Lowering front springs only, need help with the right setup

[Benjamin Hundred]

More detailed write up below, but these are key things.

- Running staggered front PS4S 305/30/20 and rear AS DWS06 315/35/20 (sits 0.75” higher in rear over stock) Largest possible tire setup for my car btw.
- Stock springs with perfect rear fit but want to lower front by about an inch upfront, will this cause any challenges due to the difference in front and rear ride height, if so how can I make it work?
- The ENTIRE suspension was literally just rebuilt except for the springs, keeping comfort in mind I went with OEM parts and Steeda Active setup. So it should all be sitting and fitting like new. Left springs OEM for maximal comfort and to then gauge from there if I should swap them.
- What springs should I use in the front? Steeda, BMR, Eibach? I already installed new front and rear Eibach bump stops btw.

Hey, I have a 2018 Mustang convertible, I was running squared summer tires, Michelin PS4S 305/30/20 all around. After the front tires wore out (alignment issue that was fixed now) I moved my back tires to the front and installed a new set of All Season Continental DWS06 Plus in a size of 315/35/20 in the rear. This was for mainly ride comfort improvement which it was a huge improvement over the PS4S, but also for the look and fitment.

Currently the rear sits perfectly and I have no desire to lower it, the 315/35/20 tire is 1.5” taller in diameter than the 305/30/20 so it’s sitting 0.75” higher up in the rear I’d assume. But up front the wheel gap is a little much, I’ve been eyeing about a 1” drop to improve the look without compromising comfort.
With the difference in front to rear ride height will there be any issues and how can I fix them so that I can just lower the front. I was looking at the Steeda Progresssive springs but they’re only sold as a full set and was told by an installer that just doing the fronts would handle bad and be uncomfortable. I’d like to keep the ride quality and the Steeda spring rate of 145-225 seemed like the softest option with capable handling still. Unless there’s a better route I should go?

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[WItoTX]

Just my opinion, you could go to a 400 lb spring and it would still ride just fine. The front is massively under-sprung.

The guy that told you that was probably speaking on generalities. Generally, yes he is probably right. But on these heavy front cars, even with the turbo 4, you can get a lot bigger springs. You will need to look for a new strut to match the dampening needed.

For my money, Ford Performance front springs would probably put you exactly where you want to be. But I don't think you would go wrong with the Steeda's, other than you likely going to be operating the spring largely closer to that 225 spring rating.

I typically don't comment on cars that guys build for looks. Not sure what it is about your car, but it is fantastic, and I really hope fit and finish is as good as the car looks! Glad to hear you got everything fixed.

 

[Arknsawchuck]

I personally wouldn't do it. It's going to mess with your handling. If you want to change the height between front and rear then go coilovers. Then you can adjust them to where you want them. But judging from your tire and wheel set up your going more for looks than handling. The springs probably won't effect your style of driving. But I'd still go coilovers. If ya just gotta go springs check out ford performance.

 

[Benjamin Hundred]

Thank you so much for the replies guys,

My front springs are the softest OEM made, so I’d guess probably 140lb upfront, so if I went with say BMR 1” front lowering springs it’d be 170lbs. I’m personally not worried about the front being too high of a spring rate, I think the 170 BMR upfront with the rear OEM would be close to a PP setup as that’s a front 165 just without the 1” drop.

I do like that with the OEM front springs when it sits higher it clears speed bumps, curbs and almost never scraps. It’s 80% a looks thing though and 20% for the extra handling as I can tell mine hit their limit with GT350 sway bars on tight turns.

 

[Benjamin Hundred]

The ride height difference is what would be causing the potential handling issues? Not the spring rates?
If I was to go coilovers how much do you think that’d run? I just rebuild all the suspension so everything’s brand new (like 1K miles)

I’ll certainly check out Ford Performance options if I go springs
I want it to look good but I also want to use it as my everyday driver so if it’s going to cause drivability issues then I’d just leave the ride height alone.

Oh also, the reason for the PS4s upfront is because I used to run those front and back and the ride quality was trash. I put the larger rear Continental DWS06 AS tires on since I needed two new tires and I was told a larger side wall would help with the ride quality (looks were a byproduct) and it has helped a huge amount along with the rear Continental also being smoother compound.
The fronts stayed PS4S’s to check ride fit with larger rear tires, I’ll be swapping them once I can get my hands on Continentals for the front size.
I noticed it gets a little squirmy during hard breaking at 80+, I’m assuming because of the front summer Michelin with rear all season Continental it’s tracking a little different.

 

[Benjamin Hundred]

Is this a safety concern/dangerous? The moron who I had install the struts and new strut plates stripped the bolts and only the circled bolt actually holds anymore. Should I just order new strut plates to install asap? I don’t have the money to be spending carelessly but this seems like it could be kinda serious potentially

 

[MidwayJ]

What size wheels are you running up front? You might want to go with 285/35r20 for more sidewall when you get the Continentals.

Be careful with all seasons in the rear and summer performance tires up front. It's easier for the rear to step out when the front tires have better traction.

Yes, I would definitely get that bolt replaced.

 

[Benjamin Hundred]

What size wheels are you running up front? You might want to go with 285/35r20 for more sidewall when you get the Continentals.

Be careful with all seasons in the rear and summer performance tires up front. It's easier for the rear to step out when the front tires have better traction.

Yes, I would definitely get that bolt replaced.

11X20 front and rear, fronts are 305/30/20 currently and I maxxed out the rear at 315/35/20.
The front 295/30/20 tires I just ordered are the same Continental’s as the rear tires I have.

I wanted to try the staggered fit first and replaced the rear tires before doing the front to see how I liked it. I have had the back end try coming out at times (first time wasbraking around XXXMPH 🫣) mainly in cold weather where the summer tires are hard though.
The summer or AS Michelins I have had in the past seem to be pretty harsh on all my cars,(great grip though), I can’t really fit anymore sidewall upfront due to already getting rubbing on tight turns, even going from a 30-35 would be too much in the front.

I’m making a trip from SoCal to NorCal today, I have a set of BMR SP089 minimum drop springs for the front I’ll be installing along with the new front tires and I just read about being able to rethread a stud since it’s not broken, so I’ll try that for the strut plate while I’m working on the front end.

 

[MidwayJ]

11X20 front and rear, fronts are 305/30/20 currently and I maxxed out the rear at 315/35/20.
The front 295/30/20 tires I just ordered are the same Continental’s as the rear tires I have.

OK. I wasn't sure you had 20x11 up front. There are people running 285/35 but they're on 20x10. I get why you're going with 295/30 since the 305/30 are rubbing. Good luck!

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