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Old 04-20-2017, 05:25 PM
Fair Fair is offline
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Default Vorshlag BMW E46 M3 CSL - V8 Downforce Monster Track Car ("Chainsaw Massacre")

Project Introduction - April 20th, 2017: Welcome to another of Vorshlag's detailed Build Threads, this time chronicling possibly one of the craziest cars we have ever built. Even though its is 4/20 day, this is no drug induced delusion - what started with more of a dare has grown into a wicked track car build for one of our customers. This car is called the Chainsaw Massacre - and yes, I will try to explain the name (given by the car's owner) in the paragraphs below.


This E46 chassis getting a custom roll cage in late 2016

The goals on this build are similar to the factory 2003 BMW M3 CSL, just taken to the extreme: start with a BMW, shoot for lower weight, maximum power, maximum tire, maximum downforce, maximum brakes, maximum reliability. To that we are adding full safety gear (cage, halo seats, belts, fuel cell, fire system) and using a plentiful chassis that is easily replaced if damaged in a track event. This "big tire/big engine/big aero" combination is a simple formula which we have built around before, but this time we have a customer that understands the benefits, and very few class rules or budget restraints to hold us back!


This shows where this project is in April 2017, after 5 months of work (with a few long delays waiting on parts)

Target weight is 2600 pounds soaking wet, with the ability to add ballast for series that require higher minimum weights. Target horsepower is 750 flywheel (650 whp), using a large displacement naturally aspirated aluminum LSx V8 engine. Tires chosen are "the biggest DOT Hoosiers available": 335F/345R with the ability to use a 200 treadwear tire of similar size when required. We are also using the biggest wing that AJ Hartman builds (72x14"), along with a diffuser (for when the wing isn't allowed) and a mega sized front splitter, canards, and hood venting up front. There are a few minor "street car" concessions like roll up windows, working wipers and lights, to meet the bare minimum "street car" racing series rules. There are virtually no racing class power-to-weight rules that apply to this build, but we're shooting for around a 3.5:1 to 4:1 pounds per horsepower - which is closer to a FAST sport bike than any production sports car. This E46 is built to run with McLarens on track.



Is this just empty smack talk? Before the 'Debbie Doubters' chime in, yes, these are all attainable goals using proven components and build practices we have used in the past. Our caged, metal bodied BMW E36 coupe with an LS1/T56 drivetrain and big CCW Classics shown above (the "E36 LS1 Alpha") was 2508 pounds soaking wet.



The power numbers used are from a proven 7.7L LS engine combination from HorsePower Research (HPR), an engine shop that I am a part of. We already have the 468" aluminum LS shortblock built, just waiting on the heads. No, we won't be using some "destroked" high revving nonsense, but a big bored, big stroke, standard deck block with sleeves. #MURCA We have proven the effectiveness of this tire package, the aero tricks, and more on our red Mustang as well as other track cars. This BMW will be one BRUTALLY fast car that should go, stop and turn like very few other unibody street legal cars.



We always take pictures to update our customers during their builds anyway, so why not chronicle the builds in detail for the public? Spread the insanity far enough and we hopefully find more like-minded customers. As with most of our build threads from the past 15 years, this one will be cross-posted to a number of forums (which we either sponsor or they like us enough to let us post there), including:
All of the pictures can be clicked for higher rez versions (#watermarked #triggered), so you can see the details. These build threads take a lot of time to put together but people seem to enjoy them, so I'm going to keep writing them up like this. If you don't like the way this is written, I'm not putting a gun to your head and making you read it.

HOW THE HELL DID WE GET HERE?

The path to this balls-out E46 V8 build wasn't a straight line - it took 2 previous cars and several years of work with this customer to get him to trust us enough to build something this crazy for him. Things like the 18x13" front wheels are borderline absurd. And while some of the pictures shown are just shown to make fun of silly fads, like #DollarBillzonDemLips, this is a serious build that will be a bit insane to drive.



Not everyone would want a car like this, or could even drive a car this light and powerful without a bunch of electronic nannies. This idea started after Mr. Chainsaw was frustrated with his supercharged track Mustang, which had heat issues on track - just as ALL boosted track cars seem to have. Overheating, heat soaking, unusable power delivery, high weight, low reliability, and high consumable costs.



After two years of improvements to the cooling system, packaging things to better vent the hood, and adding ever larger heat exchangers the Mustang was getting a lot better, but the weight was still fairly high and it was making for a frustrating experience on track for the owner. Just like we told him from the beginning, and what we tell everyone who wants to use a blower/turbo on track: power adders are great for making lots of horsepower for very short amounts of time, but they typically make compromised track cars. A power adder also doesn't make an engine MORE reliable... it does the opposite.



This highly modified Mustang (which he called the Chainsaw) was run at many HPDE events as well as Optima Ultimate Street Car qualifier, where it was damned fast. The owner enjoyed the variety of contests they do during Optima events - speed stop, autocross, and time trial. So that series became a focus for a "dedicated race car" to be built in the future. Which is now.

continued below

Last edited by Fair; 04-21-2017 at 09:07 AM.
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