[olskool]

Originally Posted by ModMustang97GT The Rev is correct. The custom 3 link set ups are superior to the irs set up. Only because the IRS that was designed for the Mustang had too many compromises that had to be made to maximize its suspension. Now on the highest level, there is debate, although generally the 3 link is generally perferred. Take a look at the field at the AIX and AI events. The typical suspension set up for 05+ and 96-04 mustangs are generally the same. Rear: Coil Overs PHB Torque arm Adjustable LCA's Front: Coil Overs SLA set up (for AIX, not as much for AI) bump steer. They also have full cages, weight reduction, aero, wide tires, and slicks. All of this ofcourse is pretty obvious. The largest difference between the cobra and the gt is 2 things. The built in SFC's on the cobra. Not sure your GT had that. And the cobra has about 100 lb/ft more torque. While you say its a technical track. Its not a down hill. The torque is going to make you leave that corner harder and faster than the gt will. Even with amazing grip, if you can't accelerate as well, your going to lose. I bet if you got coil overs and adjustable rear sway bar, with a full cage. The handling would slaughter the cobra, but your still going to lose on power.

Just top answer a couple questions. Yes it was the same driver. This car is fully caged and had the torque arm 3 link set up in it. Our driver knows both cars very well he races the GT and the cobra is his daily. And we did take into account that cobra could leave the corners harder so beffed up the 4.6 in the gt a little bit.

My biggest question is has anyone done a real comparsion in the two again we have coil overs at every corner the IRS we put in has the diff brace aluminum diff bushings and urethane every were else. so its stock VS 3 link were doing we know the out come of that. its modded VS modded its going to the alginment and tuner at the end of this weel to be put on scales and algined and tunned for the motor mods to get the intial set up done then the end of next week to the track for some testing then the week after that it will be in the Mid amercia shelby meet.

On a side not anyone wanting to convert there GT to the IRS here are the things to look for from the salvage yard you source your IRS from

The complete set up nothing missing
the brackets that bolt to were the torque shocks are to bolt the IRS to (i welded some supports on these for our application for street use not neccasry)
and make sure they didnt cut the ruber part of the brake lines if they cut the metal line comming out the car thats fine but not the rubber line
Also you will need to take the pinion flange off your old axel and put on the IRS as the bolt pattren for the cobra drive shaft is larger.
and the shock bolts (you will need NEW shocks also dont use the old ones off the cobra you will regret that in the long run) the shocks you get now will be for the cobra not the GT

Other than that its a pretty easy direct bolt in.

well we will see i will post our results after testing and after the race also and let you know what we think we are crossing our fingers right now and hopping our gamble paid off we were picking up the rear wheel last year on almost every turn and getting a ton of oversteer so i think at the least that will be taken care of now im worried about understeer

Ohh last year we had the 3 link with eibachs and performance shocks but not coilovers

[ModMustang97GT]

You were picking up the rear wheel? That is interesting. What kind of roll bar are you running back there? The only situation I can think of that would allow that would be heavy braking with alot of body roll actually pulling the rear off.

Your upgraded IRS will work better than your 3 link set up did. or at least it should. I think the flaw in your previous set up was likely the spring rates and set up. On the top cars, the irs and 3 links are close, but the 3 link pulls out in the end. I think this is due to minor grip differences and weight. But since the highest level cars are around 600 rwhp, the grip difference is large, and the gemetry of the rear suspension makes more of a difference when racing at that level.

Its possible that your front suspension could be gimping the rear also, alot of grip on the front, but with alot of body roll will put the car at a weird angle. Especially under hard braking and a stiff chassis. You said you were running the eibach springs in front and rear? Did you have the torque arm specific springs (they are alot stiffer)?

[NIghtShade]

Are these weights really true? It says that particular K member and A arms weighs 73lbs. less than the stock setup.

Performance Solution Racing 96-04 Mustang Tubular K-Member Kit [PSR-SN95-KMB] - $995.00 : Performance Parts - Ford Mustang - Cobra - Dodge Viper - Chevy Corvette - C6 - LS1

Also looking at my current alignment specs... How far should I adjust my negative camber? ( I have the MM double adjustable plates) Currently the front is even at -1.1 camber, +4.5 caster, total toe is .26

[Ke^in]

Originally Posted by ModMustang97GT Stiffness is the most important aspect of your penis once you have gotten the power and suspension bugs figured out. When your front and rear are equally stiff or atleast set up to work together, your penis will be a whole new machine. But done incorrectly, you will think your penis will be worthless if not dangerous.

