OK… I’ve tried to start this topic before… this is my last attempt on this board. As dennis miller would say I don’t want to get off on a rant here…

I want talk about the Eaton supercharger we all have, a model M112. Info on the SC can be found at http://www.eaton.com/supercharger/M112.html

Lightnings have a red line of 5250, and the blower to crank ratio is 2.1. So the blower never spins faster than 11025. Eaton states the blower is good for at least 12000RPM, but in other parts of the web pages they state all their blowers are good to 14000 rpm.

Looking at the charts for the CFM, (yes they have charts) at 11k rpm we have about 610 CFM on the inlet side. At 12k RPM the blower CFM is 680 or so. That’s an 11% CFM gain on a 9% RPM boost. If this boost was matched correctly to the fuel mixture via an after market chip (calling sal here whenever he gets back online). Wouldn’t we see a noticeable horse power difference?

What I really want to know is the diameters of the after market pulleys from Downs and whoever is making the SC one. The math says I want a 2.3:1 blower to crank ration, (12000/5250 = 2.28). I would think something more like a 2.5:1 blower to crank ration would be desired for maximum performance. This would still be way within Eaton’s claimed 14k RPM limits. (13125/5250= 2.5) Also remember that the blower would only see this kind of RPM for a couple seconds at a time during WOT. Beyond that the blower would be down in normal operating range 99.9% of the time in my case.

I’m not trying to build anything here but the performance truck the lightning easily could be with the parts we already have. I don’t think this combo would be a daily driver, but more for performance.

Lets also remember that a well-built normal aspirated engine will displace about 1 HP per cubic inch (or more). (Look at all decently built performance engines.) We have 360 Horse on 330 Cubic Engines, and this is with a blower, kind of lame in my opinion. There’s a lot of room for improvement, at least in my mind. (Not flaming my own truck, trust me, I love my beast)

I think with a good after market exhaust, the correctly calibrated chip, and a blower running at 2.5:1 we could easily get another 60 to 100hp out of our engines, but this is just my philosophy. Hoping someone else follows my logic, or even better can tell me what’s wrong with mine. I don’t want to start investing without solid logic in my horsepower quest.

Last thing, I realize this would decrease engine/drivetrain life, but I’m after a performance vehicle here, not a daily driver for 100k miles.

Opinions please!
Thanks
Brad



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* 99.5 Black Lightning
* Factory CD Changer
* Class 3 Towing Hitch
* Factory Tonneau Cover
* 8" Bazooka Tubs
* Kenwood 80 watt *2 amp
* 50% Window Tint
* Viper 550 Alarm w/ remort start
* 98 Yamaha Banshee w/ Toomey T5 Chrome pipes often found in the bed..

Injection is nice, but I'd rather be blown. 99 Lightning, the best of both worlds!

 

Brad...

You post some interesting views on this area of CFM vs. ratios. I am not at all an engineering type who likes to calculate things here. What would worry me is that sure, theoretically, what you propose may work or be somewhat close to what you are stating by gaining a extra 60-100 HP out of our engines....I think what it would come down to though is where the weak link is. As everyone knows of course, the more power you add, the more strain you put on everything else in it's path. Somewhere along the line there has to be a weak link that will break. Like all vehicles, there is always room for improvement. However, with having already 360HP at the helm, I am not sure how much more this truck can take. The motors seem strong enough, but my personal view is that I don't like to push those upper limits. Each time I do that, something breaks.

As far as the exhaust....everyone here seems to state that this exhaust flows so well and that you don't need one, etc....I am ordering a Borla for the spring and when I take off the old system, I will definately be checking how efficient it really is.

Paul G.

 

Simple solution that meets the needs of the daily driver and the beast tamer... Nitrous oxide! 100-150hp with a flip of a switch and bang on the throttle. If you really want to run some numbers with your truck get a progressive controller for the nitrous system. This is a must for high hp motors!! Let me just tell you 100-120 shot of nitrous is not alot ! We run 100-120 shots of spray on our unlimited shootout bikes. these bikes make more hp than 360hp. We have to run on DOT street tires in our class with no wheelie bars!! Progressive controllers for the nitrous is the only way to get down the track without spinning the tire!! just my .02 cents.

 

Another thing to take into account is heat generation. Spin the blower faster and you are going to heat the intake air more, resulting in a less dense charge. You would probably want to look at a more efficient intercooler to lower temperatures on a higher-speed blower.

 

i had asked this question a couple of times, about bypassing the intercooler, taking advantage of the boost lost to the intercooler, and using a water/alcohol spray to control detonation. i use this on my dodge and it works well.