Getting your car tuned by Nowack, the Saga
(Nearly as long as Lord of the Rings, but with less people eating popcorn behind you)
If you're sitting comfortably, I will relate the story of my dealings Nowack to date. It is long .......
I bought my M5 (Carbon Black, Sportiv, black Alcantara/Leather interior) in May 1999 -- one of the first in the UK. Loved it and still love it. However, like so many , after 2+ years of huge amounts of fun, I got to thinking "Wouldn't if be cool if it was even faster with even better brakes, etc. etc.". If you live in Europe I found that the only tuners that can "genuinely" improve the M5 are Nowack ( www.nowack-tuning.de
) and Racing Dynamics (various pages, but international homepage is: www.racdyn.com
) -- I don't think Dinan have a European outlet?? I e-mailed both companies from their website. Nowack got back to me within 48 hours. I spoke to Racing Dynamics' agent in the UK and then e-mailed them in Germany. After a week they never bothered to reply to my mail. Given that all of the research I had done suggested that Oliver Nowack is "the man" when it comes to M5's, my decision was easy. I subsequently found out Nowack did RD's tuning for them anyway, so in fact a very easy choice.
As an aside, I found that if you go to the Nowack website there are number of good reviews and pictures in the magazine articles that the website lists. However, most of the English language reviews read "surprisingly" similarly -- they all seem to be based on one ?base? review. The French and German reviews are more varied and worth reading (language barriers permitting).
The Nowack N-500
Nowack have a package of upgrades for the E39 M5, including engine (inc. clutch, exhausts, etc.), brakes (inc. wheels and tires), suspension (inc. anti-role bars). They call the full package the Nowack N-500. I got a quote from Nowack for the full N-500 package, which I list below:
Engine upgrade to 503 BHP and 630 Nm (479 ft lb) of torque: £12,500 or cUS$18,100.
A lot of the work here is to make the engine work more efficiently, particularly in terms of air and fuel-air mix flows. A complete list of the work is:
· New Nowack sports camshafts (probably bought off-the-rack from an external supplier).
· Prepared (smoothed, optimised) cylinder heads on in- and out-lets. Work done on in-house machines.
· Additional RAM-air inlet funnels (see website for these. They are rather obviously built into the front air dam in the company's demo car -- in my car they are now buried behind the airdam grill and thus look less obvious) and optimised air intakes/air flow.
· Free flow air filters (Nowack use K&N)
· Optimised single throttle bodies (no idea exactly what this, to be honest)
· New optimised con-rods (these are exclusive to Nowack, from an external supplier)
· New exhaust system. This is also specially made for Nowack and includes much improved cat-converters. The demo car on the website has slightly odd shaped "lozenge" pipes at the rear -- the new Nowack exhaust system just uses wider version of the four-pipe outlet set-up in the standard car (ie: very wide)
· Optimisation of the engine software. According to Oliver Nowack, this is where the real power uplift comes from. The mechanical work just makes the engine more efficient so it is capable of taking the increased demands from the software upgrade that Nowack install. As part of the software upgrade Nowack remove the 155 MPH limited and increase the rev limit from 7,200 rpm to 7,700 rpm. Nowack reckon that once they have worked on the engine it could happily go to 8,000 rpm or more, but to maximise engine life they put the limit at 7,700 rpm. The uprated rev limit and removal of BMW speed limit means that the N-500 maximum speed is 198 MPH (apparently verified by a German car magazine -- see the Nowack website). Note that the "sport" button still works, but just turns the engine response and power delivery from "mad" to "insane".
Sports clutch (700 Nm capable): £610 or US$890
No idea which external supplier this comes from.
19" wheels + Yokohama AVS Sport tyres: £4,525 or US$6,560
The Nowack light alloy wheels are in fact BBS supplied -- they do look good though.
Nowack Break system: £6,510 or US$9,440
This is a Porsche break system adapted by Nowack for the M5, including Stahlflex hoses.
· The front system is said to be from the Porsche 911 GT2. They are 380 x 32 mm doubled vented, cross-drilled discs with four-pot callipers. I must say, I thought the new GT2 had carbon brake discs and the new ones on my car are steel -- it could be these discs are from the 993 model as opposed to the 996.
· The rear system is from the 993 version Porsche 911 Turbo. They are 322 x 28 mm double vented, cross-drilled discs with four pot callipers.
