Posted By: 70gtx1
Upgrading to wider front tires, steering box?? - 12/21/11 12:30 AM
I have been slowly changing my 70 GTX from being a drag racer to more of a street car again. Im finding out I have more fun driving it on the street than racing it. I currently have 15 x3.5 drag wheels up front, and cheater type slicks on the rear. Handles like garbage on the street. I plan on getting new rims and running a set of 17x8 rims up front with 255/45 17 tires up front, very much wider. I currently have manual steering, thats a little sloppy. I plan to get the box rebuilt. My question is, am I better off getting the box rebuilt with a faster ratio, due to the wider tires, or should the stock ratio be good enough. My concern is that it will be very hard to turn the wheels. Never dealt with this before, any input would be appreciated, thanks.
Posted By: ahy
Re: Upgrading to wider front tires, steering box?? - 12/21/11 01:11 AM
Some of the changes you are making will increase steering effort. The wider tires for a start. Plus, if you set up the alignment for handling an are able to get 5-7 degrees caster, that will increase effort. MOPAR provided zero or negative caster specs to make the manual steering cars easy to turn... not good for handling.
I'm thinking you will like the faster ratio when on a roll at 30+ but not around town. It may make the car "not fun". I'd stay with the standard ratio.
Also suggest you check your front tire sizing. 225 or 235 usually fits the car and an 8" wheel. 255 may rub and probably wants a wider wheel. The larger wheel size and low profile tire is not so forgiving in wheel width. The tire manufacturer will give a recommended wheel size for 255's.
Posted By: dfsmopars
Re: Upgrading to wider front tires, steering box?? - 12/21/11 03:17 AM
I have 18 x 9 on the front of my '72 Charger with firm feel steering. I had it aligned and I am assuming to stock specs. I like the way it handles but the steering seems to be a little slow in returning after turning. Not sure but that may need some tweaking on the alignment. I like the wider 255 tires but I am not sure if the firm feel was necessary. BTW, the car is also power steering. I like the set up but it needs a slight adjustment I think I hope this information is useful.
Posted By: 70gtx1
Re: Upgrading to wider front tires, steering box?? - 12/21/11 03:44 AM
I got the idea in tire sizing from this article
http://www.moparmusclemagazine.com/featu...ules/index.htmlI love the way the car looks with those tires and wheels, thats where i got the idea from. I guess the first thing i should do is get the rims and tires, and see how it feels. Im not trying to build a canyon carver or anything, just a real nice driver.
Posted By: 340SHORTY
Re: Upgrading to wider front tires, steering box?? - 12/21/11 03:56 AM
Personally,,, Id back p to 245 on the front.
Posted By: ahy
Re: Upgrading to wider front tires, steering box?? - 12/21/11 04:33 AM
I think its a good idea to do the tires and wheels first and see how you like the steering. I checked and 8" - 9.5" is the recommended wheel size for a 255-45-17 Continental tire. 8 is just enough. If you have a friend or friendly tire dealer that can give you a test wheel/tire first you can check fit and backspace. With the wider wheels backspace needs to be dialed in real close to avoid or minimize rub.
On mine (70E), the tire dealer mounted up a 225-45-17 for me on an 8" wheel with 4" backspace as a test. I mounted and checked with T bars removed for easy full suspension travel. 4" was close but not ideal. I ordered two wheels with 4 1/8" backspace and bought the test wheel as a spare. I probably used a conservative fit guideline... 1/2" minimum clearance at extreme turn and suspension travel. If you don't mind going closer or rubbing from time to time, bigger will work.
