2001 BMW 740IL LS Turbo Swap Build Thread!
E38/E39 LS swap components can be found here: https://levelsperformance.com/products/bmw-e38-e39-ls-drivetrain-swap-kit
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I purchased my first BMW in 2010 and immediately fell in love with the value of the older 5 and 7 series. If you hop on craigslist in your local area you can probably find at least 25 neglected luxury sedans waiting to be rescued. These cars are very well engineered, from the chassis, suspension, interior, drivetrain.. It all adds up to an incredible bargain for someone who is looking for a used car. Over the course of the past 7 years, I have owned 12 various BMWs which gave me a decent understanding of the mechanical side considering I handle my own repairs and maintenance.
In 2015 I came across an ad on craigslist for one of my favorite vehicles ever produced, a 2001 BMW 740IL. The car was located out of state at a shop and had been left by its owner because he did not want to pay for the repairs. After contacting a friend of mine who was local to the shop, I made an offer to the seller and the car was transported to me here in Central Florida. I drove the car for a few months, cleaned up a few things and installed a BC Racing coilover suspension setup. After a while the car started to run poorly, indicating that the engine would need to be town down and refreshed. This is where I decided NOT to invest in another M62 BMW engine, but instead choose a swap that would suit my desires for shredding tires. Here is how I did it.
In 2015 I came across an ad on craigslist for one of my favorite vehicles ever produced, a 2001 BMW 740IL. The car was located out of state at a shop and had been left by its owner because he did not want to pay for the repairs. After contacting a friend of mine who was local to the shop, I made an offer to the seller and the car was transported to me here in Central Florida. I drove the car for a few months, cleaned up a few things and installed a BC Racing coilover suspension setup. After a while the car started to run poorly, indicating that the engine would need to be town down and refreshed. This is where I decided NOT to invest in another M62 BMW engine, but instead choose a swap that would suit my desires for shredding tires. Here is how I did it.
The E38 chassis comes with plenty of room for your choice of engines/transmissions, as it comes equipped with a 32v V8 from the factory which takes up a lot of space. I would bet that with a lot of work, and some fabrication skill any engine could be adapted into this chassis. Personally I wanted something that could handle a LOT of power, reliably and without to much convoluted technology. After debating on engines and transmissions for a few weeks I ended up choosing the 6.0 liter iron block LQ9 engine from a wrecked Cadillac Escalade. These engines are becoming more and more desirable but they can still be found for about $1000-2000 in good shape. My choice of transmission was the 4L80e automatic simply because of its ability to hold up to high horsepower setups. Even without upgrades the 4L80e is a very strong transmission.
Factory Engine
Factory drivetrain removed
Factory engine/trans removed
Once I acquired the engine and trans I began fitting everything in the car. Knowing from the beginning that I was going to run a turbo made the header fabrication much easier. The steering shaft clearance would be tight on an NA engine setup, as the driver side exhaust manifold sits very close to the shaft. An NA setup would be much easier to install and it would also keep the air conditioning setup fairly straight forward. My setup (in this form) is a bit too cramped to fit a compressor or condenser. Another clearance issue is the oil pan. I ditched the rear sump truck oil pan and purchased a 2004 Pontiac GTO front sump pan on ebay for about $250. The front sump pan must be modified to clear the subframe/steering rack.
6.0 LQ9 engine from 2004 Escalade
LS engine test fitting
Oil pan modifications
Once I had the engine components fitted properly I began fabricating the turbo setup. I initially chose a cheap 76mm turbo, but eventually sold it and switched to a Borg Warner S475. This turbo is popular with the LS crowd and makes a LOT of power on relatively low boost.The entire turbo setup was custom fabricated using stainless schedule 10 pipe for the runners and thin wall stainless tube for the downpipe/wastegate dump. The charge pipes are made from 3" aluminum tube. Vibrant performance is hands down the best source for tubing/fabrication materials in my opinion.
Old turbo mockup
New turbo setup fitment
Once the turbo was placed I was able to finish the piping and custom intercooler. The intercooler is quite large, as I did not want to compromise charge air temperatures with the hot weather we experience in Florida. Everything bolts directly to the factory radiator support. The passenger headlight is modified to feed air into the turbo area. Since the turbo is clocked with the compressor housing facing back, I didn't want to risk starving the turbo of air. I also plan to add a funnel from the turn signal lamp soon.
Final setup
I was able to squeeze a full 4" downpipe and exhaust by transitioning to oval and then finishing it ff with some Vibrant Performance resonators.
I tried a color called "New Ford Gray" on the compressor housing but it ended up looking like primer so I went with wrinkle black.