As I mention later, the decision to use brakes is a good one ? they are a material improvements and they look good in my opinion. On an aesthetic note, the BBS alloys and red Porsche break callipers (branded Porsche) are a lot more dramatic than the standard set-up. I like it, but it might not be to everyone's taste.
Suspension kit: £1,870 or US$2,710
No idea where this comes from as I didn't go for it.
Anti-roll kit: £620 or US$900
Nowack use Eibach front and rear
Nowack 200 MPH Speedo and 8,000 RPM tacho: £1,040 or US$1,500
These look exactly the same as the standard M5, but given the increase in rev limit and maximum speed, they go up to 200 mph and 8,000 rpm respectively. The rev counter has the multi-stage oil temperature indicators from 4,000 rpm as in the standard M5, but the red marker only kicks in at 7,500-8,000 rpm . Back lit in same orange colour.
I live in central London and 50%+ of my driving is in and around the city. Given bad (and rapidly deteriorating) road surfaces I decided not to go for the suspension package since I like the standard set-up and it copes well in London. Any harder and the ride for much of my life would be intolerable. So, at this stage,
· Total cost is looking to be £26,135, or US$37,900.
However, this price excludes German VAT. If you have your own company clearly you can claim this back, but I don't and so I had to add German VAT at 16% to this price. Thus,
· New total cost is now £30,316 or as near as dammit US$44,000
Swallowing hard, I took a deep breath and confirmed the order with Nowack. With no wife and no kids at this stage, it might be the last time in my life I can pour so much money into a project like this. Nowack ask you to wire to them a 50% deposit, in theory for them to start buying parts and getting parts made ahead of you delivering your car to them. Given my experience of time delays, I'm not convinced about this, but there we go. The point is, you better have a large chunk of the money ready right from the word go.
My experiences -- listed below -- have caused me to see Nowack as a group of enthusiasts, but customer service is not always their forte (and, as I will explain later, neither is quality of workmanship, attention to detail, or "finish" -- all important things given that a full conversion costs about $50,000). They are not very good at calling to keep people up to date with what is going on ? in fact communication is not a strong point. I have found them reasonably easy to get hold of when you call ,but other BMWM5.com members have really struggled to get anything out of them at all.
At Nowack/ Early days
So, I took my car to Nowack on September 15th, 2001. When I delivered my car, we put in on the Nowack Dynojet dyno. Given the details of past threads on the BMWM5.com website about dyno testing, I must say that I didn't look at exactly what the guys did (ie: gear used, etc.), but the printout suggested my car in standard form was producing 388 BHP at the engine level and 351 BHP on the road. Subsequent tests confirmed this as well. It is true that Nowack test to the rev limiter when they dyno a car -- if this adds anything to the dyno debate. Nowack told me that they have seen standard cars with "engine level" BHP outputs of anything from 375 to 405. It seems as though BMW's 400 BHP claim is met, say, 20% of the time.
Also while there I tested Nowack's N-500 tuned Z8 on a local autobahn. The car only had the engine upgrade in it, but given the acceleration from 200 to 300 KPH that I experienced (truly phenomenal), the claim of 500 BHP seems all very credible to me (although I accept that the Z8 is a lighter car). The sound was also quite awesome as well. So, I flew home later on the 15th having driven the Z8 and thinking that what I was doing was a great idea. On their website Nowack say that the upgrade takes 2-3 weeks. What I spoke to them they suggested that in fact it would be 3-4 weeks. I booked a 2 week holiday from work spanning weeks 3 to 5 after initial delivery to Nowack, planning that at some point over my break the car would be ready and thus I could pick it up and have a blast around Europe before returning to work (driving in the UK nowadays is a waste of time unless you drive 100+ miles out of London at about 3am in the morning).
Problem 1: The engine block
Sometime during week three I was called by Nowack to be told that they had dismantled my engine to discover that the inside of the cylinders of my engine block were badly scratched. I was told that Nowack find that some 20-25% of the engine blocks they see have this problem (other BMWM5. com users have been told the same thing). Apparently it is mostly to do with the way the engine is set up by BMW, although it was also suggested at one point that I had not run the engine in properly. That said, in a conversation with one of Nowack's engineers I was told that they have seen a new M5 with delivery mileage on it, which also has this problem. Apparently the cylinder scratching is not a disaster in the standard M5 -- it probably reduces power output a little, reduces engine life a little and, in the early life of the engine, might well lead to increased oil consumption. However, given that the real power gain comes from Nowack tuning the engine's ECU's to work the mechanics harder, the mechanics have to be optimal. Nowack cannot / will not tune an M5 with badly scratched cylinders.
