Good mods, bad mods.... whatta ya got??

As these cars age and transfer into the hands of people who want to make them their own, I thought it might be good to share experiences with modifications. Spending lots of $ on a mod doesn't always make it worth while, whilst a small suspension change or a cabin change like a steering wheel or paddles for example can make the driving experience that much better. What have you guys done that you thought was worth doing and what have you done which you feel just "checked a box" (a bit of a waste of mullah). Please post one of each if you can and share your experiences with the rest of us.. pictures are heavily encouraged

Tried muffler delete straight pipes to be able to judge for myself instead of listening to videos, asking for opinions. They came off in less than 24 hrs, the low rpm drone is unbearable.

Would do again:

• 'ACM' exhaust mod
• Tinted windows
• Black kidney grills
• DCT GTS flash
• CarlyBMW coding app/wireless OBD dongle
• 15F/12R wheel spacers

Would NOT do again:

• Cheap LED halo bulbs
• Stage 1 engine reflash (not sure I felt enough of a difference personally)
• Paint matched front reflectors (liked the amber reflectors more after putting them back on)

Avoid KW HAS
Avoid AVIN HU
Avoid cutting your stock X pipe for test pipe
Avoid BC Coilovers


I haven’t done any of these mods FWIW.

Everyone regrets a straight pipe after a while.

I've been on eBay exhaust cutouts placed before the muffler for like 2-3 months now, it was $280 and I would never do a different exhaust setup after this. Would consider something lighter but I worry about the weight balancing issues and aero issues with more minimal exhausts. OEM muffler helps balance F/R weight and flows air up from under the rear bumper.

- I felt an immediate difference on my local freeway offramp after pulling the alignment pins and pushing the struts inward. Great little modification. Much less "push" during hard cornering.

- I cut my stock X pipe for test pipes and aside from a small leak that was pretty easily fixed, I don't regret it at all. Getting rid of the cats was my favorite thing I've done to this, there's more power everywhere.

-Editing to say that I did notice the difference between the revised stock air filter and an aftermarket MS stage 2 intake. Felt about half as significant as test pipes. I got mine used for $150 and it cleaned right up. Had fitment issues when my motor mounts were trashed, it could use more flexible couplers. No issues after those were fixed.

- Euro / GTS tune is great as well.

amrazM wrote

Avoid KW HAS
Avoid AVIN HU
Avoid cutting your stock X pipe for test pipe
Avoid BC Coilovers


I haven't done any of these mods FWIW.

Just so that the other perspective is out there in the test pipes.... this is by far the most rewarding and best mod I've ever done. To put it into perspective, I am not 20 years old and I don't have flame shooting burble tunes.. my car doesn't stick out at my office and is subtle enough to drive my wife (occasionally) around with her not noticing any smell or obnoxious noises. But the change in the car that occurred by cutting up the stock x-pipe with resonated test pipes (leaving secondaries in) and pairing it with a nice exhaust combo (Corsa), has made this car 10 time more fun and enjoyable to drive. Mine is combined with the Alpine stage 2 tune which leaves no issues for me mechanically and a very noticeable power bump. The other route you might be referring to is going with an aftermarket x-pipe, but to find one that has HFC that aren't positioned correctly is not easy and not cheap at all... Someone recently blew their engine using an aftermarket x-pipe with HFC that were positioned forward and they ended up melting or something and clogging up the exhaust and grenading the engine.

I can't imagine driving or owning this car without this change.... yeah, it's a pain to figure out emissions in some states, but it's not terribly impossible to slap the cats back on for that once a year. totally worth it. The car drives, idles and performs so much better after those cost effective changes.

wfdeacon88 wrote

I can't imagine driving or owning this car without this change.... yeah, it's a pain to figure out emissions in some states, but it's not terribly impossible to slap the cats back on for that once a year. totally worth it. The car drives, idles and performs so much better after those cost effective changes.

I feel the same exact way, I can't imagine going back to stock after this. I am more than willing to spend 2 hours under this car every couple of years for emissions. I had to put them back on for repairs a while back and I just couldn't wait to take them back off again. Good for 440-450 crank hp and more power from 2000-8400.

