Ok i have been searching but i can not find the info i am exactly looking for. I want to add 20" Shelby razors to my Shelby inspired car. I was going to go with 18's but after seeing them in person i really do not think they will clear the big brake kit i am looking at. So far i understand i should go with +24 or +40 offset but which is better. I want a nice wide rear look on the car as if i have deep dish in the back. Should i go with different offset for front and back or keep it the same, and i really want the tire to be almost level with the fender line. Also which back spacing is better, because Shelby store offers the +24 offset in 5.5in, 6in, and 6.5in backspacing, which is good for the front and which is good for the back. That is what i have not been able to find, everyone posts the offset but noone posts the backspacing. I would also like to comment that i would like to lower the car with the FRPP handeling pack so the car will be lowered 1.5in all around.

 

Im going to say up front that i drive a stock car so im not too educated on this topic but after looking around on these forums for a long time, i am positive that the +24 offset is for the sn95 body style. Some guys that bought the early razors purchased this offset because +40 was not offered yet but i am pretty sure that the +24 sticks out from the fender a little. +40 is definitely your correct offset for a s197 but honestly i have no idea about the backspacing. I hope this helps you and good look with those great looking wheels.

 

ok so +40 offset but i still need the backspacing, thanks WTC

 

Not so fast.

I have the +24mm offset and the wheels line up perfectly with the wheel arch. Couldn't tell you about backspacing though.

 

To each his own. I also have the +24 offset and wouldnt change a thing. I cant find a straight shot of mine showing how far they might go past the fender, but I also dont doubt it can be adjusted by which tires you are putting on. I have nitto's and my tires do go past the fenders....by all of maybe 1/4" or less.



I even had doubts whether I'd be able to lower the car with these specific tires on and have found out even that isnt an issue. After alot of research myself, I intend to lower the car with the FRPP springs as well. So know lowering with +24's wont be an issue either at least with the tires I installed ( But I guess it might depending on your tire choice so research accordingly). As far as backspacing, I have no idea on that. Most here got the Shelby wheels quite along time ago where there weren't many if any choices for that. I would definately be carefull though cause I was always told that its important to be carefull on that since it might put more pressure on different parts of the suspension (tie rods, axle, etc.) that might not be designed to handle it and could cause quicker than possibly 'normal' wear. Take that with a grain of salt since I have never really looked that hard into it and am only passing along 'unsubstantiated rumors..." since I have no personal knowledge. :P


Andretti

 

That looks good on there Twin Turbo,always has. Cheers!

 

I apologize for the false info. I would have sworn that +40 was correct but it appears that +24 works as well.

 

well when i go to American Tuning they do not offer different backspacing just different offset so i might end up ordering from them. Because Summit has them cheap but you have to choose either 5.5in backspacing or 6in and they told me i have to figure it out before i order because once i recieve the wheels i can not exchange them.

 

You can go either way with the 24 or 40mm offset with 20x9 Razors. But a 24mm offset with a 20x10 wheel would definitely have clearance issues on a lowered s-197.

 

i have yet to see a 20X10 razor, only 20X9, and the back spacing is the only thing keeping me from pulling the trigger. Can someone explain to me what backspacing means on a wheel. If i can understand it better maybe it will be easier for me to make a choice.

 

I found this link for you from Discount Tires website.I hope this helps.

http://www.discounttiredirect.com/di...eelOffsets.jsp

 

You might consider the Steeda coils for a drop.The drop was only 1 1/4" compared to 2" the FRPP will drop it ,then the coils will settle after a few months.I had 20's on with that drop and still had plenty of clearance. Another option is just to drop the rear with a pair of rear Roush springs which you can get.My offset was different(42mm) but the car never bottomed out like it did with FRPP handling pack(Eibach).

 

Louie428 has 20x10.5 Razors on the back of his car. He had them widened by Weldcraft

 

I had +40 on my 05 when I first got it because I was too impatient to wait for the correct offest and they do make them stick out past the wheel wells by about 1/2" and it is noticable.

 

Eh this is just so confusing, but some where in all this i am feeling that the back spacing is the same as offset and now i need to know how do you convert backspacing Inches into offset Millimeters i think the 6.5" is the +40mm offset and the 6" is the +24mm and the 5.5" is the +12mm because from what i have been seeing from charts the bigger the wheel spacing the further the face of the wheel is going toward the outside of the fender.

 

Ira, this is correct.

6.5 = +40mm

6.0 = +24mm

5.5 = +12mm

The smaller the offset and back spacing, the further out the wheel will be from the hub. On my c ar I accidently got 2 +24mm and 2 +40mm's I didn't realize it until I had them mounted on the car with tires. Once I got the tires right since I staggered them (275/35/20 on the rear and 255/35/20 on the front). Combined with the offset difference my car has someone what of a drag look. I have an adjustable panhard bar so I have since adjusted the rear so both rear tires stick out equal as shown in the lat pick. Ther both stock out about a quarter inch

 

Thanks dude, which offset did you use for the front and back

 

Front: +40mm offset (255/35/20)
Rear: +24mm offset (275/35/20)

 

I have the +24 with 6" backspace. It lines pretty close with the body line (maybe + 1/16" at most) of the front. If you get a wider tire the tire can stick out past the rim.

I don't have any straight shots but here's a large image showing my wheels. My car is in winter storage otherwide I would get a couple of pics for you.

 

I think i am going to go with GPStangs setup, i really like how the rear just looks more hotrod like and how the tires look a bit beefier. Plus it gives me the clearence i want incase i would ever want to get the wheel widened to a 20x10. I already have the Ford molded splashguards so i am not worried about sling from the rear tires. Now i need to decided if i should get these first or order my FRPP stingers