110k refresh advice with expectation of a few track days/year

[nsk040]

I have a 110k ZHP which is due for a suspension refresh, rotors, and pads. As I'd like to do a few track days each year, what advice would you guys have in terms of refreshing the suspension, brakes...as well as anything else (i.e. oil circulation ok? need to reinforce sub frame?). I did do a few laps many years ago and the OEM pads were fading within a lap so please suggest a decent pad/rotor combo that can handle a little more heat on the track, but doesn't squeak badly on the street. I don't care about brake dust. Not looking to start turning this into a track car, but want to be able to feel reasonably comfortable driving it decently hard for a 10-15 minute session. Thanks

Additional note: FCABs were replaced at ~70k miles. Control arms themselves were fine at that time. What bushings should I be replacing during the shock/strut job?

[fw_fw]

Suspension: stock springs with Koni Yellows, unless you go high dollar coilovers. The Koni Yellows are easily adjustable, allowing different settings for track and street. Also replace all your associate mounts and rubber as you do this as it's probably ready to need updates as well.

Brakes: most on here say stock rotors with upgraded aftermarket pads are all you need for track time & autocross.

Subframe: what year/model ZHP do you have? 04 on have improved rear reinforcement compared to earlier E46s, better but still not perfect. Do a search on subframe, various options available..

[nsk040]

what year/model ZHP do you have? 04 on have improved rear reinforcement compared to earlier E46s, better but still not perfect. Do a search on subframe, various options available..

It's an 04 - good to know that year is at least somewhat less prone to issues. No oil starve issues or anything else I should be aware of?

Appreciate the help; thanks.

[sillieidiot]

I would just replace everything that hasn't been replaced already lol

[BMWCurves]

I have no track experience with our cars but from what I've heard from other members here I'd say the same.
Suspension: Go with Koni sports since they're adjustable and last a lot longer than the OEM Sach units. Alternative are coilovers like KWs or Bilstein PSSes.
Bushings: I'd replace them as well. I went with Z4M units for FCABs and RTABs with limiters for the rear since they're solid rubber as opposed to our factory gel filled ones, and the Z4M FCABs increase the caster a bit. Member Slater swears by Bimmerworld's sealed spherical RTABs. If you plan to track often you could opt for poly bushings. I have a parts list thread for my full suspension refresh here: http://www.zhpmafia.com/forums/showthread.php?16182-Help-with-Suspension-Refresh-at-50k-miles-10-years
Brakes: I believe the stock rotors are sufficient for intermittent track use. Pads I'd look into something from Hawk or Stoptech that's closer to a race pad. You could always get a race pad that you swap out for your street pads on track days. I'd flush your brake lines with fresh brake fluid before each track day if it's been a while. Consider getting stainless steel braided brake and clutch lines.

[redrumm3]

I would agree with everything said here. I have tracked and raced BMW's for over twenty years and they are very competent track cars in stock configuration. Not knowing your level of experience or how far you're willing to take your car from a street setup I would make the following suggestions. Koni adjustable shocks and struts are a very good combination for a street/track car. I would stay away from coilover suspensions they are not really necessary and although the adjustability lends itself to finding a great track setup, unless you know what you are doing and have access to a lift, scales and alignment equipment you can easily go the wrong way in setting them up, especially with the compression and rebound settings of the shocks.

Any bushings that are old or show any sign of wear should be replaced. Poly bushings are a great choice and there are many quality suppliers for these items. Poly RTAB's with limiters are an excellent suggestion. I would stay away from the sealed spherical RTABs, I don't think they are necessary for your intended use and they are noisy and harsh on the street. Remember, any time you change to a harder bushing material you are going to be transmitting additional load and force to the subframes and additional reinforcements may be necessary.

I would make sure the brakes are in top condition. Stock rotors are fine but I would suggest upgrading to a race/track pad compound for the track. Stock pads can get overheated at the track and produce significant fade even in a short session. My personal preference are the Pagid Orange RS 4-4. They are not the cheapest but they last a long time and are easy on the rotors. The other pad options mentioned are also good alternatives. Upgrading to stainless steel brake lines is also a good suggestion. Always bleed your brakes prior to any track event. My preference for brake fluid is Castrol SRF. It is expensive but I have never had an issue at the track with this fluid and well worth the money in my opinion.

I always run fresh fluids in the car before any track event. My preference is Redline for both the diff and tranny, but there are other good products out there as well.

Remember that the track is going to exploit any weakness or neglected items on the car. If you think something might need to be addressed do it in advance. Otherwise let it rip and have fun!

[nsk040]

Appreciate the help guys. Question on the Koni Yellows...where should the adjustment(s) be set out of the gate for a SLIGHTLY more aggressive than OEM feel?