Changed some words here and there.

I apologize in advance.

Great write-up BTW.. wish I had more money..

[HBK_2007]

so heres my suspension list, in the order i hope to do them
Mustang Full Length Subframe Connectors (79-04) at AmericanMuscle.com - Free Shipping!
J&M Mustang Rear Lower Control Arms (99-04) at AmericanMuscle.com - Free Shipping!
Granatelli Tubular Front End Conversion Kits - JEGS
Maximum Motorsports :: Rear Coil Over conversion
Maximum Motorsports :: Rear springs idk if those are the springs im gonna use yet
J&M Mustang 4-Bolt Caster Camber Plates (94-04) at AmericanMuscle.com - Free Shipping!
Maximum Motorsports :: Torque Arm w/ Panhard bar

[simon94]

what does anyone think about eibach pro street s coil over kit for my 97 mustang gt? is it good for handling and cornering daily driver? does anyone have it?any input?
part # 3501.710. and fits 79-04 mustangs

[risingerj]

what is the IRS suspension in a cobra equivilant to, vs. the solid rear axle. do you have to add anything to it to improve it like you do to the solid rear?

[risingerj]

is it okay to use a tubular k member setup on a v6 mustang? i ask because the ones listed on the maximum motorsports site are listed as 4.6l kits.

[HBK_2007]

i do believe the v6 kmember is different but u might ask them or look at a place that specializes in v6s like supersixmotorsports.com

[ModMustang97GT]

A tubular K member will work great on a v6. The only issue is you need one made for a v6. The ones you see on Maximum Motorsports are designed for v8's, mostly because of strength and mount location differences between the v8 and v6.


The IRS suspension is covered in this guide. The IRS needs several pieces to really help it out. New springs, some bracing and new bushings will set you up pretty well. You will still have wheel hop though, it is unfotunately all but impossible to get rid of.


HBK, that is a good list. The only thing I will say is, You might want to start at the rear end. And get the coil overs for the front. The Coil overs will be easy either way. Whether they are going on the Tubular K or not.

The rear end will really start to piss you off when you have the whole front end done up, and the rear end stock. It will plow like an SOB and the unpredictability of the rear end will really hold back the mods you have done to the front. Id try and balance front and rear mods to make it more enjoyable in the inbetween time.

[ModMustang97GT]

Originally Posted by NIghtShade Are these weights really true? It says that particular K member and A arms weighs 73lbs. less than the stock setup. Performance Solution Racing 96-04 Mustang Tubular K-Member Kit [PSR-SN95-KMB] - $995.00 : Performance Parts - Ford Mustang - Cobra - Dodge Viper - Chevy Corvette - C6 - LS1 Also looking at my current alignment specs... How far should I adjust my negative camber? ( I have the MM double adjustable plates) Currently the front is even at -1.1 camber, +4.5 caster, total toe is .26

The weights are questionable. I have heard that will Coil overs, Tubular A arms and Tubular K member, the MM kit is around 50lbs less. So onless the granatelli piece is made with really thin steel or something. I don't see it being that much lighter.

AS for you camber. Its really up to you. Race cars dial in as much as 2-3 degrees. Your average aggressive driver should not have much more than about 1 degree, and most alignment shops will get all pissy about 1 degree. I personally think Caster is about the greatest thing ever. It makes you able to have 0 degrees when the tires are straight, and closer to 5 or 6 degrees when they are turned. Greatest thing ever.

[ReverendDexter]

Originally Posted by ModMustang97GT I personally think Caster is about the greatest thing ever. It makes you able to have 0 degrees when the tires are straight, and closer to 5 or 6 degrees when they are turned. Greatest thing ever.

There's a trade-off with caster, though. It slows your transitioning from one direction to the other and it increases your scrub radius. There's some other issues as well, but I'm not remembering them off the top of my head.

