Roundelian Article: Dinan Z4

The Roundelian has featured an article written by our very own BMW Sales Manager, Nick Drum. Check out the article below for some really great info and insight into the build of this ultimate machine. Also, at the end of the article Nick Drum mentions the idea of a X1 M... Could this be the next build in the pipeline? Stay tuned for updates!

Maybe it’s my age or looking at the past through the proverbial "rose colored glasses”, but I fondly remember a day when you could jump in your car and, if the plan was to go have some fun, it didn't look like pre-­flight checkout in an F-­14 to get started. I also recall when the mere suggestion of a BMW/Toyota joint venture, as apparently there will be soon, was laughable. Other than that whole WWII thing, when, especially when it came to building cars, did the Germans and Japanese have anything in common? I know it's an age of technology, joint ventures and world markets but do we really want the DNA of the cars we love mixed with that of the Prius?
This joint venture news had me thinking about Z4’s again but in a different light. I had already been wondering why BMW didn't make more of its current winning ways in the GT3 and GTLM classes in their marketing. Granted it's an old car in a lot of ways and we don't sell many, but it's still part of the product line, a BMW and a pretty good car. There never was an M version. An is was as close as you could come but the cost/performance ratio wasn't really competitive with other cars in the same segment. It seems like BMW gave up on the Z4 and now, whatever the new Z4 is, it is also going to be a Supra.
Last year we partnered with Dinan Engineering in a couple of ways, essentially becoming each other’s customers. We've had a lot of fun building our own version of an M2 a couple of times, upgrading Alpina B6’s, building 550’s into AWD M5 chasers, and it occurred to me one day,
“Why don’t we see what an E89 Z4 is capable of? If BMW won’t do it then we will!”
— Nick Drum
We first reached out to Dinan and were a little surprised to learn the Z4 was never really very popular with tuners and their upgrades were fairly limited.  They were able to provide software, an intercooler that was twice the size of the stock unit and an external oil cooler.  All of the components are really beautifully built and look as if they have always been there. 
The remainder of the engine upgrades were a little tougher to find.  We sourced a Supersprint exhaust system from Italy, that took a while.
We also freed up airflow on the intake side with components from K&N amongst other brands.  It took a lot of work to improve the rest of the drive train.  The 7-speed DCT fitted to these cars is harder to get into than Fort Knox and the working parameters in a number of areas cannot be changed.  This led us to having a special torque sensing limited slip rear diff built that makes the most of the new power and torque.  The remainder of the upgrades included Michelin Pilot Super Sport tires fitted to 19" O.Z. wheels.  The car was lowered slightly with Eibach springs and Bilstein sport shocks and a polished aluminum Turner Motorsports strut brace helps keep the alignment where it should be.  There were several other tweaks but we need to keep a few things to ourselves.

Check out the pics below for some shots of the build process.

On the outside we did a little re-styling by painting the mirrors, side markers and roll bar covers black, installing black grilles and de-badging the car. We also did a little re-styling to the lower front bumper for both function and aesthetics.  Like most project cars, what I've described here is only an outline of the hours of planning, searching and working that were required to put it together and make it work.
So what is it now?  After approximately 300 miles of test (not abuse) driving I am happy to report the following.  On cold start, in traffic, cruising down the highway or any other normal situation the car runs and performs as well as if not better than a stock 35i.  On the performance side of things we now have a car that will arrive at 60 MPH in roughly 4 seconds flat (it's difficult to get accurate measurements without the proper equipment).  What is not difficult to do is out accelerate a 2015 M4 DCT to 100 MPH.  Okay, that's an overstatement, it is difficult, but it will do it regularly if not every time.  The car rides great. The sound, which does not come through the speakers, is very mellow. When it's time to get serious all you really need to do is flip the shifter into Sport and you're ready.  It is a car that is simultaneously advanced and simple.  It is really fast, but not obnoxious.  It's stylish, but subtle and now that the recipe has been perfected we can build them until we run out of E89 Z4s with N54 engines.
This project is one example of fun and reward with the Isringhausen family, which makes it a pleasure to go to work every day. Even though the last X1 3.5 has been built, I wonder what an X1 M would have been like...