May 26, 2020

Trueleo Racing MR2 knuckles – The best 1990-1998 Toyota MR2 braking and suspension upgrade, bar none.

Original article. http://trueleo.com/MR2Knuckle.htm

Racing Strong Motorsports – RSm Hub Failure PDF October 2014


History:
Toyota has two versions of the hubs for the sw20, the 91 to early 92 and beyond. The later versions added about 1mm raised rear section and the part number is superseded if you order hubs from Toyota to the older version. The hub is known to fail as Toyota tried to fix the issue and we have had about 10 failures, plus known of multiple failures from other teams.

We went through years of trying to make them work with different solutions. We tried different bearing grease to help with friction to keep the hub cooler, we tried cooling them with ducting, and even ceramic bearings wheel bearings. The hubs still failed over time. Our solution was to change them out every three races and hope they would not break but still did. The OEM cost is about $225 for each hub, a new nut, plus a new wheel bearing. The total cost was $550-600 every three races, plus the probable failure rate was not acceptable.

1993+ MR2 Spindle separation from hub on #79 Racing Strong MR2 GTv6
The flange side of the hub.

Solution.
When researching bearings and options we found out that bearing technology has advanced leaps and bounds in the last 20 years. Bearing sizes have increased with reliability. We found the bearing on the Nissan 370z front to be the key to our reliability issues. The Nissan 370z is a bolt-on hub and bearing assembly. The cost is low and the timeframe to wear is extremely long. I bought a set of cheap bearings, about $45 shipped for two, and have used that same set for about two years of racing. I am still waiting for them to fail and no issues.

Nissan 370Z hub on top next to MR2 sealed front bearing.

370Z huib next to broken 1993+ MR2 hub flange.

We went through over a dozen design iterations until we got to the final design on the knuckle. The knuckle is a bolt-on replacement to the stock part and there is no cutting or modifications needed.

The knuckles already have the lower ball joint location lower for better camber rise. It also has the steering rod tie rod location lower for improved bump steer. It is made from a solid block of 6061 and CNC. The reason the cost is high is due to the cost of the aluminum, the amount of machine time, and the number of machine setups. The really good news is that I purchased a dozen sets prior to the aluminum tariffs causing the price of aluminum to go up. If I do more sets in the future the price will be higher.

Trueleo Racing knuckles
Wheel side of the CNC’ed 6061 knuckle

The aluminum brake brackets that bolt on with the m12 Allen bolts are made from 7075 aluminum. There are multiple options based on what you will want.

93 Toyota MR2 Turbo calipers brackets.
You will use rotors from a 2005 Nissan 350Z sport with Brembo calipers. $750. It comes with the pair of knuckles, 4x m12 Allen bolts and washers, and pair of brake brackets.

1994 Lexus SC400 calipers.
You will use rotors from a 2005 Nissan 350Z sport with Brembo calipers. $750. It comes with the pair of knuckles, 4x m12 Allen bolts and washers, and pair of brake brackets.

Wilwood Calipers.
You will use rotors from a 2005 Nissan 350Z sport with Brembo calipers. $750. It comes with the pair of knuckles, 4x m12 Allen bolts and washers, and pair of brake brackets. Wilwood caliper part number is for the Wilwood forged Superlite caliper 120-11130 and they have options for different piston sizes based on what you need.

Wilwood calipers and Wilwood Ultralight rotors.
These rotors are about 7-8lbs lighter. $850 Comes with the pair of knuckles, 4x m12 Allen bolts, and washers, pair of brake brackets, two-rotor hats, 16x bolts, and washers for the hats.
You would buy the Wilwood rotors that cost $50-75 each and weigh 10.5lbs.  Part 160-2895 LH and 160-2894 RH.
Wilwood caliper part number is for the Wilwood forged Superlite caliper 120-11130 and they have options for different piston sizes based on what you need.

The 370z hubs come with 12×1.25 studs. You can use those and get a set of lug nuts. The other option is to use arp wheel studs from a Lexus is300 part number ARP 100-7715

For the rear I recommend the Wilhelm Racewoks rear Wilwood kit and rotor combo. His rear toe link and RCA kit are nice pieces also. His adjustable front control arm modification is a very nice addition on top of all of these parts.

I only have about 10 sets left for sale. I did not put a buy now button as I need to make sure there is availability. You will need to email me at Troy@Trueleo.com before purchase to make sure of availability.

Bill Strong

Just a guy that's obsessed with cars and auto racing. So much so that I work & play in the auto racing industry.

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