My Dec 7th blog post here was all about our E36 M3 Project #Hellrotten moving from SCCA Time Attack Max5 to Max4 class, with a BMW S65 8400 rpm 4.0L V8 + DCT transmission. I had entered the car for UTCC and been dragged into a battle amongst other automotive journalists and bloggers, which fired me up!
On December 10th we had the E36 on the lift, coolant drained, splitter removed and were about to yank the perfectly good S50 engine to get started on the swap. We had just done a compression check and videos of it running, to help sell the S50 3.0L inline 6, the 5-speed transmission, the long tube header + custom exhaust, Link ECU and engine harness, plus the S50 specific fuel system upgrades. I had a bad feeling and I bolted up from my desk, ran out into the shop, and stopped this work! I explain this in detail in this post in the Hellrotten forum thread. Long story short, we will keep the E36 as-is and move this S65 swap to an E46 chassis.
There was a very recent rules change in SCCA that allowed caged cars to use Lexan behind the driver, and we had this unfinished and ignored E46 coupe chassis that fit the bill – it was fully caged, sitting on new MCS triples, wide wheels, EPAS steering column swap, and an E46 M3 rear diff and subframe. It has been untouched since 2022. This car also had a good race seat, carbon hood and trunk, and lots more. We also had another E46 coupe with a full Flossmann GTR widebody kit, carbon doors and carbon roof. The car had Lexan rear quarter and back windows, and was thus not legal for SCCA Max until this change in late November. I talked to the crew here and suggested: “Why don’t we just S65 + DCT swap the caged E46, then steal all the carbon and widebody panels from the other coupe, and make a GTR tribute?!” They all agreed. That gets explained in great detail in this new E46 GTR forum build thread.
One of the goals for this E46 M3 GTR build is also to finally replicate the low weight, 400+ whp output, and big tires from our “E36 Alpha car”, shown above. I started building this LS swap E36 in my home garage in 2000 and due to business reasons we had to sell it in 2009 – when it made 488 whp with 315mm Hoosiers and weighed 2550 lbs with a cage and two racing seats. I have not had a race car this light with more than 400 whp in the 16 years since, and I miss it mightily! The Alpha car was so fun to drive, so light, so effortlessly fast. Which means this E46 has big shoes to fill…
In under 3 weeks in December we have made tremendous strides on this build, with the S65 engine + DCT both mounted into the E46 chassis, the bodywork from the Flossmann car moved over, the carbon roof swapped, and much more. We had an instant reaction to my daily Facebook posts of the progress on this build and we’re now considering a production run of the engine + DCT mounts and possibly the long tube headers we will have to make.
An initial weight check was very promising (see above or in this forum post), and with a bunch of known weights of parts added in we can extrapolate a sub-2500 pound finished chassis weight. The Max4 class we are building for has a 3000 pound minimum weight with driver, so we’ll need “a bit of ballast”, and for UTCC we can and will remove the ballast needed for SCCA’s Max4 class. In the UTCC “writer’s shootout” against two 3600 pound F8X BMW M cars and Tom’s gutted Nissan 350Z LS swap, we’ll possibly be the lightest car by as much as 1000 pounds (at least compared to the F80 BMWs). The S65 engine might be down 200 hp to the twin turbo Bimmers, so we will need very trick in the book!
Thanks for reading along and encouraging this madness! – Terry @ Vorshlag