I was told that the only solution to this problem is to buy a new engine block (which comes with new crankshaft and pistons). Total price to you and me a cool DM10,000 (£3,140, or US$4,550). Now, I faced a dilemma -- my engine is in pieces and I'm now told that unless I come up with another DM10,000, I'm screwed. Turning a slighter paler shade of white, I agreed to pay DM10,000, plus 16% German VAT. The annoying thing here is that I have no ability to check whether this is true or not, and to be honest I have no idea whether I have just been conned out of DM10,000 or not.
Total cost of project now looking to be: £33,960, or US$49,280 (ignoring flights to and from UK, etc. etc.)
Nowack tell me that they should be able to get a new engine block from BMW in a week or so, so they could well have my car ready by the end of week five. My holiday plans are looking shredded, but I might just get a few days blast at the end.........but no. I didn't hear anything from Nowack until I was back at work in week six, when they called me to tell me the engine block had arrived (that's 2.5 weeks later, not quite the five days I was told it would take) and that they can start work of my car. Oh good, I thought, you now can now start my car some six weeks after I delivered it to you. They hoped to have it ready by the end of week six, but.......
Problem 2: The brakes
During week six I got a call telling me that Nowack have now got the engine up and running, and have installed the Porsche brakes (apparently 996 model 911 GT2 discs up front and 993 model 911 Turbo discs on back) . However, when testing the brakes they found that one of the front GT2 callipers was leaking a little. They could replace this free on guarantee, but given that it was a specialist part from Porsche Racing, not standard Porsche, it would take another week to arrive. The end of week six passes and we enter week seven. I got a call to tell me the brakes had arrived and the car might well be ready for the end of week seven.
I work from 7am to 7pm+ and find it difficult to get away from work during the week, so I can only collect the car on Saturdays -- I told Nowack I hoped the car would be ready by the end of week seven, because if not I wouldn't be able to pick it up until the end of week eight (that's Saturday 10th November). Low and behold the car would be ready in early week eight. By now I'm not surprised, and arrange to fly to Dusseldorf on Friday 9th, stay overnight in the airport Sheraton hotel (which is 50 yards walk from the front of the international arrivals part of the hotel -- not a wonderful hotel but if you need to fly to see Nowack, cheap and easy to stay in.)
Problem 3: Insurance
My M5 was initially insured through AXA Insurance. Before I embarked on this project, I checked with my car insurance agent whether my insurance costs would go up very much. I did not tell them exactly what was being done, but did tell them the power hike, the type of work being done, etc. They came back saying that they had spoken with AXA Insurance and that while they would need to see the details of the work, in principal it would not cause too much of a problem. This surprised me, but I let it lie. I faxed through the details of the Nowack upgrade sometime in week six and heard nothing. I thought about this as week eight was drawing to a close and so called my insurance agent, who claimed not to have received the fax I sent (I have the confirmation that it went through OK, but anyway.....). I re-sent the list of work and 20 minutes later I was called back saying that AXA could no longer insure me because they won't insure modified cars.
Given that I thought I was collecting my car in about 48 hours, I had a panic, bought every car magazine I could find and called all of the so-called specialist sports and performance are insurers. Every single one said that they did insure tuned cars, but when I told them the details of the Nowack upgrade, they all came back saying it was
1. "too heavily modified"
2. "not in Central London"
3. "what, it?s a tuned car painted black? Oh, we don't insure those...." (OK this last one didn't happen)
I don't know what it's like in the US, but if you have an M5 and live in London, think long and hard about having it modified. I was getting rejected for insurance even before I mentioned my speeding conviction (28 day ban for 115 MPH). It might just be the current insurance environment post September 11th, but I was finding my car was going to be very nearly uninsurable. I eventually tracked down a company that actually know who Nowack are, knew what I was talking about and were happy to insure me (despite ban). The one stipulation was that the car has to be garaged overnight (previously I parked on the street) and the cost is going to be a somewhat hefty £4,226 per year. Given that I was paying £1,850 per year including parking it on the street overnight in Central London pre-modification, this is a more than 2x increase in cost and with a harder stipulation. Beggars can't be choosers (I couldn?t ask Nowack to restore the car to the way it was before), but this was getting ridiculous (and it took some time and cost to find a garage locally).......
