Critique My Build Plan - 15yrs of ownership and ready to refresh

[tnord]

Looks like a very familiar build to me too, haha. It'll be a GREAT street setup, I actually think my car is more like a M3 CS. A little bit tarted up, but not a total track car by any means.

One comment. Ditch the CSF. Either go OEM, or DO88. I went CSF and my car started overheating, for whatever reason, it's does not evacuate heat well with the S54. If you really want the CSF, I'll sell you the one sitting in my garage for a deal 🤣

I'm not married to the CSF, it was the largest radiator I knew of so I put it on the list. If the DO88 is a higher quality part, I'll absolutely use that instead, and that's exactly the type of feedback I'm looking for in this thread - thank you.

A bit more of my background is I raced Spec Miata and ITA with SCCA from 2003-2010, where there was no such thing as too much cooling. I put a new OE radiator in when I did everything else to avoid a catastrophic failure, but for track purposes I really think the car needs more cooling. With as much compression as the car has, how close the bores are, and the propensity for high oil temps I really think you need to throw as much cooling capacity at it as you can. Even beyond reliability reasons, the miata ECU used to start pulling timing and you'd lose power when water temps got beyond about 210, and I'd bet there's similar safety measures built into our DME as well.

[oceansize]

https://www.pwrna.com/product/bmw-2001-2006-42mm-radiator-e46-m3

PWR is highly thought of. This statement came with my supercharger from ESS which I thought was interesting:

"-If you run any other performance radiator than PWR, remove it and replace it with OEM. There is a lot of cooling problems with so called performance radiators when the system is stressed, do not ignore this warning."

[tnord]

If this is a street car, then yes, the parts you've selected are going to transmit NVH and you probably won't be happy. Especially hearing you say things like a "3 hour road trip"

When you go spherical you have to understand the nuances and limitations that come with it... you are going to hear clunking, things will be loud, and the car will be stiff. Parts require maintenance, and with no deflection in the rubber, everything better be up to snuff or you're going to have other parts fail. It is not suggested for street cars. My car sees little to no street use... and when I do drive it on the street I'm prepared for the sacrifices in comfort and noise.

That being said - if you buy quality parts with good bearings (Aurora, FK) and you make sure things are serviced in a timely matter, and everything is greased, you shouldn't have any issues. A spherical car can be surprisingly compliant on the street if setup properly.

Can you elaborate on this a little more? Are you running sphericals on your car? It kinda sounds like you have them and think the NVH is too high for street use, but then in your last sentence you say if everything is in good condition then it can be surprisingly compliant (to me compliant=comfortable).

And I absolutely agree that replacing rubber with sphericals transfer force to other parts of the car. That's another reason I was leaning towards the higher quality damper vs a PSS10 as it will be doing more work. The idea behind all this being that I'd run a quality damper on reasonable spring rates with a harder wearing and softer 18'' tire instead of a 19'' RE71 or whatever. That's where all the streetability comes from, and the rest of the suspension is solid monoball so you don't get the inconsistent twitchy handling that comes from deflecting components.

I'm very willing to be wrong about my approach.

[9kracing]

My car is full spherical.



Suspension & Chassis Modifications:

OEM BMW M3 Competition Blue Tag Steering Rack
Ohlins Road & Track Coilovers
Ohlins Spherical Camber/Caster Plates
Millway Motorsport Billet Offset FCAB
Millway Motorsport Spherical Rear Damper Mounts
SPL Parts Spherical Front Endlinks
SPL Parts Spherical Rear Camber Arms
FDF Spherical Rear Upper Control Arms
MRT Engineering Spherical Tie Rods
Dinan Spherical Rear Trailing Arm Bushings
Hotchkis 30.2mm Hollow Front Swaybar
Hotchkis 25mm Hollow Rear Swaybar
Hotchkis Adjustable Rear Endlinks
CMP Solid Subframe Raising Bushings
CMP Weld-In Front RACP Beam
CMP Bolt-In Front RACP Brace
DMG Autosport Comp GT RACP Brace
DMG Autosport CO+OP Bar
DMG Autosport Pro 46 Strut Bar
Rogue Engineering Aluminum Chassis V-Brace
Turner Subframe Reinforcement Plates
MSW Swaybar Mounting Reinforcement Plates





"it kinda sounds like you have them and think the NVH is too high for street use, but then in your last sentence you say if everything is in good condition then it can be surprisingly compliant (to me compliant=comfortable)."


Everyone has their own tolerance for NVH. I grew up in the Honda world where we drove gutted EG hatches with no air conditioning, minimal sound deadening, and 14K spring rates, so almost anything is comfortable compared to that.

