Notices
Race Prep Miata race-only chat.
Sponsored by:
Sponsored by: 949 Racing

These corner weights possible?

Thread Tools
 
Search this Thread
 
Old Sep 7, 2013 | 06:04 AM
  #1  
Nagase's Avatar
Thread Starter
Elite Member
iTrader: (6)
 
Joined: May 2009
Posts: 1,805
Total Cats: 2
Default These corner weights possible?

My corner weights seem way, way out of line with everyone else's.

2001, naturally aspirated, power steering removed, shock tower brace removed, trunk stripped, behind driver's seat stripped, no passenger's seat, passenger airbag removed, glovebox gone, TSE radiator, single fan, aftermarket header/exhaust, roll bar, 3/4 tank of fuel, charcoal delete.

With 200 lbs of ballast total (passenger and driver's side), I got:

FL 673 FR 695
RL 574 RR 572

Suspension is 12" front, 12.38" rear (raised rear to hit camber).

So, that's 54.4% on the front end. That just doesn't seem right to me. I know I removed more weight in back than in front, but I added a lot back with a roll bar.

Thoughts? Thinking of calling and asking where they put the ballast. I don't see them putting it in the footwell, but it's the only explanation I can think of. Don't see how rake would make that big of a difference.
Old Sep 7, 2013 | 06:20 AM
  #2  
triple88a's Avatar
Elite Member
iTrader: (2)
 
Joined: Apr 2006
Posts: 10,522
Total Cats: 1,830
From: Chicago, IL
Default

Passenger foot well?
Old Sep 7, 2013 | 06:21 AM
  #3  
Nagase's Avatar
Thread Starter
Elite Member
iTrader: (6)
 
Joined: May 2009
Posts: 1,805
Total Cats: 2
Default

I have no idea what you're asking...

Yes my car has a passenger foot well?

If you're asking if the ballast was there, I said I don't know?

Yeah, not sure here.
Old Sep 7, 2013 | 06:30 AM
  #4  
triple88a's Avatar
Elite Member
iTrader: (2)
 
Joined: Apr 2006
Posts: 10,522
Total Cats: 1,830
From: Chicago, IL
Default

My assumption of the location of the ballast.

Take 3 bathroom scales next to eachother, toss few planks of wood on it to level the scales and do a 1 corner weight?
Old Sep 8, 2013 | 07:49 AM
  #5  
ChrisGriffin's Avatar
Junior Member
 
Joined: Apr 2010
Posts: 60
Total Cats: 0
Default

Just a couple questions first. Are the scales perfectly level? How much fuel do you have in the car? Is this with out you in the car? Is the car being built for a certain spec and that is the reason for the ballast?

It seems like you have spent time with the ride heights in order to get the side to side balance well. I would just start moving the ballast around if possible. The first place to start would be to place it in the spare tire well.

If the weights are without a driver in the car, then I would find a friend to sit in the car that is of similar weight to you and start over again. If still nose heavy I would look to move the weight to the right rear trunk.
Old Sep 8, 2013 | 07:52 AM
  #6  
Oscar's Avatar
Elite Member
iTrader: (2)
 
Joined: Jan 2007
Posts: 3,022
Total Cats: 120
From: Bolton, UK
Default

My guess is the 300lbs of sand you've accumulated under the hood.
Old Sep 8, 2013 | 02:00 PM
  #7  
Nagase's Avatar
Thread Starter
Elite Member
iTrader: (6)
 
Joined: May 2009
Posts: 1,805
Total Cats: 2
Default

Originally Posted by Oscar
My guess is the 300lbs of sand you've accumulated under the hood.
I've actually washed out at least 200 lbs of that by now.
Old Sep 8, 2013 | 02:02 PM
  #8  
Nagase's Avatar
Thread Starter
Elite Member
iTrader: (6)
 
Joined: May 2009
Posts: 1,805
Total Cats: 2
Default

Originally Posted by ChrisGriffin
Just a couple questions first. Are the scales perfectly level? How much fuel do you have in the car? Is this with out you in the car? Is the car being built for a certain spec and that is the reason for the ballast?

It seems like you have spent time with the ride heights in order to get the side to side balance well. I would just start moving the ballast around if possible. The first place to start would be to place it in the spare tire well.

If the weights are without a driver in the car, then I would find a friend to sit in the car that is of similar weight to you and start over again. If still nose heavy I would look to move the weight to the right rear trunk.
Fuel load is listed above, 3/4.

Not my scales, it's a shop that works on NASA cars, so I'd hope they were level, but I can't verify that.

No, the ballast was to simulate a driver and a (heavier than I told them to put) passenger's seat.

Last edited by Nagase; Sep 8, 2013 at 02:24 PM.
Old Sep 9, 2013 | 10:11 AM
  #9  
Seefo's Avatar
Elite Member
iTrader: (5)
 
Joined: Dec 2010
Posts: 1,961
Total Cats: 48
From: Raleigh, NC
Default

doesn't seem that bad. If you are concerned about the Left having more weight than the right, its because you asked for passenger ballast weight also... I think we tend to have more passenger side weight if you don't have a driver...
Old Sep 9, 2013 | 02:18 PM
  #10  
charliemouse's Avatar
Newb
 
Joined: Sep 2013
Posts: 1
Total Cats: 0
Default

You're doing those weights with the driver in and race fuel, right?

I always get front wheels within 10lb max and preferable perfect. More than 10lb in my seven or midget and the lighter wheel will lock first... MX5 will be slightly more tolerant but it's not ideal. Don't stress too much over perfect 50/50 front/rear until you do some testing. The tyres will heat up differently due to driving style, circuit, RWD etc... you can play as part of testing by moving the ballast. Make different mounting points for the ballast to enable it to be moved on a test day...

CM
Old Sep 11, 2013 | 08:34 PM
  #11  
mrjones2's Avatar
Junior Member
iTrader: (1)
 
Joined: May 2008
Posts: 53
Total Cats: 4
From: snohomish, WA
Default

I would worry more about the cross weight - your at 50.5%, you need 50.0
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
Apr 12, 2021 04:21 PM
asmasm
Build Threads
82
May 26, 2016 04:37 PM
Rick02R
WTB
3
Jan 3, 2016 07:18 PM
bigben
Race Prep
16
Sep 11, 2015 03:41 PM




All times are GMT -4. The time now is 09:55 AM.