Karter16's E46 M3 Journal

[Karter16 472]

3 hours ago, deedub said:

Thank you. I'm a complete noob when it comes to vehicle ECU's. I've been trying to track down info around the motronic 1.x versions. Still got a bit of searching/reading to do but thanks for the heads up on the processor used. 

I don't have a read of the program ROM yet. Still trying to figure out how I connect to it so I can get it off.

I use Linux for everything except gaming. I'm hoping support for tooling on Linux is reasonable. Keep seeing windows come up in convos around diagnostics...

TunerPro have a bunch of xdf's (definition files for tunes) for the Motronics as well as binary reads of the tunes - might be worth poking in to: https://www.tunerpro.net/downloadBinDefs.htm#BMW

[Karter16 472]

Couple of updates:

1: The wheels arrived today 🎉 Mandatory photo, although we all already know what ARC8's look like 🙃

2: The male MAF sensor connectors arrived. I don't actually have need of these for myself, but I finally came across them and thought I'd order some to confirm they're a match and if so share the details with everyone as saves having to pay Turner money for their relocation harnesses.

These things appear to be the exact same item Turner are using and they come with the pins and seals.

I ordered 5 of these for the princely sum of $9.58USD total including shipping. per-unit price is $1.24USD.

You can purchase your own (you can order singles) here: https://www.hdconnectorstore.com/productdetail/32496.html 
 

[Karter16 472]

I ordered tires this evening. After much research I decided to go with the Bridgestone Potenza Sport. I had been planning to take the well-trod route of Michelin PS4S's, however they're not available in New Zealand (and importing tires was just going to be too expensive to make sense) in any of the sizes remotely close to what I need (I confirmed this with Michelin NZ directly), this was a surprise especially given I'd checked on their NZ website that those sizes were available here 👎

This meant I then needed to figure out alternative options. In Michelins that meant PSS's or PS5's (no Cup options available in NZ in the sizes I need). The PSS's are too old, and the PS5's while by all accounts very good had me a bit concerned about the softer tire wall than the PS4S. The RE050A's that I'm running currently, are fairly stiff in the sidewall department and while objectively terrible compared to modern options I am used to the stiffer sidewall. By moving to 18's I'm already introducing more compliance for a better ride and road stickability (that's the technical term 🙃), and I was a little concerned about also moving to an even softer sidewall as well.

I then looked wider, and after a bunch of research, looking at what is available in NZ, settled on the Potenza Sport. The Potenza Race would be an even better option I think, but they're not available in 18in options. The RE71-RS's while the stickiness would have been giggle-worthy, don't give the same degree of feedback and would be impractical in wet conditions, so the Sport it is. TireReviews.com have a good review of it and on dry handling it's very close to the PS4S, slightly better in the wet, and ranks worse on comfort (due to the firmer sidewall), slightly worse on noise and worse on wear. The wear doesn't bother me as I won't do enough km's anyway, the firmer sidewall I'm okay with and the noise will still be a lot better than the RE050A's anyway.

This is all splitting hairs of course, but might as well get the best option I can.


Big shout out to @Palazzo for suggesting Costco. Bridgestone NZ direct have the best price out of the rest due to a special deal currently which comes to only $2376.32 NZD for all 4 tires fitted. Costco, for exactly the same thing, is $1379.94, plus in addition you get a $360 store credit as well. Given we regularly shop at Costco for essentials this means the end cost for the tires comes to $1020. Which is quite astonishing to me. That's significantly less than I paid for new performance tires for my 318i in 2007!

[Eagle 1773]

1 hour ago, Karter16 said:

Bridgestone Potenza Sport.

I recently looked at those for my S55 as they were the only good in my sizes along with the PS5's (both around $1900 trade). Upon reading reviews they didnt have the characteristics i was after for the car so i went with the PS5's.

That pricing is insane in this day and age though, buying power that good or tyre shops got big markup, maybe both. Would of been interesting to see what the PS5 cost in the same sizing. May have to drive to Auckland for future tires.

[Karter16 472]

11 minutes ago, Eagle said:

I recently looked at those for my S55 as they were the only good in my sizes along with the PS5's (both around $1900 trade). Upon reading reviews they didnt have the characteristics i was after for the car so i went with the PS5's.

That pricing is insane in this day and age though, buying power that good or tyre shops got big markup, maybe both. Would have been interesting to see what the PS5 cost in the same sizing. May have to drive to Auckland for future tires.

