Horrible understeer

[NightmareMoon]

Buy two adjustable bars (or a good 35mm adjustable front and like a GT350R rear). Without adjustable shocks to help tune the balance, you need something adjustable in the system besides the camber to play with balance, so these will be that.

I actually disagree that the stock GT bar is enough in the rear, but to each his own., BUT my point will be that the rear bar is really easy to swap out rear bars entirely. The front is a pain, but it would be easy to experiment with rear bars with only a few minutes work, so buy both front and rear, install the front, and then toy with settings on both and/or swapping rear bars.

I'd recommend a bit more than 2.5 degrees of camber, yes it will be a little noticeable bump in grip on the front, but you can start with the bars and see how that works. I run ~3.2 and its a big change over 2.5. I don't think its a substitute for having adjustable swaybars in your case, since you have relatively soft springs and non-adjustable shocks.

Mind the tire condition too. With your current camber and spring setup, when the tires start to wear out, it will feel like really bad understeer as the shoulders go dead first. Yes, its also hard to control for driving style.

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[IPOGT]

@WildHorse

Seriously dude if you can't help, your smart ass comments are not welcome.

Yes, I can slow down and it will not understeer, I can also stab the throttle and then it oversteers.

So in your infinite wisdom should I slow down or should I stab the throttle?

I'd rather tighten the front or loosen the rear so the car is balanced.

I promise you it isn’t your shocks/struts. What tires and size are you running? Wondering if you don’t have enough tire to hold the extra force created by the firmer components.

 

[K4fxd]

Thanks all.

I know sway bars are for tuning so I'll go ahead and get a set of adjustable

@shogun32

I'll try the sways first, if that doesn't do what I want I might take you up on the offer, Thanks.

 

[bnightstar]

I actually disagree that the stock GT bar is enough in the rear, but to each his own., BUT my point will be that the rear bar is really easy to swap out rear bars entirely. ally bad understeer as the shoulders go dead first. Yes, its also hard to control for driving style.

Why ? I only run Steeda front bar 2nd hole from full soft and with both OEM shocks and Ohlins R&T I never seen an issue with the rear PP1 bar (sure not base GT bar) but overall I don't need more rear bar and car is really well balanced at the moment.

 

[Jaymar]

I'll drop out yet another theory from some interesting reading from @BmacIL awhile back. Lack of camber gain on the Macpherson strut means that body roll at the front end puts your tire off contact patch and onto the outer edges so an increase in front bar actually limits geometry change by limiting body roll leading to a decrease in understeer up until a certain point where conventional wisdom would then apply again for swaybar increases decreasing traction by applying more weight at that end in static cornering. So, try increasing the front bar to about GT350 levels first to minimize body roll/camber loss and see if that works.

 

[NightmareMoon]

Why ? I only run Steeda front bar 2nd hole from full soft and with both OEM shocks and Ohlins R&T I never seen an issue with the rear PP1 bar (sure not base GT bar) but overall I don't need more rear bar and car is really well balanced at the moment.

Well, I can’t imagine you and I drive the same.

With just a front bar its very tolerant to throttle on exit but doesn’t throttle steer as well on entry or mid corner IMHO for my car with the various spring and shock setups I’ve used. What do they say, loose is fast? I need the car to rotate when I lift mid corner, and I do believe the chassis tends to like maintenance throttle or slight throttle to turn the best. Probably something about the front heavy weight distribution.

 

[TeeLew]

OK, now that I have 99% of my suspension mods done, Steeda stop the hop, knuckle bearings, 200/800 springs, good struts and shocks, all the normal upgrades. It plows like a Mack truck, even with 295/35 19 R7's square

I read a lot where people recommend larger front sway bars?? Wouldn't this make it understeer more????

So what should I do to balance the car out. HPDE type events, no competition other than me against me per lap.

Thanks

First, let's all be honest. The loads we shift as we make as chassis changes is nothing compared to what a good driver can move with his feet. If you have a massive imbalance, it's likely something you are doing as a driver. The car may very well be not allowing you to do as you wish, but just understanding it's a feedback loop is important.

