Traction Control Needed...

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7milesout

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In the form of tires. It has become obvious, I need more gription! :lol:

I've worked on this car. I've replaced the HB, adjusted timing, replaced and tuned the carb, all new exhaust, and added an Eaton Detroit TrueTrac differential (kept the 3.23 gearing).

Before the differential, it would just burn the right rear tire. But now, with all the TLC it's different. With all the tuning and power improvements, it now BURNS BOTH REAR TIRES! Effortlessly ... and shifts to 2nd while burning out (this is NG for acceleration).
:rofl:
These are the kind of problems a Mopar guy wants to have! So, I'm not complaining. Maybe you guys have read some of my previous posts about the above work on the Scamp. And that I'm trying to have as close to a "daily driver" Scamp as possible, combined with running a 13.99 second quarter mile.

To backtrack a bit. The only thing missing from my list of improvements, TLC and care and feeding of the Scamp, is new tires. The current tires must be near 30 years old. Either way, they've got to go (old and tractionless).

But what has become clear is that there's just not enough meat on the road ... at least in the rear. And the tires I was considering are one size narrower.

Ideally I wanted to keep the 14" wheels, because to me, they just look good, tough and original with the car. But I don't think I can find a reasonable 14" daily driver kind of tire, that will have enough gription. Below is a picture of the car. With the wheels I would like to keep.

However, all ideas are on the table. Help me out here guys. I need ideas. What I might even consider is to go ahead and buy the pizza cutter tires I was considering for the daily driver aspect, and then 2 more wheels with big fat meaty tires for use at the strip. Although, I'd really rather just have 1 set of wheels and tires ... that ride good and can provide enough gription for a 13.99 second strip E.T.

I'm putty in your hands!
upload_2017-12-14_11-7-41.png


7milesout
 
first of all - nice car! I like it a lot! now.. - did you just say you are driving around on 30yo tires!!!??? YIKES! It be time for some new sneakers!! Those old wheels and tires just aren't going to get you where you want to be. You're asking a lot of those old wheels - limiting yourself to a 14" tire is probably not ever going to get you the gription you are after. It also appears you are still running the 4"bp - also a limiting factor as far as wheel choices go. The weight of the steel wheels is slowing you down too - especially up front - you have to decide between some performance up grades and the look you want though.. so - - - . Anyway - I had a 71 Scamp back in the 80's that I put 15" x 6" (or maybe they were 7") Cragars SST's on all the way around and a set of (then) lower profile 60 series tires on all four - it effectively lowered the car and made it both a little quicker and handle better. My advice on this one - get in touch with a local tire shop and talk to them.
GOOD shocks will help too.
There are some other things - pinion snubber, sub frame connectors - but that might be getting more involved than you want... ???
 
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Hoosier Quick Time D.O.T. Tires

M&H Racemaster Muscle Car Drag Tires

Coker BFGoodrich Silvertown Radial Tires
 
It also appears you are still running the 4"bp - also a limiting factor as far as wheel choices go.

Thanks! Yes, I would say those tires have been on there since the early 90's. So, maybe 25 years. The guy who gave me the car, I helped him put the engine in, in about 1996. It was the same tires then as now. Still has good tread and no dry rot. They look nice but are Maypops.

I'm drawing a blank on what a 4"bp is. Only thing I can think of is bias ply? But they're radials and I don't know what the 4" is (width?). They're 205/60's in the front and 225/60's in the rear. I was kind of hoping that 215/60's would work out. 216/60's corrects the speedometer, and I was hoping new more compliant tires would provide more gription. But after the experiment the other night, I have my doubts. The caveat being that on a drag strip, there's enough sticky down, that with new tires, lowish rear air psi, and the TrueTrac, maybe it would hook up. The tires I'm looking at are less than $400 and would be good around town, so maybe it's worth it to try it. I'm reading these replies, and appreciate it.

The front end suspension of the Scamp is great (for old school). Quiet and compliant. The rear is crap, with air shocks. Rides like a 1950 Ford F100 in the rear. I'll address that at some point. But with the air shocks at least I can adjust the ride height.

451Cuda - Right now that seems the most reasonable plan. I just would prefer not to have to swap wheels and tires in order to achieve a 13.99. I'm thinking, get the tires I planned (because they are *relatively* cheap), and see if I can hit 13.99 with them. If not, then do as you mention.