[HBK_2007]

Originally Posted by ModMustang97GT A tubular K member will work great on a v6. The only issue is you need one made for a v6. The ones you see on Maximum Motorsports are designed for v8's, mostly because of strength and mount location differences between the v8 and v6. The IRS suspension is covered in this guide. The IRS needs several pieces to really help it out. New springs, some bracing and new bushings will set you up pretty well. You will still have wheel hop though, it is unfotunately all but impossible to get rid of. HBK, that is a good list. The only thing I will say is, You might want to start at the rear end. And get the coil overs for the front. The Coil overs will be easy either way. Whether they are going on the Tubular K or not. The rear end will really start to piss you off when you have the whole front end done up, and the rear end stock. It will plow like an SOB and the unpredictability of the rear end will really hold back the mods you have done to the front. Id try and balance front and rear mods to make it more enjoyable in the inbetween time.

well im gonna do the kmember/front coil over at the same time i do the rear coilover so it wont be too bad. i wanna get the kmember done before the t/a cuz i wanna turbo my car and i gotta have a new k to do that

[simon94]

here's info- questions and answers for street suspension setup from Maximum Motorsports for my 97 gt

> say everything being stock on my 97 mustang gt what coilover spring rates
> and height do u recomend front and rear for dily driver-(street only) better
> cornering/handling but comfortable ride not too stiff or bumpy?
>
> the red headed step child 1996 gt used coil0ver springs-375 front 250 rear
> for with sport valving bilstiens for daily driver but that seems too stiff
> and eibachs coilover kit is 200f 250 rear any input please

> The MM&FF magazine project car, Redheaded Step Child, used aggressive spring
> rates and shock valving because they intended to frequent the road course.
> If you also intended to regularly thrash your Mustang around a road course,
> this is a great setup! However, if your Mustang is primarily used on the
> street, I do not suggest rear coil-overs at all. Instead, I suggest
> conventional springs with ride height adjustable rear lower control arms
> (picture attached).
>
> My favorite combination for a street driven Mustang is the Maximum
> Motorsports "Street Performance" rear springs, coupled with a front
> coil-over spring rate of 275 lb/in. The Bilstein HD shocks and struts are
> the best match for these springs and will provide a sporty yet comfortable
> ride quality..
>
> If you insist on using rear coil-overs, the softest rear coil-over spring
> rate is 225 lb/in. If you will be using this without a torque arm, the front
> coil-over spring rate will have to be 375 lb/in. This spring rate
> combination will work best with the Bilsteins "Sport" struts and the
> Bilstein "HD" rear shocks. A Panhard Bar is strongly suggested when using
> rear coil-overs.
>
> For performance and ride quality reasons, you should never lower a Mustang
> more than 1.5 inches.
>

what is the height on the front 275 lb/in. coilover spring? is it 14' or 12' ?
what is the height on the rear 225 lb/in. coilover spring?

if i do go with torque arm and or pan hard bar do i have to cut tail pipes?

i have on weld prostars 15.3.5 on vw tires front and 15by10 on eagle gt 2's rear- srtictly for the look- but i still want a daily driver street only better handling comfortable ride. the car sits raked lower in front i still have plenty of room in fenderwells to lower front and rear.

i also have poly-bushings all up front.



i also would like to dump my rear quads, what setup do i need to that?



Street Performance" rear springs-whats the spring rate?how much lowers rear?do u recomend poly-isolators?

[ModMustang97GT]

Battery Location and Weight Balancing

Well Gents and Gentiles, I have stumbled on to a new subject that it looks like some people could use. The subject of the day. Weight Balance, specifically with respect to your battery.

First some Background. In general, on a car designed for ideal handling, the best weight distribution is acheived in a few ways.
1. All 4 wheels have same corner weight.
2. Front to back and side to side 50/50 weight distribution.
3. Center of gravity at the center of your axle line.

The reason for this, is the whole car ALWAYS naturally rotates about its center of gravity. Even when the suspension is set to move otherwise, that is where the car wants to go. So the goal of course is to get everything to move the same way. Set the rear suspension and front suspension to move around or in parallel to the center of gravity. And with the center of gravity in the exact middle and parallel with the axles, you will never have body dive or lean. This means perfect traction on all 4 wheels at all times. While this is IMPOSSIBLE, you can get damn close.

Now, in our cars. There are a few things you can do to help out. Switching to race seats takes weight off the front half of the car. Switching to an aluminum block or tubular front suspension takes weight off the front of the car as well. This will help move the center of gravity back twords the middle of the car as well as, reduces the over all weight.

The next option after reducing weight is to move weight. There are a few parts of your car that can be moved around. Your position in the car, the battery, speakers etc.

Your battery weighs something like 40 lbs. And is in the front left corner of the car. This is of course, an aweful place for it. While convenient, its totally off weight wise. With a relocation kit, you can move this where ever you want. The best place, is opposite the driver seat in the trunk. So, the back right corner of the trunk. This helps to cancel out not only the driver's weight, but also the engines weight in the front of the car.

