Track forum general chit chat.

[M3MPH1S]

Originally Posted by kpewpew

Sooo I'm on stock subframe and diff bushings. If I go to the next best solution below solid mounts, it'll be good gainz? (would love to hear parts recs that don't have completely insane NVH)

Any downsides to the SPL part? I heard they clicky-clicky a lot?

Before the SPL arms, I had Fall Line monoballs pressed into my stock arms and they were definitely clicky-clacky, the SPL arms are pretty much as quiet as stock most of the time. Is there a big difference in these vs monoballs in stock arms? No. It's hard to even tell if they feel slightly better or if it's just placebo, but if I had to do it all over again I would just skip straight to that because it's not much more money and you're getting a brand new purpose built control arm if nothing else.

For the subframe, I'd definitely just go solid metal, there's no NVH increase at all. On the new F8X M3/4, they come with solid metal subframe bushings from the factory, so that should give you some confidence if you're concerned. For the diff though, I wouldn't go metal unless it's a full track car. I have metal mounts for all 3 diff mounts and it's very noisey. I think poly would suffice here. Diff and especially subframe are very much worth upgrading and make a very noticeable improvement in feel/control from the rear end.

The only other bushings I've replaces are the motor and transmission (DCT) mounts. I went with delrin for both of those and surprisingly there was barely any vibration increase from the motor mounts and really only a moderate increase in mechanical noise of the engine which is quite pleasing imo. I put soft poly motor mounts in my E46 ZHP and the vibration increase was very significant. The engine feels like it revs just a little bit smoother but it's not super noticeable. For the DCT, there's not much room for improvement, but my main concern was just locking the entire drivetrain down, from end to end. No perceivable difference, but it is hilariously loud switching in and out of neutral/reverse. I did poly trans mounts on my 6 speed E46 ZHP and it very much improved shift feel, so I assume it has to help somewhat even on DCT.

[///Mobbin]

Originally Posted by M3MPH1S

Before the SPL arms, I had Fall Line monoballs pressed into my stock arms and they were definitely clicky-clacky, the SPL arms are pretty much as quiet as stock most of the time.

Great to know, I really disliked the click-clack sounds of pressed in monoballs on my prior car, one reason I've avoided them on this car. May go SPL sooner than later with this in mind.

[kyippee]

Originally Posted by M3MPH1S

Before the SPL arms, I had Fall Line monoballs pressed into my stock arms and they were definitely clicky-clacky, the SPL arms are pretty much as quiet as stock most of the time. Is there a big difference in these vs monoballs in stock arms? No. It's hard to even tell if they feel slightly better or if it's just placebo, but if I had to do it all over again I would just skip straight to that because it's not much more money and you're getting a brand new purpose built control arm if nothing else.

For the subframe, I'd definitely just go solid metal, there's no NVH increase at all. On the new F8X M3/4, they come with solid metal subframe bushings from the factory, so that should give you some confidence if you're concerned. For the diff though, I wouldn't go metal unless it's a full track car. I have metal mounts for all 3 diff mounts and it's very noisey. I think poly would suffice here. Diff and especially subframe are very much worth upgrading and make a very noticeable improvement in feel/control from the rear end.

The only other bushings I've replaces are the motor and transmission (DCT) mounts. I went with delrin for both of those and surprisingly there was barely any vibration increase from the motor mounts and really only a moderate increase in mechanical noise of the engine which is quite pleasing imo. I put soft poly motor mounts in my E46 ZHP and the vibration increase was very significant. The engine feels like it revs just a little bit smoother but it's not super noticeable. For the DCT, there's not much room for improvement, but my main concern was just locking the entire drivetrain down, from end to end. No perceivable difference, but it is hilariously loud switching in and out of neutral/reverse. I did poly trans mounts on my 6 speed E46 ZHP and it very much improved shift feel, so I assume it has to help somewhat even on DCT.

Thank you!! What are the brands/specs of the parts you mentioned? Will be shopping..

[roastbeef]

Originally Posted by kayha12

Hey Roastbeef, with the rear bumper off, can you take a direct shot of the rear? Wondering if there's anything intruding directly behind the wheel well - thinking about shaving that area off the bumper

A dude that's used to come on there called sebringjetta did something like what you're describing. There is room to do it, and if you get creative with the plastic bumper hanger, you can make it larger. I think he did it to be about 1.5-2" open, and that's about how much room you'd have without cutting the plastic bumper hanger.
The bumper is still off the car if you want anymore specific pics. Both sides look the same, there doesn't appear to be any hidden electronics or bs.

[fsmtnbiker]

Originally Posted by kpewpew

Sooo I'm on stock subframe and diff bushings. If I go to the next best solution below solid mounts, it'll be good gainz? (would love to hear parts recs that don't have completely insane NVH)

Any downsides to the SPL part? I heard they clicky-clicky a lot?

I just did delrin subframe and diff mounts in my car, you should take it for a spin. Feel is much better but it’s definitely noticeable inside due to the diff mounts.

[k_mann]

Just got SS lines installed and had the shop throw on my pfc 08's while at it. Come to find the track days got pushed out finally lol. Not surprised.

Looks like I won't be at the track til end of may earliest. Am I okay to run my track pads on the street? I usually do maybe 500 miles a month tops. I mean outside of noise/dust, I'm not causing any excessive wear on the rotors or pads running them cold on the street?

[dparm]

Originally Posted by aututto

Just got SS lines installed and had the shop throw on my pfc 08's while at it. Come to find the track days got pushed out finally lol. Not surprised.

