Performance Pack suspension bouncy?

For those who have a stock PP car.

-Jack rear of car up
-Remove wheels
-Remove Shock
-Remove dust boot / bump stop
-Trim Bump stops down to 2-3/8" total height.
-Re-install everything

This was the single best modification I did to my stock 2016 GTPP in terms of ride quality, from the factory.

BMR Tech said:

For those who have a stock PP car.

-Jack rear of car up
-Remove wheels
-Remove Shock
-Remove dust boot / bump stop
-Trim Bump stops down to 2-3/8" total height.
-Re-install everything

This was the single best modification I did to my stock 2016 GTPP in terms of ride quality, from the factory.

Click to expand...

I'll be honest, the best thing I ever did was ditch the factory shocks/struts. Fixed so much about the car that was frustrating me that I can't even begin to think of any other place to start.

What is also fascinating is that in all the hubbub Ford made over "IT HAS AN IRS ZOMG!" they did a fantastic job of reminding you how a live axle car felt driving down the road with the factory dampers... I think Ford should just give up entirely on shock design for their performance oriented packages and just let an aftermarket company like Koni or Bilstein have at it again like they used to.

I agree Chris, but as you know not everyone dives straight to replacing all of the OE suspension bits and pieces.

Then again, just making the change to better shocks and struts is enough of a mod in its own right to not be a reason for replacing anything else in the suspension.

It doesn't work nearly as well the other way around, particularly with stiffer springs and firmer sta-bars (the way too many people go about this).

Even at the OE level, damping that's a little less than it should be now seems to be the rule, where it seems the dampers were compromised a little too far toward producing a soft-ish ride that lets the car move around on its suspension a bit too much. My guess - they went too far in the soft direction after producing years of S197's with a bit too much rear shock damping and hearing those complaints.


Norm

My 2017 GTPP felt unstable and bouncy to me on highways. I was very disappointed , there is no performance in this suspension. With a selection of bmr and steeda components the car now handles incredible. Cant wait to do the sway bars and I am done.

I just bought a used 2017 base GT a couple weeks ago. Yanked the Near Zero's off after a week, and put some decent tires on (Kuhmo's this time around). Previous owner did a muffler delete, but that's the extent done to the car.

I had the opportunity to drive this at an AutoX on a kart track at Road America yesterday, classed in F Street. First in class by a good margin, and there were many "better" cars in the class including some GTPP's and such. I haven't had the chance to get it to an HPDE yet.

I haven't really noticed "bounciness" in this car (granted, it doesn't have the PP springs either), although at night, you can really see the edge of the headlights jiggling to the contours of the road.

My thoughts, with the experience that I've had on other cars, is that the Performance Package, with the chassis stiffening, stiffer springs, and better cooling, is actually targeted at track days and actual performance driving.

This means your average speed is going to be more than what you'd legally find on the roads. Once you get up to those track speeds, I wonder if you'll find that the ride actually smooths out and becomes very comfortable at speed. Spring rates are determined in part by the Motion Ratio, which is determined in part by the wheelbase and estimated speed the car will be operated at.

anecdote:
I had one car that had the typical drifter 8k/6k springs on it, and it was BRUTAL on the interstate at legal speeds (between Madison WI and Beloit on I90, southbound towards BlackHawk Farms, For anyone who cares.) Once, I was running late, and trying to catch up to the rest of the caravan, I was doing 90 over the same stretch of road as the previous weekend, and the ride was as smooth as butter. Played around a bit, anything over 82mph was great, anything below was like riding a hobby horse. Did some research as to why, and learned more about suspension than I thought even existed.

My point in all of this.. my opinion, and not belittling or disparaging anyone, but 'Murika is finally getting "sports car" right, and it's awesome that it happens to be during the Muscle Car Renaissance. I would never expect a car with an explicit 'performance package' to have a ride like a luxury car.

Has someone who's encountered the bounciness while street driving had the same issue while at an HPDE?

just my opinion in passing, when researching differences in the suspension of the PP vs non-PP to see if I wanted to put some OEM PP things on this car.

