Thursday, January 17, 2013

A Lotus Gone Wild: How an A/C Leak Turned into a 400-WHP Monster - Part IV

It takes a crumbling garage floor for all this magic to happen!
Here is Part IV of the amazing 400-WHP, 2,000 LB Lotus Exige S built by a regular guy without any tuning experience, all done in a small garage, without a lift, and in his spare time.

Part I of the series covered the background of the project and why the Toyota 2zz engine was not the best choice.

Part II focused on the research that went into the motor and why the Honda K-motor seemed like an intriguing choice.

Part III focused on some of the critically important setup choices: supercharger, exhaust, and intercooling.

Today's Part IV covers the Rotrex setup, the tear down, and pulling the motor out. Again, Chris is continuing the write-up in his own words --

Rotrex Setup
The Rotrex bracket
The only Rotrex supercharger bracket for sale in the U.S. is designed to get mounted where the A/C compressor is located on the K-series engines. This is the typical design by Kraftswerks performance group. The design is awesome but unfortunately the very tight area on the Honda/Lotus setup makes it hard to install, plus I did want to keep my A/C! I was going to design my own supercharger bracket and have it machined but after some more research, I discovered Jaydee Quantum, an Aussie Arial Atom custom builder who’s even crazier than I am! It turned out he had developed the exact supercharger bracket that I required and he agreed to sell it. One less thing for me to manufacture while I continued my build! The Rotrex charger comes with its very own oil, reservoir, and filter, but required a custom oil cooler, which still needed to be sorted out.

And We Are off! Time to Buy!
With all the major components figured out and an action plan in place, it was time to open up the wallet and start sourcing those long lead time items. So I ordered the engine conversion kit from Innovative Mounts and the exhaust from Hytech. I started the hunt for my K20A2 motor utilizing most of the Honda and K20A forums out there to see what type of used motors or complete swap kits were for sale. There is one major point that needs to be mentioned: the Honda community has a huge following and probably the biggest used parts market out there! Unfortunately, it also has the most scammers! People even sell counterfeit Hondata K-pro ECUs! So you need to be extremely careful who you buy from and how you conduct the transaction. I can’t stress this enough. Be very careful who you buy from!

Let's Get That Motor!
Now, I ended up finding a full K20A2 swap that had a motor/tranny out of an 02 RSX-S, Quaife Differential, Karcepts, fuel rail, Honda RBC intake manifold, stock throttle body, stock injectors, axles, but a blown transmission. The price was really good - it was almost like getting a free tranny and Quaife LSD! So to me it was worth having the trouble of getting the tranny rebuilt. It was already in a car (EP3 Civic), so I could see it run prior to purchasing. I had the seller send me a video of the engine running and also pictures of the VIN number so I could confirm they weren’t stolen. The only problem was with the location: the motor was in Long Island and I live in Massachusetts, so it would be quite the road trip for the transaction. We settled on a price and I hit the road with a pocket full of cash, a cherry picker, and a pickup truck!

Damn Yankees!
The motor came with a broken tranny case
I forget how long it took me to get there, but it was dark out and the motor still needed to be pulled from the car. The owner seemed nice and honest with the whole transaction and very helpful with all my questions. We dropped the motor out of the car onto a small cart with wheels and lifted the car up over the engine. Planning ahead on this was also key: I brought the cherry picker not to pull the engine but to help put the motor in the back of the truck. It’s a good thing I planned that out or we would have never been able to move the motor into the car. We loaded it up and I headed home! I got home really late, so I just went straight to bed and figured I would unload the motor in the morning when I could actually see it. The next day I went out to unload the engine and the first thing I noticed was a crack and a piece missing in the transmission’s bell housing. Someone didn’t mention that! I then called up the seller and gave him a hard time about it but he apologized and said he totally forgot about it. Not a good sign for the rest of the items purchased. That day I boxed the tranny up and shipped it out to K20Tuned to get it rebuilt while I worked on the rest of the car.

Teardown Time!
I already had the front clam off the car while inspecting the A/C leak so now I just had to remove the rear clam and most of the interior. Taking the Exige interior out was pretty easy since it is already minimalistic. It only consists of 2 seats, a floor divider, and a center console. To remove the rear clam, you need to remove the hard top, undertray, and rear diffuser. It was pretty easy to remove except for the 2 screws behind the rear speaker grills. The plastic on the rear trim panel was razor sharp and I had to shove my arm deep into the panel and basically tear my arm up during the process! Once I got the car completely torn down, I started taking off the OEM SC kit, which I sold to someone with a normally aspirated Exige. Before going any further, I labeled every single plug on the factory wire harness and also numbered all of the coolant lines for the header tank when taking detailed photos. I really wanted to avoid any of those “hmmm… I wonder what this is for” moments!

Let's get this swap done!

Pulling the Motor
With the car on jack stands, I removed the wheels, the factory Bilstein Track pack suspension, exhaust, fuel lines, ECU, coolant lines and started unplugging the sea of wires. I also had to remove the rear upper A-arms so I could get the axles out. The passenger side was really easy to remove since it has a half shaft that bolts to the motor to keep it in place. Then the time came to remove the driver’s side axle and CV joint. This CV joint has a little C-clip at the end that helps hold it in the tranny. I pulled out the biggest pry bar I had and it wouldn’t budge! I even took a trip out to Harbor Freight and bought a 5’ pry bar and it still wouldn’t come out after hours of attempts. I ended up having to run to my local mechanic’s garage and borrowing a massive Morgan knocker with a choke chain. I slid it around the CV joint and smashed it 3 times and it finally broke loose! With everything disconnected and labeled, I lined up the cherry picker and hooked the motor on to it. I unbolted the motor and out she came! I must admit it felt pretty good to pull a motor out but it was a little unnerving at the same time with quite a few “you'd better pull this off” thoughts running through my head.

There's no going back now!!

To be continued...

Related Posts:
A Lotus Gone Wild: How an A/C Leak Turned into a 400-WHP Monster - Part I
A Lotus Gone Wild: How an A/C Leak Turned into a 400-WHP Monster - Part II
A Lotus Gone Wild: How an A/C Leak Turned into a 400-WHP Monster - Part III
A Lotus Gone Wild: How an A/C Leak Turned into a 400-WHP Monster - Part IV
A Lotus Gone Wild: How an A/C Leak Turned into a 400-WHP Monster - Part V

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