My Alpina Roadster S (supercharger conversion @ ESS)

[DHK]

fun pictures!
Beautiful car!

[Dreamer]

I love those seats! If i still have mine a a couple of years and i haven't found some M seats on ebay ( ) they are a must!

[Topshelf]

Hey Femme, beautiful car! I'm new to the Z4 world, picked up an '06 SI Coupe a few weeks back and am loving it. But I have to ask you a question about that rear diffuser setup which I am just totally in love with. I would just love to do this mod, but it looks like you had to cut both the diffuser and the bumper for the dual exhaust outlet, is that correct? If so, was cutting the diffuser a difficult job? If there's one cosmetic mod I think the Non-M's need, it's a dual exhaust setup, and this looks even better than the M version. I so need to do this, so any info would be appreciated.

[Wondermike]

Topshelf, the carbon diffuser is a BMW aerokit part for the facelift bumper, which would fit your car OK, and the dealer could do for you, although maybe the cut-outs would be more awkward. So just the 4 pipes to sort, which is probably best done the same way as here witha custom exhaust.

[ZetaTre]

Why is the engine Single-VANOS?

[Topshelf]

Thanks for the help Mike. Just need to clear 2 things up. I know it's a BMW diffuser, and I found out I can order that through a few BMW parts sites for cheaper than it would be from the dealer. Cool! I also see how that second set of pipes is run and it does seem like the simplest solution...just need to find an exhaust shop with a little skill and some nice chrome tips for all 4 pipes. Doesn't seem too bad. So then that only leaves 2 questions...

1) If I had an exhaust shop weld a pipe into my muffler like that, I'd have to assume that would void some warranty there, no?

2) Cutting of the diffuser still has me a little confused. I'm sure the bumper isn't as bad since it will be covered by the diffuser, so if it's not perfect, nobody will ever know. But if you look at this pic Femme posted, you can see that the OEM cutout is trimmed out if you know what I mean. Cutting the matching opening will obviously not have that detail. Is that something you can notice? Or is it so low that you would need to be under the car to pick that up? I'm guessing I should really have a professional make that cut if possible? I can't get over how nice that cleans up the tail end of this car.

[Topshelf]

Pic of single diffuser opening...Notice how nice the factory opening is trimmed?


Pic of dual diffuser opening.

[Wondermike]

Topshelf, I see what you mean now about the opening in the diffuser being trimmed. I don't think you'd notice unless you were down really low, I suppose the best way would be to get large pipes to make sure the hole was "filled".

With the backbox, yep you'd void the warranty on that part for tapping into it, but it's got to be the easiest solution rather than trying to accommodate another muffler or something like that under the car.

[Wondermike]

Why is the engine Single-VANOS?

Curtis will be along soon and tell you for definite, but I believe the engine actually dates back to the S50 engine used in the E36 M3, bored out a bit and updated obviously, and no doubt loads of other things too, but I think it's base is that engine.

[Curtis]

Your quite right, the basic engine was E36 based, it's the S52B32 (E36 M3 US; grey cast iron crankcase version) to be exact, however the block, crank, pistons, rods, head etc all have unique Alpina part numbers so they are not standard "off the shelf" BMW parts. I think the extra capacity came from the use of a longer throw crankshaft more than anything but I could be wrong, the cylinder bore is 87.00mm but I don't know how that compares to the E36 M3. Alpina say they used the single Vanos purely for reliability.

[Topshelf]

Thanks Mike. I agree that following Femme's pipe technique is the best bet. I'm not really looking for performance here, just aesthetics. So that setup is completely fine for my needs. I'm going to see if I can find someone local who could do the cut in that diffuser properly. Hate to ruin a $600 part. But I'm going to save these pics today so I have something to reference. What a superb mod to the Z this is!

[ZetaTre]

Why is the engine Single-VANOS?

Curtis will be along soon and tell you for definite, but I believe the engine actually dates back to the S50 engine used in the E36 M3, bored out a bit and updated obviously, and no doubt loads of other things too, but I think it's base is that engine.

Your quite right, the basic engine was E36 based, it's the S52B32 (E36 M3 US; grey cast iron crankcase version) to be exact, however the block, crank, pistons, rods, head etc all have unique Alpina part numbers so they are not standard "off the shelf" BMW parts. I think the extra capacity came from the use of a longer throw crankshaft more than anything but I could be wrong, the cylinder bore is 87.00mm but I don't know how that compares to the E36 M3. Alpina say they used the single Vanos purely for reliability.

Thank you guys.

[FemmeT]

2) Cutting of the diffuser still has me a little confused. I'm sure the bumper isn't as bad since it will be covered by the diffuser, so if it's not perfect, nobody will ever know. But if you look at this pic Femme posted, you can see that the OEM cutout is trimmed out if you know what I mean. Cutting the matching opening will obviously not have that detail. Is that something you can notice? Or is it so low that you would need to be under the car to pick that up? I'm guessing I should really have a professional make that cut if possible? I can't get over how nice that cleans up the tail end of this car.

