HPDE Tracking Tires Set Up Question
1 - 13 of 13 Posts
Joined
·
2,964 Posts
Do you have aftermarket rims? If not, those 305s are going to be marginally too wide for the stock wheel and you will have a lot of sidewall-induced instability. Similar problem exists if you put 285s on the front. The wheels need to be about an inch wider for this kind of change. Stick with the stock rubber.
I'm running 345s in the back and 285s in the front, on custom wheels so the tires fit properly.
I'm running 345s in the back and 285s in the front, on custom wheels so the tires fit properly.
Joined
·
16 Posts
Thank you!
Either tire set up would be on new wheels - hopefully a little lighter than the OEM wheels.
Joined
·
243 Posts
I run 18"x9.5" +40mm TSW Nurburgrings wrapped in Falken Azenis FK510 275/40-18 square, weighing in a 48.5 lbs per corner on my sedan. I ran them the weekend before last and was happy with their performance versus the stock setup. When stepping down to 18" diameter, make sure you bring your tire pressure up. I ended up at 42psi warm and probably could have used a little more.
The square setup reduced understeer substantially. I can't overstate the improvement over the 255/285 stock stagger, even though my tires on the stock setup are anecdotally better. Note that car companies stagger tire sizes specifically to induce understeer as most people can better handle it than oversteer.
The square setup reduced understeer substantially. I can't overstate the improvement over the 255/285 stock stagger, even though my tires on the stock setup are anecdotally better. Note that car companies stagger tire sizes specifically to induce understeer as most people can better handle it than oversteer.
Joined
·
16 Posts
Great feedback! Thank you!
Joined
·
3,625 Posts
A square setup is good for rotating tires. The stock setup is how the car was designed.
Depending on your wallet will dictate the square setup.
Front camber I would increase to 2.5' +. Rear Camber stock. Toe leave stock. If this is your street car full time I would adjust the front camber to stock when you go back to the street. Corner balance is a must.
Because the car is heavy, dial the understeer out by rotating the car and then getting on power. If the car is not rotated and the throttle is applied you will introduce additional understeer. This will feel like the car is snowplowing through the turn which does not make for a fun track day.
Have Fun and post some pictures. What track ?
Depending on your wallet will dictate the square setup.
Front camber I would increase to 2.5' +. Rear Camber stock. Toe leave stock. If this is your street car full time I would adjust the front camber to stock when you go back to the street. Corner balance is a must.
Because the car is heavy, dial the understeer out by rotating the car and then getting on power. If the car is not rotated and the throttle is applied you will introduce additional understeer. This will feel like the car is snowplowing through the turn which does not make for a fun track day.
Have Fun and post some pictures. What track ?
Joined
·
16 Posts
LOL - you sound like you saw me this past weekend! I'm so used to throttling through a corner and using the torque on the street. On the track, it was just the opposite. I need to wait about 2 additional heartbeats and let the wheel start to unwind before full throttle. While my instructor said we experienced understeer, honestly, it was hard for me to feel. We definitely took the current front tires to their limit, but honestly they weren't great ones to begin with (we just purchased the car about 6 weeks ago).
We were at Eagles Canyon in Decatur, TX. Here's a couple videos. It was my first time there and only 2nd time ever on a track. My son drove my V3 - and yep he passed me LOL. But it was a blast! Time to iron out the kinks in the coupe and get it properly set up so thank you for the feedback!
Joined
·
16 Posts
Next event is June 4 in Cresson, TX and then June 25/26 south of Houston. But fair warning - it's SOOOO addicting LOL
Joined
·
3,625 Posts
Good for you for getting on track. Lets say I have a little experience in newbs with street cars. Don't waste money on mods, learn from a quality instructor and spend $$ on track time.
Happy tracking.
ps the door stop was always one of my favorites.
Joined
·
2,964 Posts
Actually, IMO the best mod you can make for the track is stiffer, adjustable sway bars. Like I have on my car, on top of the 285s and 345s. The car is heavy, the suspension is the weakest point in the design, IMO. Sway bars are harder to get, but make more of a difference than the tires. At least, in my experience.
Joined
·
243 Posts
Perhaps in entirely stock form the suspension is weak, but swapping coils makes a big difference. I have Eibach coupe coils on my car, stock dampers, and stock sway bars. I'm letting the car eat in the photo below and the roll and understeer are acceptable. If the car is not allowed to roll, transferring weight to the outside tires and using the camber change that happens as a result will suffer, which will negatively affect the handling. Despite their name, sway bars are mainly used to dial-in over and understeer, similar to playing with tire staggers or lack thereof.
Tires can make a poor handling car decent, but the same can't be said for sway bars. The better your tires, the harder you can accelerate, turn, and less you have to abuse the brakes, which is most important in our cars. Sway bars are important, but to me on the bottom of the list for track days. This applies equally to my V as it did for my 350Z.
1 - 13 of 13 Posts
