Handling Upgrade

[TeeLew]

For myself, I wanted to know what springs should I choose to get my base car as close as possible to a GT350.
BmacIL, Norm, and many others here recommended the 200/800 rates as a good starting point for most people who wished to upgrade a base or even PP1.
It was a great recommendation, 200/800 is very close to the PP2 in rates. It fit me perfectly matched with the FP Track Dampers.

Everyone told me 200/800 was the hot ticket when I showed up, too. How many combos have you tested?

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[TeeLew]

From time to time you can get PP1 front brakes take offs from shelby american via ebay for $500.

It was $700, but this...

 

[Seanuf99]

It was $700, but this...

Ha thats right. I paid 480, but that was a slightly different arrangement. Thats why I was thinking 500.

 

[bnightstar]

Everyone told me 200/800 was the hot ticket when I showed up, too. How many combos have you tested?

for daily 200/800 is great combo. Even the GT4 cars only go to 1000 lbs and they have ton's of aero. So for daily 800 should be plenty. 200 on the front is soft but we are talking daily car / canyon carver here not a dedicated track car. My 515/800 works great but it's a bit harsh on the street.

 

[Järn]

Everyone told me 200/800 was the hot ticket when I showed up, too. How many combos have you tested?

The 200/800 are the only spring rates I have used. I also replaced 5 of the 8 binding rubber bushings in the IRS. The resulting suspension is vastly improved from the base GT.

 

[TeeLew]

I love your chart very useful thanks for putting that together. 200/800 rates springs are the perfect combination for a daily car not to stiff and good handling. This is why so many people recommend it.

I don't agree. It's an improvement over stock, but only in that *anything* increasing front stiffness would be better. The front spring controls pretty much everything, and 200 #/in is not stiff enough to do what we need. Everyone is concerned about inducing understeer when increasing front spring rate, but, in practice, this doesn't happen. Take your car! You run over 500#/in on your front spring and an 800 rear without excessive understeer. Yes, your dampers are better than most, but the rates are the rates. The roll-couple shift with increasing the front spring rate is relatively small and all the other things that it gains you more than compensates for it. Increasing front spring rate gives a much better front end throughout the corner. I'm on a 450 #/in front. We're not that far apart.

Most people probably won't want more than about 250-300#/in front spring on the street for ride, but most of the canned spring packages give you a bunch of unneccessary rear stiffness with the stiffer front, which makes the car ride like crap. A lot of ride harshness comes from the rear of the car. I bet a 650 #/in (~base GT and Mach 1/no HP) or lower would work well for most if the front stiffness were in the 300 #in range. The Ford Performance kit is the package that comes the closest to this, which is why I recommend it.

The GT4 doesn't really have much aero. It's biggest advantage is really the tire. They are so much better than what we have that the rates are not directly applicable. The front is 700/750 and the rear is 900/950 (at the damper position, not spring pocket).

 

[bnightstar]

I don't agree. It's an improvement over stock, but only in that *anything* increasing front stiffness would be better. The front spring controls pretty much everything, and 200 #/in is not stiff enough to do what we need.

The GT4 doesn't really have much aero. It's biggest advantage is really the tire. They are so much better than what we have that the rates are not directly applicable. The front is 700/750 and the rear is 900/950 (at the damper position, not spring pocket).

I know we are on the same camp here but for a street car I could argue that even the PP1 rates were perfect though the PP1 dumpers were not. With that in mind everything over the PP1 rates is going to be harsh on the street. Here in Bulgaria we have lots of potholes everywhere 515 lbs springs is surely not fun on the street to a point where I barely drive on the street anymore. I only do drives in the car to and from the track. So yeah I can see how 200 lbs will be perfect spring for such conditions. But I can't argue with the performance on the track though I run my shocks really soft in rebound because my track is also not smooth enough. And even with this soft shocks the car is still not fun on the street.

 

[TeeLew]

I think we could probably both do with reducing rates front and rear. I've got a pair of 650's and 500's in the garage for the rear. One of the two will find their way under the car when I do the rear end gear ratio. I've been waiting on the differential, but now that is just about finished. I'll get a read on something softer in the rear of the car before too long.

In the end, I agree that the PP1 overall stiffness level is not a bad place to be, I just don't like the front to rear stiffness distribution from Ford and think they could have produced a better car if they'd done it differently.

 

[bnightstar]

In the end, I agree that the PP1 overall stiffness level is not a bad place to be, I just don't like the front to rear stiffness distribution from Ford and think they could have produced a better car if they'd done it differently.

