Ok so I just got my bone stock 95 240sx aligned, cause I just installed my Tein Tie rods. However there is a bunch of stuff out of spec and it pisses me off!!
Aside from the front camber/caster being non-adjustable (since its a TINY bit out of spec) my rear is to! The guy put the driver rear in spec at about -1.2 camber and the pass rear he said woul not adjust past +0.1 degress camber!! I can't understand this. The control arms are not bent, what would cause this? He said he could not get it to go out any farther? I really hate not being able to do my own alignemnts... I told him to explain to me and he barely spoke english and was saying how it would just slide back and forth and thats all he could do. <--- doesnt make sense to me. Did I get screwed out of $60? I bet I could have done it properly myself. The car rides straight now, but having the camber unmatched in the rear like that I do not like. Also how does the front go out of spec? TC rods, ball joints and all buschings are in good shape.... bent frame?
I am going to be getting some coilovers very soon with front camber plates so thats taken care of I guess. For the rear camber I am not sure what I am going to do yet. I mean the car is bone stock and unless somethign is really wrong with the frame or something could there really be anything else? If a car is stock shouldn't it be able to be put to stock spec? THe shocks/springs dont sag and are in pretty good shape. Any help.... thanks :ylsuper
just got alignment--out of spec?
I suppose the frame could be bent, if you say the control arms are fine and everything. Take out you FSM and it should have all of the frame measurement and illustrations of where to take them from. Jack the car up, get out a tape measure and have at it. There are many measurements to do but since your problem is only in the rear and most of the measurements are up front...it shouldn't be too bad.
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Nismo_Freak
- Posts: 10314
- Joined: Wed Jul 24, 2002 10:42 pm
- Car: 89 Nissan 240SX
No... there is no "frame" in a unibody car. The only way to measure for a bent chassis would be to compair overall differences in toe, caster, camber, and chassis centerline deflection.
As the vehicle wears your bushings will as well... remember how that cam bolt just moves the arm a slight amount to change the alignment? Well when the bushings and the rest of the suspension begins to sag you get various alignment angles.
You should have +/- 0.75 of camber change in the rear with the cam bolt, but remember you will not start at 0 deg. of camber. For performance, depending on spring rates, height, etc. an amount of rear camber between 1 - 2 deg. of negative camber is ideal. Toe should be zeroed out if not toed out a little to increase the steering response.
You have the same three measurements in the front as you do in the rear... however rear caster angles don't do anything because they aren't turning.
As the vehicle wears your bushings will as well... remember how that cam bolt just moves the arm a slight amount to change the alignment? Well when the bushings and the rest of the suspension begins to sag you get various alignment angles.
You should have +/- 0.75 of camber change in the rear with the cam bolt, but remember you will not start at 0 deg. of camber. For performance, depending on spring rates, height, etc. an amount of rear camber between 1 - 2 deg. of negative camber is ideal. Toe should be zeroed out if not toed out a little to increase the steering response.
You have the same three measurements in the front as you do in the rear... however rear caster angles don't do anything because they aren't turning.
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Q45tech
- Moderator
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Members keep confusing NEW OEM MISALIGNMENT NUMBERS [so called alignment specs] [created by measuring the car in motion] and coming up with numbers that work brand new on an alignment machine.....what's in the FSM and alignment machine's computer.
With what the REAL alignment should be with worn [used bushings].
Radial tires are optimized to operate with a negative 0.5 degrees of camber. Unfortunately the suspension changes camber as the body rolls so a preset error is introduced in the suspension so that in moderate handling the tire doesn't go too positive yet doesn't cause too much extra force on the inside edge.
Assymetrical tires [those marked " this side out"] usually have a reinforcement belt on the inside edge to help support the extra non flat across the tread weight.
Michelin assumes extra camber and caster on certain tires designed for heavy lux performance cars {MB,BMW, AUDI}
With what the REAL alignment should be with worn [used bushings].
Radial tires are optimized to operate with a negative 0.5 degrees of camber. Unfortunately the suspension changes camber as the body rolls so a preset error is introduced in the suspension so that in moderate handling the tire doesn't go too positive yet doesn't cause too much extra force on the inside edge.
Assymetrical tires [those marked " this side out"] usually have a reinforcement belt on the inside edge to help support the extra non flat across the tread weight.
Michelin assumes extra camber and caster on certain tires designed for heavy lux performance cars {MB,BMW, AUDI}
You are right... however I coudl care less about the new specs. I have a pretty good idea what I would like my car to be at. I am not comparing anything from the "stock" new spec really... I am pissed cause its so far out of spec from side-side! THe rear tires are 1.3 degrees off from eachother!
Nismo freak could you tell me what to measure and how to turn those measurements into a hypothesis? I can get the alignment printout of the car and get those measurements of camber, caster and toe but I am not sure about chassis centerline deflection. I would guess that it would be to prove that the centerline of one point and the centerline of another line up correctly. Any help? I think it would be good to kow if the chassis is tweaked before I go dumping lots of money into this car. Thanks!
Nismo freak could you tell me what to measure and how to turn those measurements into a hypothesis? I can get the alignment printout of the car and get those measurements of camber, caster and toe but I am not sure about chassis centerline deflection. I would guess that it would be to prove that the centerline of one point and the centerline of another line up correctly. Any help? I think it would be good to kow if the chassis is tweaked before I go dumping lots of money into this car. Thanks!
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Nismo_Freak
- Posts: 10314
- Joined: Wed Jul 24, 2002 10:42 pm
- Car: 89 Nissan 240SX
What do you mean pull problem? So you think that this is a possibility? OR is having 0 and -1.3 camber something tht can happen after time and wear take place on the chassis/suspension? Ofcourse I hope everything will be good to go... it rides very smooth and doesn't shake or pull or feel out of balance when cornering, but since I got the alignment the *** end has been able to come out easier. Anyhow so you are saying in order to really see there is nothign that I can do... its got to be on an alignment rack?