Looks like I won't be at the track til end of may earliest. Am I okay to run my track pads on the street? I usually do maybe 500 miles a month tops. I mean outside of noise/dust, I'm not causing any excessive wear on the rotors or pads running them cold on the street?

You won't cause enough wear in that period of time for it to matter. I run Hawk DTC-70s year round.

Re-bed them if they start to get really loud, that should help for a week or two.

[Ximian]

PFC 08s on a stock rotors are even louder after bedding them in. They’re noise free when cold but that doesn’t last long. They’re also not as kind to the rotors as street pads as the idea behind endurance brake pads.

[SQ13]

Originally Posted by Ximian

PFC 08s on a stock rotors are even louder after bedding them in. They’re noise free when cold but that doesn’t last long. They’re also not as kind to the rotors as street pads as the idea behind endurance brake pads.

They’re abrasive when cold, but they’re not hard on rotors when hot. My stock E46 M3 rotors (one piece blanks) always require replacement due to cracking way before they reach the min thickness.

[roastbeef]

Has anyone really taken any track rotors down to the minimum thickness? Sounds like a myth... I thought they all cracked before that.

[k_mann]

Originally Posted by dparm

You won't cause enough wear in that period of time for it to matter. I run Hawk DTC-70s year round.

Re-bed them if they start to get really loud, that should help for a week or two.

That's good to know! Unfortunately I'll be back at the shop tomorrow. For some reason the line was leaking where it connected to caliper. Not sure why I checked and it was snug. Tightened it a bit more but will check tomorrow.

[M3MPH1S]

Originally Posted by kpewpew

Thank you!! What are the brands/specs of the parts you mentioned? Will be shopping..

Motor/trans mounts are Revshift, subframe mounts are Turner, and diff mounts are AKG. I chose Revshift based on a thread about aftermarket motor mounts and they seemed to be one of the top 1-3 recommendations (there didn't seem to be an agreeable "best"). I went with Turner for the subframe purely because they had them heavily discounted for Christmas and metal is metal for the most part. Diff mounts is the same story. AKG had good reviews with other products and were selling them cheaper than anyone else.

[k_mann]

Originally Posted by SQ13

They’re abrasive when cold, but they’re not hard on rotors when hot. My stock E46 M3 rotors (one piece blanks) always require replacement due to cracking way before they reach the min thickness.

I figured that would be the case with OEM e9x rotors as well

[kyippee]

Originally Posted by M3MPH1S

Motor/trans mounts are Revshift, subframe mounts are Turner, and diff mounts are AKG. I chose Revshift based on a thread about aftermarket motor mounts and they seemed to be one of the top 1-3 recommendations (there didn't seem to be an agreeable "best"). I went with Turner for the subframe purely because they had them heavily discounted for Christmas and metal is metal for the most part. Diff mounts is the same story. AKG had good reviews with other products and were selling them cheaper than anyone else.

Great - I'm running Vibra-Technics' "fast road" (not full race) motor mounts. Based on what you shared, it seems like I've got a list to look at - are the hardness numbers correct? I assume you went with 95A for transmission and diff.

Revshift transmission mount - 80A or 95A?
https://www.revshift.com/product-p/ptm-e9xm.htm

AKG 95A diff mount
https://www.akgmotorsport.com/produc...yurethane-95a/

Subframe: I'll pick a solid one, maybe Turner

[ayao]

Originally Posted by roastbeef

Has anyone really taken any track rotors down to the minimum thickness? Sounds like a myth... I thought they all cracked before that.

A guy I drive with has a Focus RS and older gen GT500 with AP BBKs with J-hook rotors and he regularly gets the rotors down to where the J hooks are worn gone and rotor is down to min thickness, before cracking. Based on the amount of heat checking I have with my AP rotors I cannot fathom experiencing the same thing (I.e. rotors will crack first) but I’ve seen the worn rotors with my own eyes.

[roastbeef]

Originally Posted by ayao

A guy I drive with has a Focus RS and older gen GT500 with AP BBKs with J-hook rotors and he regularly gets the rotors down to where the J hooks are worn gone and rotor is down to min thickness, before cracking. Based on the amount of heat checking I have with my AP rotors I cannot fathom experiencing the same thing (I.e. rotors will crack first) but I’ve seen the worn rotors with my own eyes.

I wonder if that's a combo of track conditions, cooling, and pad material. I've seen the jojoba barely visible on the internet, but I assumed it was from a street/track car with a ton of street miles.

[okusa]

Originally Posted by roastbeef

Has anyone really taken any track rotors down to the minimum thickness? Sounds like a myth... I thought they all cracked before that.

I have. The cracks were not even severe.

[ThunderMoose]

Originally Posted by okusa

I have. The cracks were not even severe.

Same here. On the last set of fronts I replaced, the slots were almost gone.

I run pagid yellows on a 4 pot 355 millimeter brembo set up in a 3000 lb car mainly doing TT's. I also don't run TC. I think all of these factors really help to conserve rotors.

[StripclubDJ]

Originally Posted by okusa

I have. The cracks were not even severe.

That means you don't track, bro

[okusa]

Originally Posted by StripclubDJ

That means you don't track, bro

Haha certainly not for several months. Seriously though, the AP rotors are a work of art and ridiculously durable.

[roastbeef]

You guys ready to chuckle? Titanium crash bar hardware!

[Richbot]

Did you catalog what the part lengths were for each of these? I looked at this last time I had the bumper cover off and couldn't figure out one of the bolt lengths and gave up