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Discussion Starter · #1 ·
Hey guys, I'm pretty new to mustangs and even more so having a powerful car such as the 5.0. I'm not sure how to say this without sounding like a ***** but here goes: I think that when under full power the rear torque steers way too hard and it feels like the rear is flexing or diving down. I even have to let off the gas at the end of 2nd gear at WOT. I feel like the car is going to steer off sideways if I keep the power on. I've attended one autocross event with this car and it was just a beast but I felt like I'm wrestling with it.

I came from a E46 M3 so the difference is huge; I'm used to confidence inspired steering and turn in and manageable power, so this is a step further than I'm used to. Can anyone recommend some suspension mods to keep the power in check?

I've just purchased a set of H&R Super Sports and a Boss Strut Brace to keep it in check but I haven't installed them yet so; I'm hoping it will help but I don't think it will resolve the issue of the torque steer.

Thanks again! Oh and I just got it back from the bodyshop! Here's a pic of the rear.

 

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Try some LCAs and sway bars for the front and rear. You can also try getting a set of coilovers, they help a ton with handling. I think your alignment might be off because torque steer doesn't really happen with RWD cars. Doesn't hurt to check right?
 

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best place to start is tires. better and/or wider tires would probably make a good difference. I think rear control arms are supposed to help but I haven't tried myself so I can't say for sure.

no matter what you do though, I'm sure you will have to re-adjust your right foot modulation because what would have been enough grip for a certain throttle position in an E46 M3 will not be enough grip now.
 

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tires, i like bmr lower control arms. bmr upper control arm, bracket to complement your h/r springs. i went with koni str.t struts /shocks. i love em. thats for starters, if you have a chance, ride in a boss stang. if you like it, copy there suspension setup.
 

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Speaking of wider tires/rims. I am selling mine ;D
 

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OK please don't take this the wrong way but welcome to a modern American muscle car! These things are somewhat unrefined when pushed and require some deliberate actions but what a blast. Coming from an M3 has made your transition harder as that is a very refined and well mannered driver.

I think what you are feeling is the limitations of the solid axle/panhard bar design. It does not move straight up and down but slightly side to side as it raises and lowers. It contributes to that steering sensation that you felt.

A watts link will allow the axle to move straight up and down and probably solve your issue but they are pretty expensive. You could also consider some driving schools to help you get more comfortable with your car.

Experts if I am wrong here I defer - I am slowly learning about these cars.
 

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Your problem is you went from a pretty gutless and oversuspended car to a powerful and undersuspended one. You didn't even pop for the Brembo brake package which would have helped alot with your concerns.

At this point, better tires and good shocks/struts will help alot, as will tightening either or both top an bottom control arms in the rear with arms of your choice.

You can go wild with this stuff but, a simple tire and shock upgrade will give you pretty big bang for your buck. Lowering springs on stock shocks isn't a good idea, no matter what anybody says, if you plan on pushing it hard.
 

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First off congrats on your new 5.0 and welcome to the Modern Muscle Performance World!

You went with a great handling spring that will make a huge difference in your handling. I know you're coming from an M3, so you may want to take a few more steps in the suspension department to get your GT sticking to the road a little tighter/smoother.

Since you're lowering the car with H&R springs, you're definitely going to want an adjustable Pan-hard bar. This will get the rear end centered correctly under the car since the body lowering significantly. Whiteline makes a killer Pan-hard bar. They're easily one of the highest quality suspension components on the market. Check them out when you get a chance!

The next step I would take is getting an adjustable Lower Control Arm. Again, since the car is lowered, the geometry of your suspension is off, so the LCA's need to be adjustable in order to get the correct arm length/angle. Adj LCA's will also help eliminate any wheel hop and keep your Mustang on the road.

Basically- adj Pan-hard bar & adj LCA's are the first steps I would take with your H&R lowering springs. You'll see a huge difference in your Mustangs performance and it should make you feel more confident around the turns. Of course, new struts/shocks will help dramatically as well, but I think you should try these few mods first, then go from there.

Hope this helps!

Shane
 
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You'll need to use the search function, but there was a post with a link to a site that listed the suspension differences between the stock 5.0, the Brembo suspension, and the BOSS suspension. If you can find it, maybe use Google in some manner to find it, that could be a good base of information to start considering some LCA/Springs/shocks changes (plus wheels and tires, which will give you the best "bang for the buck") to help you have more control.

As another poster stated, if you had started with a Brembo/Track Pack car, you might not have these concerns.
 

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Hey guys, I'm pretty new to mustangs and even more so having a powerful car such as the 5.0. I'm not sure how to say this without sounding like a ***** but here goes: I think that when under full power the rear torque steers way too hard and it feels like the rear is flexing or diving down. I even have to let off the gas at the end of 2nd gear at WOT. I feel like the car is going to steer off sideways if I keep the power on. I've attended one autocross event with this car and it was just a beast but I felt like I'm wrestling with it.

