Suspension Geometry Kit

Wilhelm Raceworks suspension geometry kit

Based on extensive study of the geometry of the 90-99 SW20 MR2 suspension, the Wilhelm Raceworks Suspension Geometry Kit is designed to correct the negative effects of lowering, and to improve on the stock geometry by reducing dynamic toe (aka bump steer) and adjusting the roll axis of the chassis.  The result is significant improvements to turn-in and front end grip, while also reducing the oversteer tendency that the SW20 is so known for.  The kit also makes it much easier to catch or control oversteer once it starts.

Made in the USA!

Package deal: Purchase a geometry kit and a full set of coilover top mounts and save $80!

SKU Suspension Geometry Kit
$600
2 In Stock
* Rear Tie Rod Type:

* Front Rod End Option:



Description of Options:
Short tie rods are typical for US market '91-'92 cars, '90-'91 in the rest of the world.  Long tie rods for US '93+ cars, '92+ elsewhere.  Please double check your cross member before ordering, a previous owner may have changed it!

High misalignment rod ends highly recommended for stock struts due to large droop travel.  With most aftermarket coilovers either front rod end may be used. See instructions here for how to measure droop to verify which rod end you need.

Installation Instructions

Ride Height Calculator


The included bump steer spacers should be close enough for most users, but if you wish to fine tune a little you will need some additional spacers.  This kit includes 2 each of .030", .060", .100", and .200" aluminum bump steer spacers.  You will need to remove the spring, and jack the suspension through it's range of motion using a bump steer gauge to properly adjust bump steer.

Bump steer spacer kit

SKU Bump Steer Spacer Kit
$12
In Stock



Replacement Rod Ends

Eventually, it is possible that the original rod ends supplied with the kit will need replacement.  A full replacement set of six premium quality FK rod ends is $220 with the high misalignment front option, $150 without.  Please contact me to purchase.


Technical

This kit improves the MR2's suspension geometry in several ways. First, it corrects the negative effects of lowering. As discussed in my suspension geometry analysis, lowering the MR2 (or any McPherson Strut based vehicle) has negative effects on the suspension geometry.  In particular, lowering degrades the camber curves and excessively lowers the roll centers, resulting in more body roll.  The kit is designed to fully compensate for 1.25" of lowering. However, lowering further than that will not negate the effects of the kit. If anything, the lower your car is the more you can benefit from geometry correction.

Second, the front RCAs are thicker than the rears.  This raises the front roll center above the rear resulting in improved turn in AND improved rear end grip.

Third, significantly reduced rear toe change on a Rev1 (91/92) MR2. I have found this to have a significant positive affect on stability at the limit, making the car much easier to drive fast, and consistently.  With this adjustment I run my 91 at 1/8" total toe in with no loss of stability, leading to greatly improved rear tire wear.  On the Rev2+ cars the kit restores the stock toe curve, which is otherwise significantly altered by lowering the car.

This kit is designed to be bolt-on, and completely reversible. A little work with a press is required on the rear knuckle.

All kits use 3-piece, USA made FK rod ends.


Geometry kit installed on my car:

Front Geometry Kit

Rear Geometry Kit


Front tie rods use a custom made tapered stud, aluminum spacer matched to the roll center adjuster (RCA), aluminum tie rod adapter, and FK rod end.

For the rear tie rod the spherical bearing is removed from the knuckle and a steel slug is pressed in its place. The tie rod drop bracket is a welded steel assembly that simply clamps onto the knuckle. In addition to shifting the pivot point down to match the RCA, this also shifts the pivot point rearward, which reduces the natural toe changes of the rear suspension, aka bump steer. The stock rear tie rod is completely replaced by an aluminum hex tube with 3-piece FK rod ends at both ends, and custom bushings to adapt the rod end to the chassis at the inner end.

Roll center adjusters are machined from 6061-T6 aluminum, and designed to fix and improve the suspension geometry.  All aluminum parts are anodized black, the steel front tie rod studs are yellow zinc coated, and the rear tie rod brackets are powder coated in black.  All hardware is grade 8 standard / grade 10.9 metric.

This kit requires at least 16" wheels. The rear may require 17's, depending on the exact shape of the wheel.  The stock brake dust shields will need to be modified (bent) or removed to clear the front ball joint / RCA.