I also remember that thread about a collapsed cat on one of the banks. Part of the cat broke, started plugging up the exhaust, it got hotter, everything melted together, plugged up the entire side.

Having said that, I can't imagine how you wouldn't notice the engine wildly out of balance before a catastrophic failure.

When I began the process of buying my M3, I made a promise to myself that I would avoid unnecessary mods that involve a healthy chunk of cash. So for me, no aftermarket suspension, no engine tuning, no major exhaust work, no interior mods, etc. I was lucky that the previous owner already added carbon fiber splitters, rear spoiler, side gills, etc.

The mods I have done (or plan to do) will be small, cheap or just for preventative maintenance:

Replaced Kidney grills
Replace emblems (side gills, trunk roundel and M3 emblem)
AFE Dry Intake filter
Spacers
Rod Bearings

Future mods I will do (which will be the last of them):

Dinan DCT Tune
OEM Muffler Mod
Replace EDC shocks/structs with low mileaged take offs.

-Ultimate clutch pedal.. total waste of $ with stock clutch. Don't do it.

- I do agree that catless m's are tough to daily, the smell is noticeable and living in California I constantly await a state ref ticket. They'll let the Harley guys get away with it all day but not us. I do enjoy a sweet sounding M though...

- I do think a shift kit for the 6 speed guys is a great mod. Definitely a good value mod which one will appreciate every time you drive.

SAMM3Y wrote

-Ultimate clutch pedal.. total waste of $ with stock clutch. Don't do it.

- I do agree that catless m's are tough to daily, the smell is noticeable and living in California I constantly await a state ref ticket. They'll let the Harley guys get away with it all day but not us. I do enjoy a sweet sounding M though...

- I do think a shift kit for the 6 speed guys is a great mod. Definitely a good value mod which one will appreciate every time you drive.

if you can smell it, it’s leaking

chocstraw wrote

SAMM3Y wrote

-Ultimate clutch pedal.. total waste of $ with stock clutch. Don't do it.

- I do agree that catless m's are tough to daily, the smell is noticeable and living in California I constantly await a state ref ticket. They'll let the Harley guys get away with it all day but not us. I do enjoy a sweet sounding M though...

- I do think a shift kit for the 6 speed guys is a great mod. Definitely a good value mod which one will appreciate every time you drive.

if you can smell it, it’s leaking

I'm more talking about the cops/other motorists can smell it.. I can smell mine windows down when coming to a stop. It's also been known if you leave clothes etc. in your trunk with a catless car, the smell will waft up and cause them to smell, the trunk isn't airtight and being close to the exhaust exit you'll get some penetration. Thirsty tuned motors burning all that gas without cats are stanky...

SAMM3Y wrote

I'm more talking about the cops/other motorists can smell it.. I can smell mine windows down when coming to a stop. It's also been known if you leave clothes etc. in your trunk with a catless car, the smell will waft up and cause them to smell, the trunk isn't airtight and being close to the exhaust exit you'll get some penetration. Thirsty tuned motors burning all that gas without cats are stanky...

Ahhh yes. It will also stain vinyl wraps.

I was surprised by how much of a difference it made when I finally sealed up a pinhole leak. I had written it off as typical catless smell but it was night and day even with the tiniest of a leak.

But in regards to cops, IMO it’s very difficult to legally prove unless you explicitly admit that you removed the cats. There are enough chop-shops and failing cats around LA / CA to introduce plausible deniability.

I have seen some of those mobile emissions testing stations but (shockingly) only in low income areas, and they were waving all of the newer cars through.

Previous owner did these that are a waste IMHO:

Dinan ITBs (pricey for nothing IMHO)
Dinan strut braces (cosmetic and expensive)

Things the previous owner did that I would do again:

Dinan pulley
Dinan cat-back (sounds nice)
Dinan intake (nice induction sound)
Dinan 4.10 LSD (sold it because where I used to live I did a lot of highway driving - wish I had not now that I live where the roads are twisty - it had a nice pre-load - will likely buy another 4.10 at some point)

Things I have done that I would not do again:

Test pipes (ultimately ended up with a proper x-pipe)
Bolt to stud conversion (should have simply bought larger bolts as I rarely remove the wheels and gone with 15mm and 12mm spaces on day one)
12mm spacers on all 4 corners (due to stud kit - ended up going with 15mm front and 12mm rear)

Mods I did and would do again:

15mm front spacers and 12mm rear spacers
Challenge sport x-pipe (HFC to limit smell but Stage II tune)
Alpine tune (nice to have access to different tunes, still have the Dinan tune but it has cold start...)
50% front tint
40% rear tint
AutoSolutions 18% reduction stock height short shifter with 80A bushings

Future mods:

4.6L stroker with Schrick 292 cams
4.10 LSD of some sort

It is all about the journey.

