Help with traction problem

[XH29N0G]

Thanks for all the help with other things related to my car (power steering, driveline, etc...).  I have another question that I am hoping the forum can help with.

I recently had my engine rebuilt and now I have problems with traction in 1st gear.  I cannot floor it and keep the rear wheels from spinning. 

I realize this is probably saving some parts of the drivetrain, but I would like to have the car stick a little better on the street.

In retrospect, I realize I do not have the best tires for this.  Right now I have BFG 275 16R15 on the back at 30 psi (cold). 

What I would like to know is what would be the steps I can take to improve traction.  I have seen discussion of pinion snubbers (I do not have one), caltracs, and other tires. 

The car has the original HP suspension, a 4.30 rear, and a TKO600 transmission.  It does not have torque boxes or any other modifications. 

Thanks in advance for any thoughts and advice on what to do and in what order.

[six-tee-nine]

Most guys on here would be very happy with the "problem" you have.

You dont say what HP you are running but if you are putting out lets say 450 hp on the wheels then you can kinda expect the result.
Also a 4.30 really makes the car pull hard. Add the fact that your 1st gear is smaller than the one in a 4 speed or a 3sp auto.

My guess is that sticky tires will help alot more at this point then other suspesion parts. On the other hand with sticky tires mounted you will be needing those upgrades on your suspesion also....

[XH29N0G]

Thanks for the reply.

I  am very happy with it, but it isn't moving as it should and being a newby to this, I thought I would ask what others do to improve the traction.  Myguess is less than 450 hp at wheels (engine dyno indicated ~530 hp/590 ft-lbs).

Do you have any recommendations of sticky tires that I can use on the street?

[70redbee]

Try lowering your tire pressures maybe 2lbs at a time until you get it a little better and to your liking. I have run as little as 15lb in my rear tires. Be careful to make sure the tire still hits the road flat. This is a cheap way to help, but you may still have to upgrade other things.

[Ghoste]

There is some good information in the thread stickied at the top of this forum "operation hook", as well.

[cdr]

THE ONLY way that car is gonna hook better is with some sticky tires!!!!!!!!

[XH29N0G]

Thanks again. 

The link is very interesting read. 

I still have a number of questions about the order of doing things and what needs to be done together.

It does seem like the first thing I need is more sticky tires.  I am still looking for more information.  I am running 275 60 15 now.  Should I be able to get by with a sticky version of the same size?  I get the sense that this should be possible and it is where I am headed (unless there is a strong reaction against it).  I also don't think I have as much power as many of you others do, so I would like guidance. 

Second, as far as I can tell, the next steps should be a pinion snubber and caltracs and after that would be frame stiffeners and driveshaft loop.  How much can I do independently?  I suppose this could change, but I am not planning on racing.

[cdr]

what are your engine specs?

[XH29N0G]

what are your engine specs?

It is a 383 block (something like 0.030 or 040 over) with a 3.91 stroke built by muscle motors.  The cam is hydraulic flat tappet custom grind with 112  LSA 519/514 lift.  Their engine dyno indicated >575 ft lbs from 3400-4500 RPM and >520 HP from 5200-5500.  The car has a TKO 600 a first gear ratio of 2.87.  The rear is a 4.30 489 case.  This may be more information than you want.

[JB400]

What rear springs do you have?

[Ghoste]

Good point.  You mention original HP suspension but if the car was an XH with a 383 and those are the springs you have, a new set of Hemi style ones will help a lot.  That and a pinion snubber with good tires will go a long way.

[XH29N0G]

It has 6 leaves on the drivers side and 5 (plus 2  half springs) on the passenger side.  These are the original springs.  I think they are the HP springs for two reasons, the spring count, and also because my dad said he ordered as heavy suspension as they would let him.  I do not know if the XH designation locked out some options. 

[cdr]

thats gonna need some SLICKS.

[cdr]

THIS IS OFF THE WALLACE site of what your car is capable of if everthing is right,that engine is no slouch!!!!!

Your ET / MPH computed from your vehicle weight of 3900 pounds and HP of 520 is 11.40 seconds and MPH of 117.51 MPH.

in that heavy car it needs a STICKY TIRE 

[XH29N0G]

Not with me driving....  I also wonder if that is optimistic because I will lose a fair amount of power through the drivetrain.  

Either way, I still need to figure out whether other things will be needed, and I still need to figure out whether 275 60/15 is still an OK tire even if sticky.

I am happy with it, just want to get the car to stick better in 1st.  

[cdr]

THIS http://www.summitracing.com/parts/mtt-90000001536  & caltracs will help a lot.

[XH29N0G]

Thank you very much.   

[XH29N0G]

Another question.  Can I do tires without something like Caltracs or am I likely to break something? 

