New alignment and corner balance
08-05-2013, 08:56 AM
#1
Rennlist Member
Thread Starter
New alignment and corner balance
I just got a new alignment and corner balance on my car done by one of the local Cup racers at his skunk works shop. All I have to say wow! It is much better that my last alignment as my old alignment specs were scrapped and as it was set up to new specs per his recommendation. With some sway bar and shock tweaking done by him at the track this past Friday, the car feels fantastic. It feels so good that I was able to take almost 2 seconds off my best time on a 2.5 mile course late Friday. One interesting thing about his alignment is the fact that instead of attaching the alignment gear to the wheel itself, he removed the large 26mm hub nuts and screwed the alignment gear directly onto the hub. This was done so that the alignment sensors are perfectly aligned with the wheel hub instead of clipped onto the wheel as most shops do. When you clip the alignment gear onto the lip of the wheel, any minor wheel run out or even irregular paint build up on the lip surface will result in errors to creep into the final product. I never really though of that but it makes sense. The corner balance was performed by the weight sensor pads all perfectly leveled with a laser. Total weight of the car with 13 gallons of fuel without driver ballast is 3248lbs. Good stuff. Enjoy....
http://www.flickr.com/photos/87731073@N06/9442295482/http://www.flickr.com/photos/87731073@N06/9442295482/ by http://www.flickr.com/people/87731073@N06/, on Flickr
http://www.flickr.com/photos/87731073@N06/9442297070/http://www.flickr.com/photos/87731073@N06/9442297070/ by http://www.flickr.com/people/87731073@N06/, on Flickr
http://www.flickr.com/photos/87731073@N06/9442298456/http://www.flickr.com/photos/87731073@N06/9442298456/ by http://www.flickr.com/people/87731073@N06/, on Flickr
http://www.flickr.com/photos/87731073@N06/9439515399/http://www.flickr.com/photos/87731073@N06/9439515399/ by http://www.flickr.com/people/87731073@N06/, on Flickr
http://www.flickr.com/photos/87731073@N06/9439517193/http://www.flickr.com/photos/87731073@N06/9439517193/ by http://www.flickr.com/people/87731073@N06/, on Flickr
http://www.flickr.com/photos/87731073@N06/9442295482/http://www.flickr.com/photos/87731073@N06/9442295482/ by http://www.flickr.com/people/87731073@N06/, on Flickr
http://www.flickr.com/photos/87731073@N06/9442297070/http://www.flickr.com/photos/87731073@N06/9442297070/ by http://www.flickr.com/people/87731073@N06/, on Flickr
http://www.flickr.com/photos/87731073@N06/9442298456/http://www.flickr.com/photos/87731073@N06/9442298456/ by http://www.flickr.com/people/87731073@N06/, on Flickr
http://www.flickr.com/photos/87731073@N06/9439515399/http://www.flickr.com/photos/87731073@N06/9439515399/ by http://www.flickr.com/people/87731073@N06/, on Flickr
http://www.flickr.com/photos/87731073@N06/9439517193/http://www.flickr.com/photos/87731073@N06/9439517193/ by http://www.flickr.com/people/87731073@N06/, on Flickr
Last edited by powdrhound; 08-05-2013 at 11:42 AM.
08-05-2013, 01:48 PM
#4
Rennlist Member
Thread Starter
Front camber: -2.7 per side
Front toe: +0.05' total
Castor: 7.5
Rear camber: -2.3 per side
Rear toe: +0.34' total
Ride height: 101mm front, 120mm rear
Weight: 3248lbs with 13 gal. of fuel without driver ballast.
A huge improvement was him actually driving my car at the track and setting the rear sway to a softer setting and readjusting the shock settings on my JRZs. I was getting a good bit of sudden oversteer prior to this and now the car is much more neutral and stable at the limit, really feels like a new machine. Chris initially made one lap in my car and pulled into the pit lane, looked at me and said "I'm scarred like a little girl, we need to make some changes". Out came the jack, wheels came off and 30 minutes later I had a much more stable machine.
Front toe: +0.05' total
Castor: 7.5
Rear camber: -2.3 per side
Rear toe: +0.34' total
Ride height: 101mm front, 120mm rear
Weight: 3248lbs with 13 gal. of fuel without driver ballast.
A huge improvement was him actually driving my car at the track and setting the rear sway to a softer setting and readjusting the shock settings on my JRZs. I was getting a good bit of sudden oversteer prior to this and now the car is much more neutral and stable at the limit, really feels like a new machine. Chris initially made one lap in my car and pulled into the pit lane, looked at me and said "I'm scarred like a little girl, we need to make some changes". Out came the jack, wheels came off and 30 minutes later I had a much more stable machine.
Last edited by powdrhound; 08-21-2013 at 08:39 PM.
08-05-2013, 08:25 PM
#5
Burning Brakes
Front camber: -2.7 per side
Front toe: +0.05' total
Castor: 7.5
Rear camber: -2.3 per side
Rear toe: +0.34' total
Ride height: 101mm front, 120mm rear
Weight: 3248lbs with 13 gal. of fuel without driver ballast.
A huge improvement was him actually driving my car at the track and setting the rear sway to a softer setting and readjusting the shock settings on my JRZs. I was getting a good bit of sudden oversteer prior to this and now the car is much more neutral and stable at the limit, really feels like a new machine. He initially made one lap in my car and pulled into the pit lane, looked at me and said "I'm scarred like a little girl, we need to make some changes". Out came the jack, wheels came off and 30 minutes later I had a much more stable machine.
Front toe: +0.05' total
Castor: 7.5
Rear camber: -2.3 per side
Rear toe: +0.34' total
Ride height: 101mm front, 120mm rear
Weight: 3248lbs with 13 gal. of fuel without driver ballast.