Problem 4: ECU compatibility
Anyway, insurance once again secured, I called Nowack in week eight and was told the car was totally finished and would be ready for me to pick up on Saturday 10th November. Tests had been done and all was ready. I flew out Friday night and the next morning I was picked up and taken to Nowack?s garage in Kamp Lintfort, near Dusseldorf. We arrived at Nowack and I was shown to my car, which was connected up to Nowack's BMW diagnostics computer, which I thought was not a good sign. I was told that they were just downloading some software changes to correct a couple of glitches seen on test -- putting in 2001 software into my 1999 car to bring it up to date, etc. This, I was told would take an hour. We could then put the car back on the dyno -- test to show the increased power, have a test drive and then I could go home (I had already paid the second and final payment to Nowack by this time. They will not release the car without it, but it does mean that at that time they had my car and my money -- I had nothing but high blood pressure).
The hour passed and another came and went. After much dithering, secret huddles in German (which I don't speak) etc. etc. I was eventually told that in fact there was a problem with the EWS computer. This, apparently, controls the security in the car, in that it talks to all the other ECUs and, if they are not set up in the way the EWS expects (ie: they've been tampered with), the EWS just shuts the engine down. The EWS apparently didn't like the way my car was set up and was shutting it down immediately after the ignition caught. They didn't know why this was happening and all looked mightily confused. Quite frankly I don't pretend to understand this, but it strikes me that if you know anything about modifying BMWs, you would learn very early on all the problems with dealing with the EWS system -- by definition it is not going to like what you are doing. Also, how come the car was (supposedly) working on Friday when it was tested? Given the track record here, I took the explanation given to me with a large pinch of salt, but I am totally screwed because I'm not an engine management computer specialist.
The long and the short of it -- Nowack bought me a plane ticket back to London. I got back on the night of November 10th with no money, no car and no idea what's wrong with car.
Problems 5 and 6: Steering/Engine vibration
I was called in the middle of week nine to be told that Nowack had taken my car to a local BMW dealer, which has a better (more up to date) diagnostic computer system than they do. They discovered that apparently my EWS and one of the central ECUs were totally shot and thus they needed to get new ones. This would not take any added cost from me, as they could be got on guarantee. To be fair, the new EWS and ECU chips were acquired by the Thursday of the same week and installed by the Thursday night. Nowack got my car running and I arranged to pick it up on the Saturday (17th November) after they spent the day testing it on Friday.
Long and the short of it is I got there, we put in on the dyno and it read 498 BHP at the engine level and 452 BHP ?on the road? after transmission inefficiencies. Nowack explained that on a static dyno you don?t get the ram-air effect ? with it, the BHP would increase to 503 BHP or a fraction more. Hard to prove, but I was pretty happy with a 100 BHP hike in ?on the road? power. So we took the car out, and I have to tell you it is quite phenomenal when it gets going ? you can?t help but smile. Engine noise is fabulous. Brake feel was not too great and they were initially no better than standard. They do need to get up to working temperature though, and when they did they were strong. Also worth noting that Nowack say you need to be gentle with them for the first 1000 Km to ?run them in?.
I?m happy for about 10 minutes.
Next problem is that the steering would suddenly harden up badly, like if you put on a double-strength ?Sport? button steering setting. Is wasn?t pressing any buttons, it was just suddenly hardening up and then letting go as you drove along ? worrying.
We carried on and this is when the next major glitch hit. As a pulled hard up through about 6,500 RPM (c120-130 MPH in fifth) the engine suddenly lost power and felt worse than pre-modification. We pulled off the autobahn and turned the engine off. When we turned in back on, all was normal and we drove again. Hit 6,500 RPM and same problem. Clearly not mechanical, but electronic again, since it kept re-setting itself when I turned the engine off for more than 10 seconds.
Anyway, long and short of it is I returned car to Nowack. They immediately started tests, and fairly quickly found that the car was losing power because at 6,500 RPM the computer was shutting the eighth cylinder down to protect it from excess vibration. They didn?t know why this was because no other ECU was registering problems with vibration or with the eighth cylinder. I stayed, saying to them that I was not leaving until my car was fixed. At about 7pm (I had returned after the failed test at about 1pm and had been sitting around for 6 or so hours) they took me to a hotel and put me up. Went back the following morning and while they had found the steering software glitch, they had to admit defeat on why the engine was shutting the eight cylinder down and buy me another ticket to return to London for a second time without my car.
