Spring Install affected my car's weight - NOT GOOD for racing

[Duke]

Thanks Mike. Also, wondering if you checked the weight with you in the car? What was the total weight?

[mlee]

Originally Posted by Duke

Thanks Mike. Also, wondering if you checked the weight with you in the car? What was the total weight?

LMAO... why yes we did...


....all you need to know is it did not have much affect if any in the distribution on all 4 corners...

[GTAHVIT]

Originally Posted by Orange2SSRS

How will coilovers prevent this? Don't they mount to the same holes?

adjusting the ride height on each coilover helps keep the car flat from left to right. And if you get a dual adjustable coilover you can set bound and rebound stiffness independently on each shock which helps with weight transfer and controls the bounce on rebound.

Originally Posted by mlee

Mainly just an excuse cuz I want some..

...but you would be able to adjust them up or down to change the weigth distribution.

I was also suprised at the effect a small amount of air pressure does...

Dont forget adjustable endlinks will help balance out the car as well. But I'm not sure if that is as important for drag racing...

[mlee]

Originally Posted by GTAHVIT

adjusting the ride height on each coilover helps keep the car flat from left to right. And if you get a dual adjustable coilover you can set bound and rebound stiffness independently on each shock which helps with weight transfer and controls the bounce on rebound.

Dont forget adjustable endlinks will help balance out the car as well. But I'm not sure if that is as important for drag racing...

Oh Yeah... I believe those endlinks would get you right on the button...

Believe me weight distribution is very important on launch and all the way down the track. I had the ride of my life last Saturday...

[TJ91]

Originally Posted by mlee

Get a sharpie and draw circles around the bolts before you loosen them.

If your racing I would find someone with scales like these to see where you are at... It's a pretty quick job but finding scales might be a problem


Here's one video of a slightly crooked run, but the go pro on the front of the car really shows it last week.

thanks man, your awesome!!!

[Mindz]

Mike, when you do get scales, I can be your test subject for corner balancing alignment =P

[Ovenmitt]

Originally Posted by mlee

Damn... you had me thinking on that one...

We swapped the rear tires and wheels while we had them off adjusting springs. The 18" Mickeys are getting packed in the trailer for C5Fest and I have a set of Nitto DR's on the stock rims. Now I have to swap them all out at home to roll on the 22's to AZ

And I did weigh the tires while they were off.
58 lbs for the 18"
61 lbs for the 22"

and it even adds up...

Stock rear wheel/tire @ 67.4 lbs with lugs
Weld RT-S rear wheel(17x10) with 295/45/17 Mickey ET Radial with lugs @ 54.2 lbs


I weighed these earlier this month. Going to put a list together

[mlee]

Originally Posted by Ovenmitt

Stock rear wheel/tire @ 67.4 lbs with lugs
Weld RT-S rear wheel(17x10) with 295/45/17 Mickey ET Radial with lugs @ 54.2 lbs


I weighed these earlier this month. Going to put a list together

Good Deal... Milk has a sticky with all the stock combinations listed. Would be nice to add the race wheels too. I should add my 61 lb stock weight was with worn down slick Nittos and not the Pirellies.

I'm going to weight my D2 Forged 22's today for grins...

[PoleCat2SSRS2010]

Mike,

I applaud Owen for having done the right thing. I am glad to see the problem was found and easily resolved.

There is a question. Was this problem from the install or did it happen over time from repeated launching or just driving around? You might want to put the car on scales again later confirm if the springs are moving or not over time and use.


The use of scales is something that I have been asking and recommending about and known about for at least 20 years. There is a publication of a chassis mod book for building a bracket car that I have had forever.

Always use scales especially during spring suspension modifications. The reason is as clear as for what you have just shown. You have to wonder how many of the other folks have done a spring install w/o ever once checking the corner weights and ratios.

Coil over designs and scales now begin to show their advantages with their adjustability of ride height and spring replacement and rate increment availability. The results always have to be confirmed on the scales. This may seem like splitting hairs to some people but I like to think that the factory engineers went to the same length.



This is for apples to apples comparison OEM to OEM replacements. Not meant to compare OEM springs to coil-over springs. However, if comparing to coil-over springs to the same diameter coil-over spring then the design and spec is relevant for comparison.

Just to be clear though, springs with higher rates will tend to make the chassis stiffer and suited for road racing where chassis and frame separation is not wanted. Drag racing suspensions prefer weight transfer from front to rear to maintain rear traction with the weight being applied to the rear tires as it increases from the transfer and the front is lighter. This effort is ideally gained with drag race springs and drag race shocks. The springs are typically made from smaller wire and have more windings than compared to road race springs that use larger wire and fewer windings. Drag race springs for the front have more stored energy than factory or road race and allow the front end to snatch up easier than the OEM or road race designs.

Waiver---Drag race springs and drag race shocks are for one purpose only and are not ideal for daily driving and the handling of the vehicle can be easily upset to the point of being dangerously unstable.

[bob vogel]

Originally Posted by ADV.1 Matt

Interesting info! Thank for posting it up.

+1 thanks

[mlee]

PoleCat you hit on some great points we have been discussing... My chassis is very stiff and doesn't allow the rear end to squat on takeoff. We may do something with the front sway bar (also not stock) to allow the front end to come up. Also don't think anything moved. Fastland did the spring install a while back. On the other hand, Chris with a stock suspension cut a 1.55 60 foot.

Spend the entire day helping Owen and Jay get all our cars finished. We weighed 3 more cars and one needed the same adjustment as mine although it was no where near as bad. Chris' weight was dead on the money w/ stock factory suspension so the GM setup was perfect.

Owen had a brand new set of DR's mounted for me so we making sure all bases are covered now. Willl need to give them a good breaking in at Firebird.

[Mr Twisty]

You read that tree pretty good!

[mlee]

Originally Posted by MisterCamaro69

You read that tree pretty good!

Thanks...was a hole shot win on that Vette too... .155 reaction to his .333.

11.72 to his 11.70 FTW...

[bmwdon]

one thing I know the drag racing hemi guys like to do to get their cars to squat a bit more at the strip is put V6 springs in the rears...I know you got a BMR setup, but a cheap set of V6 springs for drag days might be helpful I just happen to know a guy with a set of V6 springs in his shed