Bought an old BMW M3, filled with regret...

[Demon]

Because the reg check shows the tyre sizes for all variants of M3.

Stick with standard.

They generally only show a single tyre selection although do tell you front/back are different:

Hence when I checked and found standard fronts/CSL rears, I had to go to the internet to do some research and was surprised that so many people upsize to CSL dimensions and thought since my rears are already that size, might as well do the fronts so at least they are correctly balanced.

[edit]
Bizarre, putting in mrk's reg gets:

Maybe they amend their DB based on previous owners purchases, or mine is 2004, slightly older, maybe official sizes don't go back that far and they've picked one set of defaults for older cars..

 

[[TW]Fox]

I have no idea why people keep up sizing. It seems like pointless extra expense and it's probably more to do with people desperate to have some sort of CSL taking point I guess.

 

[Demon]

I have no idea why people keep up sizing. It seems like pointless extra expense and it's probably more to do with people desperate to have some sort of CSL taking point I guess.

Searching around for the newer tyre designs, I found the 235's cheaper than the 225's.. e.g. Goodyear F1 AS3's and Dunlop SportMaxxRT2's are £125-£130 vs £140/£150, and pretty much teh reverse difference for the rears.. swings and roundabouts cost wise..

It's not just about 'size', but obviously popularity etc..

I get what you mean though, although I would say that for an M3 at least the DSC is so archaic, having a bit more grip is something most people can appreciate..

And Shocker in Fox doesn't understand petrolheads..

 

[[TW]Fox]

Come on it's 1cm wider, it's not going to give you any more noticeable grip.

 

[Demon]

Come on it's 1cm wider, it's not going to give you any more noticeable grip.

We all know you upgrade on theoretical advantage, pfft to your real world metrics..

Fatter tyres = more man points, I thought everyone knew that?

Although, scientifically remember it's a contact patch, so 1cm wider * width of contact path,a nd rubber being adhesive will equate to more grip than you would think.. or we'd all undersize by 20mm if that meant super cheap tyres..

 

[Atari]

How strange then, could my Evolve remap have locked module ECUs down from being modified perhaps? Can't see how that would affect the Mk60 though. I'll try the silver cable in position 4 soon.

I'm 75% certain it will be locked down. I tried seeing what changes were made for a mate who wanted the CSL warm up lights and was unable to make any meaningful progress. I guess it's locked down to stop someone from stealing their map

I believe I remember seeing the degree's before DSC kicks in under M-Track mode, but I've never played with those, everyone just wants M-Track, innit

 

[[TW]Fox]

We all know you upgrade on theoretical advantage, pfft to your real world metrics..

Fatter tyres = more man points, I thought everyone knew that?

Although, scientifically remember it's a contact patch, so 1cm wider * width of contact path,a nd rubber being adhesive will equate to more grip than you would think.. or we'd all undersize by 20mm if that meant super cheap tyres..

The manufacturer hasn't fitted a certain size for a laugh or at random. I can think of no credible reason to deviate from the stock tyre size on an M3. It wasn't pulled out of a hat.

There is a school of thought that staggered setups actually offer less grip anyway - some track setups run square sizes.

People do it because 'CSL this' and 'CSL that' on the modz list is ubercool.

 

[Demon]

The manufacturer hasn't fitted a certain size for a laugh or at random. I can think of no credible reason to deviate from the stock tyre size on an M3. It wasn't pulled out of a hat.

There is a school of thought that staggered setups actually offer less grip anyway - some track setups run square sizes.

People do it because 'CSL this' and 'CSL that' on the modz list is ubercool.

No, people look how bmw evolved the m3 and since they put all that effort into figuring out slightly wider tyres was actually better, they are just following suit..

Not to mention that most people also enable m-track mode on their standard m3, another CSL improvement that is absolutely worthwhile, or fit the brakes etc..

If you want to portray people that do this as uninformed chavs I think that says more about you than them.

 

[[TW]Fox]

No, people look how bmw evolved the m3 and since they put all that effort into figuring out slightly wider tyres was actually better, they are just following suit..

No, this isn't what happened at all. The CSL runs different tyre sizes because it has physically different wheel sizes. The CSL has an 8.5" front wheel width, the CS and the 19 inch wheel on the regular M3 has an 8" front wheel. Hence the variation in tyre size.