I came from a E46 M3 so the difference is huge; I'm used to confidence inspired steering and turn in and manageable power, so this is a step further than I'm used to. Can anyone recommend some suspension mods to keep the power in check?

I've just purchased a set of H&R Super Sports and a Boss Strut Brace to keep it in check but I haven't installed them yet so; I'm hoping it will help but I don't think it will resolve the issue of the torque steer.

Thanks again! Oh and I just got it back from the bodyshop! Here's a pic of the rear.
Welcome to the Mustang world! The Mustang community is very large, yet, so small...I think you will have a great time modifying your car and meeting other Mustang owners who share the same passion as yourself.

I agree with the above statement about the handling improvement from the springs, and think you will be very happy with those considering your previous car experience.

I also agree with the recommendation on the Adjustable Panhard Bar. There are quite a few to choose from, so I recommend going with a quality piece made in the U.S.A.

When lowering the car, it will be in your best interest to adjust/correct the pinion angle. Me, personally, I do not recommend adjusting the pinion angle with the Lower Control Arms. I highly recommend non-adjustable Lower Control Arms and an Adjustable Upper Control Arm. There are a few reasons for this, first being, the margin for error in adjusting the LCA instead of the UCA is quite large. You have to ensure both are exactly the same, while hitting your target pinion angle. You have to be very careful of your thrust angle, as well. One complaint I commonly receive when customers use the LCA to adjust pinion angle is, they usually seem to move the tires too much within the fenderwell.

*Lowering the car substantially without correcting the pinion angle has shown to cause premature leaks from the pinion seal, abnormal wear on differential components, including bearings, increased noise in the cabin, and unnecessary drive shaft bind.

If you put a generous amount of mileage on your car each year, you will also want to correct the camber. When you lower the car, you will gain negative camber up front. This camber works well for handling, but can be a bear on the front tires. There are many options on the market, including camber-bolts and camber plates. You can also slot the strut mounting hole locations as well, but most do not choose to go that route. The camber bolts are the cheaper route, but of course, the camber plates are going to work better. With the better camber adjustment also comes a premium price, in comparison to the bolts.

Traction: If you are concerned with traction after these modifications, there is a solution, and they are called lower control arm relocation brackets. These will help tremendously with traction and wheel-hop.

When you lower the chassis of the car, the front mounting point of the LCA is also lowered. The rear mounting point is attached to the axle, so that point does not drop. An S197 will perform best with a parallel LCA, or even having an angle that protrudes "upwards" towards the chassis of the car, from the rear axle. When lowering, the arm will angle "downward" towards the chassis, from the axle.

This downward angle throws your instant center point way out of wack, much lower and further out to the point where excessive rear squatting and tire spin can become an issue.

Here is a good example of our Relocation Brackets and Billet Aluminum LCA's on an American Muscle customer's car:



So, I hoped that helped a little.

If you have any questions, please feel free to ask or even give me a call. I talk suspension all day, everyday, and would love to assist you with your suspension planning.

Check out our web-site when you get a chance. We have the largest selection of S197 Suspension pieces in the industry, designed, manufactured, tested, coated, packed and shipped right here in the good ole' USA.

BMR Suspension S197 Suspension Components

:bigthumbsup
 

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Hey guys, I'm pretty new to mustangs and even more so having a powerful car such as the 5.0. I'm not sure how to say this without sounding like a ***** but here goes: I think that when under full power the rear torque steers way too hard and it feels like the rear is flexing or diving down. I even have to let off the gas at the end of 2nd gear at WOT. I feel like the car is going to steer off sideways if I keep the power on. I've attended one autocross event with this car and it was just a beast but I felt like I'm wrestling with it.

I came from a E46 M3 so the difference is huge; I'm used to confidence inspired steering and turn in and manageable power, so this is a step further than I'm used to. Can anyone recommend some suspension mods to keep the power in check?

I've just purchased a set of H&R Super Sports and a Boss Strut Brace to keep it in check but I haven't installed them yet so; I'm hoping it will help but I don't think it will resolve the issue of the torque steer.

Thanks again! Oh and I just got it back from the bodyshop! Here's a pic of the rear.
That's a good looking car!

With regard to the handling comparison with your M3, you car is essentially a set of upgraded dampeners away from being able to meet or beat your M3 in terms of lap times on a road course. However, from a driving dynamics standpoint, you'd want to take a more comprehensive approach.

