Suspension mod list help

[505bbjason]

Hey all,

I've done a fair amount of research, and have put together a list of goodies to help sort out the suspension of my 2018 GT PP1 6MT. The car is my daily, but I definitely enjoy some spirited canyon carving/backroad blasts, and might do the occasional autox or even a track day. I'm not looking to squeeze out every last bit of performance on-track, but I would definitely appreciate settling the car down through the twisties, and I wouldn't mind a little bit of lowering as well.

Ford Performance FR3 Track Strut and Shock Kit
BMR SP083 Handling Springs
BMR CB006H 4-Point Chassis Brace
BMR CB005H Cradle Bushing Lockout Kit
BMR BK047 Poly Subframe Bushing Kit
BMR BK049 Poly Differential Bushing Kit
Steeda 55-4915 Front Roll Center & Bumpsteer Kit
Ford Performance M-5490-E Performance Sway Bar Kit

Am I forgetting anything, are there better options for what I have selected?

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[BmacIL]

Hey all,

I've done a fair amount of research, and have put together a list of goodies to help sort out the suspension of my 2018 GT PP1 6MT. The car is my daily, but I definitely enjoy some spirited canyon carving/backroad blasts, and might do the occasional autox or even a track day. I'm not looking to squeeze out every last bit of performance on-track, but I would definitely appreciate settling the car down through the twisties, and I wouldn't mind a little bit of lowering as well.

Ford Performance FR3 Track Strut and Shock Kit
BMR SP083 Handling Springs
BMR CB006H 4-Point Chassis Brace
BMR CB005H Cradle Bushing Lockout Kit
BMR BK047 Poly Subframe Bushing Kit
BMR BK049 Poly Differential Bushing Kit
Steeda 55-4915 Front Roll Center & Bumpsteer Kit
Ford Performance M-5490-E Performance Sway Bar Kit

Am I forgetting anything, are there better options for what I have selected?

I'd personally not do any of the items in bold, and the underlined one isn't compatible with your other parts. If you really do want to do the subframe bushings, no need for BMR CB005 or CB762.

To your list, I would add camber plates, the BMR CB762, and BMR BK081 or BK055 RLCA bearing. Another thing you may consider later is a an adjustable front sway bar. With the rates of the Handling springs, the stock bars are really close, and deliver a great balance. An adjustable front is recommended to tune the balance in. If you would like to discuss more, feel free to pm me!

 

[505bbjason]

Thanks! Might I ask why a no go on the K-member brace? Not worth the cost? What about shock mounts? I only want to get one alignment, so I was thinking I would do all the bracing and whatnot first, then add in the springs/shocks and bump steer kit. A little easier on the wallet to spread things out a bit.

 

[BmacIL]

Thanks! Might I ask why a no go on the K-member brace? Not worth the cost? What about shock mounts? I only want to get one alignment, so I was thinking I would do all the bracing and whatnot first, then add in the springs/shocks and bump steer kit. A little easier on the wallet to spread things out a bit.

Missed shock mounts! The SM760 will be available soon. Those can be done any time and do not affect alignment.

The brace is not a big improvement for a street driven car that does the occasional track/autocross event. Noticeable? Sure. Worth it? I don't think so personally. The bearings for the front and rear control arms are a much, much bigger improvement and take a lot of slop out of the car's feeling.

 

[Roadway 5.0]

I personally wouldn’t get such a stiff spring set, but that’s all in your preference. I think 200F/800R is a great street / track compromise, or bump up a bit to 225F/880R if you want to be more daring (I run this). At 300F/980R I think you would have to be much more track focused to ignore the ride quality trade-offs.

I agree with Bmac that sway bars should come later. Pop for shock mounts now. I’m also a fan of the kmember brace, though the much less expensive two-point was my choice.

 

[BmacIL]

I personally wouldn’t get such a stiff spring set, but that’s all in your preference. I think 200F/800R is a great street / track compromise, or bump up a bit to 225F/880R if you want to be more daring (I run this). At 300F/980R I think you would have to be much more track focused to ignore the ride quality trade-offs.

I agree with Bmac that sway bars should come later. Pop for shock mounts now. I’m also a fan of the kmember brace, though the much less expensive two-point was my choice.

250/980. It honestly rides really well. Getting the dampers right is the key. A lot of folks have ridden in my car and been shocked how well it rides, knowing the stiffness and mods. It's certainly a firm sports coupe, but it doesn't jostle you and hurt your back, nor jiggle around (creating some odd harshness) like the stock setup. Everything is felt, but not in a way that's harsh.

 

[Roadway 5.0]

250/980. It honestly rides really well. Getting the dampers right is the key. A lot of folks have ridden in my car and been shocked how well it rides, knowing the stiffness and mods. It's certainly a firm sports coupe, but it doesn't jostle you and hurt your back, nor jiggle around (creating some odd harshness) like the stock setup. Everything is felt, but not in a way that's harsh.

