StickShifty

i will be doing a suspension overhaul next month. after a bunch of research i believe i made my final choices:

-Tokico HP Shocks/struts (the non adj ones)
-Steeda Ultralight Springs (lowers the car about 1.25 in front - 1.5 in back)
-J&M street fixed LCAs
-BMR relocation brackets

my biggest concern is the pinion angle, i know the pinion angle will change. the steeda springs are not a big drop, 1.25 and 1.5 i also am under the assumption that i do not need to adjust for the pinion angle, but it is a good idea to do so.

right now i am looking to leave the UCA stock and use fixed LCAs, what are your opinions about this setup and pinion angle. and over several years.


EDIT: my biggest concern about the pinion angle is adjusting it, i personally do not know how. also, i will be doing all the work on the car myself with 3 friends. we have done suspension work before. but i personally never dealt with pinion angle.

Sp3kter

You will need an ajustable upper controll arm. You can google tutorials on how to ajust the pinion it is very easy. You will also need an ajustable penhard bar to recenter the car after the rear has been droped.

chub46

I have the Steeda sport springs and the BMR relocation bracket with stock LCA and UCA. I am also concerned about the pinion angle, even though I read that with the stock driveshaft pinion angle should not be a problem. I decided to get the spyder aluminum driveshaft, the Steeda adjustable UCA and the nonadjustable LCA's to ease my concerns. Better safe than sorry. Plus I drive my car hard sometimes.

moosestang

If traction is important to you, then get the relocation brackets. I also felt an improvement in the ride with them. When you lower the rear, the angle of the upper and lower control arms will change, moving the instant center. The instant center is the point where the imaginary lines of the control arms will intersect.

The stock drive shaft will absorb a lot of vibrations from improper pinion angle, but a 1 piece will transmit more vibration. If the pinion is to far down, then you will get a vibration when you let off the gas at high speeds. It feels like running over those lines in the road designed to tell you to slow down.

Even a small difference in the angle of the upper control arm, or 1 degree difference in the pinion angle(pinion angle itself does not affect traction, but with our suspension you can't change the pinion angle without changing the angle of the control arms), can make a big difference in traction, at least it seems that way on my car. I'm still not entirely sure if it's the angle of the arms or if the pinion angle is robbing more power, making it seem like there is more traction, but my butt dyno tells me it's more traction from better weight transfer.

StickShifty

thanks for the info. i am just worried about lowering the car and having the pinion angle be off.

degeze

After lowering the car it is suggested that you get either adjustable LCA's or a adjustable UCA to adjust the pinion angle. Since you already ordered fixed LCA's you should get a adjustable UCA. Also, you need to buy a angle finder (to measure your pinion angle).

If you don't want to worry about your pinion angle being incorrect, you will need a adjustable UCA .


I have a good amount of suspension parts and after lowering my car my pinion angle was incorrect, and needed to be corrected.

tx_zstang

You can put the UCA on IF you need adjustment. With relocation brackets, you might or might not need to adjust your pinion angle. I would put the springs/dampers on, and relocation brackets, and then if you need pinion adjustment, put in an adjustable UCA.

Once you know how to measure the pinion angle and see how it changes with adjustment, you'll be able to get it where it needs to be. FWIW, an adjustable UCA changes the distance of the top of the rear end in relation to the underbody of the car. By moving the top of the rear end, it changes the pinion angle.

StickShifty

i believe that relocation brackets do not affect your pinion angle. just changes your instant center back to normal. not 100 percent tho. i am prob going to order a steeda adj UCA just to be safe. I will be putting many miles on this car, i dont want any problems down the road. i figure that i am changing all the other junk, throw in a UCA to be safe.

degeze

+1.
After installing everything check to see if the body is centered over the rear wheels and if not you will need an adjustable panhard bar to line it up.
Good luck.

157dB

This might help explain proper pinion angles:
http://iihs.net/fsm/?dir=77&viewfile...easurement.pdf
http://iihs.net/fsm/?dir=76&viewfile...e%20System.pdf