Roadrunner stance.

[ashy22]

Quick question guys.

What's the best way to lift up the back end of my 69 Roadrunner - say 2-3 inches or so. I love the stance like that.

Smaller tires on the front bigger on the rear?

I have 2 sets of wheels. The original 14 inchers and a set of 15" steel rims with hub caps that are on the car now. Should I get some Cragers?

Nor sure what to do.

 

[69hemibeep]

Hope you know its just for the look because it messes up weight transfer off the line. Tire size, lower the torsion bars a bit, re arch springs or add a leaf. and my least favorite air shocks. Forget long shackles they just put a negative arch in the spring.

 

[ashy22]

Thanks 69HemiBeep. No I didn't know it messes up the weight transfer.

maybe I will leave it alone for this year.

I need to work out which wheels I like. I have just put the original wheels back on (they were in the trunk when I bought the car) and hey! ......it's a lot easier to steer (manual steering)

:cheers::cheers:

 

[quikbird]

remember that if you change the tire size in the back you will need to swap the speedo gear in the tranny otherwise speedometer will not be accurate.

 

[ashy22]

Will the geometry of the car change in so much as I will have to have the wheels re alined afterwards?

 

[quikbird]

Probably not

 

[jays69bird]

Mine was jacked up when I bought back in 85 with air shocks. When I redid it I threw them into the metal dumpster at work and put gas shocks all the way around. It also had taller 60's series rear tires in the back. I put the 70 series(225/70R14)all the way around.It rides and handles a whole lot better now.

 

[Basketcase]

no need to worry about the speedo being accurate...there's always someone willing to let you know how fast you're going......

Mine only had four leaves on each rear spring when I bought it. We added an extra main leaf, and two shorter leaves. set the torsion bars a tad lower too.

 

[Ranger]

I have both factory 14" wheels and 15" Cragars' and I did ran a few of the online calculators for the RPM difference between the two. It was 200 RPM at any given speed. I didn't pay particular attention to the speed difference, but I seem to recall it being rather negligible.

 

[ashy22]

no need to worry about the speedo being accurate...there's always someone willing to let you know how fast you're going......

Mine only had four leaves on each rear spring when I bought it. We added an extra main leaf, and two shorter leaves. set the torsion bars a tad lower too.
View attachment 9195

Is setting the torsion bar lower an easy task?

Any vids or websites to show me how?

Would these be ok from a size point of view as far as the wheels are concerned?

http://www.ebay.co.uk/itm/111700501968?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT


Cheers

Ashy22

 

[quikbird]

look good on the wheels. front backspacing may be a little shallow. you are looking for a 5 on 4.5 bolt pattern. means 5 lug holes on a 4.5 inch circle. also check if you have original wheel studs. roadrunners had a left hand thread on one side originally so need special lug nuts for that side, or change the studs to a normal right hand thread.

adjusting torsion bars is extremely easy. there is an adjusting nut on the lower control arm. you tighten it and the car goes up. loosen it and the car goes down just remember to turn the nuts the same amount on each side. adjusting rear height is a whole lot more complicated but the front is a piece of cake.

 

[MadBird69]

When I first got my RR, the torsion bars were set ridiculously high. Was running 255/60/15's all around and it looked like it had a reverse rake to it. Looked silly and handled like a dog. As Quikbird said, lowering the bars are very easy. Clockwise raises, counterclockwise lowers. Just go a little at a time, bounce the front end, then I would measure the distance between the ground and the top of the wheel arch of the fender on both sides to make sure the measurements as close as possible. Look to get aligned afterwards too if you're making a big change. I lowered mine almost 2" so an alignment was a must. Then I went from 255's on all 4 corners to 275/60/15's out back, and 245/60'15's in the front. The height difference between the 2 sizes is about 1-1/2 inches. Before and after pics below.

 

[ashy22]

"front backspacing may be a little shallow"

What do you mean by that quikbird?

 

[quikbird]

backspacing is the distance between the rim of the wheel and the mounting surface of the hub. most mopars average about 4-4.5 inches for this dimension. there are some previous threads on the site that go into this in more detail. at 3.5 inches on the backspace the wheel will sit a little farther out toward the side of the car about an inch than normal. as this wheel is not real wide there should be plenty of room and not cause a problem with rubbing on the fenderwell.

 

[ashy22]

can you guess at the maximum tire widths that I could have on these wheels?

Is this correct? I got it off a wheel and tire website.

Front Size:15x6

Front Backspace:3 1/2

Front Tire Size:215x65x15


Rear Size:15x8

Rear Backspace:4 1/2

Rear Tire Size:295x50x15


Rear seems wide !!


AND indeed my RR has the left handed thread on the drivers side wheel studs.

Are the left handed nuts readily available?

 

[MadBird69]

Based on your rim size and backspace, the 295's should fit with no rubbing, but they'll be a tight squeeze with an 8" rim.

Summit carries the LH lugnuts. http://www.summitracing.com/search/part-type/lug-nuts/lug-nut-thread-size/1-2-20-lh-in

 

[quikbird]

make sure the sidewall height is the same on both sets of tires. looks funny if they aren't. at least they look funny to me

 

[Basketcase]

I think 50s would be a bit much for an 8" wheel, but we used to just run a lower air pressure.

 

[ashy22]

The Cragars that I am looking at say a uni lug Jag/Chevy bolt pattern.
See eBay link earlier up the thread.

I know that I need 5 x 4-1/2 inch.

Will these uni lug fit guys? :confused:

 

[Basketcase]

they should, my rears came off a '68 Camaro. He said in the listing all the center caps are included, three aren't in the pics so make sure of those.