Maybe a dumb question  , but I ask because I don't know whether I am likely to be near the power level where this is needed.

[JB400]

Tires alone will be a vast improvement, but they do wear out.  Using Caltracs or other similar products give you a little more consistency in your launches compared to just tires.

[HPP]

I recently had my engine rebuilt and now I have problems with traction in 1st gear.  I cannot floor it and keep the rear wheels from spinning. 

Congratulations, this is a problem most guys would like to have. Unfortunately, this additional power often times means you need to learn how to re-drive the car. You can no longer just dump the clutch and let it hook.

In retrospect, I realize I do not have the best tires for this.  Right now I have BFG 275 16R15 on the back at 30 psi (cold). 

That's a huge problem. BFG TA might as well be hockey pucks. They are designed as a high mileage cruiser tire, not a hook em up and move the car tire. For a dedicated street car, you want to keep reasonable wet weather traction and all around driveability , so you may not want a dedicated drag tire. Therein is a problem as most 15" street tires are designed for mileage, not traction. Most drag tires are designed for traction, not mileage. The best reasonable compromise in a 275/60, may be Cooper Cobras, MT ST, or the BFG G Force drag radial, which has more tread than other drag tires.

What I would like to know is what would be the steps I can take to improve traction.  I have seen discussion of pinion snubbers (I do not have one), caltracs, and other tires. 

The car has the original HP suspension, a 4.30 rear, and a TKO600 transmission.  It does not have torque boxes or any other modifications. 

Thanks in advance for any thoughts and advice on what to do and in what order.

I'd start with tires and technique first, but I'm assuming you have a street driver and you never take it to the track. If you track the car, then you do want racing slicks. If you only street it, you will NEVER get traction like at the track. Especially with your rear gear and trans rations. Tires will make a vast improvement, and with technique you can learn how to hook it up, but even with slicks and commuter grade asphalt, you will be able to spin the tires.

Pinion snubber would be helpful if you car is squatting when you take off or if you have wheel hop. Cal-tracks are an expensive solution to a street problem that I wouldn't mess with unless you are racing regularly. Super stock springs may be a possible solution, that is less expensive than Cal-tracks, but before I went there, I'd try removing the rear most clamp on your current leaf spring pack and maybe adding a clamp in the front spring section at the thickest part of the pack nearest the axle housing. That combined with tires, will get you heading in the right direction with the lowest amount of cash outlay.

[XH29N0G]

HPP - Thank you very much. 

From what I have read, I am leaning toward starting off by trying the Mickey Thompson ET Street Radial Drag Tires, and then I will take it from there.

I am not dumping the clutch on any of this, just putting the pedal down.  With the BFG TAs it also spins when I do this in 2nd, but it still moves forward at a good clip. 

I think I have some reading to do.  I don't yet know if I could tell if it is squatting right now, but I'll keep learning. 

[HPP]

A properly set up mopar leaf spring suspension will lift under acceleration. This is because as the axle tries to leverage the pinion up, it begins lifting the front segment of the leaf springs, which in turn, lifts the car and uses its weight to press the tires into the pavement. If your springs are working correctly in this manner, a snubber becomes useless, unless you springs are weak enough to allow over-rotation. This is the principal the SS springs work on and it is the same principal the Cal-tracks imitate.

So, in that regard you want to make the front segment of your XHD springs stiffer and the rear segment looser.

ET  Street radials are a great tire for traction. Just know that with their reduced tread depth and limited grooving, they are marginally better than slicks in wet conditions, if that is a concern. MT ET Street Radials are race tires adapted to the street. BFG G Force are street tires adapted to the track. Just IMO.

[charge69]

XP29N0G:  My car is a cruiser with a 3.23 suregrip 8 3/4" rearend and traction was a problem even with a 727 auto.  My friend has a '69 Roadrunner with a 451 stroker (400 block) and a solid roller cam that turns 11.0's at 120 MPH thru the mufflers! He turns that time with 275X60X15 tires and will dip into the 10's with true drag slicks but he says the slicks are much harder on the drivetrain.
His choice of tire and mine for the rear is the Nitto Extreme Drag Radial in 275X60X15. His only warning is they are very slippery on wet streets and not very good for those conditions. They are available at numerous places such as Summit and Jeg's.  I got mine at Jeg's with very reasonable shipping. They come from Nitto with a 15K mile warranty but ....... I am not worried about the warranty.  Here is a quick look at them on my Charger!

[XH29N0G]

Thank you both for the additional information. 

Charg69 you have a very nice charger.   

[Cooter]

Remember, as soon as you hear what we refer to as " duct tape ripping" somethings gonna break. Sticky tires and dead hooks spell disaster for 8 3/4 rears. I twisted stock axles twice so far.