So far we've transformed the exterior of the coupe to a 100% stock appearance and the interior with a clean and functional hatch. It's dramatically safer with brand new rotors and pads and the engine is healthy with new fluids and fully functioning oil lines. The final step in the process is to clean up the final exterior details, test how powerful the supercharger really is, and find this coupe a new loving home.
As I mentioned in the first article, the wheels were in pretty rough shape when I first took possession of the car. So, while I had the coupe on the jack, I removed the dirty pitting chrome roadstars to get them freshened up. I brought them to a tire shop to remove the tires, and then had them looked at by a local powder coating shop to discuss pricing. They informed me that the chrome would need to be removed before they could do any powder coating, and that they did NOT remove chrome (emphasis theirs).
I asked if they knew anyone that removed chrome, and they surprisingly didn't have anywhere to point me. Odd, considering how many chrome wheels they must see. Anyway, I found an industrial de-plating place in San Jose called San Jose Valley Plating. They quoted me $50/wheel and a 4 day lead time. It sounded kind of steep, but when I let the powder coaters knew they'd be working with bare aluminum, they lowered their price so it would work out to about the same cost as I was originally quoted just for the powder coating.
Four days and $200 later, I had four pristine aluminum roadstars! The bare aluminum was sort of soft to the touch with a bright white color. No bends, cracks or rash to worry about...these were going to look awesome.
On a tip from Eric, I dropped them off with RMS Powdercoating in San Jose right after picking them up from the plating company. I let them know that I wanted to get as close to OEM Hypersilver as possible, and we settled on a light chrome color with a clear coat finish. I was skeptical after just looking at color swatches, but he assured me it would be a close match to Hypersilver. Just a few days later, I got the call that the wheels were done.
It was a match!
I got the tires back on the wheels and had everything mounted back on the car. It looked phenomenal! I sent some quick photos over to Jon and he was blown away by how good of a match this was to Hypersilver. Success!
With the wheels back to perfect condition, it was time to focus on the body panels. I called Chris from Diablo Dents to come take a look at the two small dents in the coupe. The passenger side rear quarter panel dent came out with no problem, but the dent between the kidney grills took some work. That thin strip of metal is bent so easily, but if you overcorrect and bow it out too far, the hood might never look right again. He worked carefully with light taps from a rubber mallet, and a handful of other leverage tools. Before too long, the spot was smoothed out and the stock kidney grills snapped into place with all tabs fitting perfectly.
Aside from some minor rock chips on the front bumper, the Arctic Silver paint on this coupe was in fine shape. It was slightly rough to the touch, though, so after a thorough soapy wash, I used a Meguiar's white clay bar on the roof, hood, rear wheel flares and rear bumper. Any flat, horizontal surface where air particles can land on the car can cause small dirt particles to stick to the surface. It's amazing the before and after feeling of claying a car. It felt like fine sandpaper before and like glass after.
The only remaining item was adding the "M" Motorsport badges to each of the freshly powdercoated wheels, and once they were secured the project coupe was finished!
Before we could accurately list the car for sale, we needed to verify exactly how much power this supercharged S52 was putting out. To do this, I searched the Bay Area for shops offering dyno testing. It was more difficult than I thought to find one, let along align our calendars to get an appointment scheduled. I finally came across a place in San Jose called Dynospot Racing that was willing to offer unlimited runs on the dyno and provide all the collected data for a flat fee. I scheduled an appointment for the following week. I tried to get some other local coupe owners to join for a dyno day, but with such short notice I only managed to persuade active Bimmerforums member (and closet wheel hoarder) Eric Sondel to ride shotgun. Eric has joined many of the NorCal Coupe Gruppe gatherings in his gorgeous Titanium Silver over Dark Gray S54 coupe. If you're interested, you can learn all about the progress he's made on the car in his often updated Bimmerforums thread here.
Eric met me in San Ramon and we hopped in the project coupe for a the 45 minute drive down to San Jose. Once we arrived, the Dynospot Racing rep pulled the coupe onto the dyno himself, secured it in place with four straps, and we were ready to roll.
I brought my GoPro along to record some of the runs since we couldn't stand anywhere inside the dyno area, so here's a quick video from the GoPro mounted near the rear wheels:
After four runs on the dyno, we saw the power max out at 265.7 hp and 218.98 ft-lb torque!
Stock S52's are rated at 240 hp at the crank, which would equate to about 204 hp at the wheel after the 15% power loss. So if we're measuring 265.7 hp at the wheel on this coupe, i's a whopping 61.7 hp more powerful than a stock S52. That's over 30% more power. If you calculate out the 15% power loss, you go from 265.7 hp at the wheel to over 312 hp at the crank, nearly matching the S54's advertised 315hp. It appears to have a fatter torque curve though.
Not quite the 370hp that the original owner had advertised, but it confirmed the suspicions I had after driving it. It's a very powerful coupe, but not overwhelmingly more powerful than my personal S54. So these readings made sense and should make any future owner very pleased.
So, there you have it folks. The third project coupe, our first with forced induction, has been babied and brought back to it's original glory. The previous two project coupes have sold prior to the publishing of the final article, but this one is available as of me writing this. You'll find an official Sales Listing for this coupe by clicking here.
You'll also find links to the AutoCheck and CarFax reports, and we'd be happy to provide you with all of the car's service history. In line with market pricing for coupes in this condition with this mileage, we've valued this coupe at $25,368. It'll be available exclusively here on M Coupe Buyer's Guide for a few days when it will then be offered in the Bimmerforums classifieds (Z3M & Forced Induction) as well as AutoTrader and eBay later this month.
If you have any questions, you can reach out to Jon (firstname.lastname@example.org) or you can reach out to me (email@example.com) to schedule a test drive. Thanks for following the progress and stay tuned for our next project..