15" TIRES

tinnocker

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I am thinking of 15" wheels and red line tires on my red 94gt. I am seeking a better ride and have new shocks. I don't like the jar your teeth feel with the 17" tires. I know more sidewall will help. I also know handling will suffer a little. My Mustang is just a cruiser and I am 75 years old. I think the redlines would make it stand out from the crowd but a raccoon tail on the antenna would also. Any one ever run 15" wheels and what size works, width and backspacing?
 

badass98svt

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I am thinking of 15" wheels and red line tires on my red 94gt. I am seeking a better ride and have new shocks. I don't like the jar your teeth feel with the 17" tires. I know more sidewall will help. I also know handling will suffer a little. My Mustang is just a cruiser and I am 75 years old. I think the redlines would make it stand out from the crowd but a raccoon tail on the antenna would also. Any one ever run 15" wheels and what size works, width and backspacing?

If you want to know what 15" wheels look like on a sn95, take a look at any 94-98 V6

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tinnocker

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Thanks "well known member". Were those the stock wheels that came on it? Did you ever install 17" or 18" wheels and did it change the stiffness of the ride if you did? If so, all I need is to find the width and backspacing that came from the factory. TTOCS, I have confirmed that they will fit a GT but not a Cobra which has the bigger brakes.
 

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It shouldn’t be that rough a ride on 17’s you sure there’s not something else work out in the suspension ?
 

shovel

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I coincidentally just fooled around with this idea on my 1996 V6 , with Jeep wheels

If it helps the specifications for the factory mustang 15" wheels are 15x7 with 24mm offset. If I was doing this permanently which I may actually do, I would track down a set of OEM wheels as I think they look great
 
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badass98svt

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Thanks "well known member". Were those the stock wheels that came on it? Did you ever install 17" or 18" wheels and did it change the stiffness of the ride if you did? If so, all I need is to find the width and backspacing that came from the factory. TTOCS, I have confirmed that they will fit a GT but not a Cobra which has the bigger brakes.

That's not my car, but yes those are OEM wheels.
I've had 17s and 18s and there really isn't that much of a difference between the 2 as far as ride harshness goes.
15s will fit on any 94-04 with V6 or GT brakes.

As Musturd mentioned, it shouldn't be a very rough ride at all with 17s. Maybe you need shocks/struts/springs? If they are original then I can tell you now, yes you need to replace them.

Have you thought about 16s? Early SN95 GTs came with 16s. I have a set of chrome 16" reproductions around somewhere. They aren't in great shape though. What 17s are on your car? The tri-soke wheels?
 

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I was going to test fit the tires and wheels I got for my 05
To my 95 gt or my cobra
15 all around for my 05 15 s drove good on the 05
I may test them on one of my sns
 
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tinnocker

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I have new shocks and struts, one of the old brand names, maybe Monroe's top of the line. I bought them for the soft ride. I still have the horizontal shock in the rear. Would it affect the stiffness of the ride? Any consequences of taking the rear horizontal shock off. All I can see that it would do is improve the handling on a curving road. I am thinking that the air pressure in the 17" tires and the short amount of rubber makes for a stiffer ride than a 15 inch tire.
 

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what springs are in the car ? There’s more to ride quality than some shock and struts . How are the control arm bushings etc ? Are they factory old and dry rotted ? These cars usually ride fairly nice on 17’s 18’s , shit I’ve had 20’s on two of my stangs . My 93 fox coupe had 20” cobra r’s and my 94 at one point . With out a doubt 15’s will ride nice but that’s a bandaid to the other work out parts in your suspension .
 
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tinnocker

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Thanks Musturd, I will check springs and bushings first. They are probably what came on it. Car had only 70,000 miles and had not been modified any way.
 

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I still have the horizontal shock in the rear. Would it affect the stiffness of the ride? Any consequences of taking the rear horizontal shock off.

The horizontal shocks, or "quad shocks" as most people call them are there to prevent wheel hop when accelerating, especially when accelerating while turning or accelerating or braking on an imperfect surface and they also prevent hysteresis (harmonic bounce) since the suspension is symmetrical (incidentally the same reason some trucks with leaf springs have one shock angled forward and the other shock angled backward from the axle)

You won't gain any smoothness by removing them, and if yours are original you may gain some smoothness by replacing them with new ones.
 

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I've considered 15 x7 wheels for track use. Have the original wheels from a 1990 Ranger 4x4 that I had bought new. So test fit them before refinishing. Rears fit fine, fronts needed small spacer to clear caliper/bracket. Wheels are 15 x 7 with 4.5 backspacing.
 

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tinnocker

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Shovel, would the quad shocks replace the old school traction bars which also reduces wheel hop upon acceleration?
 

badass98svt

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Shovel, would the quad shocks replace the old school traction bars which also reduces wheel hop upon acceleration?

