The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Should I add sway bars or T-springs?

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

348
181
US
I am not looking to go full triple adjustable coilovers and full race set up with my 2012 boss.
But.....
I do want to improve what I have so far just a bit more and I think a small tweak will really help.

Current setup is stock dampeners front and rear with Ford P- springs. Stock sway bars. MM CC plates and about -2.7 camber. I run 285 645 18 Pirelli slicks on 10" SVE rims. Have the gt500 rear rotors and carbotech 24/10 pads with boss 302S abs module. Boss 302s lower control arms and adjustable mounts for its angle. (In middle position) stock upper control arm. Thats it.

The car performs well on track but i have excessive body roll due to the slicks gripping so well. I have less grip in the rear than the front and I feel like that is what limits my cornering speeds and long sweeper speeds. The rear is the first thing to let go. I run the front shocks on 5 and rears on 4. I found that to give me a bit more grip in the rear. The slight bit of extra roll in the rear helps but not enough. And when it lets go, its not an even sideways slide that you can saw the wheel and catch. Well, you can but not it requires a slight reduction in speed too. Id like to be able to have that even, controlled slide that you just stay in it and saw the wheel and widen the line and keep going.

So... Would You suggest adding adjustable sway bars or changing springs to a stiffer spring or both? My research prior to asking in this post shows people switching to a softer rear sway bar or even removing it to get more rear grip. The variable though is the level of tire grip. I feel like on a 200 tw tire, maybe my set up would be ok. But with the extra grip the slicks provide, i think the set up may require a stiffer front sway and keep the rear sway bar stock. Or increase front a lot and rear a little, still biasing for more rear grip.

Or do I actually just need to step up to stiffer springs also? You guys have probably went through all this 6 or 7 years ago so hopefully someone can point me in the right direction.

Thanks!!!
Lee

Sent from my LG-H932 using Tapatalk
 
Keeping it simple I ran Cortex JRi single adjustable dampers with stiffer springs. Use adjustable sway bars to balance the car.
 
348
181
US
Keeping it simple I ran Cortex JRi single adjustable dampers with stiffer springs. Use adjustable sway bars to balance the car.
I'm not sure how long I'll be in the s197. Might go s550 so dont really want to go to coil overs in this car. JRi would definitely be my choice though.

Sent from my LG-H932 using Tapatalk
 

Norm Peterson

Corner Barstool Sitter
939
712
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
I am not looking to go full triple adjustable coilovers and full race set up with my 2012 boss.
But.....
I do want to improve what I have so far just a bit more and I think a small tweak will really help.

Current setup is stock dampeners front and rear with Ford P- springs. Stock sway bars. MM CC plates and about -2.7 camber. I run 285 645 18 Pirelli slicks on 10" SVE rims. Have the gt500 rear rotors and carbotech 24/10 pads with boss 302S abs module. Boss 302s lower control arms and adjustable mounts for its angle. (In middle position) stock upper control arm. Thats it.
You might try moving your rear LCAs up to the higher holes on the relo brackets.


Norm
 
898
544
Only make one change at a time.

I would ad an adjustable front bar and set it to full stiff for your current square setup.

I would not go with a smaller rear bar or stiffer springs. The OEM struts won’t work well with springs much stiffer than the current P springs. Also, you don’t have enough rear spring rate to go with a much smaller rear bar.
 
348
181
US
Only make one change at a time.

I would ad an adjustable front bar and set it to full stiff for your current square setup.

I would not go with a smaller rear bar or stiffer springs. The OEM struts won’t work well with springs much stiffer than the current P springs. Also, you don’t have enough rear spring rate to go with a much smaller rear bar.
Which front bar do you think has the proper range of adjustment? Full stiff on one bar is over 1100! Lol

I appreciate the help! I already ordered an 18mm rear bar. If I end up with stiffer springs or coil overs, it'll be handy.

Thanks!!14cd0a3d89e43d60c5a4999301e0c000.jpg

Sent from my LG-H932 using Tapatalk
 
348
181
US
All good suggestions above. I'd try the 24mm rear GT bar or the LCA angle first. LS struts up front if you can find a pair.
I'll probably start with the lca angle 1st. I am pulling them off to change out the bearings in them for a fresh set anyway. I'll install them up a hole. That's more of a pain to do at the track anyway. I can swap front or rear sway bars pretty easily at track.

Its too bad these boss struts can't control stiffer springs.

Sent from my LG-H932 using Tapatalk
 
348
181
US
I'd say the BMR 35mm, unless you can find the Strano bar. My understanding is the Strano bar is not available new right now.
Which would be nice since full soft on that is equal to stock. Install prior to going to track and can check off the lca change first. Then tighten that bar up. I'll see what I can find.
Thanks again

Sent from my LG-H932 using Tapatalk
 

Norm Peterson

Corner Barstool Sitter
939
712
Exp. Type
HPDE
Exp. Level
5-10 Years
a few miles east of Philly
I'll probably start with the lca angle 1st. I am pulling them off to change out the bearings in them for a fresh set anyway. I'll install them up a hole.
I think that would be the better order of doing things, technically. LCA inclination affects axle steer directly and is independent of lateral load transfer distribution effects (what you do by tweaking spring, bar, and damper stiffnesses, which affect slip angles somewhat less directly). Axle steer + slip angles add to give you a total effect.


Norm
 
898
544
I am assuming the OP has a Boss with the 34.6mm front bar and the 25mm rear bar. That combination with P springs and a square tire will oversteer at the limit. I’ve driven this combination enough to be familiar with its characteristics.

Putting the LCA back to the factory position may help. It’s also free. If the OP is not satisfied after that adjustment, I would look at the adjustable front bar.

I ran the Strano front bar set to full stiff with a similar combination on my Boss for a couple of years. With the relatively low spring rates, I preferred to stiffen the front vs going to a softer rear bar.

If the OP had better dampers, I would recommend higher spring rates all around and a small rear bar.
 
Last edited:
348
181
US
That's is correct for what I have now. I have the bmr 3 position bar on the way . 441:506:587. Vs the stock 436 sway bar.

You say go to 587 setting- will do! I'll try both.

Sent from my LG-H932 using Tapatalk
 
348
181
US
The price to change shocks and springs to better ones is nearly half the price of coil overs so if I make that jump, I'd just go to coil overs.

Sent from my LG-H932 using Tapatalk
 
348
181
US
Thanks for the help based on your experience! Really appreciate it !!

Sent from my LG-H932 using Tapatalk
 

TMO Supporting Vendors

Top