The rear wheel is the same size but the M3 CSL's rear tyre size is slightly wider in order to keep the same rolling radius as the front tyres, which as I've explained above is required because of the physical wheel size.

Look at the final edition of the E46 M3 - the very last 'evolution - the CS. This has the same tyre size as the non CSL on 19 inch wheels. This is the optimal size for a 19 inch wheel of the dimensions fitted to the M3.

It's nothing to do with following an 'evolution'. They are the wrong tyre size for the wheels.

Fitting the wrong size tyres just because they are the same size as the CSL is nothing like the same thing as making a worthwhile upgrade to CSL brakes.

 

[Demon]

No, this isn't what happened at all. The CSL runs different tyre sizes because it has physically different wheel sizes. The CSL has an 8.5" front wheel width, the CS and the 19 inch wheel on the regular M3 has an 8" front wheel. Hence the variation in tyre size.

The rear wheel is the same size but the M3 CSL's rear tyre size is slightly wider in order to keep the same rolling radius as the front tyres, which as I've explained above is required because of the physical wheel size.

Look at the final edition of the E46 M3 - the very last 'evolution - the CS. This has the same tyre size as the non CSL on 19 inch wheels. This is the optimal size for a 19 inch wheel of the dimensions fitted to the M3.

It's nothing to do with following an 'evolution'. They are the wrong tyre size for the wheels.

Fitting the wrong size tyres just because they are the same size as the CSL is nothing like the same thing as making a worthwhile upgrade to CSL brakes.

Source?

I doubt they wanted to increase front grip tyre stiffness and didn't care about making a similar change to the rear and only dId it for RR.

Although why does it matter? It was an improvement, as are the brakes, dsc etc.. and since the tyres don't really cost any more on balance, I don't get the chastisement. I actually have CSL width rims.. but I'd still have considered standard tyre sizes if there was a huge price difference.

 

[[TW]Fox]

Source?

Source for what? It's fact - the CSL front wheel is wider than the CS and regular 19 inch M3 front wheel.

Obviously there is a reason why the CSL was blessed with wider front wheels but it's also got different suspension too - presumably the two were designed hand in hand, as BMW M GMBh tend to know what they are doing.

It was designed ground up with a wheel, tyre and suspension package to suit the design brief. As was the non CSL...

You can't just pick and choose random bits and expect them to work as well together.

Although why does it matter? It was an improvement, as are the brakes, dsc etc.. and since the tyres don't really cost any more on balance, I don't get the chastisement. I actually have CSL width rims.. but I'd still have considered standard tyre sizes if there was a huge price difference.

If you've got CSL width wheels front and back then obviously the CSL tyre sizes are the correct size for you to run. That's a rather salient fact you neglected to mention Most people running CSL tyre sizes are simply fitting them to the regular sized wheels simply 'Because CSL'.

If there was a credible performance benefit to just fitting wider tyres all round to the regular M3, BMW would surely have offered it - after all, the M3 was designed by BMW M to be a proper drivers car. It's not a 118d M Sport bling edition - it's a proper performance car, with almost all production decisions made around making it a proper performance car. If it'd have been better on 265's with no downside it'd have rolled off the line on 265's.

If anything BMW tend to over-tyre cars rather than under-tyre them. Wider and wider tyres doesn't result in a linear increase in available grip.

Sometimes your tyres can be too wide...

I wonder if Housey and his mates had CSL size tyres in 2004? If not, why not?

 

[mrk]

My car came with CSL tyre sizes so I stuck with it as I do plan on getting CSL wheels at some point in the near future.

No, this isn't what happened at all. The CSL runs different tyre sizes because it has physically different wheel sizes. The CSL has an 8.5" front wheel width, the CS and the 19 inch wheel on the regular M3 has an 8" front wheel. Hence the variation in tyre size.

The rear wheel is the same size but the M3 CSL's rear tyre size is slightly wider in order to keep the same rolling radius as the front tyres, which as I've explained above is required because of the physical wheel size.

Look at the final edition of the E46 M3 - the very last 'evolution - the CS. This has the same tyre size as the non CSL on 19 inch wheels. This is the optimal size for a 19 inch wheel of the dimensions fitted to the M3.

