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View Full Version : A Corner Ballancing Story.....



Z3_GoCar
05-10-2010, 04:06 PM
I did a corner ballance on the Z3 last Saturday. I'd planned to install 45lbs of weight. I didn't bolt it down in case I needed to move it. Well when I finished I had 695 on the LF and 696 RF, but my total weight with ~7 gallons in the tank was 2763lbs. So I'll need to add more weight, maybe ~ 20lbs should be enough. I guess I'll have to redo the corner balance. Oh yeah, Front/Rear was 50.2/49.8, I guess the car's a tank if it could take the roll and still be this close on the corner ballance :D

benspeed
05-10-2010, 05:18 PM
Try putting 165 pounds of balast in your car! I've got that and still struggle to hit 3055 :-(

quadzjr
05-10-2010, 05:35 PM
Try putting 165 pounds of balast in your car! I've got that and still struggle to hit 3055 :-(

psh.. 165.. that's nothing!

200 in the MR2, and if they do move the 99 si to ITA it would require so much weight ~400+ that we won't run it.

joeg
05-10-2010, 05:37 PM
How about a fire system or an Accusump placed dead denter in the car?

JoshS
05-10-2010, 05:48 PM
I don't think he was complaining about the ballast, he was showing off how well-balanced the car is.

Z3_GoCar
05-10-2010, 11:35 PM
How about a fire system or an Accusump placed dead denter in the car?

I've already got a fire system... I could use an accusump, or maybe a suit cooler.

Josh, pretty much nailed it :D

Though I have to wonder how much reinforcement is needed. Also, has anyone used RTV between the plates to keep the weight room sounds to a minimum?

Andy Bettencourt
05-10-2010, 11:42 PM
Josh, pretty much nailed it :D

Though I have to wonder how much reinforcement is needed. Also, has anyone used RTV between the plates to keep the weight room sounds to a minimum?

Betcha that isn't legal per 9.1.3.L but I would also think that if you fasten them properly, you wouldn't hear any noise, no?

Nice numbers. I especially like the front L-R numbers. Some people shoot for the best possible cross at the expense of throwing the LF-RF out of whack - and then they wonder why they get lock-up in a straight line...

Z3_GoCar
05-11-2010, 12:03 AM
Betcha that isn't legal per 9.1.3.L but I would also think that if you fasten them properly, you wouldn't hear any noise, no?

Nice numbers. I especially like the front L-R numbers. Some people shoot for the best possible cross at the expense of throwing the LF-RF out of whack - and then they wonder why they get lock-up in a straight line...

Two 1/2" grade 8 bolts per stack with grade 8 washers, the largest stack is five 10lb weights, the second is a 10lb and two 5lb'ers. So what additional reinforcement should I use maybe some 1/8" plate?

Z3_GoCar
05-13-2010, 01:32 AM
So, I went back to Walmart and got an additional 25lbs of weight plates, for a total of 70lbs. I'm glad I asked for the re-evaluation of this car because I'm not installing an additional 30lbs. Before I started drilling holes I decided to move my fire bottle closer to the tunnel to allow the weights to be closer to the outside. I put the 50lb stack to the rear, and the 20lb stack just ahead. Then I started the ballancing again. When it was close I went ahead and marked then drilled the holes, bolted the weights in place, and futzed with the corner balance one last time. The results with a full 12 gallon tank are 2818lbs total, so I can use all but about the last 3 gallons of fuel and make weight. The final corners are: LF: 700lbs RF: 700lbs RR: 700lbs and LR: 718lbs. So, I'm starting out slightly tail heavy, but by a half tank I'll be a little nose heavy. I've also decided to go back to the oe sway bar on the rear, it's tiny like about a 1/2" bar, but it'll allow me to continue running my 550lbs/in rear springs instead of purchasing a set of 600 or 650 springs. I was running with out the rear bar, but I think the car was running a little tight, while the adjustable bar I was running on full soft was a little loose. My next race is this weekend, I'll be running ITR and STU, wish me luck :026:

Z3_GoCar
05-19-2010, 09:15 AM
Thanks to all who wished me luck because I scored my first first, in STU. It was a well fought race aginst David Allen in an e-30.

http://www.youtube.com/watch?v=6Rh3iJo3r5A

Z3_GoCar
05-25-2010, 08:59 PM
Here's some laps from my ITR win:

http://www.youtube.com/watch?v=cWJHPOaI0-E

What you won't see is my car overheating ending my weekend. I've since pulled the head and discovered a very slightly burned head gasket.

timo944
05-27-2010, 01:31 PM
Two 1/2" grade 8 bolts per stack with grade 8 washers, the largest stack is five 10lb weights, the second is a 10lb and two 5lb'ers. So what additional reinforcement should I use maybe some 1/8" plate?

Yes - or at least 1/16" When I used to have weigh in my car (200 lb. or so) I used a rectangular plate that was about 8" x 3", with the two mounting holes about 5" apart (the weights were made about 10" x 6" and came from a stock car shop and were pre-drilled). Underneath the floor I used large and strong fender washers.

You don't want that s&*t coming loose when you roll the car!