The cutout is completely filled with the exhaust pipes and very low to the ground. You can't see it unless you're lying on the ground.

All of the work has been done professionally by a local workshop. They like a little challenge and don't step back for cutting holes, molding things, etc. . I don't know how difficult cutting the carbon fibre is. It won't be easy to get a perfectly sharp cutout, so it's best to repaint the diffuser like I did.

There is not enough space underneath the right side of the car to locate a second muffler unless you remove the battery compartment, which will be a lot of work and will mean you will lose valuable trunk space.

I also liked the sound of the Alpina exhaust and only wanted subtle improvements of the sound.

[Topshelf]

Thanks for the update Femme. I didn't realize you had the diffuser repainted after being cut. I'm going to have to get some estimates for the work, but I really love the way it came out.

Did you happen to research a diffuser for the M? Wonder if there's already one that has dual cutouts that would just fit right onto our bumper once cutting out the second exhaust opening.

Thanks again for the info, and your car is just awesome!

[FemmeT]

Exciting times ahead: my car is finally in Norway for a supercharger conversion at ESS Tuning. Here's a part of my post on E46Fanatics.com:

One of the downsides of having an Alpina is the non existence of off the shelf engine upgrades. Thanks to its resemblance to the M52 and M54 engines it should e possible to fit a supercharger for this type of engines with only minor physical modifications. I have been wanting the ESS twinscrew the moment I read about its existence. After several attempts to schedule a custom conversion in Norway, which failed because the shop doing all the mods on my car was taking much longer than planned, I was finally ready to deliver the car to ESS on the 6th of October.

Because it was a 1250 km drive to Norway I decided it was the best way to spread the journey over two days and to leave for Puttgarden, where a ferry leaves to Denmark, on saturday evening. I washed the car, packed my stuff and left for the 500km drive at 19.00h. The weather conditions were perfect with no rain so there would be no trouble driving high speeds on the Autobahn. I had a TomTom navigation device at hand as a backup and to accurately measure real speeds. I have driven it many times on top speed before but I never measured the actual speed. The car accelerated easily to 260km/h. After several tries I managed a top speed of exactly 270km/h, which made me happy because the official top speed is 265km/h with soft top and 270km/h with hard top according to Alpina.



Ready to leave:



First pit stop:



That's me with my new toy :



After four hours I arrived at the hotel, averaging a speed of 146km/h. Not bad since about one fifth of the route was off the Autobahn and there were also several lengthy construction works with speed limits of 60-80km/h. Obviously driving this hard was not good for fuel economy, which averaged 16,4l/100km.

The next day it was raining. I only had to wait five minutes to get on the ferry. After 45 minutes I arrived in Denmark at 12.00h and started to drive all way up to Norway through Sweden, which wasn't all that exciting because of the bad weather and low speed limits of 110-120km/h. Eventually I reached the city of Halden at 20.00h. From there on it would be about 30km to ESS the next day.



Queued up for the ferry:







Leaving Germany:



Somewhere in Sweden close to the Norwegian border:







On monday morning the weather had turned around to beautiful blue skies. ESS is located in the rural area of Aremark. I knew finding their shop was going to be a little challenging because the streets had no names in this area. Instead they use the name of the property as the address are something like that. Google Maps, TomTom and the MK4 nav have no idea how to deal with that. I asked for instructions at a nearby petrol station and the guy behind the counter instantly recognized what I was doing there even before I mentioned the name ESS . The scenery and roads where incredibly beautiful with the autumn coloured trees and lakes everywhere. They should consider changing some of the roads into a one way toll road with no speed limits and call it the Aremarkring . Following the map which I bought the petrol station and with the help of Hans I eventually found the ESS site, which was near a big country house. Hans was not there and Asbjorn was in the US. I had a talk with someone who looked like the gardener and had a look around the countryside. After 20 minutes someone arrived who did assembly work. He showed me around and I got to see all the beautiful pieces of the twinscrew kit. There were several interesting cars inside, one of them an E30 with M5 V8 and a new M3 with some missing parts under the hood.







There was also a dog but it was naturally aspirated and the only mod looked like a restrictor on the dog's air intake:

















I was given the keys to a VW Caddy so I could catch the train from Halden to the Oslo airport where my flight would leave at 18.00h. It's a strange feeling to leave your beloved car 1200km from home . The Norwegian trains were comfortable and clean and Oslo has a very nice airport. I arrived in Amsterdam, took the train home and got there at 22.30h.





I called Hans yesterday and he had already been working on the car. There was some issue with the fuel rail but he did not expect a lot of trouble getting the other parts to fit on the Alpina engine. When everything turns out well the car should be ready in two weeks.