My brother and I were talking yesterday. He has a Focus with a 2.0 in it. I jokes about how the supercharger on my truck is almost the size of his engine. Then I got to thinking and researching.

All the positive displacement blowers for our trucks use an Eaton M112 (Roush, Powerworks, Trilogy), except for the Whipples and Saleens. (2004+)

M112 is a 112 cubic inch supercharger.

Whipple is a W140ax Twin screw blower. 2.3 litre/140 Cubic inches.

Not only is the Whipple bigger, it's more efficient in the higher RPM range.

So why aren't the Whipple guy making ALOT more HP? You'd think they should all be right at or under 400HP.

My thinking is a Whipple blower with longer snout and Roush's dedicated belt-drive, You could turn the wick up alot higher. Basically what Rafa has.

Is my research incorrect? Is my thinking off base?

Any thoughts?

 

I don't think Whipple's get efficient till more boost is thrown in 16lbs or so..


I could be wrong.

 

Right off the line, the roots blower will make more power. The problem is, once it gets over 4500rpm, it starts falling off and losing boost. Max boost will occur in the 2500rpm range, and will fall off the more you go over 5k rpm.

A twinscrew blower still makes decent power down low, but really shines as rpms' grow. Unlike the roots, it doesn't lose boost, but instead creates far more boost.

If boost levels are equal at 10psi or less, the roots will make more low end power (just a little) and the twinscrew will make more high end power (just a little). The ability to hit 16+ psi is something a roots blower cannot do, therefore the twinscrew wins out in the long run.

 

Also keep in mind that head flow plays a large role in peak HP.

Add cams and intake design into the mix, and these shortcomings are more significant than blower efficiencies at somewhat normal boost levels.

 

This is my thought as well...the cams and heads are somewhat leveling the playing field...with more agressive cams and ported heads, the Whipple SC would separate itself...

 

But the bigger question, and probably more often asked... is which is better for the typical daily driver / occasional romper?

 

After Mike Troyer was nice enough to give me a half hour conversation on this (btw considering the service you get these days everywhere and that I haven't spent a dime with him I thought this was nice) I believe I would go Roush for this type of activity. As my daily driver, I don't care much for winding this type of set up more than 4500 or 5k or going high psi anyhow and don't care about racing at the track either. Just want tons of low end power for pulling, fun driving and maybe even freaking out an occasional sports car.

 

Considering that Ford uses the M112 on factory vehicles and offers them with a full factory warranty, that's got to say something for durability.

I personally have had a Trilogy (M112 based) kit on my Mercury Marauder for 20k miles without a single problem. I've had another Trilogy kit (M112 based) on my truck for 5k miles now without a single problem. Lot's of low-end power, easy install, quality products, great support and durability.

 

Roots or twin-screw are going to be ideal for daily driving duties.
Most OEMs use one or the other on factory installs.

 

The Whipple web site shows the twin screw makes more power at both ends of the RPM range, but it would.

 

Maybe I just missed it, but what type of warranty does the Whipple come with? The biggest factor for me at least in leaning towards the RoushCharger is the 3/36 full powertrain.

Just curious.

 

This will give you some idea of the power band for a twin-screw blower.
Kenne bell Lightning upgrade blower at 17 psi.
http://fordtruckworld.tenmagazines.c...=1&album=53116

Phil

 

Good numbers, those KB's are nice.

 

I went to the Roush web site and could not find any information on the warranty.

I am undecided at this point if I even want to add an SC. If I do, I am not going to be pushing it hard and will keep the 8 psi boost level. Hopefully I won't need to take advantage of a warranty. I noticed that it looks like Whipple makes that charger for Roush or do they just look alike? A couple of things I don't like about the Roush is the long snout, double the belts and pulleys, what seems to be a smaller intercooler, and an air intake system that is not really a cold air intake. I am sure there are good reasons for the differences, but really can't grasp them just looking at a couple of pictures over the internet. There are things that I don't like about the Whipple, no freely available manual, uses stock injectors, difficult to run an under-drive pulley, stock narrow belt may slip under load.

Those are some of the pluses and minuses that I can think of, please add - correct

 

YOu won't have any belt slip at stock boost levels.

The Roush is good because it DOES have a dedicated belt drive system. This means you can up the boost and spin the blower faster without speeding up the other accessories.

The Heat exchanger can be upgraded a larger one without voiding any warrenty.