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Discussion Starter #1 (Edited)
The car is 100% stock 88' T-top. Even on OE Struts (for now :smile: ). Power windows and power locks.

Total Weight (without Driver and with a full tank of gas): 2465lbs

Corner Weights:
LF: 526lbs RF: 555lbs
LR: 697lbs RR: 686lbs

Front to Rear ratio:
1081lbs/1382lbs
43.8%/56.2%

Left to Right ratio:
1222lbs/1241lbs
49.7%/50.3%



So the heavy points are the right front and the left rear. This poses a problem once you add driver weight in. Then the rear gets even worse.


These numbers are with my 145lbs body in the driver seat:

Corner Weights:
LF: 582lbs RF: 572lbs
FR: 751lbs RR: 686lbs

Front to Rear ratio: 44.5%/55.5%

Left to Right ratio: 51.5%/48.5%



I wanted to do as much stock legal weight reduction as possibly, however those options car cut short. Pulling the A/C would make the ratio even worse. So would cutting the exhaust off after the cat.

This was done with the donut still in. Leaving it in when racing would probably be good to have some more weight in the front.



I'm going to re-weigh in the spring. By then I will have exhaust done (most likely pacesetter, if not custom) and probably a ST front sway bar. I'll also do it with only 1/4 tank of gas (how I would race). So we'll see how the figures come out then.

I hope this was helpful to you guys :)

-Mike
 

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That gives me a good idea what my 87 t-top stock is. my only difference is my HKS exhaust, lighter 15's
 

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Discussion Starter #3
Oops! This car has slightly different 12's on it. 14X6 American racing rims. So maybe 5-10lbs more per corner. Still wouldn't throw off the corner weights though :)
 

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A couple questions... anyone know how much gasoline weighs per gallon? Also, how much do t-tops and power equipment add to the weight of the car? Just trying to base some numbers off of these figures for my '88 hardtop stripper model.
 

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Gas is around 6lbs per gallon
 

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Kind of nit picking but....There is only a total weight difference of 127 pounds from when you weren't in the car and when you were. You said you weighed 145lbs, well where did the other 18lbs. go?
 

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Discussion Starter #7
qwik_MR2_5sfte said:
Kind of nit picking but....There is only a total weight difference of 127 pounds from when you weren't in the car and when you were. You said you weighed 145lbs, well where did the other 18lbs. go?
I was wondering that a little myself. I imagine % of error, plus that we weren't perfectly on all the scales the same. We actually pushed my car forward from our first reading and realized it was putting some weight on the ramp still.

We were somewhat rushed today. Dan had stuff to do, so we set it up quick.

One factor in that may be that my garage isn't 100% level. Don't know how much that affects it.




With a 1/4 tank of gas, you could drop the cars weight to around 2420lbs. Electric and t-top, you could drop around 100lbs more give or take.
 

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If I remember right:

Power windows/locks - 2lbs
T-tops vs hardtop - 150lbs
AC - 45lbs

Rory, your stripper model will also save weight on the thin carpeting and the lighter seats, I'm guesstimating about 30lbs saved with the carpet and 20lbs with the seats
 

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Discussion Starter #9
Nitsud said:
If I remember right:

Power windows/locks - 2lbs
T-tops vs hardtop - 150lbs
AC - 45lbs

Rory, your stripper model will also save weight on the thin carpeting and the lighter seats, I'm guesstimating about 30lbs saved with the carpet and 20lbs with the seats
150lbs? That seems a little much
 

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SmokingTiresV6 said:
So the heavy points are the right front and the left rear. This poses a problem once you add driver weight in.
Ya know, the left rear is where the battery is. Thanks for gathering and posting all this data. Good stuff.