Like I mentioned before, all sphericals are not equal either. I specifically listed FK and Aurora, as they are known to be of "aircraft quality" and you will run into less issues with those. Notice I said "less", and not none.

You just have understand what you're doing when you move to spherical bearings. If you are prepared to accept the limitations associated with them, then yes they can be great on the street.

But, like I said, what I find acceptable as far as clunks and noise someone else may find abhorrent.

[tnord]

thanks for the perspective - I think we're of the same era.

I have some BW "lifetime" rear shock mounts that seem to clunk when it gets cold, which annoys me. And if that annoys me then I probably wouldn't be happy about clunking from other solid bushings. At the least, unless I hear otherwise from people who have logged significant miles on them, I should put these items at the end of my priority list and wait to see if I really feel like I want them after everything else is done. I had been thinking of them as low cost items that would be easy to knock out if I ever see them on sale, so the discussion is helpful.

Does this also go for the subframe mounts and camber arms? Or is it primarily a FCAB/RTAB thing since that's where a lot of load seems to go on these cars?

[E46m3zcp]

Any solid bushing or monoball conversion will add some NVH, or otherwise almost imperceptible discomfort which added up makes a difference. I’d refresh everything with rubber, and if it’s not going to be driven much on track I’d go with a set of non-adjustable Bilstein shocks, because who cares about adjustability. I’ve driven a M3 on fresh OEM all around and dang it’s fun to drive on the public roads. But I know my opinion won’t be popular, don’t flame me for it. (I have a track car, but here I’m talking about road driving)

[1000hp]

You sure you want to put $27k into a $27k car?

Just sell it and buy a 911 if that's what you want.

[dreamdrivedrift]

thanks for the perspective - I think we're of the same era.

I have some BW "lifetime" rear shock mounts that seem to clunk when it gets cold, which annoys me. And if that annoys me then I probably wouldn't be happy about clunking from other solid bushings. At the least, unless I hear otherwise from people who have logged significant miles on them, I should put these items at the end of my priority list and wait to see if I really feel like I want them after everything else is done. I had been thinking of them as low cost items that would be easy to knock out if I ever see them on sale, so the discussion is helpful.

Does this also go for the subframe mounts and camber arms? Or is it primarily a FCAB/RTAB thing since that's where a lot of load seems to go on these cars?

For another point of reference:
I can’t speak to FCAB but my car with solid CMP subframe bushings OE differential bushings SDW RTAB spherical RSM and rubber jointed rear LCA rides great on street. My use case is 80% street 20% track. Harsh impacts like expansion joints are a bit more pronounced. RSM makes some noise. noise is adequately damped by the rear seats. Overall it rides very well and I find it comfortable for long 6h+ road trips.

[elrichmeister]

You sure you want to put $27k into a $27k car?

...

[tnord]

You sure you want to put $27k into a $27k car?

Just sell it and buy a 911 if that's what you want.

realistically, I'm not getting all the way through that list. and also the cost if I did everything would be significantly higher for shop labor on things like the RACP, paintwork, and refreshing other OE bits like door seals, glass, etc.

I like the 911, but to me it's a comparable experience to my car, and I couldn't really see it being worth an extra $20k. It's not like I'd keep it bone stock, or that it didn't need any work either. I didn't do a ton of research into it, but the P Car ownership costs have to be significantly higher. Dealing with those coolant pipes and rads won't be cheap, it didn't have the IMS addressed, etc. I haven't ruled out buying a 911 entirely, but even if I bought one I don't think I'd be selling the M3. I'd be selling the F30, and using the F15 for winter/beater duties and the G05 would become the new daily for the wife.

at least that's how I was selling the plan at home to get approval.

[1000hp]

realistically, I'm not getting all the way through that list. and also the cost if I did everything would be significantly higher for shop labor on things like the RACP, paintwork, and refreshing other OE bits like door seals, glass, etc.

I like the 911, but to me it's a comparable experience to my car, and I couldn't really see it being worth an extra $20k. It's not like I'd keep it bone stock, or that it didn't need any work either. I didn't do a ton of research into it, but the P Car ownership costs have to be significantly higher. Dealing with those coolant pipes and rads won't be cheap, it didn't have the IMS addressed, etc. I haven't ruled out buying a 911 entirely, but even if I bought one I don't think I'd be selling the M3. I'd be selling the F30, and using the F15 for winter/beater duties and the G05 would become the new daily for the wife.

at least that's how I was selling the plan at home to get approval.

Hot take here, but have you considered a 6th gen Camaro SS 1LE? 😆
It's not German but, based on your list, it does all of the things that you want your M3 to do. And it will do all of it right out of the box without touching anything.
If I was looking to spend sub-$50K on the experience it sounds like you're after, that would top my list. And if you don't need a back seat at all...C6 Z06.