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Ford Performance GT350 spring rates

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Ive looked and cant seem to find them.
Does anyone know the FP GT350 lowering spring rates?

BMR now makes a true linear spring for the GT350 with spring rates of:
250 lb/in front linear
980 lb/in rear linear

I’d much rather run a linear spring but I’m also wanting to compare the two rates.
 
Those are stock springs correct?
I’m looking for the Ford Performance GT350 spring rates

That's the FP springs.

Stock rates are attached on this message.
 

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  • Front Spring Rates Graph GT350.jpg
    Front Spring Rates Graph GT350.jpg
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  • Rear Spring Rates Graph GT350.jpg
    Rear Spring Rates Graph GT350.jpg
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That's the FP springs.

Stock rates are attached on this message.

The 949 spring chart that includes M-5310 and M-5560, those are not ford performance springs. Those are oem springs rates.

The ford performance GT350/R springs are M-5300-W
These are the springs I’m interested in seeing rates of.


Sent from my iPhone using Tapatalk
 
The 949 spring chart that includes M-5310 and M-5560, those are not ford performance springs. Those are oem springs rates.

The ford performance GT350/R springs are M-5300-W
These are the springs I’m interested in seeing rates of.


No, those are the correct individual part numbers. I just installed them on my car. The M-5300-W is the part number for the F/R set.

Here is the front.

 
No, those are the correct individual part numbers. I just installed them on my car. The M-5300-W is the part number for the F/R set.

Here is the front.


I have the FP springs, but I’m more interested in the linear springs from bmr.
I have eibach front and rear sway bars and I’m curious on the bars matching with the FP & BMR springs.

Appears ford performance went with a soft rear spring ?

Now I’m curious of the bar rates.


Sent from my iPhone using Tapatalk
 
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Digging up old threads here...am I reading these graphs correctly with the following rates:

Ford Performance Springs (progressive)
Front: 250 lbs
Rear: 565 lbs

GT350 (linear)
Front: 216 lbs
Rear: 931 lbs

GT350R (linear)
Front: 264 lbs
Rear: 836 lbs

Does anyone have Eibach or BMR #'s?
 
Digging up old threads here...am I reading these graphs correctly with the following rates:

Ford Performance Springs (progressive)
Front: 250 lbs
Rear: 565 lbs

GT350 (linear)
Front: 216 lbs
Rear: 931 lbs

GT350R (linear)
Front: 264 lbs
Rear: 836 lbs

Does anyone have Eibach or BMR #'s?
BMR: 250 front, 980 rear, both linear rate. You'll find this combination is excellent.

Sent from my SM-G973U using Tapatalk
 
I'm trying to wrap my head around why Ford took the rear spring rates down 6% with the 2019 OEM suspension update to compensate for the additional downforce and new tires on those models. Then the FP released springs that took the rear spring rate down by 31%.

It seems widely accepted the car understeers more than it would ideally and softening the rear would increase rear grip and increase understeer further. I suppose they just expect us to control the car while giving us as much grip as possible, but then the aftermarket seems to disagree and give us even more rear spring rate to make the car more balanced at the expense of overall grip.

I believe everything I stated above to be objectively true, but since they are in direct conflict with each other (do we need more grip or more balance for these cars?) I don't know what to do. I've found the car to be very much to my liking as-is, but I want to turn faster lap times and thus looking to tinker. Someone help meeeeeeeeeee.
 
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Bay Area
Go square and it will balance it out and eliminate the understeer. That’s going to be your quick easy fix for track use. If you really want to increase lap times you need to go with coilovers and more aero. But from your other posts you seem to want to keep it fairly stock so you’re limited to what you can do.
 
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1,243
In the V6L
I'm trying to wrap my head around why Ford took the rear spring rates down 6% with the 2019 OEM suspension update to compensate for the additional downforce and new tires on those models. Then the FP released springs that took the rear spring rate down by 31%.

It seems widely accepted the car understeers more than it would ideally and softening the rear would increase rear grip and increase understeer further. I suppose they just expect us to control the car while giving us as much grip as possible, but then the aftermarket seems to disagree and give us even more rear spring rate to make the car more balanced at the expense of overall grip.

