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Discussion Starter #1
OK, I have been asking about slicks and rims for a while now and profess to really know nothing. I have been talking with different people online and with my father. I have several sets of stamped steel rims in the shop that are standard 14" rims from the 60's and 70's (stuff that came on some of our mustangs). I have a possiblity of getting a set of 15" rims off a 94 mustang. Now here is the question, assuming that the total height is the same for the wheel tire combo, is it better to have narrower smaller rim or a larger wider rim? My father has been talking about stuff they were doing in the 60's, but he does not know whats going on now so I am turning to you folks. I don't see 14' rims on anything anymore, all the track cars are running min of 15" rims from what I remember. Give me the info!!!!

67 mustang coupe
70 mustang mach 1
88 mazda/ford mx-6

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Most tire manufacturers recommend running a rim width within one inch of the tire tread width. So, if you're running a 7 x 26" slick, you'd want to mount it on a rim that is between 6 and 8" wide.

Personally, I've run a 13" wide tire on 10" rims and the car ran fine...I always thought the mushy feeling in the top end was aerodynamics...when I went to a 12" rim back in '95, I was amazed at how much more stable the car was at speed...

A little change can make a big difference...

The vast majority of racing tires come in 15 and 16" diameters....the tire I mentioned above or a 9 x28 (if you're running a 4.57 or higher gear) would work fine on your '67 or '70 with the properly backspaced wheel...

Remember, thick center wheels will require the installation of longer wheel studs to pass tech at most NHRA and IHRA tracks...

There's a lot more to hooking up at the track than buying slicks and, if you have any questions in that vein, please post the particulars...

Good luck!

Pat
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Discussion Starter #3
Pat, thanks for the info. What I am trying to do is find the cheapest way to get numbers with slicks, but not spend a bunch of money on something that I will only use once every 2 months or so. Last friday I ran a 14.6 @ 94 on street tires (BFGoodrich 245x60 r 14 radial TA's lowered to 20lbs). I am running an open 9" with 3.89 gears. I am having to come off the line soft and let the motor pull down the track. Full power off the line just burns rubber all day long (not one side but both almost equally from the rubber sprays). Shoot even hitting second, is tricky not to break the tires completely loose sometimes. I have some more tuning and addtions like new exhaust to do first, but would like to know what the car will run in comparison to all these guys that are running mid 13's on slicks. I would never be racing it, just test and tune for time slips. I don't know if I can do it, but I would like to get 14.3 on street iires. There is a real satisfaction knowing that I am doing that stoplight to stoplight! But, yaknow, I just want to know what the car is capable of! I think it is strong enough, I would only add a drive shaft loop (going to do that anyway). What do you think?

67 mustang coupe
70 mustang mach 1
88 mazda/ford mx-6

http://mhacf.com/chadn672b.jpg
http://mhacf.com/chadn672a.jpg
http://mhacf.com/mm1.jpg
 

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Going to a T-loc will help your ET's with street tires and I'd consider making that change first before going to slicks....the price will be roughly the same...

Personally, I wouldn't race a car with an open rear but I know a lot of street guys who do...as did I when I was a kid and didn't have the money for a T-loc or posi...

My old '67 with a 4.62 gear and H60-15's ran 14.00's @ 100 on street tires, corked up and with a pesky open 8"...

You can do some suspension work to get the car to hook up better...transferring weight to the rear over the tires helps, either by spring and shock adjustment and traction bars or by the old method we used, sandbags in the trunk...*G*

I left my tool box in the trunk when racing (back when I flat-towed the car), just secured it so it wouldn't go rattling around...I also had the battery in the trunk...

This was back in the 70's so things (and track tech) were pretty crude...*G*

You're ET sounds about right for your MPH....you might be able to get into the 40's at that MPH if everything is right...
Hooking up better, if you're spinning a lot, might net you 3-4 more MPH but it's surprising how terminal speed doesn't change that much when traction is briefly lost...

Read up on suspension and shock tuning and, if you have any further questions, post back...

Personally, I think you can get the car in the 13's on street tires.....if you don't have your entire combo posted somewhere, do so...

Good luck...

Pat
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Discussion Starter #5
The thing to keep in mind here is this is a street car. I don't mind the open rear (and like I said, both sides go at the same time). It may be an issue with the slicks though. Check out:
http://www.mindspring.com/~cmmaggio/carstuff/pony67.html
I have to admit I am a little stealth. That engine is actually an x head ford gt40 longblock with the alumium heads, roller hydrolic cam ect. Its the 345 HP on. The intake is a cobra aluminum unit, holly 650 double pump with 66/74 jets. I have a MSD pro billit disributer and coil to go in soon. Exhaust is currently a stock 2" gt setup (transversal), but soon will be a 2 1/2" flomaster setup.

67 mustang coupe
70 mustang mach 1
88 mazda/ford mx-6

http://mhacf.com/chadn672b.jpg
http://mhacf.com/chadn672a.jpg
http://mhacf.com/mm1.jpg
 

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Yup, mid-low 13's are possible...

Get the T-loc....trust me...especially if you plan on racing the car at the track with slicks...

You're just making so much power now that you fry up both tires instead of just one....

Pat
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Discussion Starter #7
Any suggestions on the traction lock? Is that going to help me at all with hooking up with street tires? I figured if I am already spinning, I don't need the help.

67 mustang coupe
70 mustang mach 1
88 mazda/ford mx-6

http://mhacf.com/chadn672b.jpg
http://mhacf.com/chadn672a.jpg
http://mhacf.com/mm1.jpg
 

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Since you have a manual trans, your options are somewhat limited...driving skill will play an important role here......

A T-loc will make sure both tires are spinning (or not) as opposed to the open recovering on one tire, with the other still spinning and you not really going down the road that fast......I've never used one since I've always used spools...you might post a specific question about a brand recommendation or do a site search on the subject...

You didn't talk about your shock setup or spring rates....these play an important role in weight transfer...

Try putting a couple 60lb bags of concrete in the trunk and see what happens....old street racer trick....

Pat
http://www.jps.net/binay/webdocs/strtmstng002_sml.JPG
 
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