Thanks

[BMWCurves]

I set mine at 3/4 turn from soft and haven't touched them since. They're slightly more stiff (but still more compliant) than the factory shocks they replaced and I love it.

[nsk040]

I set mine at 3/4 turn from soft and haven't touched them since. They're slightly more stiff (but still more compliant) than the factory shocks they replaced and I love it.

Thanks. Before pulling the trigger with something very similar to your refresh....what would rough incremental cost / benefit be of going to coil overs? Don't care about ride height, just want fun to drive.

[sillieidiot]

Thanks. Before pulling the trigger with something very similar to your refresh....what would rough incremental cost / benefit be of going to coil overs? Don't care about ride height, just want fun to drive.

Well if you don't care then it doesn't matter lol Really, it's just adjustability. There's different levels depending on what you get though.

[nsk040]

I keep seeing a different set of parts suggested for the standard refresh. The shop I'm talking to says I only need shocks/struts and mounts as well as FCA and FCABs. Figure I may as well spend a little more for reinforcement plates and bump stops so that's an easy decision.

What about sway bar end links and RTABs...what's the cost/benefit of doing/not doing these as part of the refresh (both $ as well as post-refresh performance)?

Also, roughly how many hours should a suspension refresh take a decent shop (labor cost)?

Thanks for all the help guys.

[sillieidiot]

I don't know what else there is to clarify. We've pretty much suggested everything based on your original post. For a standard refresh with no track events, of course you can get away with the absolute bare minimum.

Endlinks you don't really need. But if you're modifying the suspension, you may need shorter ones.

RTABs, keeps your rear in line. You will probably need to replace them.

Not sure how much a shop would charge. Could you DIY? Saves money and it's a great way to learn more about the car.

[nsk040]

Would really enjoy giving the DIY a try, but probably would want to do it under the watchful eye of someone who was experienced.

[mko9]

Suspension: I have just about 120K on my ZHP, and just did a suspension refresh prior to a couple trackdays this past year. I went with the Bilstein HD, which feel a bit harder than the old OEM units. I did the Z4M FCABs, front tower reinforcement plates, and reinforced rear shock mounts. The shop said I didn't need rear RTABs, so I didn't do them (still have them if you want to buy them). What I regret not doing was some caster/camber plates for the front suspension. There is very little camber up there. And the reinforcement plates means you can't even slide the suspension the little bit available from the slotted holes.

Brakes: I normally use Hawk DTC-60 up front, and an aggressive street pad in the rear. I have a set of slotted rotors up front, too. This last trackday, I had to buy a set of Carbotek XP12 of a guy. They performed with no issues, but I felt like they had less bite than the Hawk pads. If you are going to use an r-compound tire, then you will definitely need a trackday brake pad. Once you have done it a couple times, it only takes a few minutes to swap the pads. I have used street pads with street tires twice. Once was a rainy session at VIR, the other was also at VIR when I forgot to pack my trackday pads. That is how I ended up with the Carbotek pads. I was in the morning on street tires. I just limited my speeds on the front and back straights to about 90mph, rather than running it up to 120+mph.

[sillieidiot]

Would really enjoy giving the DIY a try, but probably would want to do it under the watchful eye of someone who was experienced.

Just skype someone if you run into a problem. I've been one of those people that people skype to tell/show me the problem they were having and how to work around it lol You have a whole forum of people you could ask if you run into a problem. The DIYs on E46f are a great resource. You'll be fine.

[nsk040]

Appreciate all the input from everyone. Think I'm going to try DIY for brakes for the experience, but will let a shop do the suspension. What's a fair labor quote for shocks/struts/mounts/rtabs assuming I drop the car off with all the parts in the trunk?

[anandoc]

I got my rear suspension done recently. Things I got replaced were RTABs (with limiters), upper and lower (outer) ball joints, sway bar bushings and end links. The old ball joints and RTABs could sometimes be difficult to pull out. The shop charged me 5 hours of labor - which I feel is quite fair. If you throw in shocks and RSMs, the number should not go up. The rear shocks are very easy to replace.

The front suspension stuff I got done in early 2015. I got steering guibo, FCABs, control arms, outer tie rods, sway bar end links and bushings replaced. It was a different shop and it took them 5 hours to do all of this. The struts may add another hour to that. You get the idea - the front and rear suspension combined would take almost 8-9 hours to do.

[mko9]

It can be pretty expensive. I did not go to the dealer, but there is not a great/cheap shop where I live. It cost me $2100 for rear shocks with new reinforced mounts, front struts, FCABs, rear upper ball joints, RTAB limiter bushings, and an alignment; plus install a new theromstat and recharge the A/C.

[nsk040]

Is this Eibach kit any good? http://www.modbargains.com/eibach-pro-system-plus-for-bmw-e46-323-325-328-330.htm