Where is the understeer? What type of corner? What can you do to influence it? Is there a video? Talk about the corner where you struggle the most and tell us everything you can, especially what happens the moment before you lose the front. Are you on throttle? Brakes? Where is the steering? Have you watched other cars through this corner? All is important info.

Here's my opinion and it will likely be one you initially reject, but really think about it. It might be worth something. This is not an argument from authority in any way, but I work on a lot of cars and this scenario is very common.

You're likely either driving in too deep or not deep enough. If you're driving in too deep & still heavy on the brake, then you'll pick up a grinding understeer as soon as you turn the wheel & you'll have to wait a long time for the car to slow before it can turn. Don't ask so much on entry and it will turn. The alternative, which is much more common, is not carrying enough speed on entry.

This is what I personally found with the S550. With either a stock spring setup or one similar to yours (which has also lowered the front ride height more than the rear, adding static rake), I find the Mustang has a serious lack of front support and entry stability is not good. If you find yourself driving on your fingertips, then you agree with me, whether you're aware or not. To make a front engine GT car turn, you need to be able to carry the brakes into the corner to keep tire load forward in the car. As long as you're shifting weight forward with your feet, you can basically make *anything* turn. What I've found with stock-ish front spring rates is that the car will oversteer if you carry brake into the corner, but it understeers if you don't, which makes for a Catch-22. A very easy 'Do loop' to find yourself in is trying to fix the understeer, which is not really the root issue. By 'fixing' the understeer, we introduce more entry instability and make the problem worse.

My advice? Put on a big front spring, either the Steeda or BMR, without stiffening the rear spring. You don't can't afford to give up any grip on the rear of the car. A cheap and easy way to see if my advice has any merit is to put a 70 or 80 hardness spring rubber in the front and try it. https://www.resuspension.com/springs/spring-rubbers/res-5-00-spring-rubber-re-sr500-1500-xx.html

I believe that Ford delivers a fundamentally loose car. They give it understeer by reducing front camber, but the spring/bar/ride height combo is tail-happy as shit. That's why you see so many Mustangs with the back end hanging out of a crowd of people. The bloody things are hard to control as delivered and honestly, I put a lot of blame on the chassis engineers. They spent too much time on a computer and not enough in the seat. The Mach 1 is the first stock S550 to even go in the direction I'm talking about & it gets pretty good feedback from the track.

So there's a lot to chew on. See if it does anything for you.

 

[K4fxd]

Lack of camber gain on the Macpherson strut means that body roll at the front end puts your tire off contact patch and onto the outer edges so an increase in front bar actually limits geometry change by limiting body roll

Maybe this is why I see large front bars for this car.

A cheap and easy way to see if my advice has any merit is to put a 70 or 80 hardness spring rubber in the front and try it. https://www.resuspension.com/springs/spring-rubbers/res-5-00-spring-rubber-re-sr500-1500-xx.html

I'll give this a try.

My corner entry technique is to apply hard brake before entry then ease off the brakes through the apex where I apply power. That is the general way I do it, I'm not real good at putting things in writing.

It could be an age thing too, I'm past my prime and don't get enough track time to hone the wanning skills. I drove a Tiger competently in the 70's 80's era. Another front heavy high powered car. It was balanced pretty well. I'm looking for that feel from the GT

 

[shogun32]

Do the zip tie thing. I think you're running out of travel

 

[bnightstar]

Well, I can’t imagine you and I drive the same.

With just a front bar its very tolerant to throttle on exit but doesn’t throttle steer as well on entry or mid corner IMHO for my car with the various spring and shock setups I’ve used. What do they say, loose is fast? I need the car to rotate when I lift mid corner, and I do believe the chassis tends to like maintenance throttle or slight throttle to turn the best. Probably something about the front heavy weight distribution.

