks Jim13, also do you run a pinion snubber, what brand was those street tires you mention. Ah! Flyboy01 everyone is not on the same plane, some of us still trying to fly on street tires and some like you are flying on slicks or  DR's . I think a car can be dialed in either way! What is wrong with extracting the best ET's using street tires? Can you explain yourself ?   

[67Satty]

I think it is cool you are trying to see what the quickest you can go on true street tires is, but, you are never going to realize the full potential of that car at the strip until you put some slicks on it.

I think there are still a few tricks (besides the ones already mentioned) you could pull out if you insist on true street tires.

#1)  Bigger tires.  225s???  My Satellite with a very, very tired, stock 318 has no trouble spinning 255s.  I'm not even going to bother trying to get on it with these tires when my 440 is in - it would just be dangerous.  I don't know how you managed to hook up at all on 225s with the motor you've got.

#2)  Ditch the air shocks.

#3)  There's some traction compound goop that the F.A.S.T. racers use on their little 7"  bias ply tires.  The guy with the '67 Hemi GTX that runs 10s rolls multiple layers on his tread with a paint roller starting a couple days before each race.

[moparrr07]

hook up you washer pump to spray vht in front the the rear tires

[guzzimike]

A comment and a question:

I see that a couple of you guys recommend ditching the Air Shocks...Why is that..?

I had assumed that a more solid (i.e. = air) shock would transfer more power to the ground rather than to have that same power being dampened (absorbed) by a non-air shock..

[Capt Jack]

its been my experience that air shocks dont react to violent input consistantly.  they resist compression decently, but dont offset that reaction as well as more common gas type shocks.  that and regular air stores more heat than their nitrogen filled counterparts and with that heat, the inherent changes in volume and pressure change their rates.  their rates can also vary depending on changes in the air temp, track temp etc.  where nitrogen and other inert gasses, considerably less so.

the air also tends to store moisture moreso than other types of gasses.

my understanding is that the shocks arent really for transferring energy to the ground, just keeping the rebound in a controlled state so the actual suspension components can do their job consistantly

this was my understanding.  I could be wrong

[chryco]

Traction Aid !

[flyboy01]

For a Dart, she would go on the trunk.

[Capt Jack]

oh lord.  that actually frightened me when it popped up 

 

[67Satty]

A comment and a question:

I see that a couple of you guys recommend ditching the Air Shocks...Why is that..?

I had assumed that a more solid (i.e. = air) shock would transfer more power to the ground rather than to have that same power being dampened (absorbed) by a non-air shock..

Air shocks were for when high school kids back in 1982 or so wanted to be able to fit some big ol' N50-15s up under the back end of their hot rod and the only way to do it was to jack up the rear end sky-high.  Ditch the air shocks and don't put traction bars on Mopars!  OK, now we're caught up to cutting edge rear suspension technology from about 1968 or so.   

I know, I know, there's probably someone on here who's run into the 10s with air shocks, but in general I think you want to avoid them.

[67Dart383]

Thanks everyone, I don't think I'm gonna realize the full potential of this DART until I put 15000 hp motor in it!!   

[guzzimike]

Thanx for the responses regarding the Air Shocks...

We run a set in our Dart because our purpose is a 99.9% street / daily driver. We also have 255 BFG tires back there and there isn't much wiggle room left in the wheelwell.

Having air shocks gives a laterally stiffer ride (little to zero sidewall rubbing during hard cornering) with the advantage that if we load 4 up, we can just crank the air and purchase more vertical room in the wheelwell..

[6469mopar]

Traction Aid !

 

[Jim13]

what brand was those street tires you mention.

The tires are Sigma TR 275/60/R15.  Just some off brand cheepo tire that I use on the odd cruise night when it might rain.  I don't want to take a chance on getting caught in the rain with the MT's on.

When I get the Duster ready for the track the smaller MT 235/60/15 are going on it for track duty and I will buy some MT's that are 275/60/15 for the Dart.  If I had known that large of tire would have fit, I would have bought that size to begin with.

I do not have a pinion snubber.  There is some debate wether or not they even work with SS springs.

[flyboy01]

You can add more tire in your dart:

I have 15x8 4.5BS rears with 265/50r15's, I have cut 1/2" from the rear fender lips with tinsnips for clearance. I have 5/8" from sidewall to lip with these tires. 255's would be easy. 275's are possible with the perfect backspace. I could have done it if I had 4 7/8" backspace.

Before


After:

[67Dart383]

Well on our tire combo, which are BFG's 225/60r15's, they measure 25.6 by 10" side wall too side wall with a tread width of 7.2"   we have 1" between leaf spring and sidewall of tires at closest pt., and on the other side we have 1/2" between fenderwell and sidewall closest pt. we may try some p255/60r15 . I think a 27" tall tire with no more than 101/2" sidewall to sidewall is all we can use now, maybe later we might move rear end back 3/4 too 1" and move leafsprings inward by 3/4 too 1" . this would get us a taller and wider street tire one day. FlyBoy how wide and tall are your tires and Jim13 , our best 60' is 2.00 , on a 12.82  ET for the 1/4. Jim13 what was your ET.?   We would like some 1.8's on street tires.    Thanks Everyone!    

[bOb shingler]

i'd highly recommend rounding that wheel well lip over or it will cut your tire.

[flyboy01]

I think the tires are 25.6" tall, they are 10 3/4 wide. My et's are:

garage-bound @ not-enough-money   

The car came off the trailer in December and immediately went onto jackstands in the garage, I am currently working on getting it prepped for paint. I do have the car drivable now, all new brakes, but I really don't expect to have it on the road until late November. In the past I have always worked on priojects as I drove them, but this one will be different. Chassis, brakes, and safety was first, bodywork and paint next, then the interior, and finally, next winter, the engine will get my attention with a stroker build.

Its hard to tell from the pics, but the fender lips have been rolled upward after cutting, I have yet to grind the edges smooth, but I will do that after I do some additional bodywork. The inner fenders actually are closer to the tire than the outer., but its hard to see from the pics.

[moparrr07]

i read you can use brake line to make a really nice fender lip