Some performance numbers and the weigh in- Post your numbers!

[ehansen007]

I took ole' Stinky (he runs rich) out today for some performance runs just get a baseline before I put in the cam and roller rockers. I pulled three consecutive 0-60 times at 4.99 and did the 1/4mi in 13.5 at 103. Granted this is on a normal street but this is bone stock with the top on. I know I'd do better at the track. I also had him weighed at the Del Mar show and this is what it came out to. Again, with the top on.

http://i897.photobucket.com/albums/ac177/ehansen007/Help%20Topics/RideTech.jpg

[ehansen007]

I thought there were some guys here who took their cars to the strip? No?

[j33ptj]

Can you explain the differences between left and right (and rigt and left??), odd that there seems to diagonal change in weight...

[Jay Mann]

Are you using your Speedhut speedo for the info? I also have the GPS speedo for this reason. Triple digits on a normal street?

[MPTech]

I'm asking.... do you need to increase your spring on the left (DS) rear to better balance it? (or the right front?)

[Jeff Kleiner]

I'm asking.... do you need to increase your spring on the left (DS) rear to better balance it? (or the right front?)

The car is what I call "cross jacked". Think of the teeter totter effect of sitting on a 4 legged stool with two diagonally opposite legs being shorter than the opposing pair. To balance it the spring adjusters on the LF and RR need to be backed off (or the RF and LR can be tightened for the same result).

Jeff

[MPTech]

Thanks Jeff. That's exactly what I thought, but no one has ever explained how jacking works to me, just seemed logical from an engineering perspective. Will tightening (turning the adjuster to make the shock longer) the rear left shock > reduce the weight on the right rear & left front (both)? Will you still have the same front to back weight? or will it increase the front with and reduce the back weight too?

[crash]

The things to remember when setting up a car's corner weights are that you can NOT change weights side to side or front to rear without physically moving weight around. The ONLY thing you can do with spring collars is to cross jack weight, and change ride height.

It is ALWAYS a balancing act to get ride heights correct, cross weights right, front/rear/left/right splits right, etc. To set a car up properly, even when starting with very close numbers, usually takes me a few hours. I do my weights first and then go for ride heights, but some people do it the opposite. :)

[ehansen007]

Are you using your Speedhut speedo for the info? I also have the GPS speedo for this reason. Triple digits on a normal street?

Yes, I'm using the GPS speedo. The street I was on is an old back road out behind the air force base. It's nice and quiet. :)

[ehansen007]

The car is what I call "cross jacked". Think of the teeter totter effect of sitting on a 4 legged stool with two diagonally opposite legs being shorter than the opposing pair. To balance it the spring adjusters on the LF and RR need to be backed off (or the RF and LR can be tightened for the same result).

Jeff

I do agree with this and it's interesting that Ridetech didn't say anything about it but I also asked if they were sitting on flat ground. I know they weren't. I probably didn't notice it because of the amount of time I've spent on barstools. :) I'll do it again at the next event and get it all set up. I've got some suspension settings to tweak as well while the engine is out.

http://i897.photobucket.com/albums/ac177/ehansen007/IMG_03592.jpg

http://i897.photobucket.com/albums/ac177/ehansen007/IMG_03602.jpg

[Tom Veale]

Hi Erik,

When I first checked my FFR Challenge car (with me in the driver's seat) It was more than 100# out on Cross Weight even when the car ride height was right on the money. However, if I remember correctly, it took only a half turn on the "light" corners to bring the car within +or- 10lbs on cross weight. For the race track that small shift did make an improvement in Left/Right turning symmetry. And, there was no measurable change in ride height at any corner.

#007 was off by more than 100# cross weight when we first finished the car in 2009. If I remember correctly it took more adjustment on the Konis (turns) to correct the cross weights. Maybe they have finer threads than the shocks on the Challenge car. Also, I had to fiddle with all four to keep ride height on target along with cross weights.

Your car is currently about 75# out on cross weights, but I don't know if that's with or without a driver. That will require only a small amount of adjustment per shock to correct.

If you are usually the only driver or are going to autoX or road course the car, then do the cross weights with you in the car. If it's going to be street driven and with a passenger, then doing the cross weights without anyone in the car is just fine.

The reason my "cross weight" measurements are as "loose" as they are is that I use the County's scales (which are free) but only +or- 10# accuracy! :)

Here's how my car weighs in now. I've not adjusted anything but ride height since installing the new QA1 Shocks, but cross weights are close enough for street use.

Without Driver or Passenger in the car and with about 1/4 tank of fuel:
http://www.ffcars.com/forums/members/albums/3187-tom-veale/more-33-photos-007-646-picture5325-cross-weights-w-o-driver.gif

With Driver and 1/4 tank of fuel:
http://www.ffcars.com/forums/members/albums/3187-tom-veale/more-33-photos-007-646-picture5324-cross-weights-driver-car-1-4-tank-fuel.gif

I'll probably tweak those cross weights with me in the car to be a bit closer before taking to the track, but this is better than where it was when I first checked the cross weights after the car was first finished.

My car dyno'd with 300 RWHP and 300 Lbs/Ft torque (5.0L Ford with E303 Cam, Ford GT Heads and Intake, 24# Injectors) but I don't have any acceleration or 1/4 mile times as of yet. But, I was the fastest guy at Road America's track in the White Walls category!

Best regards,

[Marty Prario]

Eric, I would not do any suspension setting tweeking with the motor out.

[ehansen007]

Sorry, I was referring the steering rack, not suspension settings.