Dropping it and tire size.

[Sergeant]

Hello, I'm not new to the car craze but new to G/N. I will be buying my friends in a week. The car is an 87. He told me the car needs shocks even though the car only has 40,000 miles on the car. My question is does the car going to also need new springs due to the cars age? And if so how many inches can I drop it and still not have any problems with every day driving? Also the car has 15 X 7 weld rims. How big can I go with or without the drop without rubbing? I appreciate your help.

 

[Red Regal T]

I think you probably have a lot of decisions to make. For example, to run 15, 16, or 17" wheels. Get the car and then decide. There are many combinations and price ranges to consider.

 

[Sergeant]

I will be staying with the 15 x7 rims in order to save money, I am mostly concerned about tire size. From what I have heard 275/50/15 are the limit on the rear and 255/50/15 for the front. I'm I correct?

 

[Red Regal T]

I ran 295 50 15s on stock ttype rims which are 15 X 7. Depends on your backspace on whether you can run them or not. On the front, I just ran a 70 series of similar height. I don't care for fat tires on the front, but that's your decision. Many do.

 

[Steve Wood]

Dropping is relative to where it sits now...I have the Eibach springs on one of my cars which are reputed to drop it an inch. From the ground to the fender lip thru the center of the wheel, mine measures a hair over 25" in the front and two hairs over 25" in the rear. Yet, it sets at least two inches lower than a T that I own. Now I don't know what springs are on the T.

25" is about as low as one would want to be and have to enter drives and such that are built up.

 

[Sergeant]

Steve what size rims and tires are you running? I'm asking because your info of 25" is a great help to me but I think I need to consider it in relation to your tire and rim combo. A smaller 15" rim compared to a 17" rim (tires being relative) would have the car sit lower.

 

[Spoolinup]

Sergeant, with 15x7 rims here is a nice combo.
255/60 (rears)=10.0 inches of section width, 27.0 inches tall
225/60 (fronts)=8.85 inches of section width, 25.6 inches tall
Stock tire size 215/65 (fr & bk)=8.4 width, 26.0 inches tall

As long as the offset or backspacing is similar to the stock rims you will have no problems with wheel well rubbing or frame rubbing. And with the 1.4 inch difference in height from the front tires to the rears, the car will look more aggressive with a slight slant down in front.

Even with a 1 inch drop the car will be fine if you have a similar offset to the stock rim, which if I recall is split equally 3.5/3.5.

Age and vehicle weight do effect the stock springs. So if you have the money it is a nice upgrade.

 

[BuickTom]

FWIW I've run 235/60/15's in the front of my car which is lowered. Sits just a hair over 25" in the front like Steve's. They were real tight fight but didn't rub at all. They might rub at full steering lock, I have a f-body box with closer stops, so I didn't have a problem, except making U-turns I still have my snow tires on which are 225/60/15's. They fit no problem. This is all on stock GN rims.
I'm running f-body Jamex drop springs which are supposedly slightly stiffer than the eibachs. With 5 people in the car, I've had problems with the mufflers on my hooker exhaust dragging on bumpy roads, or when riding over the crown of the road. With two people though I've never had any problems.

Tom