So, what does this all do for you? Better camber curves, reduced bump steer, improved tire wear, improved roll center location (reduces body roll), and reduced roll center movement for more stable cornering.

17 comments

  1. Tuesday, 01 February 2022 22:22
    Hey Alex, can you give me an estimate of how much the whole package may weigh? Thank you  
    1. Wednesday, 02 February 2022 08:28
      Shipping weight on the geometry kit is about 10lb, maybe a little more.
    2. Wednesday, 02 February 2022 16:01
      Thanks mate. Looking forward to having the product back on the site. Cheers. 
  2. Saturday, 02 April 2022 23:55
    Hi is there any kit if you have 15" wheels , or do you have suggestions on what I can do  for similar improvements with having 15"s . I plan on going to 16 or 17 but not sure when ,but doing an almost full suspension replacement on my 92 turbo right now 
    1. Sunday, 03 April 2022 08:01
      Hi Dustin.  The only way to get a similar geometry adjustment on 15" wheels is to use an inverted ball joint control arm (Hux Racing makes them), combined with the rest of my geometry kit (everything except the RCA).
  3. Monday, 25 April 2022 15:14
    My car has 225/50R16 tires in the rear, is that compatible or do I need 17's?
    1. Monday, 25 April 2022 16:17
      You almost always need 17's, although some 16" wheels might clear.  The critical point is the roll center adjuster / ball joint.  Just check that you have at least 1.25" of clearance between the bottom of the ball joint stud and the inside of the wheel, and you should be good.  And know that this clearance will change a little as the suspension moves, and will be greatest with the car jacked up, so you kinda need to check it with the car on the ground.  And obviously, you want some extra clearance on that 1.25"
  4. Wednesday, 27 April 2022 10:41
    Just wondering what type options for front tie rod ends and rear tie rods i should choose for a 91 MR2 lowered on BC racing coilovers. I'd love to order these asap before they go out of stock again.
    1. Wednesday, 27 April 2022 11:00
      On a 91 you would choose the short tie rods, assuming someone has not swapped the sub frame for a later model.  It does happen, so it's worth checking.  There are lots of pictures online that show the difference.  With BC (or virtually any other coilover) you can use the cheaper standard rod ends on the front.  It's only stock struts with lowering springs that require the high misalignment option.
  5. Saturday, 14 May 2022 17:52
    I purchased a car with this kit installed. Id like to remove it and put it on mine. Problem is my car is a 93 and the car its on is a 91. Can I purchase the bits required to put it on a 93 or do i have to get a whole kit?
    1. Tuesday, 31 May 2022 14:44
      Of course.  The only difference is the rear tie rod tube, which is about a $15 part.  You can either get them from me, or from somewhere like Summit Racing (they are off the shelf parts).  Send me an email for more details or to order.
    2. Monday, 27 June 2022 16:02
      Just seeing this now thanks for the reply ill reach out when i get it off the car. 
  6. Thursday, 19 May 2022 04:12
    Hello,   I was wondering if some parts of this kit would fit the front of the MK3 MR2. Specifically the parts highlighted in this photo: https://ibb.co/ZTgV8sc   Thanks, George
    1. Tuesday, 31 May 2022 14:41
      The front tie rod studs and tie rod ends may work on the Spyder, but I don't know for sure.  The rest of the hardware circled there is for the rear tie rod on the SW20 and wouldn't be helpful.
  7. Thursday, 26 May 2022 18:34
    Alex, Would you touch base via email?  91 Turbo. I already purchased a set of roll center adjusters, not knowing the full scope of the geometry issues. I would like to purchase the remaining items within the kit, if possible. 
  8. Saturday, 18 June 2022 21:05
    Hello Alex, I’m looking at this kit as I plan out a build for time attack. A lot of the rule sets don’t allow you to change oem “pickup points” but I’m having a hard time finding a definition for this.  Do you know if something like this would be legal in GridLife?
    1. Sunday, 19 June 2022 08:18
      Usually that wording is used with regards to the suspension points on the chassis, which this doesn't change. So you should be ok, but it may be worth double checking that the rules don't have other provisions against changing the geometry.

Questions or comments?

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