A huge improvement was him actually driving my car at the track and setting the rear sway to a softer setting and readjusting the shock settings on my JRZs. I was getting a good bit of sudden oversteer prior to this and now the car is much more neutral and stable at the limit, really feels like a new machine. He initially made one lap in my car and pulled into the pit lane, looked at me and said "I'm scarred like a little girl, we need to make some changes". Out came the jack, wheels came off and 30 minutes later I had a much more stable machine.
08-05-2013, 09:02 PM
#6
Rennlist Member
Thread Starter
I have a H&R rear sway which is the stiffest sway bar out there, 24mm and solid. I had it on the middle hole and it was reset to full soft. Front bar was a stock turbo bar which is fairly soft. The car still has a slight tendency to oversteer albeit fairly progressively and to fully dial it in the recommendation is to get a matching H&R sway for the front set fairly stiff and the rear set back to middle. That should balance it while still keeping the car very flat in the corners under load.
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08-05-2013, 11:25 PM
#8
Rennlist Member
Thread Starter
08-06-2013, 03:46 AM
#9
Former Vendor
08-06-2013, 04:10 AM
#10
Rennlist Member
Thread Starter
I am looking into either getting both the front and rear GT3 sways or getting a front H&R adjustable bar to match up to the rear H&R bar on the car. I do like the much stiffer H&R bar in that I can run fairly soft 600F/800R rates and keep the roll in check with the sways. My track has some bumpy sections on it and I don't want to go too stiff with the rates. I'll leave it up to my guy to decide. Another recommendation is to go with a smaller front to rear spread on the springs on the order of 800F/900R, or somewhere in that ball park. I do know that what's been done to the car so far has made it much better and faster. We are getting close... I'll try to post up a video of Chris in the car chasing down a couple of grand am 997 cups after the last few changes this past Friday
Last edited by powdrhound; 08-21-2013 at 08:39 PM.
08-06-2013, 06:05 AM
#11
Former Vendor
I'm pleased with GT3's sways, they provide a lot of adjustability. If necessary... But I'm also running much, much milder springs, 45 Nm/mm & 95 Nm/mm out of a 996 GT3RS. (= 256 & 542) My car's also about 50kg lighter.
Alignment seems to be more or less the same, just got it realigned and mildly tweaked, results are to be seen next weekend.
Alignment seems to be more or less the same, just got it realigned and mildly tweaked, results are to be seen next weekend.
Last edited by pete95zhn; 08-06-2013 at 05:14 PM.
08-06-2013, 08:48 AM
#12
Rennlist Member
Thread Starter
I'm pleased with GT3's sways, they provide a lot of adjustability. If necessary... But I'm also running much, much milder springs, 45 Nm/mm & 95 Nm/mm out of a 996 GT3RS. (= 256 & 542) My car's also about 50kg lighter.
Alignment seems to be more or less the same, just got it realigned and milldly tweaked, results are to be seen next weekend.
Alignment seems to be more or less the same, just got it realigned and milldly tweaked, results are to be seen next weekend.
08-06-2013, 09:10 AM
#13
Race Car
The GT3 sways are great but very soft even at their stiffest setting. They are probably a great match for the rather mild stock GT3 spring rates like you are running. I'm thinking that the much stiffer H&R sways are probably a better match for my slightly heavier and much stiffer sprung car. I'll let you know what the final result will be once all the tweaking is done. Surprisingly, my current JRZ set up with 600/800 rates seems very streetable, pretty much on par with my previous H&R coilovers that had similar rates to what you have. Speaks volumes of the JRZ shocks.
Ideally you control roll with spring rate only, use soft bars for high level balance changes and then fine tune with shock settings.
There's no perfect setup for our street cars though without a punishing ride. I doubt your big bars are hurting you that much but with that much spring rate GT3 bars would be just as adequate as you have enough spring rate that the adjustability is more important than the size of the bar.
08-06-2013, 09:26 AM
#14
Rennlist Member
Thread Starter
Big sway bars are a band-aid for a car that's too softly sprung. The more spring you have in a car the more a stiff bar is going to take away grip not help. It's all about controlling contact patch and camber curves. Once you get closer and closer to doing this with springs only there's less and less need for big bars.
Ideally you control roll with spring rate only, use soft bars for high level balance changes and then fine tune with shock settings.
There's no perfect setup for our street cars though without a punishing ride. I doubt your big bars are hurting you that much but with that much spring rate GT3 bars would be just as adequate as you have enough spring rate that the adjustability is more important than the size of the bar.
Ideally you control roll with spring rate only, use soft bars for high level balance changes and then fine tune with shock settings.
There's no perfect setup for our street cars though without a punishing ride. I doubt your big bars are hurting you that much but with that much spring rate GT3 bars would be just as adequate as you have enough spring rate that the adjustability is more important than the size of the bar.
08-06-2013, 10:30 AM
#15
+996
Big sway bars are a band-aid for a car that's too softly sprung. The more spring you have in a car the more a stiff bar is going to take away grip not help. It's all about controlling contact patch and camber curves. Once you get closer and closer to doing this with springs only there's less and less need for big bars.
Ideally you control roll with spring rate only, use soft bars for high level balance changes and then fine tune with shock settings.
There's no perfect setup for our street cars though without a punishing ride. I doubt your big bars are hurting you that much but with that much spring rate GT3 bars would be just as adequate as you have enough spring rate that the adjustability is more important than the size of the bar.
Ideally you control roll with spring rate only, use soft bars for high level balance changes and then fine tune with shock settings.
There's no perfect setup for our street cars though without a punishing ride. I doubt your big bars are hurting you that much but with that much spring rate GT3 bars would be just as adequate as you have enough spring rate that the adjustability is more important than the size of the bar.