jbl comp alignnment numbers btb (by the book)

vector1 · #1 (**permalink**) 10-01-2012, 05:02 PM

here's an alignment i did earlier this year and just checked it recently to see how things were holding up. forget the rear camber numbers as the machine for some reason doesn't calculate them too well and must be done by other means. notice the setback, which is the distance either right or left side difference. in this case it is .050. this number is a function of thrust angle and front upright location, so if i was to be able to get the thrust angle centered and the toe on the rear to 0 this number would change also. 1/4" if i remember is good. this means the chassis is relatively square. good numbers anyway and there's a lot of work in getting them there.

951mat · #2 (**permalink**) 10-01-2012, 05:32 PM

Must be nice having that Machine in your garage. Bring that car to Hallet and really test that alignment!
Mat

AL427SBF · #3 (**permalink**) 10-01-2012, 06:04 PM

Quote:

Originally Posted by vector1

here's an alignment i did earlier this year and just checked it recently to see how things were holding up. forget the rear camber numbers as the machine for some reason doesn't calculate them too well and must be done by other means. notice the setback, which is the distance either right or left side difference. in this case it is .050. this number is a function of thrust angle and front upright location, so if i was to be able to get the thrust angle centered and the toe on the rear to 0 this number would change also. 1/4" if i remember is good. this means the chassis is relatively square. good numbers anyway and there's a lot of work in getting them there.

Good to know vector, I look forward to the day I'm burdened with that same work

vector1 · #4 (**permalink**) 10-02-2012, 02:48 AM

good luck with your build brett, i feel for you.

vector1 · #5 (**permalink**) 10-02-2012, 03:18 AM

Quote:

Originally Posted by 951mat

Must be nice having that Machine in your garage. Bring that car to Hallet and really test that alignment!
Mat

somebody needs to tell your registrar i am still uncommitted, got a good laugh though.

RICK LAKE · #6 (**permalink**) 10-02-2012, 03:24 AM

vector1 Did you have your weight in the drivers seat? If yes the numbers are good. It's a pain but having the thrust angle at "0" is also important for having a car lay the power down and go straight. The number is low and you have no weight in car to match yours. If you do another check with you in the car you will find different numbers. There the corner weights setup first? This will also change the numbers if not done. I have been there though all this. It's a pain but at the end the car handles so much better. Rick L.

RICK LAKE · #7 (**permalink**) 10-02-2012, 03:34 AM

vector1 Did you have your weight in the drivers seat? If yes the numbers are good. It's a pain but having the thrust angle at "0" is also important for having a car lay the power down and go straight. The number is low and you have no weight in car to match yours. If you do another check with you in the car you will find different numbers. There the corner weights setup first? This will also change the numbers if not done. I have been there though all this. It's a pain but at the end the car handles so much better. Rick L.

vector1 · #8 (**permalink**) 10-02-2012, 03:49 AM

yes driver weight was in the seat, good point.

the infinitely adjustable a arms could put the thrust at 0 but i don't have these, unfortunately or fortunately it is at a good place now, 1/2 turn of 1 heim joint puts the thrust angle at 5 or 7+, about a 7 or 9 deg. swing, can't remember now. with the inboard joints and toe adjustment it gets to be a 3 dimensional slinky.

Clois Harlan · #9 (**permalink**) 10-02-2012, 05:00 AM

That would be me! I was telling Larry Goins you were coming and he said he doubted you would make it so I put your name on the partiicipants. Told him to check it out. Forgot to take you off.

But, it will be done, if I can talk Mark into going back into our web site and changing it. I don't have administrator rights.

vector1 · #10 (**permalink**) 10-02-2012, 06:07 AM

larry needs to buy that car so he can use it in his shop as a demonstrator!

Clois Harlan · #11 (**permalink**) 10-02-2012, 08:04 AM

you are probably right Mark. Have you ever used the automatic sway bar adjuster while driving on a track? If so, could you tell there was a significant difference in the handling?

Clois

vector1 · #12 (**permalink**) 10-02-2012, 09:43 AM

Quote:

Originally Posted by Clois Harlan

you are probably right Mark. Have you ever used the automatic sway bar adjuster while driving on a track? If so, could you tell there was a significant difference in the handling?

Clois

i don't have extensive experience with it on track but i do use it on the street and can tell a significant difference between full soft and where it is adjusted for the street which would be similar to the track.

at an autocross because the car was not designed for the tight corners i made some adjustments using the sway bars to be able to slide the rear around the turns and it worked well, very predictable.