S2000 Whipple 1.6L Supercharger Development

Boost Engineering & Fab began from the idea to bring positive displacement superchargers to the Honda S2000.  We knew that we could bring an unmatched driving experience.  We knew of the old SOT supercharger kits that utilized the M62 mounted over the exhaust header and piped to the intake manifold, but were determined to create a more efficient system mounting the blower on the cold side with an integrated air to water intercooler. 

First we need to decide what supercharger we wanted to run.  After reviewing the options of Roots style superchargers from eaton and the twinscrew Whipple superchargers we decided Whipple was the way to go.  They have a great performance reputation and offer a wide range of sizes.  We decided the smallest supercharger they offer, the W100ax (1.6L) would support up to 550hp which meets our goals for the project.  It is also the most compact version they have which is also important with how tight the intake side of the engine bay is on the S2000.

We then got do designing components around the supercharger.  The first round of parts was designed around a machined intake flange to mound the throttle body, custom intake flange and adapter to the intercooler and a sheet metal plenum for supercharger outlet.  We got to designing the new manifold with integrated intercooler to mount the blower in the car.  To get as much room as possible on the intake side we used a direct drive pulley system which offset the supercharger forward.  Because of this and analyzing the flow, we had to put dividers into the plenum to better distribute flow.  We quickly learned that it was extremely tight and nearly impossible to fit with the stock tensioner and alternator in place.  We pivoted the alternator toward the frame rail and fabricated a new mount with an integrated tensioner pulley.  Then onto the intake, we found there was virtually no room as the firewall comes back toward the engine where the supercharger was mounted.  This meant that the throttle body could barely fit in this location with restricted airflow.  

Even with all these hurdles we decided to continue on and create a running car from this system, knowing we had plenty of changes to make.  We got the car running and with some pulley adjustments fixed a pulley slip issue.  It was onto the dyno!  We battled many small changes and issues along the way and finally got some results of 300whp @ 11psi.  We drove the car some when it was dry enough to here in late winter upstate NY, and even at 11psi the car was insane.  The instant response and torque completely changed how you can drive the car. 

While it was nice to have a moral victory we know we had a lot of work left to do.  We needed to find a way to better package things.  One of the drawbacks we continued to review was removing the auto-tensioner and creating a new mount.  We didn't like how that limited the space upfront for potentially bringing the intake forward.  We also reviewed the option of using a jackshaft to transfer the inlet to the same side as the drive pulley.  The trouble with that is the supercharger needs to run clockwise.  To do that the jackshaft has to either be on a gear drive or run on the backside of a belt system to have the clockwise spin of the engine spin the supercharger the correct way.  Both of these options added complexity and cost to an extremely tight space.  We then utilized a 3D scanner to scan the s2000 engine bay to better be able to place our models in and see how they fit without having to machine them yet.  We also decided to start 3D printing our designs to test fit them in the engine bay to verify the dimensions.  This was a huge step forward as it allowed us to go through several iterations without making new parts. 

Finally we were able to find a way to leave the stock belt system factory and add a secondary pulley to the crankshaft.  This allowed us to isolate the supercharger belt system so even if the belt were to fail, you could still drive the car home.  This also allowed us to utilize a GT2 style belt and pulley.  A toothed won't slip and will allow us to run higher boost numbers to produce more hp.

We then made the components out of billet material.  You can see that some are very complex parts but it allows us to create the best quality piece possible.  Perhaps the most impressive part is the intake flange/runners/plenum part.  This part integrates the fuel injectors, runners, MAP sensor and IAT sensor all from one solid billet piece.  We were also able to better optimize flow for the system.  The intake was brought under the blower and placed in front so the air intake was approximately where the stock intake is.  The second setup should be far more efficient than the last.  With this one all built it was onto the dyno again.  

This time we got great numbers.  We were able to make 440whp and 320wtq @ 17psi!  Taking this setup onto the street was so incredible.  No more did you have to rev the S2000 out to go.  You have torque on tap any time you hit the throttle at any rpm!  Overall we are happy with the product and look forward to bringing this product to the S2000 community.