Two weeks after that, (ie: near the end of week twelve) they called me to say that another new engine block had been delivered and that they would work on it over that weekend to make sure the car was ready for the middle of the week of week thirteen. They will then test it for two days solid and let me pick it up the following Saturday (about the 12th of December, or something like that). I asked why the car needed another (third !) engine block, and was told it was because the vibrations in the eighth cylinder were caused by a slight fault in the block. They had tested all the electronics, software, etc. and it was all-fine.
I sent back an e-mail saying that I wanted A car back before Xmas. Either they were doing to get my car ready for me, working perfectly (I will fly to Germany to test it again) or they are going to buy me a new (unmodified) M5 and give me my money back.
Finally, picking the car up, and first impressions
Well good news comes to those who wait, as they say. I didn't hear anything for a few days, but ....... I did at last get my Christmas present a few days early, in that Nowack called me on the 14th or 15th December to say that the car was ready. I picked it up on the Monday the 17th -- only just before Xmas, but at least they did deliver.
First impressions are that the engine is everything I remembered on the Z8 -- great sound, huge pulling power from 2,000 RPM or less and phenomenal performance when the sport button is in, particularly in the 4-6,000 RPM range. I drove back from Germany with a huge grin !!! On reflection, the Porsche brakes are a noticeable improvement (when they get warm) -- I had a shock when I first tried driving it back in the UK and tried the brake at a set of lights -- those babies REALLY need to warm up before they perform, but when they do, they are very strong -- great feel, lots of initial bite, but also progressive grip and fade free (I tested the latter on the way back from Germany....)
However, all is not 100% wonderful......
The main problem relates to an issue I mentioned before -- the engine shutting down the 8th cylinder as a result of it triggering the "knocking" (vibration) sensor. As part of my problems, I was on my third engine block and also now using 2002 model software. Apparently, as part of the changes made to the 2002 model BMW have made some changes to make the engine run smoother at 3,000-5,000 RPM (cruising revs in 5th and 6th gear). This has reportedly led to a change to the knocking sensor to make it more sensitive at certain RPM levels. Guess what -- the work that Nowack do means that at very high revs under heavy loads the knocking sensor is triggered every now and then. They semi-fixed my problem, but they have sent me away with a car which will run into this "closing down a cylinder" problem every now and then (it's happened once since in the UK when I was deliberately pushing to see if it still triggered).
As I'll explain later, my car is now with my local dealer, and their master technician thought that this explanation sounded like bullsh#t. He did find that Nowack had deliberately shut the knocking sensor down permanently to try to avoid the problem. Not exactly a high class solution (and it doesn't always do the trick anyway, suggesting Nowack's diagnosis is wrong), but at least I've got my car back from Germany......
However, this problem basically renders the car "neutered" in track conditions, because you can never really push it for fear of having to stop to reset the engine after a cylinder has closed down !! I don't do much track time, but this is bl##dy annoying. Nowack are working at a fix and hope to have one in 3-6 months, which they will then install in my car for free, but that's more time in Germany, more expense, etc........
Other issues relate to the quality of the "ancillary" work done by Nowack:
1. After getting the car back, the steering wheel controls (buttons) lost power. Nothing worked (including horn, which is illegal) and the airbag warning light came on to show that it is not working either. Probably just a fuse gone, I thought but annoying (and in fact worse than this).
2. There was a new rattle in the dashboard where something is clearly loose after they installed the new speedo/ revcounter set-up.
3. They did some work on the wing mirrors for me, but ended up leaving them rather loose and not working properly (the fold-up function did not work)
4. The on-board computer wouldn?t set up properly.
So, I booked the car into my local BMW dealer: Milcars in North London. Just before I took the car in the front bumper got cracked a little as well, so it definitely needed to go in (I?m just not having any luck with this car !).
The more I learn, the worse my view of Nowack
As I write this, my car has been at Milcars for two weeks now and their master technician is trying to figure out all the stuff that Nowack have done. The good news is that he has fixed the steering wheel (a small part had failed), but he has found a whole load of new interesting stuff:
1. All of the airbags had a major fault and the software controlling them was trashed. He has downloaded the software and taken out all these faults (he showed my the diagnostic computer printouts to prove his point)
2. The on-board computer software was also dodgy and he reprogrammed that.
3. Where Nowack had done some work on the wing mirrors, the inside of the door panels was filthy and the box/ECU in the drivers side door was faulty, hence the problem there ?. and Nowack had wired up one of the mirrors incorrectly as well. This has now all been fixed.
