Chasis set up

[rsnider]

OK... I've read some about the center of gravity (CG), and instant center (IC). It is starting to make sense to me now. Has anyone done the math and the balancing act to determine how our lower control arms should be modified to get the traction needed at the strip?

There are a dozen or so ads in the magazines for lower control arms, but if they are in the same position as the stock arms the gains will be minimal (Only the advantage of the pinion angle if you can adjust the lower arm).

I've only seen one TINY insert in an ad that lists two little brackets to change the angle of the lca's. I believe that this is the mod that will make the biggest traction gain.

You know that for the NMRA guys to be turning 9's on street radials they have found the holy grail in chasis tuning. Is this their secret?

Comments?

[Indy]

I'll let you know soon. That is what we are going to be working on with my Mach next. I need to work on making it hook off the line now that I have a T/C and trans that work. That way I'll see the full potential from my 3500stall and built trans. I'll let you know what works as soon as I make a few changes. I'm not even going to start using the bottle again until the Mach hooks off the line.

[rsnider]

Hey Indy,

From what I've read it all works together. If you set up the car without NO2 you will have to re-adjust everything once you start using the bottle. Believe it or not my neighbor has 340 RWHP, 486 gears, 4-spd, gutted 69 Camaro using MT E.T. Streets and he has TOO MUCH hook at the line. He has to run 20+ psi in the tires to get them to spin at all. He managed to finally get traction by using the instant center to shift weight. Now he is working to lessen his traction. I've found some really good short articles on the internet. I'll make a copy and drop it off at the shop if you want?

From what I can see of the aftermarket kits, all they do is drop the LCA connection to the differential a couple of inches. Which raises the IC into the 100+% range planting the rear tires harder when you pull the trigger.

[Indy]

I've found some really good short articles on the internet. I'll make a copy and drop it off at the shop if you want?

Thanks I'll read any info I can get my eyes on. I've done some research on this in the past now its time to use what I have learned. I'm going to find what works best with both set ups, then find the happy medium.

I found alot of good info at BaselineSuspensions.com check it out when you have a chance if you haven't already come across it.

[rsnider]

Interesting... I hadn't seen "Baselinesuspensions.com" but the info I read was cut directly from their web site? The coat hangar/springs and the refrigerator analogy's were both the same. It's good stuff. I can see many of your shops cars soon with 1.4-60's times on MUCH smaller tire/wheel combinations.

[Indy]

I'm going to try to find time to plot my suspension this week. Then I'll figure out what I need to do to relocate the UCA mount position. This should make a huge difference in how the Mach applies the power to the ground. I'll post up what the results when I get it dailed in.

[rsnider]

DANGER WILL ROBINSON! (Don't worry about it... you're too young to understand).

Sam found that when he hooked to the point of 100% traction things started breaking. He has a 4-spd so his "hit" will be a lot faster and harder than our automatics. You have made the two expensive fixes already (converter and trans). He actually tore the base plate welds from the traction bar on one side. He is now working with squat and anti-squat to slow the shock to the drive line and tires. Man, there are many different directions the energy can go on launch. All are trade-offs. You will be "The Place" to have a SN95 preped for the track when you get your car dialed in. I don't ever remember hearing anyone talk about chasis work being done at AMP or SVC. It's always about horse power. I believe that a lot of GT's and Machs are going to surprise the stock Cobras if they gain .2-.3 in the 60'. That equates to A LOT of time in the traps.

[TRUUBLE]

FWIW . . . my car is going pretty consistent 1.4x 60 foot times with a fairly simple setup. When weighed, the car was 52%/48% front/rear. I'm using Maximum Motorsports adjustable LCAs, UPR double adjustable UCAs, and a Competition Engineering antiroll bar.

I'm still on the stock shocks and springs (with over 100k miles on them) and I haven't even played with the pinion angle yet. Once I get some nice adjustable shocks and some drag springs, I expect to see 60s in the 1.30s.

That said . . the car hooks . . . like this:

[rsnider]

I must have missed something when I read about the control arms. I thought the only reason for changing the control arms was to adjust the pinion angle, and maybe take out the sloppyness of the bushings?

Your car is awesome on it's launch!!!! You haven't messed with the instant center?

[TRUUBLE]

Nope . . haven't messed with the instant center. BUT . . . I took over 600 pounds of weight out of the front of the car. So, when it weighed in at 52% of the weight in front and 48% in back and 60 pounds heavier on the driver's side front (with me in it) we knew it was a pretty balanced car.

At this point I'm less worried about the IC and more worried about pinion angle and proper shocks/springs in the back. FWIW, I'm running coilovers in the front with 14" 175 pound springs and Lakewood 90/10 drag struts. Never forget the front end when you're setting up a car.