7milesout
 
Thanks! Yes, I would say those tires have been on there since the early 90's. So, maybe 25 years. The guy who gave me the car, I helped him put the engine in, in about 1996. It was the same tires then as now. Still has good tread and no dry rot. They look nice but are Maypops.

I'm drawing a blank on what a 4"bp is. Only thing I can think of is bias ply? But they're radials and I don't know what the 4" is (width?). They're 205/60's in the front and 225/60's in the rear. I was kind of hoping that 215/60's would work out. 216/60's corrects the speedometer, and I was hoping new more compliant tires would provide more gription. But after the experiment the other night, I have my doubts. The caveat being that on a drag strip, there's enough sticky down, that with new tires, lowish rear air psi, and the TrueTrac, maybe it would hook up. The tires I'm looking at are less than $400 and would be good around town, so maybe it's worth it to try it. I'm reading these replies, and appreciate it.

The front end suspension of the Scamp is great (for old school). Quiet and compliant. The rear is crap, with air shocks. Rides like a 1950 Ford F100 in the rear. I'll address that at some point. But with the air shocks at least I can adjust the ride height.

451Cuda - Right now that seems the most reasonable plan. I just would prefer not to have to swap wheels and tires in order to achieve a 13.99. I'm thinking, get the tires I planned (because they are *relatively* cheap), and see if I can hit 13.99 with them. If not, then do as you mention.


7milesout
sorry - 4" bp = 4" bolt pattern
 
Coker BFGoodrich Silvertown Radial Tires

That Coker / BFGoodrich Silverton comes in a 265/50R14. That's 18% more width than I have now, and 98% the sidewall height (96% sidewall height would be perfect for fixing the speedo error, 98% is close enough). Those are very interesting. PLUS - I could bet BFGoodrich in the front and have 4 "matching" tires. Very interesting. Thanks. Didn't know about those tires. I think it would make the Scamp look even tougher with fat tires on the rear.

But, it says it recommends a minimum of 7.5" wheel width. Does anyone know how wide these 14" rallye wheels are?


7milesout
 
That Coker / BFGoodrich Silverton comes in a 265/50R14. That's 18% more width than I have now, and 98% the sidewall height (96% sidewall height would be perfect for fixing the speedo error, 98% is close enough). Those are very interesting. PLUS - I could bet BFGoodrich in the front and have 4 "matching" tires. Very interesting. Thanks. Didn't know about those tires. I think it would make the Scamp look even tougher with fat tires on the rear.

But, it says it recommends a minimum of 7.5" wheel width. Does anyone know how wide these 14" rallye wheels are?


7milesout
they do look pretty tough with bigger rear tires... :D (goes ok too)
dascamp-jpg-jpg.jpg
 
But, it says it recommends a minimum of 7.5" wheel width. Does anyone know how wide these 14" rallye wheels are?
7milesout

IT really doesn't matter. If it's narrower it will cup the tread depending on the tire pressure. If it's wider it will flatten it out.

Ever see a dually? They run 265's on a 6.5" tire and guys put 12.50's on those wheels.

I run 11.25" wheels on a recommended 10" wheel tire.
 
Video of it losin traction or it ain't happenin. lol
:thumbsup: I had my son run a video from INSIDE the car. It was dark, can't really tell much. I'll repeat it (from outside) once I have 500 miles on the diff. I want to "feel" like I've broke the new diff in a bit.
 
IT really doesn't matter. If it's narrower it will cup the tread depending on the tire pressure. If it's wider it will flatten it out.

Ever see a dually? They run 265's on a 6.5" tire and guys put 12.50's on those wheels.

I run 11.25" wheels on a recommended 10" wheel tire.