A set of quality lower control arms would negate the need for quad shocks. I always recommend Maximum Motorsports
 

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Shovel, would the quad shocks replace the old school traction bars which also reduces wheel hop upon acceleration?

Traction bars were a solution people implemented on leaf springs, and very loosely for the same reason but it should be noted that traction bars introduce more NVH and although they can improve launch traction when drag racing they introduce a new traction problem when they bind. Longitudinal leaf sprung vehicles have never really been associated with good handling anyway so it rarely gets mentioned but when a suspension's compliance changes rapidly the car is very difficult to control. A common example of this is when a lowered car runs out of suspension travel during cornering and transitions onto its bumpstops, the next thing that usually happens is an uncontrolled exit from the road or track.

SN95 Mustangs don't have leaf springs of course so the leaf spring "wrap" behavior doesn't exist but all linked suspensions respond in some way to torque input and nearly all of them have at least one unrestrained or "less restrained" axis that can enter a harmonic or hysteric state under some specific conditions. In this case the quad shock is a solution that takes care of both of them.

Incidentally I have a V6 SN95 and a GT, both drivers in good condition but the V6's never came with quad shocks. Both are at stock ride height with new KYB shocks - and it's easy to feel the difference when going around a sharp corner (four way intersection) if there is any kind of crown to the road or change in road surface height.


A set of quality lower control arms would negate the need for quad shocks. I always recommend Maximum Motorsports

It's worth mentioning that the quad shocks were not free for Ford, they had to weld an extra bracket on the axle, they had to construct an extra bracket for the chassis and bolt it on, they had to pay for the shocks themselves and include its installation in the manufacturing process. Car companies exist to make money and we trust their engineers with our lives... I'm certain these capable engineers tried every kind of arm and bushing imaginable to avoid the expense of the quad shocks.

Why would you want to get rid of them?
 
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badass98svt

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Are you saying that since Ford put all that money and research into it, all the OEM stamped rear suspension components are a-ok and dont need an improvements? Things progress and improve as time marches on. Those quads are/were a band-aid for poor suspension components.
Once you lose the flimsy stamped rear LCAs, their rubber bushings, and OEM UCA bushings, those quads are useless.
Maybe on an all stock suspension they are doing something (assuming they are not still the OEM units which are well worn out by now). Even then it's a reach. 1000s have removed them with no noticeable affect.
They often get in the way of wider tires and tailpipes too.
 

shovel

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I'm saying what I said. There is no new technology in anybody's control arms that wasn't available in 1993 and a company whose sole purpose is to make money would not spend money on a complex solution if they could have just put stiffer bushings and tubular arms on there instead.

My speculation is that they tried stiffer and multi-durometer bushings and decided the NVH was unacceptable. When manufacturing them new for the first time there is no difference in cost to manufacture a stiff bushing or a soft one. If they had to fabricate tubular arms with welding that costs more than a stamping, but is still less cost and time than welding the brackets on the axle tubes and stamping the chassis brackets and bolting on the quad shocks.

In the aftermarket we always shift compromises around either by spending more money or by trading one characteristic for another. We'll put more free-flowing exhaust on because we're willing to accept louder exhaust sound than the OE would want to produce. We'll put monotube shocks on because we're willing to spend money that the OEM didn't want to spend because if they added one extra dollar to the cost of a thousand parts then the car would cost a thousand more dollars to build.

It's just a lot of hubris to think that any of us are somehow smarter than the teams of engineers and the centuries of man-hours they spend bringing these to market, their job is to make it sell for the greatest profit margin possible and if there is some big expensive assembly present on any car you can bet they looked into every possible avenue for eliminating it.

Regarding the "no noticeable effect" , that is highly subjective. If your car is already modified to have worse NVH than stock with stiff springs, a poorly done lowering job, smashed or urethane motor mounts, a loud exhaust etc then you probably wouldn't notice a small change in vibration. If you aren't a professional driver on prepared courses you probably wouldn't notice a sharp transition when going from suspended to bound or bump-loaded. If you just spent money on fancy powder coated parts you definitely 100% won't be looking for any reason to doubt them and if your vanity convinces you that you need 300+mm tires on a car you're not competitively drag racing then you definitely won't care about any technical considerations because just look at them fancy meats.

Anyway do whatever you want with your car, OP asked about making his ride as smooth as possible and I don't see any reason replacing a factory part designed to increase smoothness and stability with some parts whose literal purpose is to be more stiff, would achieve that goal for him.
 

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interesting conversation. Let me throw another variable into the mix and ask then about sub frame connectors, would they make a difference here? I think we can all agree that they do a big job on the suspension when they are installed correctly unless I am missing something?
 

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