Horrible understeer

[NightmareMoon]

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.

I'd be timid about oversteer if I was testing on clover leafs too.

The feeling of the rear starting to come around is disconcerting, but that's also exactly what it should feel like to drive at the tires ideal slip angle. The car is rotating just a bit ahead of what normal 'tracking straight' feels like, and as long as it holds a 5 - 8° slip (slide) angle and doesn't get away from you, that should get the most possible grip out of the tires. That's what I'd call driving 10/10ths.

If you get to that slip angle and then lift suddenly, you done f%&ked up and its probably going to spin, so don't do that. Keep driving the car, but accept its committed to the turn and you'll need to be gentle to get into and out of that state with control. whatever you do, DON'T PANIC

The rear IS coming around on you, but slowly and exactly as quickly as the car is rotating around the corner so it all balances out. Done right, your nose will be pointed a few degrees inside of where it would normally point for a corner that radius, and you'll be using a few degrees less steering input. It doesn't feel normal, but that's the feeling to hunt for. Its not a drift where you're counter-steering or anything, its just a very mild slide which should result in all four tires working optimally.

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[NightmareMoon]

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.

If you prefer, I could quote Ricky Bobby, or talk about how the most important thing about Swaybars is Family.

 

[shogun32]

If you get to that slip angle and then lift suddenly, you done f%&ked up and its probably going to spin, so don't do that. Keep driving the car,

I drive my car like i do my Ducati, once opened the throttle stays open and my only options are lean more, feather the rear brake slightly or unclench the seat and ride it out.

Unfortunately the car doesn't lean so I just keep the throttle steady and let the car come back to me a little bit before I venture back deeper into the pedal.

 

[saleen367]

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

^^^^ This ... from everything I've learned (which ain't much), slicks require a much higher spring rate then even a SC2. I believe I was told that by someone who schools with Kenny Brown.

 

[TeeLew]

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.

Don't quote words I never wrote ever fucking again asshole.

 

[TeeLew]

If you prefer, I could quote Ricky Bobby, or talk about how the most important thing about Swaybars is Family.

The one you chose is far and away the most popular. I've literally had hours-long drunken conversations started by it.

 

[TeeLew]

^^^^ This ... from everything I've learned (which ain't much), slicks require a much higher spring rate then even a SC2. I believe I was told that by someone who schools with Kenny Brown.

Yep. The higher the accelerations & loads, the more suspension stiffness it takes to support them.

 

[TeeLew]

I'd be timid about oversteer if I was testing on clover leafs too.

The feeling of the rear starting to come around is disconcerting, but that's also exactly what it should feel like to drive at the tires ideal slip angle. The car is rotating just a bit ahead of what normal 'tracking straight' feels like, and as long as it holds a 5 - 8° slip (slide) angle and doesn't get away from you, that should get the most possible grip out of the tires. That's what I'd call driving 10/10ths.

If you get to that slip angle and then lift suddenly, you done f%&ked up and its probably going to spin, so don't do that.

This is a really good point. Driven fast enough, any car will assume a significant yaw angle. The magnitude of the yaw will give us an idea of the balance, but just because the car has yaw does not mean it's loose, just that the front and rear tires are deflecting differently.

 

[WildHorse]

Don't quote words I never wrote ever fucking again asshole.

Oops. Give yer balls a tug bud.

 

[baazooka]

Hello again,

I recently put on a gt350 front bar which made a wonderful difference, along with steeda links with 0 preload. I don't have the tire setup you do but similar spring rates. I picked up mine from ebay for around 120 shipped.

By the way, if you are interested in a test drive swap, maybe we could both learn something.

 

[baazooka]

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

Great info here.

I have a noob question: do camber plates replace the spring rubber you mentioned?

 

[kz]

Great info here.

I have a noob question: do camber plates replace the spring rubber you mentioned?

They're two completely different things. Spring rubber is a rubber piece you put between spring coils for additional spring rate (make spring stiffer), camber plate replaces OEM strut mount and allows top of strut move laterally resulting in camber change.

 

[AvalancheSVT]

Tons of great info in this thread guys. great work.

 

[TeeLew]

Oops. Give yer balls a tug bud.

I take that shit seriously, Fuckwit.

 

[dmcg940]

So what should I do to balance the car out.

If it's plowing you need more REAR stiffness, not front stiffness. Higher-rate rear springs and/or bigger rear bar. Conversely, softer front springs, softer front bar. All those things work to reduce understeer.

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