My mistake, I forgot that the fronts were reduced to 250 in the refresh. Do you have the linear 980lb/in or the GT350 dual rate rear springs?

 

[BmacIL]

My mistake, I forgot that the fronts were reduced to 250 in the refresh. Do you have the linear 980lb/in or the GT350 dual rate rear springs?

Linear 980, with the old drop of 0.5". GT350R front but it's a 245 lb linear. Close enough to be no real difference.

 

[Norm Peterson]

I personally wouldn’t get such a stiff spring set, but that’s all in your preference. I think 200F/800R is a great street / track compromise, or bump up a bit to 225F/880R if you want to be more daring (I run this). At 300F/980R I think you would have to be much more track focused to ignore the ride quality trade-offs.

Preferences in (or tolerance for) spring rates is subjective and quite variable. And I have a feeling that looking at the raw spring rates confuses the issue once there's much of a motion ratio involved - I agree, 980 sounds awfully stiff when you only look at the number and see it being just shy of a thousand lb/in. But at the wheel (what you actually feel) it's only around 250 lb/in, which sounds a whole lot more 'sane' and isn't that bad at all if you're at least somewhat oriented toward cornering & handling performance.

A 200 lb/in wheel rate isn't a bad place for people who are more - or much more - into appearance than handling. By 220-ish,it's clearly started to be intended more for handling over appearance, provided the amount lowered isn't severe. Past about 240, you're probably looking at coilovers (likely having to) and more track/fewer street miles.


Wheel rates on my S197 fall in the 220-ish range, and it easily remains daily-drivable as long as I've got the shocks set appropriate for the prevailing road conditions. Be a no-brainer place for the PP2 to be, with appropriate mag-ride tuning.


Norm

 

[BmacIL]

Preferences in (or tolerance for) spring rates is subjective and quite variable. And I have a feeling that looking at the raw spring rates confuses the issue once there's much of a motion ratio involved - I agree, 980 sounds awfully stiff when you only look at the number and see it being just shy of a thousand lb/in. But at the wheel (what you actually feel) it's only around 250 lb/in, which sounds a whole lot more 'sane' and isn't that bad at all if you're at least somewhat oriented toward cornering & handling performance.

A 200 lb/in wheel rate isn't a bad place for people who are more - or much more - into appearance than handling. By 220-ish,it's clearly started to be intended more for handling over appearance, provided the amount lowered isn't severe. Past about 240, you're probably looking at coilovers (likely having to) and more track/fewer street miles.


Wheel rates on my S197 fall in the 220-ish range, and it easily remains daily-drivable as long as I've got the shocks set appropriate for the prevailing road conditions. Be a no-brainer place for the PP2 to be, with appropriate mag-ride tuning.


Norm

The stock car is quite a bit below 200 wheel rate. ~160 for the base and ~167 for the PP, averaged F/R.

The GT350R/SP085 setup is roughly 235 all around. It's quite nice.

 

[Norm Peterson]

The stock car is quite a bit below 200 wheel rate. ~160 for the base and ~167 for the PP, averaged F/R.

I suspect there'd be some aftermarket "appearance" springs closer to those rates, except for the matter of crashing into the bump stops all the time. They're sort of stuck having to go firmer.
Heh . . . Ford has at least seen fit to move the stock GT wheel rates up by about 25 - 30 lb/in (~15% or a bit more) from what they were in 2008 . . . the car didn't get that much heavier.

The GT350R/SP085 setup is roughly 235 all around. It's quite nice.

I can believe it.


Norm

 

[BmacIL]

I suspect there'd be some aftermarket "appearance" springs closer to those rates, except for the matter of crashing into the bump stops all the time. They're sort of stuck having to go firmer.
Heh . . . Ford has at least seen fit to move the stock GT wheel rates up by about 25 - 30 lb/in from what they were in 2008 . . . the car didn't get that much heavier.



I can believe it.


Norm

Roadway's setup is around 215 for reference. When you look at it that way vs 235, it's not a big difference...approx 10% stiffer. A far cry from a lot of the popular CAMC autocross setups at 450-500 front and 1300-1600 rear springs.

 

[Roadway 5.0]

The stock car is quite a bit below 200 wheel rate. ~160 for the base and ~167 for the PP, averaged F/R.

The GT350R/SP085 setup is roughly 235 all around. It's quite nice.

These statistics are great; I appreciate you and Norm taking the time the share this information.

So for the silent onlookers of this thread, the 250/980 combo is about 40% stiffer than a PP GT, the 225/880 is about 30% stiffer, and the 200/800 is ballparked at 20% stiffer. Wheel rates were used for the math (and hopefully it’s right).

Ride comfort is surely subjective, but these wheel rates and percentages of stiffness can help someone, who may think the stock PP is WAY too soft — or just needs a bit more, make a more informed decision.

Thanks again for the info.

 

[505bbjason]

Thanks guys for all the input, this gives me a lot to think about, and was hopefully enlightening for others as well. Luckily springs and shocks aren’t going in right away, so I have some time to decide.

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