How important is suspension for traction on an FI setup? Suspension before Tires?

[Ptrug]

2019 Mustang GT Convertible Premium PP1
ESS G2 Supercharger - 700HP
275 rear PS4 Tires
Stock Suspension
Low mileage daily driver with 75% street and 25% track usage.

I know I need to take tires into consideration, and I plan on getting PS4 315's on the rear but I want to know how much of an improvement a performance suspension will give me to be able to keep the road and is it suspension first, tires second or vice versa?

Right now, just over half throttle at 50 mph and she breaks loose and goes 180 on the street.

Any recommendations on suspension setups. Any other tracktion suggestions would be appreciated.

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[Emilbadal]

I'd recommend to take it step by step, to prevent unnecessary spending. First take care of your tire width issue and see how it goes. Suspension helps, but you can go overboard with upgrades really quickly and compromise the ride quality.

 

[MCS]

Tires are what keep you glued to the road. Start there then ask the question again.

I'm running 555 G2s in the front and 555 RII in the back on Steeda Ultimate Handling Lowering Springs (0.5" drop) and Magneride. That's it. Unless you are competing for "How much money can I spend" or "I really am going to track this car regularly" I wouldn't go much beyond that. Maybe a STOP THE HOP next but other than that it's good.

 

[Ptrug]

I'd recommend to take it step by step, to prevent unnecessary spending. First take care of your tire width issue and see how it goes. Suspension helps, but you can go overboard with upgrades really quickly and compromise the ride quality.

I asked the question the way I did to specifically not force this answer

My issue is I already have the best street tires there are in PS4s, they just need to be wider. Will 315s really make that much of a difference over 275? Because right now I can't really go much over half throttle.

Anything else outside of suspension and tires i should consider?

 

[Ptrug]

Tires are what keep you glued to the road. Start there then ask the question again.

I'm running 555 G2s in the front and 555 RII in the back on Steeda Ultimate Handling Lowering Springs (0.5" drop) and Magneride. That's it. Unless you are competing for "How much money can I spend" or "I really am going to track this car regularly" I wouldn't go much beyond that. Maybe a STOP THE HOP next but other than that it's good.

As I told the first commenter, I asked the question this way specifically to not force this answer BUt i agree with it.

I have some of the best street ribber on now so how much better would 315s be over the 275 PS4? I am not trying to spend money, I am just trying to make her safe and usable.

Tell me more about this Stop the Hop? My thought with suspension was that it would keep the tires down for better contact so maybe the STH is really what I was looking for? I did a quick search and see the components but would that really make noticeable difference as well? I don't think she really "hops" with the PS4s but she definitely gets a huge hunch when I start opening her up.

STH before replacing the PS4 275s also or still go 315 even before the STH?

The power I am getting from this ESS supercharger is crazy!

 

[MCS]

I asked the question the way I did to specifically not force this answer

My issue is I already have the best street tires there are in PS4s, they just need to be wider. Will 315s really make that much of a difference over 275? Because right now I can't really go much over half throttle.

Anything else outside of suspension and tires i should consider?

Going to 305s or 315s will make a difference yes, then going to a softer compound sticky tire will also make a big difference however you are driving a street-legal car that has the power of a racecar. There is no magic bullet that lets you put the pedal to the firewall and hang on. Not and still be street legal or in any way shape or form a comfortable ride.

 

[DougS550]

2019 Mustang GT Convertible Premium PP1
ESS G2 Supercharger - 700HP
275 rear PS4 Tires
Stock Suspension
Low mileage daily driver with 75% street and 25% track usage.

I know I need to take tires into consideration, and I plan on getting PS4 315's on the rear but I want to know how much of an improvement a performance suspension will give me to be able to keep the road and is it suspension first, tires second or vice versa?

Right now, just over half throttle at 50 mph and she breaks loose and goes 180 on the street.

Any recommendations on suspension setups. Any other tracktion suggestions would be appreciated.

Matching your suspension to your cars power capability is paramount. Wheel hop will be violent at times and this can be devastating to the Drive shaft, Axles and rear end. For me, I completed all of my suspension mods/upgrades first, and now I am ready this winter to FI. Good Luck

 

[NoGo5.0]

Suspension is HUGE, but if you're deciding between tires and suspension I would get some new rubber first. Either way I would get both down the line, but tires will be a way bigger difference than suspension alone. We have all the popular performance tire brands along with great suspension kits we put together over at Lethal Performance that help with keeping the rear end planted. Depending on how hard you drive the car will determine how much suspension work you'd need to do to keep it planted.

 

[Ptrug]

Going to 305s or 315s will make a difference yes, then going to a softer compound sticky tire will also make a big difference however you are driving a street-legal car that has the power of a racecar. There is no magic bullet that lets you put the pedal to the firewall and hang on. Not and still be street legal or in any way shape or form a comfortable ride.

I completely understand that. I guess I'm trying to do whatever I can to build her right based on my power upgrade. I knew this journey isn't over But at least I don't have any more power adds to do.

I hear the 555 RII only last a few thousand miles even as a street tire. Is that correct? And you think they are a better choice for hooking over the PS4s? From what I have been reading the PS4 are the premier street tire, although yes, I know they are very hard.

 

[Ptrug]

Suspension is HUGE, but if you're deciding between tires and suspension I would get some new rubber first. Either way I would get both down the line, but tires will be a way bigger difference than suspension alone. We have all the popular performance tire brands along with great suspension kits we put together over at Lethal Performance that help with keeping the rear end planted. Depending on how hard you drive the car will determine how much suspension work you'd need to do to keep it planted.