Re: SgtRauksauff

Yes, the suspension performance does depend on the bumpiness of the road and the speeds you're running at.

The bouncy feedback is mainly targetted at highway driving, not track use, but then again, tracks tend to be a bit smoother (on average) than some highways.

My PP car did just fine at it's first track days with the stock dampers, but I definitely felt like it was a bit bouncy going down the highway and hitting expansion joints at 85 mph.

The car does well at the track in stock form. For autocross in FS class, you can really take advantage of overly high shock rates to compensate for the fact you aren't allowed to change springs.

When I swapped to Konis, the highway bounciness went away (or at least I've got them dialed on settings where I like them), and they're easier to slalom in an autocross course, but honestly I didn't go any faster around TWS or Harris Hill Road with the stiffer shocks than I did with the stock PP ones.

I'm on stock PP springs and dampers - this is exactly my experience too. I'm generally pleased with how the car rides, am skeptical of doing further suspension modifications, but do love the look of these cars lowered. I just don't want to go for a look at the expense of performance.

mikeyjobu said:

I'm on stock PP springs and dampers - this is exactly my experience too. I'm generally pleased with how the car rides, am skeptical of doing further suspension modifications, but do love the look of these cars lowered. I just don't want to go for a look at the expense of performance.

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BMR sport or min drop springs shouldn't upset the apple cart. They are just a few ticks stiffer than stock.

mikeyjobu said:

I'm on stock PP springs and dampers - this is exactly my experience too. I'm generally pleased with how the car rides, am skeptical of doing further suspension modifications, but do love the look of these cars lowered. I just don't want to go for a look at the expense of performance.

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You would love BMR SP080 springs.... ;)

[MENTION=11389]Strokerswild[/MENTION] [MENTION=23614]SVT-DADDY[/MENTION]. Thanks guys - have been considering the SP089 minimum drop fronts with performance rears - I do feel that BMR makes/resells quality products.

TNcoupe said:

Springs will change the car completely. When pushed the PP springs have a terrible corner entry double bounce/wiggle that will make you pee a little the first time you experience it. Swapped mine over to Steeda sport springs and sway bars at 800mi or so and it makes the car feel in the road not just on it. Plus they drop it just the right amount without sacrificing ride quality. Definitely a must do mod if you are into that sorta thing.

Click to expand...

^^^^^^^^
Lol - It does make you pee the first time you feel this on the track. But the car does grip.

BMR Tech said:

For those who have a stock PP car.

-Jack rear of car up
-Remove wheels
-Remove Shock
-Remove dust boot / bump stop
-Trim Bump stops down to 2-3/8" total height.
-Re-install everything

This was the single best modification I did to my stock 2016 GTPP in terms of ride quality, from the factory.

Click to expand...

^^^^^^

Hi BMR, will the above trimming of the bumpstop help me not to pee when I go into a fast corner? :headbonk:

I've upgraded struts and shocks installed with base GT springs, along with your CB005 lockout kit.

Must_Tang said:

^^^^^^^^
Lol - It does make you pee the first time you feel this on the track. But the car does grip.




^^^^^^

Hi BMR, will the above trimming of the bumpstop help me not to pee when I go into a fast corner? :headbonk:

I've upgraded struts and shocks installed with base GT springs, along with your CB005 lockout kit.

Click to expand...

1) good tires, 2) springs, 3) billet shock mounts

In that order, will greatly improve the handling from what you already have.

Heh, I almost forgot I have a set of Steeda shock mounts sitting on the shelf waiting to be installed.

:headbonk:

Strokerswild said:

Heh, I almost forgot I have a set of Steeda shock mounts sitting on the shelf waiting to be installed.

:headbonk:

Click to expand...

:headbonk::headbonk:

Dude it takes like 45 minutes, including jacking the car! Make sure you get that top nut nice and tight (strut nut tool is immensely helpful here, with an offset wrench or allen key, depending on what dampers you have).