Supercharger Performance and Engine Performance Parts

Posts Tagged ‘effeciency’

The other day I had a thought about DIY modifications, possible fuel savers and other performance tricks and tips to increase gas mileage. See, although this is a performance oriented blog, as the cost of oil per barrell crosses the 70 dollars per barrell threshold once again, and as the economic depression in the USA (and thus in many other parts of the world) seems to be very much a mainstay till around 2012 according to analysts, I can’t help but think about mileage and how so many people might want performance parts for their car, but they may also NEED better fuel mileage.

Ouch. My first gas tank in the USA I paid 75c per gallon @ 1998

This got me to thinking about how we as automtive enthusiasts modify our cars for increased volumetric effeciency and higher performance in a specific rpm range of around 4000 rpms and higher. This is mainly due to the fact, that when you are racing, you spend alot of your time on the eastern half of the tachometer in the higher end of the rev range and thus it makes sense that most performance products and tips are focused towards higher rpm effeciency. However, there are some (but not all) performance modifications (and racer’s secrets quite frankly) that we as enthusiasts may use to gain that power advantage, but can be utilized to effectively boost gas mileage.

This isn’t only a theoretical debate as I’ve done this ‘accidently’ on my first car, a 1991 Toyota Celica GT back in 1999. In typical 10 year old car fashion it ran horribly when I first bought it, as indicated by my first tank of gas that was over in about 180 miles. Over the next two years I modified it and tuned it, not only increasing its performance and acceleration, but also acheiving over 32mpg (which is about 4 mpg over the factory figures, when the car was brand new, and more importantly I was doing this on a 10 year old car that was definately not babied throughout its life).

My friends and I also went out and replicated these results on a 1988 Celica GT-S, a 1996 Jeep 4.0 I6, and my friend’s moms Nissan Quest V6. My uncle also bought a 1993 Cadillac Deville that was getting double the mileage on cruise control as it was during normal driving. I recommended he change one thing on his car, he did and he got his mileage back. Then I went ahead and did a similar electrical fix (different part though) on my dad’s 1994 Cadillac Fleetwood brougham.

Anyway, enough stories of the past, let’s look at the future… I’ve sat down and brainstormed every thing you can do to boost mileage on an older car and I have come up with a hand written rough draft of performance modifications that you can do to your car to gain back it’s factory mileage and to even go beyond that by another 4+ mpg.

I am thinking of turning this draft into a fully detailed guide, but first I’d like to know that there is serious interest in this guide before I go ahead and invest time in this product….

If you are seriously intersted in a mileage booster guide please show us your interest by subscribing to this topic below.

The beauty of these kinds of modifications is that they obviously pay you back with time, so if you start out with a horribly performing car, or if you put a lot of mileage on your vehicle, then this information will end up saving you money in the long run, which is really cool.

Technorati Tags: boost, cadillac, effeciency, Jeep, Mileage, RPM, Toyota

The whipple supercharger is a unique and very practical chager. The unit is a great compromize between a positive displacement supercharger (that creates boost pressure by over pumping and over feeding the engine with air) and a compressor (similar to a turbocharger) that compresses the air inside the supercharger housing before sending it out to the charger piping. 

The unique three-five design of the whipple screw clearly showing how the lobe from the three lobe screw tightly fits between two lobes from the 5 lobe screw to compress the air for inter-screw compression.

The secret to this style of ‘hybrid’ blower is the two intermeshed rotors of different lobe numbers (see illustration). The combination of an intermeshed 3 lobe and 5 lobe rotor means that the rotors inside the housing are operating at different rpms with a ratio of 5:3 to keep the rotation of the lobes (3 lobes to 5) in synchronsim. This complex design allows the rotors to capture air (in its natural volume) from the back of the blower housing, and push it foward as the screws rotate. As the air is moved forward it is captured and compressed between the intermeshed rotors as well as being pumped (in positive displacement) from the inlet port at the back of the charger housing to the outlet port near the front. 

Because of this unique design, screw style chargers are able to outperform simpler rotor based chargers in two aspects:

1- The blower is able to acheive a higher pressure ratios because the compression is combined between positive displacement (overfeeding) and between direct compression of the air (inter-screw compression). 

2- Since the air is compressed inside the housing, the housing is able to ingest and move more air (higher CFM ratings) for a similarly sized roots style blower. 

So how is the whipple best used. Some people are interested in SIGNFICANTLY boosting their small displacement motor to make it not only have better low rpm torque but also unrestricted peak RPM power. In two of our articles (one, two) we have talked about how you can combine a typical roots style charger for low rpm instant boost, with a high rpm solution of turbocharger or even a centifugal supercharger that is sized proparly to elevate your motor to the required peak psi -- that above which your typical roots style supercharger may not be able to provide effeciently.

Well here’s the whipple solution. If you use a whipple charger, then you have the best of both worlds, you have a positive displacement charger that has no spool up lag, as well as internal compression allowing you to achieve high PSI levels without the need to for overspeeding your blower to do so. 

So, with the use of a whipple charger you can have a fairly flat torque curve from zero to redline giving you very predictable traction and launch control (which is why whipples and other screw type chargers are popular in drag racing or coming out of corners in road coarses). A predictable and linear torque curve also is more forgiving to overgeared cars and more forgiving with different driving styles. 

A video of a whipple-charged GT-500 mustang and dyno showing the infamous flat torque curve…

Here is an overview of whipples available chargers:

For more Information please visit:

Whipple

Technorati Tags: CFM, effeciency, Rotor, twincharging, Whipple