This is what I wanted to know! Someone suggested a stop the hop over suspension and some softer tires like 555 RII in the rear. What are your thoughts on all that? I thought i heard the 555 RII only last a few thousand miles even in regular use.

 

[NoGo5.0]

I mean anything on a FI setup is going to be difficult to make last. That being said the R2s aren't terrible in terms of lifespan, they are a decent tire though, for a street / strip application I would go with something a little more aggressive for you since you are making around 700hp. Maybe like an R888R which won't last very long but will give you excellent traction, or some wider PS4s which will last a little longer than the R888s but still be a little stickier than the 555R2s.

As for suspension a stop the hop kit would be perfect for a street car, Just don't get solid bushings unless you don't care about the ride quality being harsh.

 

[Ptrug]

I mean anything on a FI setup is going to be difficult to make last. That being said the R2s aren't terrible in terms of lifespan, they are a decent tire though, for a street / strip application I would go with something a little more aggressive for you since you are making around 700hp. Maybe like an R888R which won't last very long but will give you excellent traction, or some wider PS4s which will last a little longer than the R888s but still be a little stickier than the 555R2s.

As for suspension a stop the hop kit would be perfect for a street car, Just don't get solid bushings unless you don't care about the ride quality being harsh.

You think the PS4s are a little stickier than the 555 RII? The thing with the PS4s are they are very hard so I could see how a softer tire like the 555 RII could be better.

 

[NoGo5.0]

It depends on what you are looking for in the tire, longevity or grip. Those are basically tires on either side of the spectrum you'd want. If you want your tires to last longer while sacrificing some grip, get the PS4s. If you just want all the grip but will have to replace the tires more often, the R2s would be better.

 

[BluePonyGT]

I started my build with wheels and tires first before suspension. I went with Michelin PS4s all the way around, but 285/35R19's in front and 325/30R19's in the back. At that point all I had done from Steeda is to add the collars in the subframe to re-align it and take the play out of the mounting bushings on the rear subframe, but hadn't done anything else.

I noticed immediate improvement on the handling and "stickiness" of the car with the new tires. The grip on the pavement was way better than the stock Pirelli P Zeros could ever provide. Those were tiny 235/50R18's.

Then as I added suspension and frame stiffening the car gradually over the course of a year or so. It drove better, and better, and better every time I changed something.

Since then I've done a complete suspension conversion front and back. Sway bars, shocks, struts, progressive lowering springs, bump steer, front control arms, rear tow links. The car hugged the road - esp. around corners. That pesky understeer was gone. So was the wheel hop. Cornering was significantly improved - a really good baseline.

So I chose to tackle braking next, and thats when things got interesting. This was a real problem with the stock brakes and thinking I could corner while going downhill into a tight turn, so I wanted a kit that instills confidence that I know will let me lean on the brakes if I had to. I chose to go with the full kit GT350R brake conversion which of course brings new rear knuckles and half-shafts, and better hubs.

BUT - I was forced to switch wheels and tires as part of the conversion. My existing wheels wouldn't work with the GT offset my original wheels/tires had, and the fronts did NOT have the barrel to fit around those massive calipers in the kit. I had to go with a combo that served a GT350R range of offset instead. LMR provides their SVE wheel/tire package for those doing this brake swap. I didn't have the wallet to mount Michelins on these new SVE R360 wheels either, unfortunately. They look great, but I decided to simply stay with the default Nitto NT555 G2's mounted on the rims from LMR to keep the cost of the project down. I also moved down in size in the rear from a 325/30R19 to a 305/35R19.

I can tell a difference right away. Although I have massive 4-corner braking that is super awesome the tires are a bit more yielding. They heat up quickly, which is great, but they do NOT handle well in wet weather. I've lost grip a few times where I didn't expect to, which is always fun. I'd have a lot less confidence handling a corner in wet conditions for sure. Michelin PS4s are just a better tire - period.

So now I'm at the point where I've done just about everything I could think of suspension wise, but the tires make ALL the difference now.

 

[m3incorp]

This....and the stop-the-hop kit and you should be good to go. If you aren't experiencing any hop....well then just the tires may be the answer......for now.

Just so you know, if you drive it, don't expect to get much over 7k miles out of the Nittos. I have my second set ready to go on with only about 6k on the first set of rears....fronts, well those will make it through a few rear changes.

This is a question where you get to pick your poison. Any tire will almost work if you aren't driving the car hard...but there is a reason you slapped that supercharger on it. If you want the ultimate hook, then some type of drag radial is mostly likely in your future. If you want a compromise, then maybe the PS4S in a wider size will do it...in the end, you could possibly end up with suspension parts AND sticker tires. To be honest, I think most of us can only say what we have done in the same situation or would do (without having experienced it). For me, it has been a combination...which can definitely get to be costly....as I keep two sets of wheels and tires with different abilities and switch them out based on the weather and how I plan to drive the car.

Tires are what keep you glued to the road. Start there then ask the question again.

I'm running 555 G2s in the front and 555 RII in the back on Steeda Ultimate Handling Lowering Springs (0.5" drop) and Magneride. That's it. Unless you are competing for "How much money can I spend" or "I really am going to track this car regularly" I wouldn't go much beyond that. Maybe a STOP THE HOP next but other than that it's good.

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