PS5’s came to $1775.94. The fronts (245/40R18) were cheaper than the Potenza Sports, but the rears (255/40R18) were significantly more for whatever reason.

[Palazzo 513]

10 hours ago, Eagle said:

I recently looked at those for my S55 as they were the only good in my sizes along with the PS5's (both around $1900 trade). Upon reading reviews they didnt have the characteristics i was after for the car so i went with the PS5's.

That pricing is insane in this day and age though, buying power that good or tyre shops got big markup, maybe both. Would have been interesting to see what the PS5 cost in the same sizing. May have to drive to Auckland for future tires.

Friends got tyres direct from importer last year. A set of 4 was about 20% more than 1 from a (cheap) retailer.

So somewhere between the importers margin and the retailers margin is a healthy number.

[Eagle 1773]

11 hours ago, Karter16 said:

PS5’s came to $1775.94. The fronts (245/40R18) were cheaper than the Potenza Sports, but the rears (255/40R18) were significantly more for whatever reason.

Yeah pricing can be odd. I run 245/45R18 fronts cost about the same. PS5's retail fitted\balanced in 275/40R18 were $820 vs $589 for Potenza's. Trade on the PS5's was $570 by itself. 

59 minutes ago, Palazzo said:

Friends got tyres direct from importer last year. A set of 4 was about 20% more than 1 from a (cheap) retailer.

So somewhere between the importers margin and the retailers margin is a healthy number.

Importer is probably the one making most of the money. Current advantage tyre retail Michelin pricing is a 20-30% markup on trade price all things being equal. I find a good special\sale seems bring the retail price to around the trade price lots of consumable items. The saving in trade is being about to fit them yourself and save $200 on a set, most places seem to charge $~50 per tyre for fitting and balancing.

Edited June 25 by Eagle

[Karter16 472]

Yesterday I got the tires fitted to the ARC-8's and today I put them on the car and went for a test drive.

It will surprise no one that this setup is a huge improvement over 19s with old RE050A's. The first few minutes of driving were weird, it felt like I'd lost a bunch of road sensation and it took a few minutes to realize it was just harshness and unhelpful noise that was missing. All the useful feel of the car and the road through the seat and wheel was still there, it was just a quieter smoother ride with much less of the unnecessary hum, buzz, fizz, whatever you want to call it. As soon as I realised I could still read the road as before I settled in and started comparing the difference.

I can't talk to how the Potenza Sports compare to the PS4Ss, but compared to old RE050A's they are very significantly quieter, I first noticed this by noticing that the CSL intake sounded louder! 18inch wheels are clearly what this car was designed for and are better than 19s in every way when it comes to ride quality and feel. I'm very happy I opted for the firmer sidewall of the Potenza's over the, softer than PS4S, PS5's. The accuracy and immediacy of handling is still there, significantly improved upon with new sticky tires. I need to give a big shout out to Bry5on for his advice to put 9in wheels up front with the ET42 offset. I'd always been worried about putting anything too wide up front, afraid of ending up with heavy, dull steering, but with pretty much the correct offset and lighter wheels and tires all the precision and immediacy is still there, and when you get on to windy open road the feel of the car with a larger tread patch up front and closer to square setup overall is just superb. 

On the topic of weight. The combination of lighter wheels and lighter tires means I'm almost 4kg lighter per corner, which (including weight of the rotors) is close to a 14% reduction in rotating mass, and I can really notice the difference. I'm always skeptical of my butt-dyno because I'm always concerned it is excessively influenced by the "wallet factor". But in this case there is no doubt. Acceleration and braking both noticeably benefit, not to mention how much better the car ride and holds to the road with less unsprung mass.

In summary, as you would expect, this is a fantastic upgrade in every way.

I do want to thank everyone who took their time to give me advice and suggestions on this project. It wasn't one I was planning to do right now, and as a result I had not performed my usual excessive amount of research and preparation well in advance. I'm very grateful to everyone who shared their knowledge and experience to help me arrive at the ideal outcome. Thank you!

Like heinzboehmer I've very much missed driving the car while it's been laid up, so like him when I got it back on the road a short test drive turned into a longer one. Only I ended up at a slightly less globally-famous landmark. The Mt Rex sand processing facility in Helensville 😂 Also, it's winter here, it was raining, and the sun was in the wrong place.