It's nothing to do with following an 'evolution'. They are the wrong tyre size for the wheels.

Fitting the wrong size tyres just because they are the same size as the CSL is nothing like the same thing as making a worthwhile upgrade to CSL brakes.

"CSL brakes" are only slightly bigger discs and the rear piston is slightly larger, although the rear brakes don't do a whole great deal compared to the front anyway. They still fade with heavy use Pads are the same also.

BBK is where it's at for all E46 M3 variants

 

[Demon]

Source for what? It's fact - the CSL front wheel is wider than the CS and regular 19 inch M3 front wheel.

You are missing my point.

You specific claims where
- The tyres are wider because the wheels are wider
- The rears are wider to maintain the rolling radius

That makes it sound like the tyre width was secondary in each case, where as I think it's more plausible to think they wanted wider tyres with lower profiles that give small improvements in grip and rigidity..
- Hence they widened the front rim since it's easy to do and maintain the same tyre/wheel relationship
- They couldn't widen the rear rim because it's hard to accomodate due to space constraints.

Obviously there is a reason why the CSL was blessed with wider front wheels but it's also got different suspension too - presumably the two were designed hand in hand, as BMW M GMBh tend to know what they are doing.

You can't just pick and choose random bits and expect them to work as well together.

If it was accepted that compromises are never made to align ride comfort and other non performance factors, then I would agree that there could only be one or two optimal setups worth having, but I certainly have learnt that while you can bugger things up relatively easily, you can actually make small improvements if you are prepared to choose difference compromises.

If you've got CSL width wheels front and back then obviously the CSL tyre sizes are the correct size for you to run. That's a rather salient fact you neglected to mention Most people running CSL tyre sizes are simply fitting them to the regular sized wheels simply 'Because CSL'.

Well, speaking for myself, yes I do have CSL width rims, because that's what a previous owner bought, but it's also valid that you can fit quite a range of widths on the stock rims, and whilst this will have a small effect on the tyre geometry, it's probably dwarfed by the variance in tyre wall construction etc which IME has a very noticeable impact on the handling of a car.

If there was a credible performance benefit to just fitting wider tyres all round to the regular M3, BMW would surely have offered it - after all, the M3 was designed by BMW M to be a proper drivers car. It's not a 118d M Sport bling edition - it's a proper performance car, with almost all production decisions made around making it a proper performance car. If it'd have been better on 265's with no downside it'd have rolled off the line on 265's.

Product differentiation and target audience compromises? They didn't also enable M-Track mode despite every M3 after 2002 having the same DSC ECU as the CSL, in fact it turns out it was only a simple configuration option.. And that absolutely is an improvement..

If anything BMW tend to over-tyre cars rather than under-tyre them. Wider and wider tyres doesn't result in a linear increase in available grip.

There are some benefits from wider tyres, it's not a simple subject, but I would agree that in reality you could get away with narrower tyres in a lot of cases, that doesn't nullify the use of wider tyres though.

Sometimes your tyres can be too wide...

absolutely, but since BMW saw fit to include these particular ones on a more track focused variant, I'd say they are probably OK if that's you thing.

I think we will differ on one key thing here.. my own experiences have shown me that manufacturers are happy to make different compromises to myself, so I often tweak things to my liking within reasonable constraints..

My car came with CSL tyre sizes so I stuck with it as I do plan on getting CSL wheels at some point in the near future.

I keep eyeing up CMWheels CSL reps on M3C, £500 a set seems reasonable and no reports of any major issues.. I might get some next month as I am finding mine a bit too non-oem even for me!

"CSL brakes" are only slightly bigger discs and the rear piston is slightly larger, although the rear brakes don't do a whole great deal compared to the front anyway. They still fade with heavy use Pads are the same also.

BBK is where it's at for all E46 M3 variants

Yeah, it's the one aspect I have immediately noticed, the brakes just don't feel as capable as even my more mundane cars..

 

[Demon]

As promised, a quick guide to installing a reverse cam into the boot lid.



This won't cover connecting to the head unit, as generally it's just a composite video cable and a reverse signal connection which differ depending on brand of head unit.