Maybe it would work, but wouldn't it be a bad idea? Make it handle weird, maybe defeat the purpose of the width? I don't want it to look like I'm running sport bike rear tires on the back, because the wheels are so narrow they pinch the tires into a round shape! :D
 
14" Rallys were 5.5s, IIRC; came with E70s or 7.35s or 185s

You can put a 235/60-14 on the front on a 7.5
On the stock rear end I think the limit is 255s or just maaaaybe 265s. Minimum width rim I think would be an 8.
I highly recommend aluminum wheels, cuz when the tires get fat, the pkg gets heavy, and that is unsprung weight, and so they start to put a lot of "feedback" into the chassis. Two of my 10" aluminums,IIRC, weigh about the same as ONE steel rally. 295 tires are heeeeeavy.
If the front rim is too narrow for the tires it will pull the outside edges up off the pavement, and so run the centers off, and of course you wasted money on those. To compensate for this, you have to air the tires down. Once you get down to 24psi, the handlig is GONE. The tire rolls under the car and you skate on the outboard edge and plow into stuff, while chewing up the sidewalls. Don't make this mistake, it can last for years,lol.
If the front rims are too wide for the tire, it may be difficult to get them on the beads. But if you can get them on, you will have to run extra pressure to push the centers down, and that is good for handling and gas mileage,but not so much for ride quality.
My 235s work very well on 7.5s, running 28psi all the time except on Saturdays I pump them up to 30.
 
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All I have to say is that you better post a video of you sending those old tires off with a large cloud of smoke! :D
 
On the rear
If the tires are too wide for the rims, you will have to reduce the tire pressure to get the outboard edges to sit on the pavement, for long tire life, and for maximum use of the rubber for traction. If the pressure gets much lower than 24 or so, you'll feel the rear of the chassis scoot over inside the tires when you enter a turn. This is oversteer so be ready for it. Some say this is crap handling, and yeah for track work I'd agree. But for a streeter, after the learning period, it can be a blast. They say BFGs and CooperCobras are crap tires.... but 295s at 24psi on 10s do pretty good. At least the back now stays in the back. But honestly, if you have 350/400 horsepower your street options are slim pickings.
If the tires are too narrow for the rims, you will have to run extra pressure, which leads to a harsh ride.
I recommended a minimum rim width for a certain street tire size,to be the same size as the tread width.
The size-brand on the tire is only correct on a checking rim of 70% of the brand on account of the brand is a measurement across the sidewall bulges. The tread width of radial tires is about 1.25 to 1.5 inches less than the branded size. So a 255 tire converts to 10.04 and subtracting 1.5 from that yields a rim width of 8.5..And a 235 converts to 9.25 and subtracting 1.25, yields 8.0..And 295 converts to 11.6 and subtracting 1.5 yields 10.1.. a 205 converts to 8.1 and subtracting 1.25 yields 6.8, rounds up to 7.
You can work the formula backward from a certain rim size by adding 1.25 to 1.5 and then converting to metric. For instance that 5.5 Rally is good for (5.5 +1.25)x25.4=171 rounds to 175mm.
 
Well, I keep running into issues no matter what I find. Wheel Vintiques makes a nice looking 14" x 8" wheel (5 x 4" bp) (48-4854458 if you want to look it up), and I think that wheel would look good on the Scamp. That 8" wheel would hold that 265/50-14 tire real nice.

But the way that rear fender rides over the top of the tire, I don't think a tire as wide as the 265 is going to fit in there. That sucks! Because the wheels are great, and I can get a narrower Wheel Vintiques wheel for pizza cutter fronts and that would be great. ... But the dern rear fenders!
 
Well, I keep running into issues no matter what I find. Wheel Vintiques makes a nice looking 14" x 8" wheel (5 x 4" bp) (48-4854458 if you want to look it up), and I think that wheel would look good on the Scamp. That 8" wheel would hold that 265/50-14 tire real nice.

But the way that rear fender rides over the top of the tire, I don't think a tire as wide as the 265 is going to fit in there. That sucks! Because the wheels are great, and I can get a narrower Wheel Vintiques wheel for pizza cutter fronts and that would be great. ... But the dern rear fenders!
You can get those in a custom backspace for a few dollars more. But sooner or later you'll be putting the inner sidewall into the leafspring and so that will have to get moved over. Then you can run about 10 to 15 more mm. Moving the springs is no big deal. You can also get your current steelies widened towards the inside, and the spider moved; people used to do that all the time,me included,lol.

