Welcome to Downs Engineering
We are now in our 35th year as a California company
and 55 years in the
racing industry. We have expanded our Hayabusa
product line in order to better serve our customers. We
are a full service shop and are available to do research
and development projects, from engine and oil
systems to complete car builds. We have developed
race winning products and systems for the Hayabusa
engine for the past 18 years.
Suzuki Hayabusa Engine
Undergoing Testing On Our
making you go fast is what we do best!
Hayabusa Specialty Parts
Setting up a custom design
Turbo Engine on the Dyno
Our Wet Sump and Dry Sump Oil             
Systems are the best Hayabusa               
Systems on the market today
Parts and supplies for all types of Motorsports.
Sand Rails, Kit Cars, Race Cars, Motorcycles, Track Cars,
Street Cars
Contact Mike Downs
Downs Engineering
19564 Eighth St East
Sonoma CA 95476
phone: 707 938 1011
fax: 707 935 0481
email: mdowns@downsengineering.com

Property of Downs Engineering. All rights reserved.
Having problems with your Busa? Low oil
pressure? Oil starvation in corners?
Connecting rod failures?  
Click here for
solutions to these and other problems
inherent in the Hayabusa engine.

We will rebuild your Hayabusa engine using new
OEM Main and Rod bearings. The rebuild also
includes New Piston Rings, New Oil Pump, and Cam
Chain, as well as a complete competition valve job.
We thoroughly inspect the gearbox and shift forks,
along with the condition of the clutch discs and clutch
basket. We run-in the completed engine on our
engine dyno. After run-in we make power runs on our
in-house dynamometer to insure proper running.

If you would like to upgrade your pre 2008 engine to
current power and torque levels we can install the
2mm stroked 2008-2011 1340cc crankshaft and
replacement exhaust cam.

Get ready now for the 2018 season. Racing starts
again soon.
Click here for details
We are now dealers for Wossner
connecting rods, currently the
strongest Hayabusa connecting rod
available.  Limited time introductory
offer:  $859.00 per set.  Order your
set today.
  The "best bang for your buck" parts to  improve
the performance and reliability of your Hayabusa
High Volume Oil Pump Gear                   $115.00
High Pressure Oil Pump Relief Valve      $79.95
HD Cam Chain                                        $150.00
HD Clutch Springs                                   $39.00
Offset Timing Key                                    $89.95      

Race Car Design and
Race Car Restoration
For a limited time, 10% off D/E Hayabusa Wiring
Harness. Our modified harness removes all the
unwanted bulk and mystery of your stock harness.
Attach an ignition switch, starter button, and you're
ready to go.
Below is the Lotus 35 as received from client.
Bottom picture is after restoration
200 MPH Mustang designed and built
by Downs Engineering