No Feel, car seems dead in turns

[SteveWK]

I don't have a lot of experience road racing, been at Hallett 6 times, but I just feel (pun) that my car has very little real feedback while driving. It is a 2013 Gt500. I don't know if it is the electric steering or what, but it just doesn't feel right. My suspension includes Griggs front springs, Koni's and BMR sway bar. The rear end includes Griggs GR40 shocks/coil overs, watts link, sway bar, and torque arm. It just feels dead to me. Actually it felt dead to me before the suspension mods. Any ideas?

Steve

 

[86Fbody]

Do you have the EPAS set to sport mode? Also did the springs lower the front and if so did you install a bump steer kit to correct the tie rod angle?

 

[SteveWK]

It is in sport mode. The front is lowered about an inch but I don't have a bump steer kit.

 

[86Fbody]

You may want to get a bump steer kit, may also want to speak with someone from Griggs or MM about it as they would have some good insight on this.

 

[Grant808]

Not trying to be snarky, but it's a GT500...what do you expect? You would need massive tires to make it feel tight or agile, assuming nothing is setup improperly.

What tires are you running up front?

 

[SteveWK]

I have Michelin Pilot Super Sports 275/40ZR/19s in the front and 295/35ZR/20s in the rear. I forgot to mention I have BMR front control arms too.

I'll try the bump steer kit to see if that helps, but I'm guessing it's just the nature of the beast. The car turns in hard, but at times I just don't get a lot of feedback from the road. I was just wondering if other people have had the same experience.

 

[86Fbody]

More feed back would also come from having a shorter sidewall or harder sidewall on your front tires.

 

[Grant808]

Is that on the stock 19x9 front? The super sports have really soft/flexible sidewalls and could probably use the support from a wider rim, if you want better feel. If you look at how Ford fit the Super Sports on the GT350...they're really stretched on. 295 on a 10.5" for the base 350, and 305 on a 11" for the R front.

My rain set of tires are Super Sports with 265/35-19 on 19x9 up front, and I wish I went with 285/35-18 on a 18x10. That 265 isn't even enough tire for my GT or Boss.

What pressures are you running hot? Super sports need a lot of pressure, IMO.

 

[Kartracer]

I would call Griggs or MM, I call and talk to MM after most race weekends. It also seems like you have a lot of rear suspension and the front may be over matched but you mentioned it was like that before the upgrades so maybe not. Also so it is strange that that it turns in good but then you lose the feel, if you are still getting up to speed you could be entering the corner too slow and getting on the gas too hard or soon. I assume this is a street car, are you able to add negative camber at the track?

 

[SteveWK]

Thanks for the replies.

I have the stock rims which are 9.5" wide front and back, and it is driven mostly on the street. Tire pressures, if I remember correctly, were 34 PSI hot. The current alignment settings are:

Front:

Camber = -1.4
Caster = 5.1
Toe = 0.11
Steer Ahead = 0.00

Rear:

Camber = -0.1
Toe = 0.01/-0.03
Thrust Angle = 0.02
Centered +/- 1/16"

I do have caster/camber plates and can increase the camber. The track is 150 miles away. Not sure how much camber I can add without wearing the edge of the tire out driving to the track and back, but that might be an option. Something else just crossed my mind, I don't think I've ever turned the traction control off while at the track. I'm betting that is affecting how the car feels. Don't know why I didn't think of that until now - lol. I left it on to control the rear end on the straights since it would lose traction from time to time and kick out, but since I've added the complete Griggs rear that doesn't appear to be a problem anymore.

As far as the tires go, this is what I did to one tire at the track. Probably not enough pressure and camber.

 

[darreng505]

Not trying to be snarky, but it's a GT500...what do you expect? You would need massive tires to make it feel tight or agile, assuming nothing is setup improperly.

What tires are you running up front?

Unfortunately Grant is right. That is a known criticism of the GT500. You'd have to ditch the dampers and swap out all the bushings. Lower it. Reduce weight and maybe it'll feel more nimble and responsive.

EDIT: Ok I see you put a ton of suspension parts on. Let me ask you this. Did you put them on all at once or piece by piece with testing in between? Did it feel better before and suddenly it doesnt?

 

[86Fbody]

Thanks for the replies.

I have the stock rims which are 9.5" wide front and back, and it is driven mostly on the street. Tire pressures, if I remember correctly, were 34 PSI hot. The current alignment settings are:

Front:

Camber = -1.4
Caster = 5.1
Toe = 0.11
Steer Ahead = 0.00

Rear:

Camber = -0.1
Toe = 0.01/-0.03
Thrust Angle = 0.02
Centered +/- 1/16"

I do have caster/camber plates and can increase the camber. The track is 150 miles away. Not sure how much camber I can add without wearing the edge of the tire out driving to the track and back, but that might be an option. Something else just crossed my mind, I don't think I've ever turned the traction control off while at the track. I'm betting that is affecting how the car feels. Don't know why I didn't think of that until now - lol. I left it on to control the rear end on the straights since it would lose traction from time to time and kick out, but since I've added the complete Griggs rear that doesn't appear to be a problem anymore.

