Help with rear tire size. Please read. Need traction!

astronut1885

Founding Member
Jan 31, 2002
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Assonet, MA
Hey again. I got gears the other day, and my rear tires are just not holding the ground good enough. I want to get a set of wider rear tires for my car, but I don't know what size to get. Right now, it has 225/50/R16s at all corners. I want the biggest footprint possible to help traction. I will be getting Goodyear Eagle GTHRs to match my fronts. My car is lowered 1.5" at all corners by BBK progressive rate springs, and it has quadshocks. Let me know. Thanks.
 
Not sure what size wheels you have, I'm going to assume 17's since those seem to be the most popular. Well, with quadshocks installed the biggest we could fit under mine (had eibach prokit lowering springs) was 245/45/17. You could probably squeeze some 255's in, not sure. Most folks that drop the quadshocks go with 275's, which is what I'm going to switch to. Hope this helped.
 
if i remember correctly you have ponies, 16x7 inches, so your best bet would be a 245/50/16. if you upgrade to around a 17x9 rim, you can go up to a 275/40/17 out back without too much problem, but to be safe you should consider ditching the kicker shocks and getting a good set of lower control arms. as long as you drive normally you shouldnt have much trouble at all. hope this helps
 
HyPer-50 said:
Not sure what size wheels you have, I'm going to assume 17's since those seem to be the most popular
Notice in the post where he says he as 225-50-16's right now.:stick:
:D
I am running 245-50-16s all the way around on pony wheels. It is a close fit in the front, but in the back there is still TONS of room. However, I highly recommend against going wider than a 245 on a 7" wheel. You may increase the width of the tire, but you arn't increase the contact patch on the ground. The contact patch will actaully pop up in the middle if you run a tire to wide which reduces traction.
Going to a slightly wider tire won't help much. You need to focus more on the grip of the tire itself, and the suspension set up. A 1.5" drop definatly isn't helping you.
 
bhuff30 said:
Notice in the post where he says he as 225-50-16's right now.:stick:
:D
I am running 245-50-16s all the way around on pony wheels. It is a close fit in the front, but in the back there is still TONS of room. However, I highly recommend against going wider than a 245 on a 7" wheel. You may increase the width of the tire, but you arn't increase the contact patch on the ground. The contact patch will actaully pop up in the middle if you run a tire to wide which reduces traction.
Going to a slightly wider tire won't help much. You need to focus more on the grip of the tire itself, and the suspension set up. A 1.5" drop definatly isn't helping you.


275 on 17" wheel is wider than a 245 series tire so why not go with a 275 on 17" wheel?
 
I have 16" OEM pony wheels. How is a 1.5 inch drop not helping me? Lowering my center of gravity is going to give me better grip. I am going to do control arms this summer, but for now I just want bigger rear tires.
 
The 1.5 drop will not help you at all on a strait line. If anything it probably will hurt you just a tad when trying to plant your tires in a strait line. When you launch typically your rear will drop and the nose will lift applying more force on the rear because of the higher CG. With lowering springs also being stiffer there is less movement to the rear thus less downward force on the rear tires. The lowering springs will only show improvement on lateral movement. If you are talking about handling, the best footprint is the size you have right now for your ponys. You will have to get some bigger wheels in order to fit a wider tire to get better traction. If you are stuck with the ponys, get some better rubber like some G-forces or something with a AA traction rating. The GTHRs unfortunately only have an A traction rating. They have a great treadware rating but that typically means a harder rubber= less traction. As much suspension and brake work as people do, good tires are probably one of the biggest impovements in itself because your car will only perform as well as your tires will allow. If you are talking about strait line, you can fit some 245mm tires but you will sacrifice your handling. Typically you do not want the width of the tire to exceed more than 2 inche of the width of the wheel. To help lessen wheel spin from a launch get some lower controler arms and some better tires. Those two things will help your car on both the handling and launch. You have to choose what you want your car and build it accordingly. There will always be a sacrifice. Best of luck.
Kevin
 
I also have 16 inch ponies,I just purchased a set of 245/50/16 Nitto Drag Radials.There sitting in my house rite now,,,getting them mounted next week!! There wider then my current tires,and will have alot more bite :nice:
 
I would like to keep the same tire all around. I got my current tires last November, so they're in great shape. I just want a little bigger contact patch. I might get 255/50/R16s after I do my control arms, because I can remove the quadshocks at that point, and then they'd fit.
 
the 255's would be pushing it on the stock pony wheel, but they would definitely fit under the car once the quadshocks are gone. a 245/50/16 should suit your needs perfectly until you move to a wider rim.
 
He had good traction with a modded 306, and I was able to spin my 245s easily. I want a big contact patch that will allow me to get on it a little more with less fear of breaking loose. Especially with my motor getting redone in three or four weeks, I'm gonna be planting alot of power.
 
I've run 255's on pony wheels with the quad shocks in place, and they fit just fine. I have also run the same brand and type of tire in 245's and couldn't tell any big difference in traction. As somebody stated earlier, lowering the car reduces weight transfer which hurts you in straight line traction.
 
astronut1885 said:
He had good traction with a modded 306, and I was able to spin my 245s easily. I want a big contact patch that will allow me to get on it a little more with less fear of breaking loose. Especially with my motor getting redone in three or four weeks, I'm gonna be planting alot of power.

You're not going to get a bigger contact patch -- with only a 7" wide wheel you're limited to how much tire you put on the ground. The rest will just bulge over or cause the center to cup up and lose traction.
 
89MustangGX said:
You're not going to get a bigger contact patch -- with only a 7" wide wheel you're limited to how much tire you put on the ground. The rest will just bulge over or cause the center to cup up and lose traction.

This is totally true. If you are after handling, stay with the 225/55/16 until you have bigger rims. Get some drag radials, like Nitto 555's. These will help straight line and handling. If you go any wider on that rim, it will handle like crap and you will hurt traction. I have 245/50/16's on ponies and the rear sways badly in a corner. I am sorry I did this. I did it for looks, like most people. I knew it was too wide, and did it anyway. :bang:
 
I read this someplace and it makes alot of sense to me. A wider tire does not increase traction. It merely increases the likelyhood of finding traction. You have more square inches of rubber on the road, but you have less pounds of weight per spuare inch. So you really have the same amount of traction available unless you go to a sticky compound. The downside is it will wear quickly. I just want you to know I almost lost it when I swerved to miss a car pulling out in front of me because of my tires. Before it would have handled that with ease. I have some wicked oversteer, thats where the rear tires loose tration.
 
eric88gt said:
I've run 255's on pony wheels with the quad shocks in place, and they fit just fine. I have also run the same brand and type of tire in 245's and couldn't tell any big difference in traction. As somebody stated earlier, lowering the car reduces weight transfer which hurts you in straight line traction.

no rubbing at all?