considering buying 15' M3

[bmwcedes]

So i was considering buying an F80 m3 m/t, but this SCH issue has got me second guessing myself.. I knew about this issue, but never looked in to it in depth until a few days ago.. coming from the W204 C63 amg it kind of reminded me of the head bolt issue (blown out of proportion IMO). I've been deep in the forums reading up on the SCH issue. It seems that it's mainly dct models that are tuned and alot of them are in Cali... idk what's going on with gas quality over there.. granted there are m/t cars that have sch..

all that aside.. is this issue blown out of proportion? If i buy this m3 i want to do the typical stuff BM3, down pipe, charge pipe, intercooler, spark plugs, no e85. really just want 500whp. Am i in danger of spinning my CH if i do this? I'm not willing to fork up 4-5k as preventative maintenance. I mean i've read people have spun their CH even after upgrading it lol. i dont wan't to be in fear of my ch going bad if i rev the fk out of the car (which it's designed to do) or if i do a bad downshift where the car is over revving (i probably won't do this).. people are making it sound like the CH is made out of glass.

[spuntyb]

You don't need to do anything preventive other than charge pipes imho. Those are a no-brainer. Simply put, they're a weak point, and good ones from any brand are a cheap upgrade worth the peace of mind.

That said, the SCH issue is rare. Even more rare is a SCH that results in engine damage. Unfortunately, I managed to do both with just a JB4 and down pipes, and needed a new motor:

New engine/Gintani hub after spun crank hub https://f80.bimmerpost.com/forums/sh....php?t=1752927

Just my 2 cents, but I would at least put $4-5k aside for a new crank hub if you're going to tune it in any way. That way, if you do spin it, you have that $ there for the upgrade. Crank bolt capture is another option, and could save you some $, but again, is no guarantee. Unfortunately, the numbers we have aren't fantastic or definitive. It's manuals. DCT. Tuned. Stock, etc. And driving habits seems to have little correlation either.

It's a gamble with these cars, even without a tune, but it's an incredibly small risk, so there's that. I wouldn't *worry* about it, but I wouldn't stick my head in the sand and just ignore the risk either.

Just make sure you have an extended drivetrain warranty, whether you tune it or not.

[HyeM3]

The consensus seems to be that the issue is definitely blown out of proportion. If it still keeps you up at night though you can always just install a CBC for a couple/few hundred bucks and call it a day. People swear by them since there have been no reported SCH from people running just a CBC

[bsmf8x]

Originally Posted by HyeM3

The consensus seems to be that the issue is definitely blown out of proportion. If it still keeps you up at night though you can always just install a CBC for a couple/few hundred bucks and call it a day. People swear by them since there have been no reported SCH from people running just a CBC

I think there has been a handful of reported SCH with CBC it's just a lot more rare.

93 stage 2 + not money shifting + CBC should be fine.

You can really just leave it stock and avoid SCH entirely as the chances are close to none when you're stock. The car moves stock, test drive one with TC/DSC off.

[HyeM3]

Originally Posted by murdrdf82

I think there has been a handful of reported SCH with CBC it's just a lot more rare.

I thought all the spun hubs with CBC were on cars that also had an aftermarket hub? I always see people in the crankhub debate threads preaching how there's "no reported failures with just a CBC" haha

[bsmf8x]

Originally Posted by HyeM3

I thought all the spun hubs with CBC were on cars that also had an aftermarket hub? I always see people in the crankhub debate threads preaching how there's "no reported failures with just a CBC" haha

Maybe you're right , never looked into it I thought you meant a CBC was bulletproof with aftermarket or stock hub

[RoundelM3]

You're in danger of spinning the crank hub with a stock F8x car if you beat the hell out of it, but barring that, you should be OK. My 2015 has Alpine Stage 2, AA midpipe, and Alpine GTS-level tune for the Diff and DCT, plus BMC drop-in air filters and charcoal-element delete. Not planning on doing downpipes or chargepipes, since my tune retains stock boost levels. If I were to go to higher boost level, chargepipes would be my next modification and possibly a higher-capacity heat exchanger.

[bmwcedes]

Originally Posted by spuntyb

You don't need to do anything preventive other than charge pipes imho. Those are a no-brainer. Simply put, they're a weak point, and good ones from any brand are a cheap upgrade worth the peace of mind.