4.10 gears are cool.. car always seems to be in the right gear even though the increase in ratio is pretty minimal above stock. I have an osg lsd in mine. It's noisy though, I like the sound but it would get annoying driving it everyday, especially noisy on deceleration.

E90 M3 mods:
Evo sport Power pulley
Full ipe exhaust (but running stock X, too lazy to put back plus i live in Cali and exhaust laws suck out here)
LED package
TE37rt
H&R race springs
FancyWide diffuser
Light window tints

regrets? Just one.. The infotainment is outdated and plan to upgrade it to Apple CarPlay

If this applied to previous cars, I'd have a super long list, LOL.
Fortunately I've learned that "less is more," "you get what you pay for," and that due diligence will avoid regrets. No regrets with this one yet, though subjective/styling details may always be subject to change.

Best bang for the buck:
Alpine tune and GTS flash, billet DCT paddles, PS4S tires, ...


https://www.m3post.com/forums/showthread.php?t=1455563

chocstraw wrote

wfdeacon88 wrote

I can't imagine driving or owning this car without this change.... yeah, it's a pain to figure out emissions in some states, but it's not terribly impossible to slap the cats back on for that once a year. totally worth it. The car drives, idles and performs so much better after those cost effective changes.

I feel the same exact way, I can't imagine going back to stock after this. I am more than willing to spend 2 hours under this car every couple of years for emissions. I had to put them back on for repairs a while back and I just couldn't wait to take them back off again. Good for 440-450 crank hp and more power from 2000-8400.

I also remember that thread about a collapsed cat on one of the banks. Part of the cat broke, started plugging up the exhaust, it got hotter, everything melted together, plugged up the entire side.

Having said that, I can't imagine how you wouldn't notice the engine wildly out of balance before a catastrophic failure.

Thanks for confirming I wasn't dreaming about the HFC disaster, I swear I saw it but couldn't find it. I think it was an ESS HFC x-pipe... hard to find an aftermarket x-pipe that I would trust, and if they are out there, they will easily touch 2 grand. Loving my rogue resonated test pipes + Corsa ... dreading going back stock for a few days later this month. I did see a post where someone used these https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F253299791529
and it worked passing emissions. I'm not in California, so I don't have to worry about those nut case laws, but tempted to try this ... but since I don't have jacks, I'd have to find a place to help me install....

Wanna go faster? Try a driver mod...High Performance Driver's Ed

I hope my wife doesn't read this thread but here it goes:

Akrapovic Evolution Exhaust
Macht Schnell Uber drive pulleys
Macht Schnell Stage 2 air intake
Alpine Stage 2 engine tune
Dinan DCT software tune
MFactory carbon fiber driveshaft
Performance steering wheel with carbon fiber paddle shifters
Carbon leather interior trim and IND DCT boot and parking brake boot
VR2 carbon fiber front spoiler and rear spoiler

I also had my wheels powder coated bliss black from the factory silver.

I did a muffler delete with secondary cat. Would never do that again. Yet alone secondary . Simply waste of time and money

Haven’t done much to my E90 as I like to keep it close to stock, but the things I have done, mostly cosmetic, I really like. Black kidney grills, carbon mirror covers, carbon front splitters, F10 shift knob and lastly but the best one was the M performance exhaust, which I think sounds awesome. I had an Eisenmann Race at one point but thought it was too much and it droned a lot

Seems like a lot of you guys seem to like 15F/12R for spacers. I am assuming these are put on M3 specific offset wheels?

Since I run non M3 offset wheels, I went with 15F/18R instead.