Just measure the distance from the outer sidewall bulge to the nearest offending part of the inner fender, and the same on the inside. Then remove the wheel, lay it flat, lay a straightedge over the top two buldges and measure to the floor. Add those three together and subtract; 1/2 inch for drag-racing, and up to 1 inch for soft street springs. Then convert that to metric, and voila that is your maximun sidewall cross-section with the springs moved outta the way.
Say you got 12 inches , and subtracting 1 for clearance, and converting,you get 279. The closest tire is a 275. And it wants a rim of 9.3 which rounds to 9.0
Now, say you had a 205 (8inch section-width) in there now, with 1.2 to the outside and 2.8 to the inside.
And say you currently had a 5.5 inch rim with a 3.25 inch backspace. Well just add the 3.25 inch bs to the 2.8 room and then deduct 1/2 for clearance and you get a new bs of 6 inches
Since the rim width desired is 9.0, then that rim will be 10" in overall dimension. that leaves 10.0 less 6 equals a front space of 4 inches. Your current front space with a 5.5 wheel@3"BS would be (5.5 +1)less 3 equals 3.5. So you will be increasing it by 4 less 3.5= .5 , leaving you .7 clearance on the outside. This will allow you to run a spacer if required of up to 1/4 inch to center the wheel. All numbers were pulled from a hat and may not bear any resemblance to what you have. They are just an exercise. Measure both sides of the car!! This exercise assumes you moved the springs out of the way. If you didn't then you would use the spring as the intruding inboard edge, but you can run very,very, close to the spring. I have seen guys run less than 1/8 and get away with it.
So there you go; get a tape measure, a square, a 3ft level, a plumb-line, a cement floor, and a pencil. Then get to it.
If you have a 4bbl360, any 4bbl360, or a hot 318, then you need the biggest tires back there that you can fit. And that means moving the springs, so just bite the bullet and get it done. If at some later date you decide to narrow the rear end to open up your tire selection, then because these custom wheels fit a stocker, you should have no trouble selling them.
But I highly recommend 15s on account of I don't know if you could get a 14 inch 275 street tire. Again WV will sell you just about anything.... They can put a 5on 4 14" spider into a 15" rim; I know this cuz they built me a pair.
I don't know where PTC is but if it was in Canada I'd offer them to you. 15 x 8s ,4" bc, and IIRC........about,lol, 5.5" bs for the front of my car.
 
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Get another pair of rallye wheels, put some 14" drag radials on them. With 14" wheels you're limiting yourself because most are 15"...but M&H makes a set that would fit: M&H Racemaster Muscle Car Drag Tires MSS-002
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-------------------------------------NOT THIS ! M-H HAS NEVER HELD ANYTHING for me, even sent the last set back because they didn`t work w/ the rims that they advertised. Never found a set that would even come close to holding the old hemi car , back in the day. Their rubber compound just flat sucks !!----jmo
 
^^^^^^^^^^^
-------------------------------------NOT THIS ! M-H HAS NEVER HELD ANYTHING for me, even sent the last set back because they didn`t work w/ the rims that they advertised. Never found a set that would even come close to holding the old hemi car , back in the day. Their rubber compound just flat sucks !!----jmo

Good to know, thanks.
 
Maybe it would work, but wouldn't it be a bad idea? Make it handle weird, maybe defeat the purpose of the width? I don't want it to look like I'm running sport bike rear tires on the back, because the wheels are so narrow they pinch the tires into a round shape! :D

No, and it won't look like a sportbike tire either. they look like that before you even put them on. By the way, you know there is no difference between a sportbike tire and any other streetbike tire, touring etc, right? Sportbike tires just tend to be wider however Harley has followed suit and in some cases gone even wider, 240's etc in factory trim.

It's more critical in the front but you aren't looking for huge rubber up front. To give you another idea MMT front runners are 7.50 tires and go on "approved" 3.5" wheels. Even then, you're putting stickies on the rear for a drag application. Handling isn't something we're talking about and your car unless modified/upgraded handles like...well a stock abody..lol.

I run 225's on a 8.5" wheel on my daily and it still have enough sidewall you can they then on their side gently without scuffing the wheel. In contrast my front runners on my dart are on 3.5's or 4" wheels with 12.50's out back on 11.25 wheels. I run 25lbs on street in the rear, 35 to 40 up front on my dart.

I have the same rear diff as you. It was a good choice. IMO the best choice.

As mentoned above, I'd recommend using offset hangers in the rear. If you are deadest on using those factory 14's, which I think you are crazy for..have them widened to the ideal width. Once you run offset shackles you can run a 10.5 section width tire.
 
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