I ended up supercharging the car, and enjoyed the extra 200whp thoroughly. The best numbers I ever made out of my ESS supercharger kit, @ 9psi and water/meth injection, was 546whp/453ft-lbs.
But then eventually I got used to it, and I decided it wasn't enough. After a lot of careful consideration, I determined that even though the S62 is a phenomenal engine, it wasn't the proper power plant for me to attempt to push more and more power out of. Building that engine would've been very costly, and frankly I'm not convinced the block has enough structural rigidity to handle very high torque levels. So I ended up parting out the car and returning it to stock, with intentions of buying something else that had greater power potential. After a few months of driving the car without the blower, I was going through boost withdrawal. So in an effort to deal with my boredom, I decided to do a nitrous setup in the car to temporarily deal with my speed addiction. I ran a two fogger, 150 shot, and enjoyed roasting the tires at a push of a button for a little while. The most power I got out of that setup was 460whp/574ft-lbs.
Eventually my M5 was sold, and after owning a M52 swapped E30 M3 for a while, I found myself happily back in another E39 M5.
My original intent was to keep this M5 stock, and enjoy a beater turbo E36 that I owned as my fun, go-fast car. But after some time, I realized I was driving my terrible condition, smoking, turbo E36 exponentially more than my clean, comfortable, M5. So I started brainstorming…
Why not combine the two? As my knowledge of the M5x line of engines and their power capabilities grew, I was increasingly drawn to the idea of replacing my tired S62 (the motor was in need of some refreshing) with a fully-built S52. I felt that I could combine the engine I really wanted, along with the chassis I really wanted, and then I'd have the best of both worlds. Essentially, that's what I did. I was able to sell the S62, trans, harness and ecu, and take the same amount of funds and buy a brand new, fully built S52, and Getrag 420G 6 speed trans. I took all the turbo components off the E36 and parted out the rest of the car. Then, I let the fun begin...
S52, 8.5:1 compression
Full Supertech valvetrain (+1mm intake, Inconel exhaust valves)
SS O-ringed block, with matching receiver groove in cylinder head
11mm ARP 2000's
Precision 6266 CEA, T3 .82 a/r Turbine housing
Tial 38mm waste gate
Tial 50mm BOV
80lb Siemens Injectors
Walbro 400 Fuel pump
Devils Own Direct Port Water/Meth Setup
UUC Twin Feramic Disc Clutch Kit
-My biggest goals with the build were to build a very responsive turbo kit, with a broad power band, and with as much torque as possible. Choosing the 3.2L was a great decision. I'm also running a custom 3.62 M5 differential. The combination of displacement and gearing make this 4100lb sedan accelerate and feel more responsive than my 3100lb e36 with the boosted 2.8L M52. I am very very pleased with the driving dynamics of the car overall. Far more torque and power than my supercharged S62 ever could deliver, with the only sacrifice being the loss of the immediate throttle response that the S62 is known for. But believe me, once the car comes into boost, there are absolutely no regrets!
-The engine is tuned on a factory e36 M3 OBD2 ECU, by Nick G of Technique Tuning.
The first time moving under its own power:
Here is a brief cruising video to enjoy the wonderful harmony of the inline 6 and turbo sound:
Here is a 55-145mph pull at ~650whp:
-So far, the highest peak power numbers to date are 707whp/708ft-lbs:
Unfortunately, I was having some electronic boost control issues, which left the overall power band not quite as smooth is some previous graphs, but there will be plenty more results to come! I'm looking forward to sharing progress with the car, as well as plenty of racing footage this upcoming season. Thanks to all for the interest!