You can adjust the position of the driver seat to be more central in the passenger cabin. While difficult to do, has a larger effect the heavier you are and lighter the car is. In a 2000 pound car with a 250 lb. driver, this would be huge to even move then an inch. In a tank with a 90 lb. cancer patient, its hardly any difference.

Some race cars have gone so far as to move other parts like the brake booster and fluid reservoirs into the passenger cabin, just to move the center of gravity to where it should be.

Corner Weighting
Is a methode used by race cars to balance the weight through movement of balast and height adjustment at each tire to create as close to a perfect weight distribution as possible. You want the car to have the same weight side to side and front to back. Adjusting the height of each wheel can help this. This can be done with both coil overs, and adjustable control arms.

Balast is the highest level of adjustment. Mostly because it requires you being at a less than minimum weight for your class. Then you add back the weight with balast. The goal being to add as little weight as possible as far from the center of gravity as possible, and still get the car to the ideal weight ratio. The key is having the balast as far back as you can. A 10 lb weight at the back seat will do about the same work as a 5 lb weight in the trunk. And of course, on the whole, adding 5 lbs is better than adding 10 lbs period.

[PapaSmurf]

i was hoping you could help me out with some suspension questions and give me some advice. I currently have a racecraft suspension tubular k-member and a-arms waiting to be installed my question is what length of coilover spring should i run with it? 14" or 12" and what spring rate. The car is my dd but i take it to the dragstrip as much as possible, so i guess im looking for a nice street/strip combo lol. Also any recomendations on struts? I was thinking some strange 10 way adjustables. I like my cars pretty low and i currently have h&r supersports but im actually considering raising it back up a little because i know that being to low can hurt in the weight transfer ability. Any recomendations for some new rear springs? I thought maybe a set of eibach pro's or even some rear frpp c springs. I already have a set of adjustable upper control arms and some lower control arms. My current suspension setup is listed in my garage. I appologize for so many questions. Thanks and i look forward to hearing your input.

My current suspension setup is listed in my garage

[ModMustang97GT]

Ah. A straight line question. Ok, First things first. Strange 10 way adjustables seem to be very popular. They are a good strut that I see on alot of drag queen cars.

The length of the spring for the coil overs depends on the set up. MM uses 12" springs on the front I believe, but 10" out back. You will need to contact the people who made your coil over kit and ask them which it was designed for. The longer they are the more travel you could potentially get, but the less range of adjustment you can get.

The final question. Rear springs. Well it depends, you want a set that will match your front springs correctly. Not exactly the same spring rate, but one that will work well with the front set up. When you decide on the spring rate, we can help you out a little more with spring choices. I would recommend something progressive but strong. H&R Sport is pretty similar to your Super Sports but a little less of a drop, the FRPP C springs are alot softer than the H&R's and I don't believe they are progressive in the rear, the B springs are, but are a bit softer even still.

[PapaSmurf]

The B-springs is what i would run in the rear. They are reated at 200-300 for the rear. I would like a coilover spring rate that would be similar to the front. The B-spring fronts are rated at 425-530 for referance. Im not sure what spring rate that would be for a coilover spring.

Also if i ever decided to cut the dead coil off the rear springs how would it affect the spring rate? Thanks for all your help bro

[ReverendDexter]

Originally Posted by PapaSmurf Also if i ever decided to cut the dead coil off the rear springs how would it affect the spring rate? Thanks for all your help bro

Dead coils have no effect on spring rate.

[ModMustang97GT]

Well, your front and rear springs never truly match. They will never be the same spring rate. not so long as the car isn't 50/50 natural weight ratio.

For the B springs, you figure that they are aproximatley 3 times the force of the wheel rate. So at 500 lbs spring rate, the wheel rate is approximately 166.66 lbs/in. That is pretty close to a 175 lbs/in coil over spring. Which in coil over terms, is pretty soft.

For the rear, I would not do coil overs. They do not make sense for the drag strip on a less than dedicated track car. I would probably stick with a variable rate spring that is relatively soft. You want the car to squat and the front to release. There by making your car want to wheelie. Combine that with a good set of control arms and you will have a pretty sweet launch.

The weight reduction of coil over will help up front too, and the removal of your Sway bar will be less of an issue with coil overs.