Ford Muscle Cars Tech Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
6,662 Posts
Discussion Starter #1
Has anyone tried swapping to a set of lightweight drag rims from stock steel wheels or mags with the same tires.I saw an article where one car picked up almost 4/10ths (on a 14 second car) and another article on a 10 second car where the car didn't hardly pick up anything.I have the stock 68-69 chrome GT rims on my stang and they weigh a ton.Would a set of say, weld drag stars make much difference on a mid 13 second car?
 

·
Registered
Joined
·
4,832 Posts
The physical lightness of the new race stlye rims are only part of the reason they make a car faster.

There is also rotational forces that are lighter with those rims,that in turn takes less horsepower to turn then heavy rims.

Also the skinny front rims all racers use is to cut down on the rolling resistance of a wider tire,so all these factors give you the better ETs and MPHs at the track.
 

·
Registered
Joined
·
6,662 Posts
Discussion Starter #3
Thanks for the reply DynoTom but what I was really hoping for was some actual before and after experiences from people that have done this.It doesn't seem to be strictly a matter of weight loss ,I know theres a lot more involved as you said but why would it make such a big difference on one car and not another?Maybe it has more effect on lower horsepower cars than on very high power race cars
 

·
Registered
Joined
·
749 Posts
nothing really scientific I can add.

Can tell you though that one day at the track with the stang running 13.0X's with 15x7 10 holes(stock wheels off a 90 LX 5.0) and 215/60/15 radials up front...we swapped a set of 15x4 centerline convo pros with 165/15 radials and it went 12.90 the next pass.
 

·
Registered
Joined
·
94 Posts
I did basically the samething as qtrhors, and picked up almost 1.2 mph in the 1/8th. But my old tires were not radials, new were.
 

·
Registered
Joined
·
1,929 Posts
I changed the stock ten holes rims and tires on my 85 GT. I installed Centerline auto drags that are 3.5 wide with Moroso skinnys. No other changes made, dropped 1.5 tenths and gained 1 mph. Both of the racing wheels and tires weigh the same as 1 of the stockers!
 

·
Registered
Joined
·
46 Posts
One of the secrets that experienced drag racers use is going to a front wheel/tire that is not only narrower and lighter, but also TALLER.

The increased rolling diameter makes for a longer horizontal tire distance that can block the light beams in the starting area. As you roll into the staging lights, you should stage as shallow as possible. Then, when the car begins to move it will be a few additional hundreths of a second before the larger tire area allows the time clock's starting beam to detect that the vehicle has begun to move. This effectively gives you a tiny "rolling start" down the track before the elapsed time clock is tripped.

You also can gain a reaction time advantage on your competitor if they have a shorter tire. Again, staging shallow with a long horizontal distance of tire patch allows you to react slightly quicker without a red light, because the red light is tripped when the tire's trailing edge leaves the forward staging light prior to a green light. The taller tire allows the car to move further than your competitor ("the rolling start&quot
before the red light would trip.

As my reflexes slow with middle age, I probably need about a 6 ft. tall front tire to be competitive with you young guys. Old age and treachery triumph over youth and enthusiasm again!

Steve Amos
 

·
Registered
Joined
·
6,662 Posts
Discussion Starter #8
Thanks for all the info guys.Sounds like a lot can be made up just with the front wheels and tires. Has anybody messed with the back rims as well.I'm currently using chrysler taxi-cab rims(15/7) steel but even these are lighter than my GT rims.
 
1 - 8 of 8 Posts
Top