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**9kracing** · 03-13-2026, 07:22 AM

I ultimately went with https://mrtengineering.fi/products/b...le-tie-rod-kit as the other kits required permanent modifications to the vehicle.

I was originally going to run this, but the juice wasn't worth the squeeze.

BMW E30 / E36 / E46 - RACE front control arms with roll-center / bump

https://mrtengineering.fi/products/bmw-e30-e36-e46-race-front-control-arm-kit-3

Why do you need one? When lowering your car (BMW E30 / E36 / E46) the front end geometry goes wrong. The main purpose of the kit is to correct these geometry issues.The extended mounting stud changes control arm pivot point vertical distance by 20mm correcting the roll-center and camber curve.Tie rod end pivot point is also changed by 20mm in vertical direction which corrects the bump steer curve.Perfect triangular control arm design allows very rigid, lightweight construction that in addition of all other benefits stated above, is highly desired for circuit racing applications. All control dimensions are adjustable, this also allows use of many different combinations such as spindle/knuckle swap on other chassis for example E30 5-lug swap. Does it fit my car? The kit can be combined with most of the E30 /E36 / E46 chassis and knuckles/spindles. See available variations: Chassis: E30 non-M / E30 M3 **/**** E36 non-M / Z3 non-M / E36 M3 / Z3M E46 non-M / Z4 non-M *** E46 M3 / Z4M */*** Spindle/knuckle: E30 non-M E36 / Z3 non-M E36 M3 3.0 E36 M3 3.2 / Z3M E46 / Z4 non-M E46 M3 / Z4M Control arm width: Standard +30mm (+60mm total) Is it easy to install? Installing the kit is only recommended for enthusiasts with knowledge of car repairs and welding skills. Welding is required for both subframe mount and extra weld bung for the rear bracket. If you need any further info please contact us! How about the lifetime and service of the kit? The kits have been proven on street and track applications by hundreds of our customers. We're constantly doing R&D to make the kits even better, all improvements are based on customer feedback which is very important to us.We have proven the very same bearings with no maintenance for 20,000 kilometers, through the year, in daily use without signs of excessive wear. When the bearing life comes to an end, they're easily replaceable! Bearings are available around the world from automotive and industrial dealers and any of the spare parts can be also bought separately from us. We want to keep our customers 100% happy thus we're only using the best materials and manufacturing processes available. CNC machined parts; arms, rods and steering adapters are made of aerospace grade AW-7075 aluminum, highest quality CrMo tool steel and Grade 5 titanium is used on control arm mounting studs and fasteners, rear brackets are TIG welded structural steel. We use DHL Express shipping for all items. Please find your order tracking information from DHL website.

Reach out to Mikko, he's very responsive and a pleasure to work with.

**CrisSilberGrau** · 03-13-2026, 10:43 AM

Brothers E36, had the SLR kit before changed to full MRT race front arms. Limited driving, but he mentioned it's very good under load and transitions. A marked improvement over the previous set-up.

Edit: the car in question is more of a Clubsport M3. Not the most street friendly, you have to keep in mind your fender liners and rub etc. For a street car this would be overkill.

Attached Files

**Larky7** · 03-13-2026, 10:53 PM

Originally posted by Larky7 View Post

Looking for feedback and street driving experience from owners with MRT’s roll centre/bump steer angle kit..

BMW E30 / E36 / E46 - Roll-center / bump steer / angle -kit

https://mrtengineering.fi/products/bmw-e30-e36-e46-roll-center-bump-steer-angle-kit