That said, the SCH issue is rare. Even more rare is a SCH that results in engine damage. Unfortunately, I managed to do both with just a JB4 and down pipes, and needed a new motor:

New engine/Gintani hub after spun crank hub https://f80.bimmerpost.com/forums/sh....php?t=1752927

Just my 2 cents, but I would at least put $4-5k aside for a new crank hub if you're going to tune it in any way. That way, if you do spin it, you have that $ there for the upgrade. Crank bolt capture is another option, and could save you some $, but again, is no guarantee. Unfortunately, the numbers we have aren't fantastic or definitive. It's manuals. DCT. Tuned. Stock, etc. And driving habits seems to have little correlation either.

It's a gamble with these cars, even without a tune, but it's an incredibly small risk, so there's that. I wouldn't *worry* about it, but I wouldn't stick my head in the sand and just ignore the risk either.

Just make sure you have an extended drivetrain warranty, whether you tune it or not.

if i stay stock i'm fine with taking my chances.. but i know eventually the mod bug is going to bite me and that's where i'm going to be stuck. i have a great opportunity though to buy a clean f80 m3 m/t 44k miles for $35k

[bmwcedes]

Originally Posted by RoundelM3

You're in danger of spinning the crank hub with a stock F8x car if you beat the hell out of it, but barring that, you should be OK. My 2015 has Alpine Stage 2, AA midpipe, and Alpine GTS-level tune for the Diff and DCT, plus BMC drop-in air filters and charcoal-element delete. Not planning on doing downpipes or chargepipes, since my tune retains stock boost levels. If I were to go to higher boost level, chargepipes would be my next modification and possibly a higher-capacity heat exchanger.

these cars are designed to to get beat the hell out of.. by that i mean i should be able to comfortably rev my car to 7500 rpm as much as i want.. my e46 m3 and my e92 m3 could handle just fine and i'd assume the s55 can as well.. but hey maybe not

[bmwcedes]

Originally Posted by murdrdf82

I think there has been a handful of reported SCH with CBC it's just a lot more rare.

93 stage 2 + not money shifting + CBC should be fine.

You can really just leave it stock and avoid SCH entirely as the chances are close to none when you're stock. The car moves stock, test drive one with TC/DSC off.

yeah i'm going to leave it stock for a year or so but i know i'll want to tune it eventually.. that being said ill check the CBC out and probably get it. i can get this f80 m3 for a really good price, but i wouldn't mind getting a face lift w204 c63 after reading all these issues about the SCH. it doesn't even look like BMW addressed the issue as it's still occurring w the newer f80 m3s..

[bmwcedes]

Originally Posted by HyeM3

The consensus seems to be that the issue is definitely blown out of proportion. If it still keeps you up at night though you can always just install a CBC for a couple/few hundred bucks and call it a day. People swear by them since there have been no reported SCH from people running just a CBC

i hope it's blown out of proportion.. i don't want to feel like my crank hub is going to go out every time i rev the car to 7k rpm.. and i really want to tune it.. nothing crazy.. as mentioned above.. just the regular bolt on stuff no e85 or meth

[HyeM3]

If you're just going stage 2 I wouldn't worry about spinning the hub as long as you aren't tracking the car, using launch control, or dumping the clutches doing rolling burnouts and stuff. But if you want to abuse the car like that then a CBC should be more than enough. Just my 2 cents though

[maddmatth]

Just do a crank bolt capture if you're tuning it, and be aware that as your horsepower goals increase so does the risk. E85 tunes and upgraded turbos seem to feature among most of the failures.

If you're totally stock... don't sweat it. If you have no warranty, maybe add a CBC whenever you end up having some work done or have the car at a workshop, but don't go out of your way to do it because this issue is extremely rare for stock engines.

[bmwcedes]

Originally Posted by maddmatth

Just do a crank bolt capture if you're tuning it, and be aware that as your horsepower goals increase so does the risk. E85 tunes and upgraded turbos seem to feature among most of the failures.

If you're totally stock... don't sweat it. If you have no warranty, maybe add a CBC whenever you end up having some work done or have the car at a workshop, but don't go out of your way to do it because this issue is extremely rare for stock engines.

Yeah I just don’t 500whp, nothing more nothing less.. so as far mods go prob just get bm3, down pipe, charge pipe, if, intake.. but that’s it. Never was a fan of e85 and meth etc.. I’m def going to do the CBC. I don’t think I’m ever going to track the car either

[bmwcedes]

I think I’m going to pull the trigger on the f80 m3 tomorrow.. I’ve always been team Bmw at heart.. although amg wasn’t a bad team to be on .. thanks all for the advice. Will post pics soon!

