Slon Workshop E46 M3 Carbon Front Triangulating Reinforcement Kit

[heinzboehmer]

It's incredible how something so seemingly small makes such a massive difference. One of the top mods hands down.

[Maxhouse97]

I read something that said “there’s a reason that one of the first things race teams do to prep a chassis is seam weld/brace as much as possible (besides safety)”. It’s a multi-dimensional upgrade that helps in many ways, handling, steering, braking, acceleration.

[oceansize]

I've done a ton of bracing and stiffening on my base 2018 GT Mustang and its huge what it does. The base GT doesn't come with shock tower or the shock tower to firewall braces so I added them. Then under the car I added the subframe braces and the front k-brace. Then I added the subframe bushing supports, then the ford racing control arms, track pack shocks, and slightly stiffer springs, and on and on.

Even on that pig the difference was absolutely humongous and I did each modification in isolation. One upgrade at at time, meaning I know what a difference each little step made. Its interesting to do it that way as others who didn't do the modifications one at a time (or their car came with some level of factory bracing) will say "well it doesn't make any difference". They will state that opinion as fact, but it's not true. If you wanted to measure how much faster it could make a talented driver on a track I guess its not too large a difference with respect to time, but in terms of how the car feels and the fun to drive factor, its enormous.

[Obioban]

It’s shockingly not subtle, after a lifetime of shock tower braces feeling borderline cosmetic.

[Bry5on]

So I finally installed my front brace … now let me start by saying I’m a chassis stiffness zealot, but OMG what a difference! I can’t believe how noticeable it is. Car turns in better, rides better, tracks down the highway better, vibrates less. Feels like it’s 10 years younger. I know this sounds like hyperbole, but honesty it’s in my top 3 mods for the car. Such an upgrade.

100% across the board. Welcome to the club!

[Maxhouse97]

So I finally installed my front brace … now let me start by saying I’m a chassis stiffness zealot, but OMG what a difference! I can’t believe how noticeable it is. Car turns in better, rides better, tracks down the highway better, vibrates less. Feels like it’s 10 years younger. I know this sounds like hyperbole, but honesty it’s in my top 3 mods for the car. Such an upgrade.

[heinzboehmer]

Finally got one of these - do you think you could do a HVAC blower motor after installing the bracket? I wanted to do this tomorrow but now am thinking I should replace the blower first.

+1 to doing the blower motor.

Supposedly doable with Slon's mounting point in, but the protruding design seems like it would get in the way of things: https://nam3forum.com/forums/forum/m...146#post196146

Mounting point for the E86 brace retrofit is lower profile and still makes life hard. You can see it installed in the images here: https://nam3forum.com/forums/forum/m...or-replacement

[Bry5on]

Finally got one of these - do you think you could do a HVAC blower motor after installing the bracket? I wanted to do this tomorrow but now am thinking I should replace the blower first.

Do the blower first!

[Maxhouse97]

Finally got one of these - do you think you could do a HVAC blower motor after installing the bracket? I wanted to do this tomorrow but now am thinking I should replace the blower first.

[bigjae46]

This makes sense - I had a shop quote me welding a steel panel in. The shop owner attempted to sell me real hard on bolting it in vs welding. I was concerned that a bolted joint would not deliver the same stiffness as a welded joint. Maybe he was pushing that way because of what you mentioned on weld prep.

When you say epoxy were you referring to the steel or welded panel?

Both. Bolt/epoxy to the steel and rivet/urethane to the carbon. Steel to steel...epoxy might be superior to a urethane but not sure it would make much of a difference. As long as it is prepped well.

Yeah, it would be such a pain to weld for many reasons. Setup and prep. Also its going to be a VERY awkward position.

[old///MFanatic]

Ok maybe I don’t have a path to install. I’m certainly not taking my CMP brace out. What would you recommend to get a close as possible to the rear stiffness gain from the Slon panel … buy a GTR type rear brace or weld in a metal panel similar to a E46 sedan with no pass through?

I really hate to cross post as you should have your own thread since this is unrelated to their front brace.
Obvious choice since you already have CMP floor brace is their integrated triangulated top shock tower brace. And probably their front 1/4 panel. These actually tie in the shock towers points to the subframe mounting points. This should far exceed any benefits of that panel, especially on an M3 that already has that C-pillar area strengthened from the factory beyond what the sedan achieves. As you mentioned, along the rigidity gains of a GTR engineered designed brace

[Maxhouse97]

This makes sense - I had a shop quote me welding a steel panel in. The shop owner attempted to sell me real hard on bolting it in vs welding. I was concerned that a bolted joint would not deliver the same stiffness as a welded joint. Maybe he was pushing that way because of what you mentioned on weld prep.

When you say epoxy were you referring to the steel or welded panel?

[bigjae46]

bigjae46 - Assume you mean notch out the CMP brace such that the Slon panel could be bonded in untouched and whole. This I agree would probably not make much of a difference to the CMP brace, I think it’s quite sturdy.

On the other hand the other option of going to a body shop and having them weld in a steel panel where the Slon panel would go (could weld straight to the CMP brace as well) in my mind would replicate the E46 sedan with no pass through configuration that is documented to increase stiffness. So that I believe is a third option.

Yes. Welding would be a massive PIA. The cost is in setup and you’d have to cover up so much stuff for a small job. This is a great case for rivets and epoxy. For the inside of the trunk, maybe use some black coated rivets into the Slon panel so it looks good.

EDIT: might want to use a urethane adhesive since it’s a little more flexible and I think has a higher peel strength.

[Maxhouse97]

bigjae46 - Assume you mean notch out the CMP brace such that the Slon panel could be bonded in untouched and whole. This I agree would probably not make much of a difference to the CMP brace, I think it’s quite sturdy.

On the other hand the other option of going to a body shop and having them weld in a steel panel where the Slon panel would go (could weld straight to the CMP brace as well) in my mind would replicate the E46 sedan with no pass through configuration that is documented to increase stiffness. So that I believe is a third option.

[dukeofchen]

Is there a three point brace option that isn’t carbon fiber and 4k?

Given enough time surely someone here will fab one...

If aesthetics / maximum weight savings are of lesser concern, it doesn't seem like rocket science to tie a strut bar to the firewall and achieve a sizeable rigidity gain. I imagine working around the cabin air filter housing would be the trickier part to figure out?

Absolutely no shade towards Slon or the value / quality proposition of their piece, but at that price I'd really have to have run out of modifications to throw at the car to consider it.