GN Weighed On 4 Corner Machine After Decades Of Weight Loss Planning, Rear Driver Weighs 77lbs More Than Left??

GNVYUS 1

Well-Known Member
Question...
Why the hell is the driver rear 77lbs heavier?

Dyno'd and then got the GN finally weighed on a legit machine (I used to use those Waste Management scales). I was pretty happy after all the years of taking weight out and planning what we're options etc.
(I used to have a detailed list but it got lost on this board I think and my phone). I recently added weight with liquid IC, wastegate and Leed brake booster.

3280lbs (car only)
Tad under 1/2 tank fuel and took out the tools and bags in the trunk.

Questions....
Why the hell is the driver rear 77lbs heavier?
What do some of you that race think will help?

My Guess......
It has to be the fuel tank.
I bet the spare tire bump area caused the tank design to go driver side.

Does our tank deceive the eye and is bigger on the left so in the car it adds weight to the driver side?
 

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GNVYUS 1

Well-Known Member
All those items are gone, trunk was just the t top bags, carpet and truck trim I'm putting on soon so I left it in there.
 

longbedGTs

high on gas fumes
That's probably why the RR corner weighs less...because the spare tire and jack hardware is gone. Id guess GM designed the rear weight balance by including in the weight of the spare tire and whatnot. Never weighed it all, but the spare alone has got to be atleast 50lbs.
 

GNVYUS 1

Well-Known Member
Oh ya, the spare and tools were a bunch and that does make sense in the way Buick balanced out the weight difference.

But without that stuff, where's this extra weight coming from?

Each side is identical from wheel in towards the 3rd member so it has to be the fuel tank design IMO. It's probably deceiving to the eye and is more towards the driver side. Fuel is roughly 8lbs a gallon so that's an easy way to add 77lbs to one side.

Funny enough I bought 2 tanks since 2018 getting the car back in shape and I didn't notice this.
 

Pronto

Believe nothing you hear and half of what you see.
You have rear upper and lower adjustable arms. This might give you some insight. This is on a G body framed car.
and
 

Mr.Spool

Well-Known Member
Dyno'd and then got the GN finally weighed on a legit machine
What did it make with the new turbo?
When the car gets scaled like you just did it's a real eye opener 😉
Is the goal of the car to hook on the street or track?
What tire are you looking to run.
 

Mr.Spool

Well-Known Member
You have rear upper and lower adjustable arms. This might give you some insight. This is on a G body framed car.
and
Good video!
that is for a slick car though
The suspension targets are very different from a radial to a slick tire.
 

Pronto

Believe nothing you hear and half of what you see.
The weight transfer by just raising one corner or the other small amounts is eye opening...
 

GNVYUS 1

Well-Known Member
Dyno info coming in a new post in the turbo section, gotta get the details from other dyno runs and tuner to do the TA49 comparison accurately. Made so much peak torque around 32-3500rpm @ 697wtq and 620wtq @4k (I don't believe the graph, yet it did it every run around 22-23psi).
Destroyed the 49 and we didn't max it out due to me chickening out from the runs being 140wtq more than I was comfortable for a stock built block. I thought 22% total loss on Mustang (11% converter slippage @ 6k in 2nd on road test) so that I'll stop around 565wtq and 510whp or (725tq/650hp) engine...whoops.

Street car hooking, I'll watch the video but I have a feeling I need to make the driver rear QA1 coilover firmer a couple clicks to balance it out.

I'm on stock front control arms with lowered springs but when I do the frame swap I'll go QA1 double adjustable to lift the front real nice on launches. Also drop 100lbs off the front with other things planned when frame is swapped (rear accident tweaked rear in like 2003 and they can't straighten it more).
 

GNVYUS 1

Well-Known Member
Quickly watched video, caster, wow, I guess it moves around the weight. My right front and left rear are heaviest, got the car aligned on this 4 corner machine earlier this year.
 
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