Why do you need one? When lowering your car (BMW E30 / E36 / E46) the front end geometry goes wrong. The main purpose of the kit is to correct these geometry issues.The steering adapter changes control arm pivot point vertical distance by 30mm correcting the roll-center and camber curve.Tie rod end pivot point is also changed by 30mm in vertical direction which corrects the bump steer curve, the pivot point is additionally moved closer to the control arm pivot point changing the lever ratio which gives you quick steering ratio and allows more steering angle.   Does it fit my car? The kit can be combined with most of the E30 / E36 / E46 control arms, knuckles/spindles and tie rods. See available variations: Outer joint size: 41mm (E30 non-M, E36 M3) 48.5mm (E36 non-M, E46 M-Sport, E46 aftermarket) 50mm (E46 OEM factory) 33mm (E46 M3, Z4M) thread tool included ** Spindle/knuckle: E30 non-M * E36 / Z3 non-M E36 M3 3.0 * E36 M3 3.2 / Z3M * E46 / Z4 non-M E46 M3 / Z4M Is it easy to install? The kit comes with instructions, if you know how to change a control arm or an outer joint, installing this kit is basically not any harder. You'll need a press for removing the old outer joint and installing the new outer joint, no other special tools needed. If you need any further info please contact us! How about the lifetime and service of the kit? The kits have been proven on street and track applications by hundreds of our customers. We're constantly doing R&D to make the kits even better, all improvements are based on customer feedback which is very important to us.We have proven the very same bearings with no maintenance for 20,000 kilometers, through the year, in daily use without signs of excessive wear. When the bearing life comes to an end, they're easily replaceable! Bearings are available around the world from automotive and industrial dealers and any of the spare parts can be also bought separately from us. We want to keep our customers 100% happy thus we're only using the best materials and manufacturing processes available. All parts are CNC machined: aluminum parts are aerospace grade AW-7075 with hard anodized finish (silver and black), mounting studs are made of highest quality CrMo tool steel and small spacers/adapters used on the kits are 316L stainless steel. We use DHL Express shipping for all items. Please find your order tracking information from DHL website.

Seems like a far cheaper way to get a quicker steering ratio along with bump steer and roll centre correction for lowered E46’s

Did the bump steer kit alone make a night and day difference?

**Altaran** · 2026-03-14T12:42:01

I've been on dtm style front control arms for 6 years now. Mine also have a bump steer correction in addition to the correction on the steering rods. Yes it works great.
I am not running MRT however, so I cannot comment on their quality. I have AKGs 7075 front control arms.

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**bigjae46** · 2026-03-14T18:39:17

Originally posted by CrisSilberGrau View Post

Brothers E36, had the SLR kit before changed to full MRT race front arms. Limited driving, but he mentioned it's very good under load and transitions. A marked improvement over the previous set-up.

Edit: the car in question is more of a Clubsport M3. Not the most street friendly, you have to keep in mind your fender liners and rub etc. For a street car this would be overkill.

Is that a 20mm kit? If so, was he able to run 17s?

**paulclaude** · 2026-03-15T02:21:36

I'm running the full race MRT front arms on the race car with the integrated roll/bump steer correction. Fantastic quality and loads of adjustment (maybe too much!). The front end of the car feels good, but I had big problems with the outer ball joints coming loose during track/race events last year. MRT advised to make sure all surfaces were clean and correctly torqued - which they were. I've since switched to M16 outer ball joints from the supplied M14 as suggested by MRT. They seem a much better fit in the hub taper, so hopefully that solves it.

**CrookedCommie** · 2026-03-15T06:00:11

I'm running the AKG setup with VAC bump steer tie rods, but will be changing to Strom Motorsport uprights in the future. I've also had issues with things loosening and bump steer tie rods breaking, which is why I think the Strom design that uses the OEM control arms and tie rods might be the best way to go.

STROM E46 Billet Front Uprights / Knuckles

https://strommotorsports.com/products/motorsport-uprights-knuckles-for-e46

STROM E46 Billet Upright Set Now in stock! E46 Billet Uprights (or Knuckles depending on your vocab flavor) with 25mm of geometry correction to the control arm and tie rod mounting points. Installation Instructions TLDR Points: Designed to be simple to install, easy to align and incredibly strong and reliable Correc

Announcement

MRT Engineering Roll Centre/Bump Steer Angle Kit

MRT Engineering Roll Centre/Bump Steer Angle Kit

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