[TR] Building a 150 hp engine

[Rick]

Hi Randall,

A very good question! If you check out the supercharger's plumbing it
differs from most because the throttle plate is located at the intake
manifold instead of the traditional intake boss of the supercharger. A young
fellow who once worked for me convinced me to try this S/C approach. No lag
what-so-ever as the supercharger keeps the intercooler pressurized at all
times to some degree and cracking the throttle plate charges the intake
instantly.

Non supercharged air flow is done this way;

Just ahead of the throttle plate is a large bypass valve controlled by
intake manifold vacuum. Without the supercharger running there is vacuum in
the manifold and the bypass valve is held open. Attached to the bypass is 1"
tubing used to draw fresh air from the air cleaner. At higher rpms the
supercharger windmills along supplying a little extra air via the
intercooler. The dyno testing without the supercharger revealed that this
hose needs to be at least 1.25". That will be a someday project as the car
actually runs pretty well without the supercharger. The biggest problem
encountered with this set up was when suddenly closing the throttle at high
rpms with the supercharger running, the bypass just couldn't dump enough air
to keep from blowing all the tubing apart. That was a very frustrating
period of development! There was also concern that the throttle plate would
bend and bind. Addition of a very large dump valve near the supercharger
solved that issue.

Another someday project is to incorporate a Hobbs vacuum switch and an
electronic timer that would engage the supercharger like a passing gear.
What do you think?

I probably should mention that because the supercharger can be engaged by
the flip of a switch it doesn't get used all that often. You might use it
passing or when that red Mustang pulls up along side but in reality it only
is used a few times a week and for short pulls at that.

Rick
http://sidedrafttbi.com/

> -----Original Message-----
> From: triumphs-bounces+patton=suscom-maine.net at autox.team.net
> [mailto:triumphs-bounces+patton=suscom-maine.net at autox.team.net]On
> Behalf Of Randall
> Sent: Tuesday, July 17, 2007 2:47 PM
> To: 'Triumph Sports car discussion'
> Subject: Re: [TR] Building a 150 hp engine
>
>
> >  The  blower came from a
> > Mercedes C230 coupe and has an electric clutch like an A/C
> > compressor.
>
> Where does the air flow when the blower isn't spinning ?  Some
> sort of check
> valve arrangement ?
>
> Randall