discussion Newbie with problems

[RalfMurphy]

Hi Everyone

Quick post to introduce myself and my growing list of problems with my car 😭😭:

2015 F20 FL 125i (N20) with M-sport package. Manual for the real fans
over 110,000km's so decided to start working on the car myself.

Additions:
De-catted downpipe
Stepped Intercooler
K&N drop-in panel filter
Remap
18" Aftermarket wheels in 8,5j Front and 9.5j Rear (I'd prefer not to list the type and pictures if you guys dont mind)

Problems:
1. Trying to find more grip in the rear end esp after the remap, I went for the wider wheels in the hopes of fitting 265 rear sections. I cannot find this tyre anywhere in a run-flat so, in my desperation fitted 255/35/R18 Michi PS3 to the rear. I'm starting to think these are meant for an SUV, as they are "extra load" rated and look friggen huge on my car. Ride height is raised as well. These wheels were a mission in themselves to find, as I needed 5x120 PCD and at least ET45 for the rear. Maybe most of you know the mission it is to find a good wheel in this size, and now made even worse during lockdown with backorder stock issues. When I finally found a decently priced genuine flow-formed wheel, my next problem was finding tyres and now I'm stuck with an eyesore. Goddamnit. Should I just fit something in a non-runflat and be done with this? How do you 135i/140i owners live with spinning up the rears?

2. My brake pads and discs were due and out of motorplan. I hunted down Brembo pads, apparently Midas are the only agents for them in the country. I also skimmed the discs since new M-sport discs cost the earth. Fitted them myself. Not sure if I got copper compound on the discs but the brakes feel soft and fadey and my braking performance has declined significantly. Don't think I did this wrong tho so I can only put it down to a shitty Brembo compound. I'll try find something from EBC next time, but knowing the headache I had with these M-sport brakes, chances are no-one out there makes this odd size of pad. Any recommendations will be appreciated. Even went to two BMW dealerships and the spares salespeople couldn't even tell me which brakes fitted to my car. Useless.

3. There is a vibration somewhere starting from 120-160 kph. Its annoying and unsafe. I've changed wheels and tyres, rebalanced and realigned and still have this problem. My next go-to will be a bump test on the shocks. If that doesn't reveal anything, I'll have to look at control arm bushes and engine mounts. Any recommendations for performance aftermarket bushes and dampened engine mounts will be appreciated.

I want to build this car up further, but these small niggles are adding up and stopping me from pushing this car any more. Parts availability (esp good aftermarket stuff that fits) and shipping costs are making me bleak.

Let the roasting begin....

 

[Jive_E46]

Howzit Newbie! Hope you enjoy your stay!

No roasting necessary, these are all valid queries.
1. The 255/35/ZR/18 spec tyres are all I've ever used on my F20. I don't think the extra load has anything to do with how beefy the tyre looks. I tackled the traction issue like this: A bigger sidewall will result in more traction (There's some physics behind this and I'm not inclined to explain it XD). Michelin tyres are the best in the game, anything stickier and you're looking at Michelin PS4S or softer. 265 is too big in my opinion and may cause you to rub. Runflat tyres significantly reduce ride comfort and in my opinion wears worse than non-runfat!

2. EBC yellow stuff was the best bang for buck mod I could find for my F20. If you're looking for a pad and disc replacement, EBC sell them for the F20. Alternatively, Vari brakes and other brake specialists in SA can help you out. I found that even with the uprated EBC hardware, there was still significant brake fade.

3. Vibrations is a tough one to pin down. Power Flex street performance range offer a variety of bushes and an engine mount. Just remember, polyutherane (performace bushes and mounts) are alot stiffer than OEM rubber which may cause vibrations to be even worse.

Please post some pics of your ride, would love to see whats cooking there.

 

[RalfMurphy]

Howzit Newbie! Hope you enjoy your stay!

No roasting necessary, these are all valid queries.
1. The 255/35/ZR/18 spec tyres are all I've ever used on my F20. I don't think the extra load has anything to do with how beefy the tyre looks. I tackled the traction issue like this: A bigger sidewall will result in more traction (There's some physics behind this and I'm not inclined to explain it XD). Michelin tyres are the best in the game, anything stickier and you're looking at Michelin PS4S or softer. 265 is too big in my opinion and may cause you to rub. Runflat tyres significantly reduce ride comfort and in my opinion wears worse than non-runfat!

2. EBC yellow stuff was the best bang for buck mod I could find for my F20. If you're looking for a pad and disc replacement, EBC sell them for the F20. Alternatively, Vari brakes and other brake specialists in SA can help you out. I found that even with the uprated EBC hardware, there was still significant brake fade.

3. Vibrations is a tough one to pin down. Power Flex street performance range offer a variety of bushes and an engine mount. Just remember, polyutherane (performace bushes and mounts) are alot stiffer than OEM rubber which may cause vibrations to be even worse.

Please post some pics of your ride, would love to see whats cooking there.

Howzit Newbie! Hope you enjoy your stay!

No roasting necessary, these are all valid queries.
1. The 255/35/ZR/18 spec tyres are all I've ever used on my F20. I don't think the extra load has anything to do with how beefy the tyre looks. I tackled the traction issue like this: A bigger sidewall will result in more traction (There's some physics behind this and I'm not inclined to explain it XD). Michelin tyres are the best in the game, anything stickier and you're looking at Michelin PS4S or softer. 265 is too big in my opinion and may cause you to rub. Runflat tyres significantly reduce ride comfort and in my opinion wears worse than non-runfat!

2. EBC yellow stuff was the best bang for buck mod I could find for my F20. If you're looking for a pad and disc replacement, EBC sell them for the F20. Alternatively, Vari brakes and other brake specialists in SA can help you out. I found that even with the uprated EBC hardware, there was still significant brake fade.

3. Vibrations is a tough one to pin down. Power Flex street performance range offer a variety of bushes and an engine mount. Just remember, polyutherane (performace bushes and mounts) are alot stiffer than OEM rubber which may cause vibrations to be even worse.

Please post some pics of your ride, would love to see whats cooking there.

Thanks Jive

1. I understand the physics. Thanks for the advice and good to know you also run the same size. These tyres also look beefy coz they are more rounded where as other low profiles have a more squared took as the tyre transitions from sidewall to tread. Not sure if that's down to the type of tyre or some other property of the spec. I was worried about rubbing so I won't go any bigger having seen what 255's look like on the actual car. Hopefully it still leaves me with about 10-15mm to play with if I wanna drop the ride height later.
2. I will definitely look for EBC stuff after hearing this. Thanks again
3. This one is gonna take some digging and trial and error. I'll get into it if I can find the time to put the car on jacks

I'll post a pic once I get a good wash 😅