GT4 tail wagging under hard braking? need LSD?
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Joined: May 2014
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From: Bay Area
Increasing toe, cured it! I thought I was going to have the back end come around at one point before increasing toe!
Nordschleife Master
Joined: Nov 2010
Posts: 7,804
Likes: 193
From: Bay Area
Originally Posted by doborder
I agree with @orthojoe..I fixed my braking problem with increasing toe on my 981 GTS. I had extreme wagging under hard braking coming into turn 2 at MRLS,
Increasing toe, cured it! I thought I was going to have the back end come around at one point before increasing toe!
Increasing toe, cured it! I thought I was going to have the back end come around at one point before increasing toe!
I ran 3mm toe in each side in the spyder and the GT3. GT4 is having the same setup done right now. It helps stabilize the car on corner exit too so you can power down earlier as well
Drifting
Joined: Mar 2015
Posts: 3,112
Likes: 23
From: Austin, TX
Yeah. It's really unnerving. I felt the same way at t1 at thill until rear toe was added. Zero wag after the alignment change.
I ran 3mm toe in each side in the spyder and the GT3. GT4 is having the same setup done right now. It helps stabilize the car on corner exit too so you can power down earlier as well
I ran 3mm toe in each side in the spyder and the GT3. GT4 is having the same setup done right now. It helps stabilize the car on corner exit too so you can power down earlier as well
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Joined: Nov 2007
Posts: 3,373
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From: Midwest
Wow, that's ~1/8" or on these tires ~15' per wheel. I just got an alignment after getting toe links and thrust arm bushings installed and had the tech set the rear to the stock 10' per wheel, but I guess if I experience wag I'll see how this recommendation works if it's proven on track despite being out of spec. I'm thinking that much toe might create excessive tire wear on the road since mine is a dual-purpose car, though -- is that warranted? Thanks for the data point though!
Oh well, give it what it likes and go flog it !!
Nordschleife Master
Joined: Nov 2010
Posts: 7,804
Likes: 193
From: Bay Area
Originally Posted by jphughan
Wow, that's ~1/8" or on these tires ~15' per wheel. I just got an alignment after getting toe links and thrust arm bushings installed and had the tech set the rear to the stock 10' per wheel, but I guess if I experience wag I'll see how this recommendation works if it's proven on track despite being out of spec. I'm thinking that much toe might create excessive tire wear on the road since mine is a dual-purpose car, though -- is that warranted? Thanks for the data point though!
Instructor
Joined: Jun 2014
Posts: 199
Likes: 27
From: Melbourne
Here is an interesting one. I took mine out for it's first real track session yesterday at our local track (Phillip Island - Australia). Basically the car is still as delivered from the dealer. Another mate also had his GT4 there.
T3 for us is a fast left that has a big stop into a hairpin right after it. My car I could not take the fast left flat out and get the car stopped (around 190km.hr - sorry for the metric thing) - I had to have a small lift and brake as soon as the car was straight in order to make the corner. I could not brake at 100% effort or else the car would do the whole kill-deathy rear swap thing.
My mates car he could easily take the corner flat and brake around 20m later than I was and his car shows no sign of this death wobble.
The only real difference between the 2 was his car has Michelins and I have Dunlops - but neither of us have yet seen what the alignment is on our cars. But certainly his is far more stable under brakes than mine is currently, but I expect we'll see a good alignment will make a big difference on these things.
T3 for us is a fast left that has a big stop into a hairpin right after it. My car I could not take the fast left flat out and get the car stopped (around 190km.hr - sorry for the metric thing) - I had to have a small lift and brake as soon as the car was straight in order to make the corner. I could not brake at 100% effort or else the car would do the whole kill-deathy rear swap thing.
My mates car he could easily take the corner flat and brake around 20m later than I was and his car shows no sign of this death wobble.
The only real difference between the 2 was his car has Michelins and I have Dunlops - but neither of us have yet seen what the alignment is on our cars. But certainly his is far more stable under brakes than mine is currently, but I expect we'll see a good alignment will make a big difference on these things.
Drifting
Joined: Mar 2015
Posts: 3,112
Likes: 23
From: Austin, TX
Here is an interesting one. I took mine out for it's first real track session yesterday at our local track (Phillip Island - Australia). Basically the car is still as delivered from the dealer. Another mate also had his GT4 there.
T3 for us is a fast left that has a big stop into a hairpin right after it. My car I could not take the fast left flat out and get the car stopped (around 190km.hr - sorry for the metric thing) - I had to have a small lift and brake as soon as the car was straight in order to make the corner. I could not brake at 100% effort or else the car would do the whole kill-deathy rear swap thing.
My mates car he could easily take the corner flat and brake around 20m later than I was and his car shows no sign of this death wobble.
The only real difference between the 2 was his car has Michelins and I have Dunlops - but neither of us have yet seen what the alignment is on our cars. But certainly his is far more stable under brakes than mine is currently, but I expect we'll see a good alignment will make a big difference on these things.
T3 for us is a fast left that has a big stop into a hairpin right after it. My car I could not take the fast left flat out and get the car stopped (around 190km.hr - sorry for the metric thing) - I had to have a small lift and brake as soon as the car was straight in order to make the corner. I could not brake at 100% effort or else the car would do the whole kill-deathy rear swap thing.
My mates car he could easily take the corner flat and brake around 20m later than I was and his car shows no sign of this death wobble.
The only real difference between the 2 was his car has Michelins and I have Dunlops - but neither of us have yet seen what the alignment is on our cars. But certainly his is far more stable under brakes than mine is currently, but I expect we'll see a good alignment will make a big difference on these things.
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Instructor
Joined: Jun 2014
Posts: 199
Likes: 27
From: Melbourne
I already have them. They have been sitting on my office floor since well before the car arrived.
But you still have to test it out first as delivered so you have a mark to compare against.
I'll go back in a few weeks and test again after the alignment is done.
They have been sitting on my office floor since well before the car arrived.But you still have to test it out first as delivered so you have a mark to compare against.
I'll go back in a few weeks and test again after the alignment is done.
Rennlist Member
Joined: Nov 2007
Posts: 3,373
Likes: 1,030
From: Midwest
The street car is running smaller front wheels, track, and tires than clubsport. It's also got larger rear wheels, and about as much (or more) tire than the clubsport.
I'm sure the Clubsport is way more neutral out of the box, hence more rear toe. Maybe I'm wrong.