Is This Power Usable?
With the K20A2 –Rotrex C38 engine setup finalized, now I had to figure out the rest of the setup.
The benefits of running a Rotrex centrifugal supercharger were not only massive linear power, but also the ability to utilize it like a belt driven turbo. This includes cooling and plumbing. I didn't want to get into any type of custom bodywork for a larger tire fitment and I also wanted to avoid limiting the supercharger's output by running a bigger pulley to reduce psi output. Instead I chose to install a waste gate right after the intercooler on the intake pipe before the throttle body. This way I could control the max boost output through different waste gate springs or a boost controller. The only problem with getting this to work was getting the appropriate weld-end flange. You see waste gates come with SST V-band flanges since they are used on HOT turbo exhaust systems, which are normally made out of SST. I needed this same flange in aluminum since you really cannot weld SST to aluminum.
To pull this off, I figured I could just purchase a Tial MVR waste gate and sent out the supplied SST flange to have it replicated in aluminum. One more problem solved before the project even started!
Here are the "luxurious" accommodations for all this complex work.
And this, by the way, is as clean as my garage ever got - right after
I picked up the Exige S and before any work on it had begun.
Engine Management - Wiring
It just so happens that Hondata actually makes a dash converter specifically for a Lotus/Honda swap. I know it sounds random but a K-pro co-founder is also a fellow Lotus/K-swap owner and came up with the dash converter and incorporated it into the K-Manager software I eventually ordered this and it arrived as serial number #3! (Awesome Job, Derek!)
Murray to the Rescue
Now, I wouldn't have to fabricate my own intercooler and instead I could just use theirs, which fits nicely under the driver's side cross bar. The only problem was how do I connect all the piping together. With boost pipe you want as little bends as possible, and also minimum silicone hose connectors as they can be prone to leak boost or even blow off under extreme pressure levels. Since this was a custom build, the intercooler piping and further aluminum work would require some help. I don’t have the equipment to cut or grind aluminum tubing let alone weld it. So, I looked to Eurotech Advanced Automotive for advice and assistance. Bill Pfister who is no stranger to building just about anything you could imagine for a Porsche racecar, agreed to help me with the fabrication portion, including the aluminum welding if I decided to take on the project.
My dog Dash has kept me company throughout the project.
He loves the new setup, especially the first- and second-gear pulls
with the windows are down!
To be continued...
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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