Spoiler

1. Remove the inner carpet from the boot lid.
This has 8 gray clips holding it in:

Each clip needs the head part lifting up, then pull the clip out:

There are also two screws for the hinges of the toolkit.



2. Unclip the boot release switch connector, this is the only lead going to the boot handle.

3. Unscrew the 5 torx screws holding the boot lid handle on.
You will need to remove the BMW roundel as that has one screw hidden under neath, this came off with just my finger nails prising it off..

The lead you disconnected earlier will easily pull through once the handle is loose.




4. Drill a hole
Use the provided hole saw (presuming you have bought a kit with one!)

5. Route the camera cable through the hole
It needs to come out of the gasket on the rear. I've shown where the cable egresses, the gasket needs lifting slightly, but it is very flexible and will stick back down after wards, we are aiming to get the cable behind the number plate light unit.

6. Now clip the camera in!

7. Now reinstall the handle
Threading the camera lead through the aperature for the number plate light, through to the centre part/hole where the release switch cable goes through (plenty of room to get any leads through here)

Screw all torx screws back in!




8. Route the camera cables along existing cable runs

This is the same photo as earlier, but shows the routing (red line) of the camera cables, just cable tie them to the existing loom.





9. Wire up the camera supply (Ground / 12v)
And if necessary wire up a reverse signal wire. The camera 12v / reverse signal can both come from the 12v feed to the reverse light which is close to hand. The following shows the reverse lamp connector and which of the wires you need to attach the wires to.

10. Feed all cables through the lid trunking to the body.
I didn't get any good photo's of this, but you can see the general routing I took:

I had to cut the cable since there is no way you can get any connectors through the trunking. I removed both ends of the rubber trunking (very easy, just use your fingers), compressed it until it was approximately straight, and fed a knitting needle through, then taped the cables to the end, and gently pulled them through, it's a bit fiddly as the knitting needle only just fits, and it took a couple of attempts to get the cable through. I pulled the cable from the car body up through the trunking, then reconnected the cable in the boot lid.


Then reinstall the boot carpet, clips and toolkit screws. Finally restick the roundel back on. I used de-solv-it Sticky Stuff remover from B&Q and reapplied number plate tape to the rear.

 

[mrk]

Don't get me wrong, the brakes are quite a bit better once you change the pads to something more competent. I have the PFC Z Rated which seem to provide excellent bite and progression. But the small callipers and discs just don't like repeated heavy breaking. A lot less brake dust with the PFC pads as well.

 

[Demon]

Don't get me wrong, the brakes are quite a bit better once you change the pads to something more competent. I have the PFC Z Rated which seem to provide excellent bite and progression. But the small callipers and discs just don't like repeated heavy breaking. A lot less brake dust with the PFC pads as well.

Thanks, those look good! Brake dust is a PITA!! My disks are about 50% worn so not keen to change those just yet, I see the PFC Z rated discs look good! a bit pricey though!

 

[One Vision]

Question.....
Is it worth getting my 19inch rims refurbed and diamond coated for well over 400 quid probably around 450? Or maybe buy a set of different rims for not much more money?

What would you guys do?

 

[Demon]

I've looked at 3 options myself
- Original diamond Cut 19" - Difficult to maintain, not my favourite finish
- Power coated hyper silver original 19" alloys - easier to maintain, still look 'silver'
- CSL Reps in hyper silver

Personally since mine came with csl style wheels, I do prefer the look to the standard 19s, but its quite a personal choice, I am tempted to get a Hyper Silver set of CSL reps (£500 on m3Cutters through CM Wheels), these are obviously more OEM look but as you say not much more than refurbing the originals..

 

[mrk]

Question.....
Is it worth getting my 19inch rims refurbed and diamond coated for well over 400 quid probably around 450? Or maybe buy a set of different rims for not much more money?

What would you guys do?

A full set re-cut with like for like swap at FA Wheels is £375. You have an additional £50 surcharge if your existing wheels are beyond re-cut whereby they have previously been re-cut and are now at the limit so can only be painted from then onwards. Each wheel has about 3 cuts before the limit is reached and cutting any further.

 

[One Vision]

Thanks guys always helpful.
Question 2 lol.
Whats a good set of tyres for the money, the car came with Continentals which were around 900 quid for 4!
Now im not made of money so looking for something good but not as much.
Thanks