If putting all the power suddenly to the pavement results in more tirespin, where a better transfer of weight to the rear, albeit a loss of, say ... a tenth, results in making up a few tenths when you gain better traction, isn't the REAL answer that "it depends"?

 

According to some folk's objections to transferring some weight to the rear, did I just make a mistake in ordering QA1's? If this is not what the QA1's do, then what?

Hip me ...

 

Humm some interesting info here, my best's are 1.5x's. But I only have lca's and relo's.

 

you want the rear shocks to be as stiff as possible untill you get into wheelhop.

 

they're not talking about weight transfer.. they're talking about squat...

you still want the weight to transfer to the rear tires for traction.
what they're talking about is the distance between the chassis (think wheel well) and suspension (think tire) getting closer..(squat.)

ideally what you want is no movement up or down.. going up or down wastes energy. you want to go forward.. but thats almost impossible. and in most cases, you need to use a bit of that energy you have to hook harder, so you can use the rest of the power to move forward.

when you push the tire down harder using some of that energy, the rear end lifts up a tad.
if you look in the first pic someone posted of a slow motion launch, you can see this..

first, the tires load.. you'll notice they wrinkle on the bottom... they arnt spinning like someone said.. they're slicks and thats what they do. absorb the inital hit and load up....

in the following frames, you see the rear of the car lift slightly in relation to the car... thats because the cars suspension is forcing the tires down... the equal and oppisate reaction to that is the car moves up.

if you find that hard to believe, imagine being on a bathroom scale with a heavy weight in your hand.. if you throw the weight up the scale reads higher for a instant. same basic concept. ooh, i have a better analogy.. imagine you're on the same scale yourself... watch it as you jump... as you press down, you move up, but the weight on the scale goes up too.... thats what im talking about... you're shoving the tires down, and because of this, the car moves up.

hopefully i explained that correctly and got it right... im not a chassis expert, but im trying to learn. (side note: anyone reccomend any good books on the subject, specificlly geared towards drag racing fbodies??)

 

What sort of poundage springs would be suitable for a car with approx 1980lbs over the front axle and 1540 lbs over the rear axle, total vehicle weight 3520lbs approx ??

Suitable mostly for road use, but also to assist with decent 60fts.

I currently have 200lb right side, and 175lb left side rear springs in my car.

My car is right hand drive ( I'm in the UK ) and no rear swaybar fitted as yet, hence I thought it might help to have a slightly stiffer spring on the drivers side ( right hand side )

My car does seem to squat quite easily, although last time I was racing, I did have my shocks set quite soft.
I didnt think that was a good idea, and searching here has re-enfored that idea.

Hoping to race again next Sunday, so any suspension help would be welcome.

I do have a 4-linked rear axle....
Using 245/50x16" Nittos, I can just get into 1.9x 60ft, but can all too easily spin the tyres all way thru 1st and 2nd gears.

255/50x16 MT DR's are ordered, and should be here in about 3 weeks.

 

It takes some travel to transfer weight. If your car has no travel your ganna get tire spine or wheel hope. And as long as you have tire spin your not getting the best out of your 60ft. Half the time your car dont break the beams at the track until the susp has traveled. So your relly not loseing that much. For guys with these kinda cars with low pro tires we need some travel helps transfer weight and thats what plants the tires. Now im not sayig let it go as far as it can but it does need some and you can adjust it in diffrent ways like travel limeters for the front or a good ajustable rear shock. As for runnig two diffrent springs i would never do that it will plant one tire harder than the other. And to fix the roll get a antiroll bar bmr makes them. I set up four linkes, ladder bars and do alot of ten five tire cars and all of them have some travel.

 

I do have some suspension travel. My shocks are adjustable, made by AVO. They are a road use shock though, not drag, but their adjustability should suffice for racing. I havent played with the settings enough though.
Given the nature of my car, sourcing a suitable anti-roll bar is awkward, although I do think I could adapt an F-Body's ARB. Virtually everything has had to be custom made, as nobody makes anything specifically for my car, so actually locating parts that will fit, when you cant actually hold them in your hand wihout buying them isnt easy.

I am using a Torsen diff.
As you can see in the video after the burnout, the rear was quite soft when I was racing..
http://media.putfile.com/stevieturbo-drag

As for the 4-link, I have tried within reason to get the IC near the gearstick, but its probably a bit further forward than that.

 

I personally think some squat is fine as long as it keeps weight on the backend during accelleration. If the backend squats at launch and then springs up right after launching,Thats when traction issues come about. Welcome to one of the sciences of drag racing. Thats why u have to expirement so much with the cars geometry.

 

some good points

 

Heres something pretty cool somewhat relevant

video

 

It all depends on YOUR set up.

No two cars or the same.

............LBT

 

if you watch a video of my car leave at 6500 it dont squat at all, run shocks on 5 out back on a 12 way, i can deadhook the car with no problems usually at NPR. i guess its working, any other cars this weak pulling 1.38's

 

I have been letting mine squat to get it to hook alittle cause I have road race valved shocks on the front.

 

i think its real sick and pretty relevant, you can see on the prostock cars how they end up launching and what the tires do and what the body and suspension does off the line and can really analyze it