4. Some wires/sockets were loose in the dashboard and this was causing my rattles. They had not been put back correctly.
But the worst is yet to come ??. The head tech guy at Milcars was interested in what Nowack had done to the engine, so he had a look around and found:
1. The undertray under the engine had not been reattached properly, it had been put back with small plastic rivets, not screwed properly. He described this as a "really sloppy" job.
2. Head shields on one side of engine were not reattached properly and were being held away from the engine by having steel wire wrapped around and around the shield and a nearby piece of bodywork ? a real ?cowboy? job.
3. Nowack look to have damaged some parts of the front bodywork when putting in the air ducts in the front of the car. This might have been done when the front bumper was cracked, but my dealer doesn?t think so.
4. Finally, the hoses that carry oil from the engine block out to the radiator and back were not attached to the engine properly. They were both very slightly in the block at an angle, and because the oil is under pressure the car had been ?pi$$ing? oil ever since I picked it up. I wandered about the rate of oil use, but to be fair when I got the standard car a couple of years ago it ?ate? oil for the first 5-7,000 miles and then settled down.
The undertray under the engine was covered in oil and it had sprayed around the engine onto most other parts on the left hand side of the engine bay ? really dangerous. The guy at Milcars said that in time the hoses could eventually have sprung loose and then dumped about 8-10 litres of oil all over the engine bay and front brake discs in the space of about 5 seconds. They had one guy in an M3 who had this problem after he had had his car modified and his car was written off as one of the hoses came lose on a motorway at 80+ MPH. He is fine now, but had a bit of a stay in hospital !! This was downright dangerous. These hoses are unique to the M5 (they are extra strong) and my dealer is now waiting for a new set (plus fixings) to be sent over from Germany.
I?m kind of lucky that there were other problems so I?d taken my car in, otherwise I might not have spotted this until too late ??!! I?m really REALLY pissed at Nowack now. This is not just a money thing any more, it was so slapdash as to put my life in danger.
I now know that I never should have taken the car to Nowack and I feel as though I?ve wasted the best part of $50,000 (or more, once I get the bill from my local BMW dealer). Yep, the tuning has been done, I?ve seen the dyno readout reach 498 BHP right in front of my eyes, so I know they have done what they?ve promised to do, but at what cost to my car ? What else has they damaged? There might be loads of stuff that will only come to light in time (hopefully not at the expense of my health or life).
Anyway, all the others problems (and the front bumper) are now fixed and my dealer reckons to get the hoses from Germany later this week coming, so I hope to get my car back late this week (1st/2nd of Feb). I?ll just have to see how big that bill is??..
As a final comment, I must say I have been surprised how much just changing the profile of the tyres has impacted the quality of the ride. I have not had the suspension changes made (only the Eibach anti-role-bars) but got the 19" BBS wheels and lower profile tyres installed to fit the new brakes. The turn-in on cornering is definitely improved and the car has lost that "on-centre wooliness" of steering which I ran into (a problem of recirculating ball steering set-up) -- it is very direct and stable steering now in all conditions. HOWEVER, the cost of this is much increased road-noise (surprisingly more), greatly increased sensitivity to road surface quality and a harsher ride generally. It's not unbearable, but the impact is much more than I had anticipated. Given that the quality of roads around where I live is not great (the whole in London is mostly [email protected]
, to be honest), this is a bit of an issue (particularly combined with my dashboard rattle at the moment....)
So, what are my thoughts having done about 1,500 miles since getting the car back (a lot of driving around the UK over the holiday period)? To be fair, part of the problem is that the temperature in the UK didn?t get much over 5 degrees C over the period between my picking the car up in Germany and my dropping it off at my dealer in London on 15th January. Much of the driving I was doing was when it was either freezing or only just above freezing and with lots of ice around. So, I've not really been able to "boot" it, but.....when the road conditions are right it is a huge improvement over the stock car and a lot of fun. Even just using 3000-5000 RPM shows the changes made by Nowack easily and it does move !
However, this said, given
1. the residual problems (one of which -- the knocking sensor issue -- might well be "unsolvable"),
2. the harsher than expected ride,
3. the newly discovered low quality of workmanship
means that I'm nursing a bit of a "what on earth have I done?" feeling still. I regard this as a costly lesson in life, and I will most certainly not be getting any other car I ever buy modified in any meaningful way. Maybe when I get the car back from BMW with the residual "niggles" sorted and then when we get better weather for me to use the car's full performance more my attitude will change, but I don't know yet.