[maddmatth]

Originally Posted by bmwcedes

Yeah I just don’t 500whp, nothing more nothing less.. so as far mods go prob just get bm3, down pipe, charge pipe, if, intake.. but that’s it. Never was a fan of e85 and meth etc.. I’m def going to do the CBC. I don’t think I’m ever going to track the car either

Why do you feel like you need 500whp before you've even driven it though? Especially when you're not going to track it.
Are you going to at least up the tyre size?

430hp isn't slow man, it's more than enough to light up the tyres most of the way up to the speed limit. The car very easily kicks out the back end in a corner, even at fairly high speeds.
At least get the hang of the car before you tune it and make sure you can catch the slides otherwise you'll never even make use of the power.

Reminds me of that dude who got roasted here posting his LA canyon run while displaying some piss poor driving. Car was tuned, what for I don't know because the guy could barely control it safely at normal speeds
A lot of people just tune these cars to post numbers

[Jbonly21]

Originally Posted by maddmatth

Why do you feel like you need 500whp before you've even driven it though? Especially when you're not going to track it.
Are you going to at least up the tyre size?

430hp isn't slow man, it's more than enough to light up the tyres most of the way up to the speed limit. The car very easily kicks out the back end in a corner, even at fairly high speeds.
At least get the hang of the car before you tune it and make sure you can catch the slides otherwise you'll never even make use of the power.

Reminds me of that dude who got roasted here posting his LA canyon run while displaying some piss poor driving. Car was tuned, what for I don't know because the guy could barely control it safely at normal speeds
A lot of people just tune these cars to post numbers

😂😂 that dude is still here and enjoy his car, with a track day coming up next month. But you are right, the car has more than enough power.

[maddmatth]

Originally Posted by Jbonly21

😂😂 that dude is still here and enjoy his car, with a track day coming up next month. But you are right, the car has more than enough power.

Haha yeah to be fair he deserves credit for actually taking it as feedback

[spuntyb]

Originally Posted by bmwcedes

if i stay stock i'm fine with taking my chances.. but i know eventually the mod bug is going to bite me and that's where i'm going to be stuck. i have a great opportunity though to buy a clean f80 m3 m/t 44k miles for $35k

I wouldn't let any of the SCH issues keep you from getting the car or tuning it stage 1. I did it to all my cars, and this happened after roughly 50k miles of running tunes across four BMWs. Extremely rare and unfortunate, but I just wanted to share.

Do it!

[horsepower_and_hounds]

I really would not be scared of stg 2 93 over stg 1 93. BM3 tune stg 1 is the biggest increase. Very small after that. See below

Stage 1 93: up to 22%HP / 23%TQ

Stage 2 93: up to 24%HP / 26%TQ +2/3 over stg 1

Stage 2 E30: up to 26%HP / 26%TQ +2/0 over stg 2 93 & +4/3 over stg 1 93

These are targets and only if you have all the supporting mods to achieve the target numbers

I also would do the GTS DCT flash...it help with gear slamming and much smoother

Tune, adapt and enjoy

[bmwcedes]

Originally Posted by maddmatth

Why do you feel like you need 500whp before you've even driven it though? Especially when you're not going to track it.
Are you going to at least up the tyre size?

430hp isn't slow man, it's more than enough to light up the tyres most of the way up to the speed limit. The car very easily kicks out the back end in a corner, even at fairly high speeds.
At least get the hang of the car before you tune it and make sure you can catch the slides otherwise you'll never even make use of the power.

Reminds me of that dude who got roasted here posting his LA canyon run while displaying some piss poor driving. Car was tuned, what for I don't know because the guy could barely control it safely at normal speeds
A lot of people just tune these cars to post numbers

You’re right man. I think I’ll just drive it for atleast 2 years before I tune.. but my c63 was close to 500whp, so I just wanted similar power. Although they’re 2 completely different cars, the c63 I think gave me good experience in the back end giving out, tires spinning out, even in higher gears.. but I get what you’re saying and appreciate the advice

[bmwcedes]

Originally Posted by horsepower_and_hounds

I really would not be scared of stg 2 93 over stg 1 93. BM3 tune stg 1 is the biggest increase. Very small after that. See below

Stage 1 93: up to 22%HP / 23%TQ

Stage 2 93: up to 24%HP / 26%TQ +2/3 over stg 1

Stage 2 E30: up to 26%HP / 26%TQ +2/0 over stg 2 93 & +4/3 over stg 1 93

These are targets and only if you have all the supporting mods to achieve the target numbers

I also would do the GTS DCT flash...it help with gear slamming and much smoother

Tune, adapt and enjoy

In the event that I do tune, I think I’m going to stick with stage 1.