Pontiac G8 Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
493 Posts
Discussion Starter #1
And it was one hell of a day. It was nice to see good cars not being babied and really put to good use. I'm so exhausted from wrenching on the car since 5:30 am to racing in 110+ degree weather. I ended up missing the first session because my idiot friend pulled the threads on the caliper where the bleeder goes. Luckily, he was able to go back in town and borrow one from a friend and I was good to go. I got flagged for passing in the no passing zone since I'm a novice and another time for going off the track (lost focus in the heat). I can't wait to go back again but I need to do something about my understeer and body roll. So subframe bushings hopefully in the near future for me!
 

·
Registered
Joined
·
31 Posts
No video??? :nono:

I'm about to post about my upcoming first track day, so I'm curious about your current setup. Heard that the subframe bushings are a good follow-up to shocks and springs or coilovers for controlling body roll.
 

·
Registered
Joined
·
493 Posts
Discussion Starter #3
Unfortunately, no money for a Go Pro, so I only have cell phone video of the straight near the stands. I used PPV struts, Tein springs, Moog end links, BMR strut top bushings, stock brakes with Hawk HP + pads and Centric rotors with Motul RBF600 brake fluid. I also used Hankook V12 255/35/20 up front and 285/30/20 out back so that only made my understeer worse.

 

·
Registered
Joined
·
1,697 Posts
Heard that the subframe bushings are a good follow-up to shocks and springs or coilovers for controlling body roll.
Just for clarification - Yes, stiffening the springs reduces body roll but also up-and-down motion, brake dive and ride comfort. Increasing sway bar diameters reduces body roll but increases inside wheel lift. Subframe bushings affects none of the previous items but decreases the vagueness/sloppy feeling in the rear that is felt when cornering hard. (I only notice it when near the limits of tire adhesion so not gonna do inserts for my old fart driving)
 

·
Registered
Joined
·
493 Posts
Discussion Starter #5
Just for clarification - Yes, stiffening the springs reduces body roll but also up-and-down motion, brake dive and ride comfort. Increasing sway bar diameters reduces body roll but increases inside wheel lift. Subframe bushings affects none of the previous items but decreases the vagueness/sloppy feeling in the rear that is felt when cornering hard. (I only notice it when near the limits of tire adhesion so not gonna do inserts for my old fart driving)
Even if it's not technically body roll, the sloppiness affects the actual track experience, at least for me. I'll get sway bars a little further down the road since they're a little pricy and I got some priorities like Camaro transmission pan since my transmission was running a little hot, but it was 110F outside so that probably didn't help.
 

·
Registered
Joined
·
1,697 Posts
Even if it's not technically body roll, the sloppiness affects the actual track experience
Definitely, the track is where you want/need the inserts.

(the clarification was meant for the general post reader)
 

·
Registered
Joined
·
116 Posts
How are you doing with the Hankooks? Rolling over the shoulders much? I chewed up my front pilot super sports recently in part from rolling onto the shoulders too much. As you noted, more tire up front would be a good starting point but looking for something with a good stiff sidewall will probably help also; we've got big cars and they really throw a load on the tires. Other things to look at is keeping an eye on your pressures and trying to get them high enough to not be rolling over the shoulders but low enough to keep decent traction. Adding in some negative camber is probably a good route to go too depending on what your current settings are.
 

·
Registered
Joined
·
493 Posts
Discussion Starter #8
How are you doing with the Hankooks? Rolling over the shoulders much? I chewed up my front pilot super sports recently in part from rolling onto the shoulders too much. As you noted, more tire up front would be a good starting point but looking for something with a good stiff sidewall will probably help also; we've got big cars and they really throw a load on the tires. Other things to look at is keeping an eye on your pressures and trying to get them high enough to not be rolling over the shoulders but low enough to keep decent traction. Adding in some negative camber is probably a good route to go too depending on what your current settings are.
My tires looked fine afterwards, no signs of rolling over the shoulders. I was running 37-40 PSI all around. Some negative camber sounds like a good idea actually.
 

·
Registered
Joined
·
69 Posts
I ran my '09 GT stock and with Coilovers and GXP Brembos for a few years. Stock @ Buttonwillow I was at 2:17, and coilovers took me down to 2:11. Also ran a 1:54 stock at Laguna Seca (1st time ever at that track). I think I was at 36 PSI and -1.5 camber front and -1.3 rear on square 245/40/19 Bridgestone RE11's on VMR V705 rims by the time I sold the car (I had TSW Nurburgrings for the street). I think I was up to 8-10 total track days in that car.

Leave the engine largely stock, it'll last way longer that way. All I did (in addition to Coilovers and Brakes) was put a Rotofab intake and Corsa Exhaust, and a strut tower brace. Change the oil before the track day, fill it with fuel, and you're good. I've embarrassed some seriously expensive cars with my Pontiac.

It was a ton of fun, but killed me as far as cost for consumables (tires and brakes), and the fact that it is less than common was a factor for parts availability (Pedders took months before they cancelled my order the first time I tried to get suspension parts). It's a fun car - might be more "fun" than my Vette - but it is not the best choice for track duty. Adjustable coil overs, an alignment, and GXP Brakes (Pace Performance) were a massive help.

With that being said, I dumped a lot of money into that car for track duty, but have since switched to a C5 Z06 (stock, and a '14 RT Durango tow vehicle) and ran a 2:04 (Toyo R888) and 2:07 (Nitto NT05) at Buttonwillow, and 1:47 at Laguna Seca (Nitto NT05). I've been to other tracks, but just those 2 in the G8. It's a matter of trying to make the G8 do something the Corvette was designed to do from the start, even with all those upgrades, I was still 7 seconds per lap slower than a stock C5 Z06 with some tires.

Side note, I sold it to a buddy and it got totaled while sitting out on the street in San Francisco. I miss that car.
 
1 - 9 of 9 Posts
Top