I believe everything I stated above to be objectively true, but since they are in direct conflict with each other (do we need more grip or more balance for these cars?) I don't know what to do. I've found the car to be very much to my liking as-is, but I want to turn faster lap times and thus looking to tinker. Someone help meeeeeeeeeee.
Which car do you have?
 
Go square and it will balance it out and eliminate the understeer. That’s going to be your quick easy fix for track use. If you really want to increase lap times you need to go with coilovers and more aero. But from your other posts you seem to want to keep it fairly stock so you’re limited to what you can do.

I don't know that I'd say I want to go fairly stock, I just don't want to go square since I recently bought the wheels I'm using and I like them (aesthetically and performance).

My personal experience has been that I really haven't noticed the car to understeer, now I'm sure it does, but I have yet to find myself entering a turn wondering when the front wheels are going to hook up so the car will rotate. The back end certainly isn't sliding around (unless I jump on the throttle to early on track out) so overall... the car feels nicely balanced. I'm sure those statements imply that I'm not braking nearly late or hard enough, and that's probably right (definitely right).

The above aside, all the pro driver reviews (eg Randy Pobst) I've watched complain about some amount of understeer, so even though I haven't personally experienced it, I'm trying to reconcile the different approaches to spring rates from Ford and the aftermarket given the generally unanimous feedback on the car's bias.
 
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1,243
In the V6L
2017 GT350 with satin bronze Project 6GR Ten R-spec wheels. Magnetic Metallic, no stripe.
So, if you have 11" F and 11.5" rears, you can "go square" on 305/30 x 19 tires just fine. You can't rotate front to rear, but that's not a big sacrifice. You didn't say what tires you've been running, but if it's MPSS's, then bump up to RE71R's or even MPSC2's. I have a 2016 GT350 and the first time at the track in that car with stock everything except a tire swap to MPSC2's, I came within 0.2 seconds of my fastest lap ever in a supercharged 2011 Mustang GT with a full JRZ suspension in it.

I'd avoid spring changes until you've dragged all the performance you can out of tire changes. The early GT350's were pretty well balanced, as others have said. Later ones developed more grip because they had better tires, but Ford, for some reason, dialed in more understeer as well.
 
So, if you have 11" F and 11.5" rears, you can "go square" on 305/30 x 19 tires just fine. You can't rotate front to rear, but that's not a big sacrifice. You didn't say what tires you've been running, but if it's MPSS's, then bump up to RE71R's or even MPSC2's. I have a 2016 GT350 and the first time at the track in that car with stock everything except a tire swap to MPSC2's, I came within 0.2 seconds of my fastest lap ever in a supercharged 2011 Mustang GT with a full JRZ suspension in it.

I'd avoid spring changes until you've dragged all the performance you can out of tire changes. The early GT350's were pretty well balanced, as others have said. Later ones developed more grip because they had better tires, but Ford, for some reason, dialed in more understeer as well.

Sorry I'm running Cup 2s already. I don't really see the benefit of going 305 all around since I couldn't rotate them anyway other than side to side which I can already do with a stagger setup. I'm probably being dense and missing something, what would be the benefit of that?
 
I'm trying to wrap my head around why Ford took the rear spring rates down 6% with the 2019 OEM suspension update to compensate for the additional downforce and new tires on those models. Then the FP released springs that took the rear spring rate down by 31%.

It seems widely accepted the car understeers more than it would ideally and softening the rear would increase rear grip and increase understeer further. I suppose they just expect us to control the car while giving us as much grip as possible, but then the aftermarket seems to disagree and give us even more rear spring rate to make the car more balanced at the expense of overall grip.

I believe everything I stated above to be objectively true, but since they are in direct conflict with each other (do we need more grip or more balance for these cars?) I don't know what to do. I've found the car to be very much to my liking as-is, but I want to turn faster lap times and thus looking to tinker. Someone help meeeeeeeeeee.
Because they spec'd them to be used with their (too big) rear swaybar for an overall target roll stiffness. In my experience I'd never want higher than a stock GT rear bar, and would up the spring rate to get the desired roll stiffness. Gotta make the rear diff work...
 

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