My car has stopped gripping since I changed the suspension

  1. This plus alignment. A 1" drop will change the camber so now you have a smaller patch to work with, and with no squat, there is less weight transfer to the rear wheels.

  2. Much less of a factor than what he said, but you're now running a set of springs and dampers which were not developed together. This is one of those tradeoffs you get. Id say your next upgrade should be one of the Steeda damper sets (or Bilstein, Ford Performance, etc.) that are designed and developed to be used with a stiffer spring. Especially since I'm assuming you have an ecoboost without the performance pack, which means your original suspension was mostly designed for comfort.

  3. The rearward weight transfer happens regardless of whether the car is squatting or not. If the springs were 100% stiff/stock, that doesn't mean the weight won't shift to the rear tires when you accelerate. There is still a force because of the difference in height between the CG and the line between the wheels.

  4. How stiff are the new springs compared to the stock ones? Stiff springs in the rear will just light up the tires on an unprepped surface

  5. https://www.steeda.com/steeda-mustang-progressive-sport-lowering-springs_555-8210?gclid=EAIaIQobChMIn5Kb9O-P9wIVkzY4Ch2U6AAIEAQYAiABEgLF8fD_BwE

  6. Because I’ve tried this post 3 times before and it kept getting removed cuz I mentioned tires. The automod kept telling me to check the FAQ or post on

  7. Lowering springs lower the car by the amount (1'' in your case) and that's it. They don't address any of the flaws they introduce into the suspension geometry by doing that. In general, everything about how the car handles and rides will be worse by lowering the car without addressing anything else. Perhaps you'll get a bit sharper steering under light load and less brake dive, but the actual limits will be lower because of the flaws introduced into suspension geometry. This is double so because you're chopping the springs without addressing the shocks or any other components at all - they aren't matched to your new ride height. Now, the shocks are under slightly more load & supporting more of the car's weight than normal, so they can't control the wheel as they normally would, which affects your grip and "wheel hop" over imperfections in the pavement. I'm stressing the limits of my knowledge here, but this also spills over into all of the A-arms and links in the suspension as well.

  8. This, things like camber or toe gain under compression could be exaggerated because it's already been lowered and is operating outside Ford's intended range as well, and that assumes there's nothing weird like bushing binding going on. There might be something like an adjustable link that could help with that similar to extending the traction rods on an s chassis rear end. Besides it's not like Ford has a ton of experience with IRS in these cars lol.

  9. In general, shocks don't support weight or load at all, they exclusively dampen movement at any point in their range. As long as he's not bottoming out the shocks they're fine. He might want different shocks for the different spring rate and ride but still, no weight/load supported by the shocks in 99% of applications.

  10. Temperature is perfect, tire pressure is perfect, alignment is done. Idk what’s going on. Maybe the alignment was done wrong?

  11. Surprised there's no mention of antisquat, but your antisquat values would change with the lower ride height which could mean less weight transfer to the rear under acceleration if your a/s value went up from stock.

  12. Which tires did you go with? What’s the temperature where you are? And are the tires hot when you’re attempting either?

  13. Like others have said. No compression stroke means the car won't squat and shift all the weight on the rear wheels to put the power down. Stiffer setups will always make the rear end more dicey. I'm not familiar with your tires but there's a chance they need to be warmed up properly before offering peak grip too.

  14. Makes sense. I didn’t do it for the looks though, I did it to increase my handling performance for autocross events, and it definitely made my car handle 10x better so I’m happy about that.

  15. The 'ol anti-performance mod. You're a stance guy now. Pull around back for your vape, polo shirt that the collar can't go down, and multi-colored sunglasses.

  16. Lmaoo you got me. On a serious note, I autocross a lot and I got those springs for the sake of bettering my handling when racing. They definitely did wonders when it comes to that aspect.

  17. Are you letting the tires warm up first? Higher performance tires take longer to warm up for their ideal grip. Also why were you censoring the word tires?

  18. If you have crazy stiff springs your car won’t throw the car weight onto the back tires, giving you grip. Better on the track, worse if you need a great off the line.

  19. You've decreased weight transfer. The tire change increased mechanical grip, but with less weight transfer, you lose out when only the rear wheels are trying to do anything.

  20. Just so everyone knows, lowering springs are a cosmetic only modification. If you change your springs you need to change your dampers to match. They are tuned together and need to be in harmonic balance to do their job properly.

  21. My guess is the tires aren't warmed up all the way. Summer performance tires "can" be fantastic. But in my experience, sub 75 degree weather and less than 15 minutes driving, they aren't great.

  22. This is a common problem with some “car enthusiasts”. They just throw parts at a car without much thought. Progressive lowering springs weren’t designed for performance so much as just looks. The spring rates aren’t even designed for your dampers specifically. They’re just a ball park to cover base and performance packages a like. So much more goes into suspension dynamics than just lowering it with a “uhp” tire. The performance of tires varies greatly. Some are great for everything but traction from a dig.

