Shocks and weight transfer

[whatnow123]

Would switching out my rear (or front) shocks help make the rear squat more for better traction? I'm currently running monroe "stock" shocks but think a little more weight transfer would help hooking those rear tires up..

Any advise on what shocks to use?

[Super73]

Yes, but the correct spring would make more of a difference.

Do you know what your truck weighs and what the front or rear weighs?

If not, find a local scale around you, weigh it and I can get you in the ballpark for correct spring rates.

Another thing would be to modify the lower control arm bracket to get your instant center of gravity lower which induces squat. But again, with out the right spring rate, it's not going to compress the spring.

[djracer]

Yeah what he said!

[LuckyHenriksen]

How does getting the proper spring rate affect ride height? Is it possible to have springs that help you launch well and also let you keep your 4/6 dropped stance?

[djracer]

yes that's possible! You need a soft front spring with a bunch of stored energy.

[LuckyHenriksen]

Where would someone find these soft springs

[Super73]

Give me the weight of your vehicle and I'll give you spring specs to look for.

What I did was take that info and called Moroso to find a spring that fit my needs. They told me though that the spring I thought was going to work for me was the wrong spring and wouldn't be right. Yet it was the perfect ride height and as you can see from the video in the link, tons of stored energy on the launch. So much that I moved the shock form the 90/10 setting to a 70/30 and it still was too much. Hence why I am swaping shocks again.

when you know the weight, it's easy to figure out what you need as our leverage ratios are the same.

[LuckyHenriksen]

Ok when I put it back together I'll scale it and let you help me =]

[Heavy Evy]

I like this thread. My 71 C20 with me in it about 4800 lbs. What would be a good spring for me?

[djracer]

you would need a front and rear weight.

[Super73]

Kevin is correct. If you can give me actual axle weights, I can help you out. Also, what are you looking for ride height and are you using a drop spindle?

[Lx3]

All that gets you closer but it's a combo just like motor, convertor,

gears etc.....

Front/Rear ratio, spring rate, shock ratio, I/C, even contact patch and

sidewall stiff come into play. You can take it as far as you care to go.

I've heard the PRO STOCK boys are running electronic shocks that

change rates 32 times in a pass. WOOOF

Sorry, I've got to say this again.

Find a book called AUTO Math by John Lawler

[Super73]

LX3,

Im sure the book is a good tool and you are right, there is a lot to any combo. But with out real world trial and error, you never get it all figured out. All I'm trying to do is help people get moving in the right direction. I feel that's all the book is doing too, just like Suspension Engineering by Herb Adams or the Dave Morgan seminar DVD set I have (Which is awesome BTW). There is soo much too it that I don't think any book could possibly have all the answers for all the different combs out there, but rather a good foundation and start. But I have been known to be wrong before I will look for the book.

[Super73]

I'm assuming this is the book.. BTW, his last name is Lawlor. You threw me off for a few
http://shop.ebay.com/items/?_nkw=aut...wler&_osacat=0

[Heavy Evy]

Originally Posted by Super73

Kevin is correct. If you can give me actual axle weights, I can help you out. Also, what are you looking for ride height and are you using a drop spindle?

No drop spidles just stock height. I'm not sure of the front or rear just the total haha but that don't help much.

[Wild83C10]

I'm not so sure you want the rear to squat, you lose a bunch of energy/power. You actually want the rear of the truck to raise up. This actually unloads all of the energy from the suspension to the tires. Another way is to have the rear end stay at its height and have the front end come up so the CG raises and shifts the weight from the front to the back. I've never seen the rear ends squat on cars/trucks setup for drag racing. When the rear end squats you affect your driveline angles which could actually hurt you more then help you.

[Super73]

I agree with 383 and he has a solid point. Antisquat is going to load the rear tires more "if" you have enough enough stored energy for front end travel. Antisquat "hits" the tires harder and forces them in to the ground by raising the frame and body. But, and this is a big but, if your front end is not coming up to transfer the weight, all antisquat is going to do is move that weight further forward when there is rear seperation. Antisqaut also is also antiraise for the front to an extent.

So if your instant center of gravity is above your true center of gravity then you will induce antisquat, if it's bellow you will induce squat.

Squat puts energy that could be used to move the vehicle forward in to the chasis. Some times you need to put that energy in to the chasis.There are times that you need to lessen antisquat or even induce squat. For instance:

If the track is going away and you can't loosen up the front end anymore than it is through the front shock, you might want to take some antisquat out of the chassis.

Or when track prep is next to nothing.

Or on the street (sorry, just putting it out there).

On a well prepped track with proper suspension adjustability, you would be wise to put antisquat in to the vehicle. Hence the reason I built adjustable lower control arm brackets for the trailing arm set up in my truck.

[Heavy Evy]

A little off topic but I think my biggest problem is Im topping out a little bit after half track. Im going to put 3.54 gears in the rear to see if that helps I think the 4.10's are to low since my truck is so heavy and the motor doesn't go to 8 grand(atleast I haven't gotten it that high).

[djracer]

Originally Posted by Heavy Evy

A little off topic but I think my biggest problem is Im topping out a little bit after half track. Im going to put 3.54 gears in the rear to see if that helps I think the 4.10's are to low since my truck is so heavy and the motor doesn't go to 8 grand(atleast I haven't gotten it that high).

What size tire do you have?

[Wild83C10]

Super73, I think you got it right. Good explanation.

[Heavy Evy]

Originally Posted by djracer

What size tire do you have?

I haven't ran my new tires which are 285/60/16's in the rear, The tires I used when I ran at the track were 31/10.50/16.5's, im probably going to get some slicks 29 inchers for the drags next summer.

[Lx3]

Super 73

I have used this book for many years and found it to be soooo close

it'll spook ya'. Real world conditions allways effect any combo but

that too can be calculated. I've had 3 combos run within .20 out of the

shop and off the trailer. Is that good enough? Hell NO. But it's sure not

a bad place to tune from. I'm 51 and still learning. I 've been real lucky

to be able to watch and listen to some guy's that are real pro's and have set

world ET and MPH records [Randy Merrick, Javier Silva, Earl McCoy] and

they get beat too. Everybody's lookin for that edge and personally that's

my favorite part. Someday I want to tune with my laptop and never pull

the hood.

And the beat goes on...........

Ooops, yes that's the book

[Super73]

Heavy,

What are you spining the motor too?

A 31" tall tire with 4.10's assuming 10% slip in the converter (which is very high) and 5,500rpm would = 111mph

[Heavy Evy]

Originally Posted by Super73

Heavy,

What are you spining the motor too?

A 31" tall tire with 4.10's assuming 10% slip in the converter (which is very high) and 5,500rpm would = 111mph

I can't remember but I think I got the motor to 5300-5500 maybe even 6000. I'm running a stock converter and tranny no shift kit yet. but my best time was a 16.8 at 88 mph

[Super73]

Again, assuming 10% slip which is very, very high, 88mph with 31" tires, 4.10's would equal 4,350 through the traps.

I would assume a stock converter is probably closer to 5% slip which would be 4,150 through the traps.

If you spin the motor to 5,500, the 3.42's are going to make it even worse. Right now, the steeper gear is multiplying your TQ and making you go faster. Generally speaking, you want as much gear as you can for best ET. You just don't want to run out of RPM before the finish line.

You would be better off putting a looser converter in the truck. Also running a shorter tire with yuour current combo.

The looser converter will get you in the power band faster, multiply TQ as your leaving and get your shift extesions shorter helping to keep you in your power band.


With a 26" tire, 10% slip, 5,500rpm your looking at 93.3mph.