John
 

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SmokingTiresV6 said:
150lbs? That seems a little much
yes it does..I don't think 2 pieces of glass plus that the T bar add up to 150lbs :smile:

Sweet.in this case, mine being an '88 stock T-tops with MANUAL windows and doors...should be even lighter! :thumbup
 

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I'm looking for more info on the weight differences... but in the mean time, remember that glass is heavy, the centre bar is quite thick and there's reinforcements elsewhere on the body (Correct me on this though) to make up for the flex you get by cutting out such a critical support area (roof)

150lbs may be wrong though

I haven't owned a t-top model car so I wasn't able to weigh the tops or the car compared to my '85 NA
 

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Nitsud said:
I'm looking for more info on the weight differences... but in the mean time, remember that glass is heavy, the centre bar is quite thick and there's reinforcements elsewhere on the body (Correct me on this though) to make up for the flex you get by cutting out such a critical support area (roof)

150lbs may be wrong though

I haven't owned a t-top model car so I wasn't able to weigh the tops or the car compared to my '85 NA
well just for your info...I can carry one piece (of the glass) in each hand..and believe me, if they were a bag with 2 liter sodas each, I'd be complaining. AHHAHA
 

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Discussion Starter #14 (Edited)
AustinTXmr2 said:
Ya know, the left rear is where the battery is. Thanks for gathering and posting all this data. Good stuff.

John

It still seems like a lot of weight bias. You would think the engine would beat out the tranny and a battery in weight.

But the car is really well balanced. Just not with a driver in it :(

I wish there was a stock legal way to loose that 80lbs in the RR. But the front is only 20lbs off of perfect. That's always good.

I'm glad I could supply this info for you guys. Maybe someone with a stripped hardtop could weigh theirs for comparison :)

-Mike
 

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Discussion Starter #15
Nitsud said:
I'm looking for more info on the weight differences... but in the mean time, remember that glass is heavy, the centre bar is quite thick and there's reinforcements elsewhere on the body (Correct me on this though) to make up for the flex you get by cutting out such a critical support area (roof)

150lbs may be wrong though

I haven't owned a t-top model car so I wasn't able to weigh the tops or the car compared to my '85 NA

I'll have much more time to play with things in the spring. I'll pull the tops and weigh it, along with pulling just the driver side top. I'm going to try my options to find out what the best way to run will be.
 

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I'd love to have someone else share some input, I'm sure someone has weighed equal option MKIs with a hardtop and t-tops :D

I only remember reading 150lbs here a few times before. It really doesn't seem right though
 

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MR2GT said:
yes it does..I don't think 2 pieces of glass plus that the T bar add up to 150lbs :smile:

Sweet.in this case, mine being an '88 stock T-tops with MANUAL windows and doors...should be even lighter! :thumbup

a t-top car has to have that much more reinforcing than a hardtop....just like a conv compared to a hardtop or t-top on other cars there is more structural strength needed
 

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That's kind'a what a good coilover setup is for - jacking corner weights. But for a proper reading, you HAVE to have the scales leveled. My setup has the leveling platforms and whenever we set it up, we level not only the 4 scales together, but each scale individually. It's even better if you have bind eliminating plates that take out any scrub from camber and toe settings.

I think I found your error in your with and without driver weights - the right rear didn't change at all. Maybe an error in copying it down?

You can move weight around to help front to rear and side to side. However, if you are running with fixed weight, about all you can do is to match cross-weights (ie.: total of LF + RR compared to total of RF + LR). If you had coilovers, you would adjust it with half your normal maximum fuel load plus 1 gallon - driver and gear aboard. Then you adjust the "low" numbers higher by adjusting the coilovers 1/4 turn at a time until your cross weights match. In your case, the right rear would be where you would start; since LR + RF totals higher than RR + LF, and it's the lowest number - in comparison.

Also, one of the things I've found out. Moving weight around (in my case adding ballast) doesn't always give a predictable response. For instance, adding weight in the passenger floorboard (the only place we can legally place it in IT racing) doesn't necessarily place more weight on the right and / or front of the car. (And the F/R CG on my car is slightly behind the seat.)

Sorry for the ramble. Hope this helps.
 
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