Thursday, August 15, 2013

Super. Charge.

It's been a while since I posted, but I've this is a pretty big update.  "NO POWER" now has a bit more power, courtesy of an Innovate supercharger kit we installed.  This is a constant-displacement twin-scroll supercharger that makes a maximum of about 9 psi.  It bolts directly on the top of the engine using a custom intake manifold.  The setup we went with is called the "Tuner" kit, meaning the ECU tuning is up to you.  I did the tuning on our car and came up with a maximum of 218 horsepower at the rear wheels on our Dynojet dyno, up from 160 when the car was bone stock.  For the production tune packages I would expect around 210 rear-wheel horsepower.

 I chose the Innovate setup over one of the centrifugal supercharger or turbocharger options mostly because I liked the idea of a constant displacement supercharger -- for every turn of the engine, a constant-displacement unit also turns and compresses air.  Although it can be more limited in terms of top-end power, it's hard to beat the response.  In addition to having a twin-screw compressor, the manifold design and the finish details of the Innovate package are top-notch.

Installation of the supercharger is surprisingly simple.  You remove the stock intake manifold, then remove the port fuel injectors and throttle body from the manifold and transfer them to the new manifold.  Bolt the new manifold and supercharger assembly to the block, hook up a few hoses, and you're set.  It took us less than half a day.  We'd charge $400 for the install.

I spent a couple of weeks and many, many dyno runs developing our ECU calibration for the car.  I tried for stock-like smoothness and driveability, I think I managed that.  A few customers and friends that have driven the car have given us a lot of positive feedback.

This version of the kit is NON-intercooled, so horsepower gains are limited compared to a more elaborate intercooled system.  The Innovate manifold DOES have hose fittings for a future water-to-air intercooler circuit, so that is an option once that intercooler is complete and available to sell.  I have other plans, though...I'm thinking I will use water/methanol injection to perform the same function as the intercooler.  But we'll see.

So how does the car feel with the supercharger on it?  Like stock, but more.  The power delivery is instant -- you step on the throttle and you immediately have boost, so there's never a sense of any kind of lag or delay.  The torque comes on strong and carries all the way out to red line, so although the top-end power isn't massive, the car picks up speed very nicely.  The biggest difference to me is the throttle response.  Previously I felt like there was very little difference in part throttle and full throttle -- the torque was so low it just never felt like it was pulling very hard, even when you gave it the boot. Now it surges forward.  It's really fun.

Rear-end traction is more of an issue now.  Punching the throttle in a corner will slew the car sideways and get you a bunch of flashing orange tranction control warning lights.  If you happen to have the traction control all the way off, you can get yourself into trouble easily.  I'm still working on feeling out the limits of lateral grip while on-throttle.  I may have to take the car to a track for some play time in a safe environment.

To keep track of manifold pressure, we also installed a new Prosport Premium EVO boost gauge, in a vent pod from ATI.  I'll give some details about that install in my next post.

Products referenced in this post: Innovate Supercharger kit.