  23. I had same exact problem with my 2014 CLS 550 rwd (weistec tune. 540 hp, 715 lb ft). Stock 18 wheels with all season continental conti pro sports would have almost awd grip. Switching to 20" and way wider Michelin Sport S (295 width vs 265) caused so much frustration. I would break them lose even at 60mph.I tried lowering the pressure to 32psi to no avail. I'm guessing I was not heating them up enough but who would. Lower profile might be a contributing factor as well.. I'm not a racer, just some loser who would want to floor it every now and then. Pirelli PZero PZ4 was about the same. I'm not getting an rwd car with that much power ever again. M5 competition has more power from factory with 0 issues (kept the same wheels).

  24. Have an alignment? Changing suspension can make it harder to get grip down from a dig what happens. Especially lowered more camber means less grip patch

  25. Well... lowering your car throws off geometry of your suspension, and you need to also adjust alignment, toe, camber. 1" is enough of a drop in most cases to warrant that. Stiffer spring rates and compressed suspension won't allow the squat the car had before to absorb and transfer launch energy. This also applies to tires, going to stiffer sidewalls don't allow flex/fold, it's why they corner better (and are less forgiving though). No flex/fold to mitigate the launch energy. NT555's aren't a super hot track tire so they don't necessarily need to be warmed up much to grip, just so ambient is 70+.

  26. I am leaning towards agreeing with most people here that the new springs have likely messed with the alignment and contact of the tires to the road and that is where the majority of the issue is likely stemming from.

  27. S550’s camber in a LOT when lowering, especially the rear. I’ve personally seen +1-1.5* of negative rear camber over factory specs on lowered s550’s. Your best bet is to get adjustable upper control arms in the rear and have a specialist shop take some rear camber out

  28. Off the line there’s a smaller change in the distribution of weight so there’s less load headed to the rear and therefore less grip. Camber was probably also affected by the drop. Overall the car will be much faster though.

  29. Stiffer springs resist weight transfer more, thus resulting in lower traction on the rear end when you accelerate.

  30. I'm a tad bit curious if its because the new tires need to be broken in for a couple hundred miles. I just put some Firestone Indy 500's on my civic (so unnecessary but its fantatsic), and for me the first 200 or so miles were slick because of the non stick coating they put onto the mold before the rubber is injected

  31. I’m seeking a kit of the eibach sport line lowering springs if you want to give them a shot. What really fixed my gt from hopping from 1st to 2nd and gripping on digs was the rear control arm.

  32. Well everyone is giving you answers with very little information. Some possibilities: your new tires grip better, but fall off quicker than an all season. This is by design, and you need to learn the limits of grip of each tire you use. Secondly: you changed spring rates but you likely didn't change damping. This means your weight transfer is not being handled as well as in oem format, and poorly controlled weight transfer is incredibly bad for grip, especially with sticker tires which are more sensitive to shock loading. Third: you don't have any empirical evidence, but just spent a bunch of money thinking it would make you faster, so any change that isn't immediately positive is unconsciously exaggerated in your head.

  33. Your rear camber is too aggressive from the drop. It's not really adjustable from the factory. Not easily at least. Steeda makes an overpriced rear camber adjustment kit to make the process easier. Your alignment shop, like many will, probably looked at it and said to themselves "not adjustable." I had to have that conversation multiple times with different shops and explain that it is. From others' experience even some lazy dealerships that don't look at the service manual or don't want to deal with it (two person job) will tell you that it's not adjustable.

  34. My 330d grabbed like a mfer when i bought it with leaky worn rear struts and stock springs. Because it squatted like a drag car.

  35. When I used to race my Mustang at the track, the only way to get the car to hook well was to heat the shit out of them. A big Smokey burnout. Everyone agreed that Nittos like to be hot to hook.

  36. No squat=less grip. Look at drag muscle cars (generally older ones). Usually they’ll have more height in the back to allow compression and absorb some of the energy to keep tires level

  37. Stiff suspensions reduce body roll at the cost of requiring more from the tires, and soft springs cause greater weight transfer to the rear tires as the springs absorb less of that energy. Since your car is RWD, it benefits from as much weight transfer to the rear wheels as possible. Therefore it will have the most traction under acceleration with softer springs. If a car is FWD, soft springs do the opposite of helping grip while accelerating as weight transfers to the rear tires reducing grip to the fronts.

  38. Road temp and tire temp can affect the grip as well. If they are a harder compound, the tire will be less likely to grip in cooler Temps, or when the tires are cold.

  39. Drag cars have big soft tires and soft suspension so they squat and transfer weight to the back wheels to improve traction because launch is critical to there time. Track cars hardly launch, so compromise off the line traction to gain stability and cornering performance. Performance is all about compromise. Choose your goals and focus solely on that.

  40. You know you put in a stiffer suspension and you're asking why you don't have grip? How do you expect to hook up with stiff springs lol. You set your car up for corners, not launches.

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