Joined
·
1,407 Posts
OK, all measurements are done. Measurement were compared between a set of MK2 GAB shocks (rear adj, front fixed) and AE86 Tokico shocks (all 4 adj). Here's what I've found:
FRONT:
Front strut housings between AE86 and mk2 are identical in dimensions. However, the caliper mounts are spaced farther apart (by alot) on the AE86, so an AE86 front suspension (like TEIN or JIC) would not be a direct swap in affair.
They do have the same mounting, though, so RCA's* for an AE86 will fit the MK2. ********note: after precise measurement by Don L., the mk2 mounting holes are spaced 1/8" further apart (I didn't catch that). So they will NOT work. aarrrggg...the problems with using a tape measurer....I need to get me some precision measuting tools.********
Due to their exact dimensions, AE86 strut inserts fit in the MK2 housing. The extended length is only 3/16" shorter on the AE86. THe strut insert body is 1/16" shorter than the MK2, so an extra half turn of the housing collar will clamp it down just right. The AE86 strut body is slightly narrower than the MK2, so it has a little side to side movement, but as the housing collar starts to tighten on it, it centers it right up. You cannot use the AE86 housing collar as it is different thread pitch.
I compared damping between the two, both on feel (pushing it down) and speed at which the strut returned to extended position, and the non adjustable MK2 GAB strut's damping was equal to the AE86 tokico somewhere between setting 4 and 5.
Another good thing about this is for having short stroke struts. It is common to use AE92 front strut inserts as short stroke shocks for AE86's. The AE92 inserts are 103mm shorter extended than the AE86, and the strut body is 66mm shorter. What you do is put a 66mm spacer inside the strut housing under the shock, put in the AE92 shock, and now you have a 40mm shorter stroke shock. The TRD short stroke kit for the AE86 is just an adjustable AE92 shock with the spacer. This would work perfect on the MK2.
REAR:
OK, rear is not as good news. Rear AE86 shocks were much shorter than the MK2. The AE86 extended length is 2 1/4" shorter than the MK2. Closed, however, the AE86 shock is only 3/4" shorter than the MK2. This would work for someone who is lowering their car 2" or more. Comparing the shock damping between the two, it was pretty much the same all the way through. The 5 setting on the AE86 Tokico shock was equal to the 7 setting on the GAB MK2 shock. 8 on the GAB shock is a drastic increase (1-7 is pretty linear) from the rest. 8 is VERY stiff.
Some investigation will need to be done to see what rear shock would work as stock and short stroke for the rear.
*Note- RCA's are Roll Center Adusters. Roll center refers to the lower control arm's movement, and how it changes camber and toe during suspension compression. When you lower the front, you change the position of the lower control arm. For example, lets say for every inch of travel you get -1 degree extra camber. If, say at stock height you have 0 camber, if you lower your car 1" you now have -1 degree camber at static hieght. Now when you compress the suspension 1 inch, you have -2 camber instead of -1. Same changes apply with toe.
RCA's are basically spacers which go between the strut housing mount (where it mounts to the lower control arm) and the lower control arm. This resets the control arm back to stock position. In effect it gets rid of any negative camber caused by lowering the car, so your camber remains stock. It also reduces bump steer caused by lowering of the car. They make different thicknesses, so you can choose one thats as thick as the amount that you lowered your car.
Hope this information is useful to someone.
Christian
FRONT:
Front strut housings between AE86 and mk2 are identical in dimensions. However, the caliper mounts are spaced farther apart (by alot) on the AE86, so an AE86 front suspension (like TEIN or JIC) would not be a direct swap in affair.
They do have the same mounting, though, so RCA's* for an AE86 will fit the MK2. ********note: after precise measurement by Don L., the mk2 mounting holes are spaced 1/8" further apart (I didn't catch that). So they will NOT work. aarrrggg...the problems with using a tape measurer....I need to get me some precision measuting tools.********
Due to their exact dimensions, AE86 strut inserts fit in the MK2 housing. The extended length is only 3/16" shorter on the AE86. THe strut insert body is 1/16" shorter than the MK2, so an extra half turn of the housing collar will clamp it down just right. The AE86 strut body is slightly narrower than the MK2, so it has a little side to side movement, but as the housing collar starts to tighten on it, it centers it right up. You cannot use the AE86 housing collar as it is different thread pitch.
I compared damping between the two, both on feel (pushing it down) and speed at which the strut returned to extended position, and the non adjustable MK2 GAB strut's damping was equal to the AE86 tokico somewhere between setting 4 and 5.
Another good thing about this is for having short stroke struts. It is common to use AE92 front strut inserts as short stroke shocks for AE86's. The AE92 inserts are 103mm shorter extended than the AE86, and the strut body is 66mm shorter. What you do is put a 66mm spacer inside the strut housing under the shock, put in the AE92 shock, and now you have a 40mm shorter stroke shock. The TRD short stroke kit for the AE86 is just an adjustable AE92 shock with the spacer. This would work perfect on the MK2.
REAR:
OK, rear is not as good news. Rear AE86 shocks were much shorter than the MK2. The AE86 extended length is 2 1/4" shorter than the MK2. Closed, however, the AE86 shock is only 3/4" shorter than the MK2. This would work for someone who is lowering their car 2" or more. Comparing the shock damping between the two, it was pretty much the same all the way through. The 5 setting on the AE86 Tokico shock was equal to the 7 setting on the GAB MK2 shock. 8 on the GAB shock is a drastic increase (1-7 is pretty linear) from the rest. 8 is VERY stiff.
Some investigation will need to be done to see what rear shock would work as stock and short stroke for the rear.
*Note- RCA's are Roll Center Adusters. Roll center refers to the lower control arm's movement, and how it changes camber and toe during suspension compression. When you lower the front, you change the position of the lower control arm. For example, lets say for every inch of travel you get -1 degree extra camber. If, say at stock height you have 0 camber, if you lower your car 1" you now have -1 degree camber at static hieght. Now when you compress the suspension 1 inch, you have -2 camber instead of -1. Same changes apply with toe.
RCA's are basically spacers which go between the strut housing mount (where it mounts to the lower control arm) and the lower control arm. This resets the control arm back to stock position. In effect it gets rid of any negative camber caused by lowering the car, so your camber remains stock. It also reduces bump steer caused by lowering of the car. They make different thicknesses, so you can choose one thats as thick as the amount that you lowered your car.
Hope this information is useful to someone.
Christian