As far as the tires go, this is what I did to one tire at the track. Probably not enough pressure and camber.

View attachment 33923

Being that your outside tire is wearing instead of the inside I think you either need more camber or a stiffer tire, I would think maybe a stiffer tire.

 

[MFE]

You need a shit ton more negative camber in the front, and you probably need to listen to the tires more if you're not getting feedback through the steering, which would be telling you that the car is plowing like a mother****er and to dial steering OUT of it and/or slow the **** down more before corner entry. Negative camber won't eat your tires unless you have toe in it, but it sure will save the outside edges and it'll hook the front end more. Toe is what eats tires, camber concentrates the wear onto the edge. Hell, I run my car at 2.5 degrees negative all the time during track season, both on the track and the street without uneven tire wear. The trick is I zero the toe when I do it.

 

[SteveWK]

Firstly, I am sorry I haven't got back with you sooner. Work has been a bitch and I got my walking papers today. The car isn't going anywhere soon. I will fill in the details concerning the suspension later.

Steve

 

[Grant808]

You need a shit ton more negative camber in the front, and you probably need to listen to the tires more if you're not getting feedback through the steering, which would be telling you that the car is plowing like a mother****er and to dial steering OUT of it and/or slow the **** down more before corner entry. Negative camber won't eat your tires unless you have toe in it, but it sure will save the outside edges and it'll hook the front end more. Toe is what eats tires, camber concentrates the wear onto the edge. Hell, I run my car at 2.5 degrees negative all the time during track season, both on the track and the street without uneven tire wear. The trick is I zero the toe when I do it.

This.

As far as the tires go, this is what I did to one tire at the track. Probably not enough pressure and camber.

View attachment 33923

And this.


0º toe is the way to go for your street setting, wether it is your track setting or not. Your track setting should probably be maximum negative camber.


Looking over the rest of your setup, you should also probably be running 'square' or the same wheel/tire size on all 4 corners. Seems to me that your car is currently setup to push with the staggered tires. And running square would allow you to rotate tires front to back too.

If you update this thread after each track day with pictures of your new tires, we can probably help you with fine tuning your settings. Or you could get an IR temp gun and check the tread temps across the profile and figure out what you need to do from there. More than a 10º F difference between outside/center/inside and you need to change something.

Sorry to hear about your work.

 

[darreng505]

In addition to above, make your your tires are inflated to the recommended pressure. If the edge is rolling because of low inflation and its cold, it will chunk off like that.

Although I agree negative camber is necessary to help turn it etc. It's not a solution to the wear on the edge of your tires but rather will just hide over the real problem. Your driving style needs to change. Your speed and chosen line need to keep the tires rolling forward and the slip angle on those street tires should not exceed 5 degrees in my opinion (i.e. stop pinching the car and turning the wheel so much.)

Please use zero toe. I once experimented with slight toe out and the car would not turn and I almost literally drove right off the track in the first turn. It was crazy how the car literally did not turn at all. Had to re-toe the car in the paddock.

 

[86Fbody]

In addition to above, make your your tires are inflated to the recommended pressure. If the edge is rolling because of low inflation and its cold, it will chunk off like that.

Although I agree negative camber is necessary to help turn it etc. It's not a solution to the wear on the edge of your tires but rather will just hide over the real problem. Your driving style needs to change. Your speed and chosen line need to keep the tires rolling forward and the slip angle on those street tires should not exceed 5 degrees in my opinion (i.e. stop pinching the car and turning the wheel so much.)

Please use zero toe. I once experimented with slight toe out and the car would not turn and I almost literally drove right off the track in the first turn. It was crazy how the car literally did not turn at all. Had to re-toe the car in the paddock.

That is interesting that toe out would cause that, I thought toe out was meant to aid in turning but causes straight line instability and darting.

 

[darreng505]

That's why I tried it. It might be very sensitive to other setup geometry or aero but whatever you do don't try it. I've been tracking my car for 3 years and when I went into turn 1 with toe out and the car sailed out on me it was in my top 3 pucker moments. It was undrivable.

 

[86Fbody]

That's why I tried it. It might be very sensitive to other setup geometry or aero but whatever you do don't try it. I've been tracking my car for 3 years and when I went into turn 1 with toe out and the car sailed out on me it was in my top 3 pucker moments. It was undrivable.

It must be influenced by the rest of a suspension setup, my dad's 86 had toe out for quite sometime and worked just fine, eventually we switched to 0 toe simply because we didn't want tire wear and darty street driving.