They do produce better car in the PP2, Mach 1, GT350. The PP1 is very balanced car to be fair good on and off the track. Without been to extreme in both directions. I honestly thing 800 lbs rear is just about perfect though.

 

[TeeLew]

The other side of the conversation is just personal preference. I know I prefer a relatively pushy car, so I tend to tune in that direction. It's not an arbitrary choice; it's been a successful approach for me in the past and that's what I shoot for now.

I found the chassis balance on the PP package to have excessive oversteer pretty much everywhere. It's my opinion that this is why we see so many crashed Mustangs. On the limit in stock form, the rear of the car is not happy.

 

[Cheo]

“The Ford Performance kit is the package that comes the closest to this, which is why I recommend it” I’m with Tee on this, the package overall is very good for dual purpose cars. I installed it 2 months ago on my magneride Mustang and it’s far better than I expected.

 

[MrMike]

M-FR3-FASTENA this now comes with the kit, you do not need to purchase seperately.

I did the FP control arms as well because of spherical bearings and air flow because I did upgrade the brakes to the PP brakes.

No idea if it was worth it for my application at the end of the day but seemed like a good idea when I did it.

I wonder if that's what the "A" revision added with the price increase. I emailed Ford Performance to double check. It would really suck to get the handling kit in and not have the fastener kit.

I'm currently planning to keep the stock brakes, although I've seen some decent deals on the red Bullitt brakes so I'll keep my eyes open.

Almost forgot to follow up on this.

It is not included with the kit per Ford Performance. With that said, it seems like it's ok to re-use if your bolts are in good condition. Basically, do a quick inspection before ordering or just get the FASTENA kit just in case.

Good Morning Mike,

The M8A kit does not contain the FASTENA kit. The M8A kit contains only the fasteners that cannot be reused when installing the kit (torque to yield that must be replaced). Any fasteners that can be reused are indicated as such in the instruction manual. See link below…

https://performanceparts.ford.com/download/instructionsheets/FORDINSTSHTM-FR3A-M8A.PDF

The FASTENA kit is for someone that needs to or desires to replace all fasteners involved with the kit, however as long as your fasteners are in good shape, it likely is not required.


Thank you,

Anthony Fodera

 

[Seanuf99]

Almost forgot to follow up on this.

It is not included with the kit per Ford Performance. With that said, it seems like it's ok to re-use if your bolts are in good condition. Basically, do a quick inspection before ordering or just get the FASTENA kit just in case.

Apologies, you are correct. Its been a while and I remembered the torque to yield bolts coming with it, but was forgot it was just those. My car had like 1k miles on it so reused what I could. Good luck.

 

[MrMike]

Ok so I've done a lot more reading and research based on replies in this thread and some DMs.

I found these threads suggesting that the FP Track Handling rear springs (M-5300-Y vs YA) were changed noticeably:

https://www.mustang6g.com/forums/threads/ford-performance-track-suspension-no-rear-drop.160213/

https://www.mustang6g.com/forums/th...ance-track-lowering-springs-m-5300-ya.164851/

I am not interested in a large amount of rake like those threads indicate..

I reached out to Ford Performance to double check. I saw threads where people mentioned reaching out but never followed up.


I'm going to be researching other options too, but I was hoping to avoid buying shocks+springs separately.

I've seen recommendations from Steeda, FP Track Struts/Dampers+BMR SP083, and FP Track Struts+Dampers with GT350/R springs as well. I imagine the latter with the GT350R sway bar kits from Levittown would get me awfully close to the GT350 feel.

 

[MrMike]

I haven't heard back from Ford Performance about the YA springs yet.

I read all of GT350/R springs and GT350/R sway bars.

I am considering the following setup:

• M-18000-F FP Track Struts / Dampers
• FR3Z-5310-K GT350 Front Spring (x2)
• FR3Z-5560-Y GT350 Left Rear Spring (x2)
• FR3Z-5482-J GT350/R Front Sway Bar
• FR3Z-5A772-G GT350 Rear Sway Bar

I'll also be replacing the bushings/clamps with the new sway bars. This should result in just a tiny drop (0.3").

I'm concerned that the high spring rate on the GT350 rears plus the GT350R rear sway bar might result in too harsh of a rear end on the street, and I read multiple times around here about people keeping the rear PP sway bar with the GT350/R springs. I am leaning towards the regular GT350 rear sway bar for that reason.

Is this setup a bad idea or crazy for any reason?

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