Here's what I did to my car and it handles very well. I'm certain it would out handle an E46 M3 on the same tires.

http://www.allfordmustangs.com/forums/upr-products/359130-uprs-s197-handling-package.html
 

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"When lowering the car, it will be in your best interest to adjust/correct the pinion angle. Me, personally, I do not recommend adjusting the pinion angle with the Lower Control Arms. I highly recommend non-adjustable Lower Control Arms and an Adjustable Upper Control Arm. There are a few reasons for this, first being, the margin for error in adjusting the LCA instead of the UCA is quite large. You have to ensure both are exactly the same, while hitting your target pinion angle. You have to be very careful of your thrust angle, as well. One complaint I commonly receive when customers use the LCA to adjust pinion angle is, they usually seem to move the tires too much within the fenderwell. "

How exactly do you fine tune ther pinion angle and thrust angle when doing the install?
 

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Not a 100% sure but could it possibly be underdamping?? At least I would think so. If thats the case Koni yellow or STR-T all the way.

BTW what did you do to the taillights and which deckled pane did you use? Combo looks very nice!
 

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Discussion Starter · #16 ·
thank you guys for taking the time out from the posts. From what I gather, it seems like a considerable rework of the suspension is in order to get the car to handle the way I'm accustomed to. Kelly thank you for the detailed write up on the LCA and bracket. I'm seriously thinking that theyre going to be my next mod along with a pan-hard bar. Do you think that they UCA is just as important as the LCA?
 

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Discussion Starter · #17 ·

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"When lowering the car, it will be in your best interest to adjust/correct the pinion angle. Me, personally, I do not recommend adjusting the pinion angle with the Lower Control Arms. I highly recommend non-adjustable Lower Control Arms and an Adjustable Upper Control Arm. There are a few reasons for this, first being, the margin for error in adjusting the LCA instead of the UCA is quite large. You have to ensure both are exactly the same, while hitting your target pinion angle. You have to be very careful of your thrust angle, as well. One complaint I commonly receive when customers use the LCA to adjust pinion angle is, they usually seem to move the tires too much within the fenderwell. "

How exactly do you fine tune ther pinion angle and thrust angle when doing the install?
The pinion angle varies. You will want to start with around -2 if you have any polyurethane bushings in the upper/LCA. If you have spherical bearings, you will want to start with -1.

The "-1" or "-2" refers to the relationship of the pinion flange angle, to the drivetrain angle. There are many theories about setting the pinion angle. For example, on my personal car (850HP '04 Cobra w/ SRA) I set the pinion angle with the driveshaft out of the car. I compare the angle of the crankshaft, to the pinion flange. I set it, then install Driveshaft and i'm done.

The goal is to have the drive train on the some plane when the vehicle accelerating (drive train loaded). Due to the rear-end rotating slightly, you want to set the angle of the differential a little lower.

The easiest/most simple way for me to explain is, measure the drive shaft angle...and ensure the pinion flange angle is 1 or 2 degrees lower. I try to avoid giving people the "add the two" etc....because it just confuses them.

Here is an example of what you want when the car is accelerating:


As for the thrust angle, I do not recommend messing with it, unless it is off. 9 times out of 10, it is fine as long as you are using fixed length LCA. The thrust angle is basically the rear end centered within the chassis of the car, front to back. An example of it being thrown off is, twisting an axle tube, or having one LCA that is longer than the other, causing one rear tire to be closer to the front of the car than the other.

thank you guys for taking the time out from the posts. From what I gather, it seems like a considerable rework of the suspension is in order to get the car to handle the way I'm accustomed to. Kelly thank you for the detailed write up on the LCA and bracket. I'm seriously thinking that theyre going to be my next mod along with a pan-hard bar. Do you think that they UCA is just as important as the LCA?
Correct, it will take a decent amount of work, with some quality parts.

The UCA is not going to give you equivalent performance, but it is just as crucial in ensuring proper rear geometry. It will help, sure, but I primarily recommend it due to the negative effects of lowering a car without adjusting pinion angle.:bigthumbsup
 

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Thank you for the explanation of setting the pinion angle.

For a 1" drop(on P springs) would a correction of the pinion angle be neccesary? I also have a one-piece Dynotech aluminum DS installed. Car is a '12 brembo gt.
If it is recommended, what is the best way? So far I think: non-adjustable LCA's, adjustanble UCA, and relo bracket.
 

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I typically recommend an adjustable UCA to adjust pinion angle when the car is being lowered 3/4" or more. If it is my car, it is getting adjusted even if it is lowered 1/2"

This is a real situation. If you take a stock S197 Mustang and lower it an inch without addressing pinion angle, more often than not, the car will develop a pinion seal leak, worn bearings, and more differential noise within the first 5,000-10,000 miles.

You are correct, I recommend using solid/fixed length LCA and an adjustable UCA for adjusting pinion angle.
 
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