I don't think the maintenance throttle is good for our cars and I'm struggling with trying to remove it from my driving. In fact with soft springs you just transfer weight out of the front of the car with maintenance throttle so the car is not rotating as it should. Hanse why when you lift mid corner it start to rotate. Contrary to the popular believe up to a point stiffer front bar actually help with turn in. Which is why I run 515 lbs front springs on my Mustang now with only 800 lbs rear. And I'm super happy with how the handling of the car is.

 

[NeverSatisfied]

I can only guess how shitty your setup drives with R7s and caddy spring rates. Your spring rates when corning are whatever the internal bump stop spring rate is in the front B6’s and the external rears.

I run BMR SP083s and an endurance 200tw 305s on bilsteins with similar alignment and with stock bars I could still rip it, but it has ass piles of body roll. I added whiteline bars—I’d now call it acceptable for hpde’s.

SP083’s are very comfortable for daily duty with the bilsteins.

If your truly capable of driving R7s at the limit, you’re nowhere near the right spring rates you need

 

[TeeLew]

What do they say, loose is fast?

That's a quote fun Robert Duval in _Days of Thunder_ (which dates you, BTW!). I have a long-running contention that this line has ruined the handling of more racecars than any other single event known to man. Truly loose cars suck to drive.

We usually induce instability before making it a genuine oversteer balance. Maintenance throttle is often necessary in a high-speed corner to keep the tire load to the rear of the car (provides stability & keeps rolling speed up). Being able to drive through high-speed corners on throttle without inducing excess understeer is our goal, but we'd much rather induce U/S than lose the rear. I generally define high-speed as 4th gear on up. Low speed is 2nd & 3rd. In a low speed corner, maintenance throttle *should* induce understeer. If it doesn't, you're stuck not being able to put power down and end up in a lot of drifts. If you're in a low speed corner and you have to go to throttle to 'catch' the rear of the car, you're too loose. It's important at corner exit that you're not going across the track, but down it.

Here's my caveat. Everything I've written is my opinion when a stopwatch is involved. If you're doing an HPDE day, you're unlikely to consistently drive the front side of the corner hard enough to get the appropriate rotation, which will mean the slower you are as a driver, the more loose you probably want the chassis tuning of your car (this is a bit of over-generalizing, but this is the trend I've observed). Regardless of what he's able to drive, a Pro driver will always set the car up with more understeer than an Am and that is a fact.

"PUSH" is not a 4-letter word...at least not in this usage.

 

[TopJimmyCooks]

OK, now that I have 99% of my suspension mods done, Steeda stop the hop, knuckle bearings, 200/800 springs, good struts and shocks, all the normal upgrades. It plows like a Mack truck, even with 295/35 19 R7's square

I read a lot where people recommend larger front sway bars?? Wouldn't this make it understeer more????

So what should I do to balance the car out. HPDE type events, no competition other than me against me per lap.

Thanks

Check out this. Helped me to better understand what is going on and how to correct it. https://speedsecrets.com/tune-car-handling/

 

[WildHorse]

it's likely something you are doing as a driver.

What I was trying to tell him. But apparently I'm a smart ass. I did just a tire change and it was a whole new learning curve. But whatever ha-ha.

 

[shogun32]

and I do believe the chassis tends to like maintenance throttle or slight throttle to turn the best.

I have 250lb/in front 800/1200 dual-rate rear, and the Steeda front bar on 2nd softest, PP1 rear bar and all the chassis mods. I'm off the brakes well before 1/3 into the corner and immediate back on the gas - not a lot, just some. If I try to add too much gas the nose stays put, but the REAR starts to feel like it's teasing with coming around.

A little past apex and I open the throttle the rear takes a more solid set and the nose also actually seems to track steady if not actually dig in more. If I add too much throttle then the nose hints at perhaps about to go wide.

Maybe I'm just chicken but I'm doing these tests on clover-leafs with concrete walls or guard rails to my outside (or incoming traffic) and I don't feel like smashing the car up. So my observations may be pure bunk since the speeds are so slow.

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