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Photos Mechanical Supercharger

RollingThunder51

Gunny Sergeant
Full Member
Minuteman
Feb 15, 2009
1,571
1
U.S.A.
As my son leaves for Engineering school, I insisted he work his way through a full Viper block build out. When we were done, he had wrenched it all, boosting us up to just short of 650hp. This is a mechanical supercharger (without W/M) that all fits under the stock hood. Most importantly was the time spent being able to control the millisecond injector response (independant) in open and closed loop. We can keep us at Lambda all the way out the curve. This beast will do the job everytime, if your hand isnt on the shifter at launch it isn't getting up there until 60. American Iron, think Big Daddy Roth meets Vin Diesel. Listening to this thing wind up is as good as it gets.

Next summer he will be working on the new birds at Sikorsky.
 
Re: Mechanical Supercharger

That thing is gorgeous!
Would it fit in my '00 Tacoma?
smirk.gif
 
Re: Mechanical Supercharger

I like it are you ready to do mine? Looks great what gen Viper do you have? The one thing I love about the Vipers is that there is no mistaking them for anything else, you know its a Viper from 1760 yards. Very nice indeed.
 
Re: Mechanical Supercharger

One is enough for me. GenII GTS, steel grey no stripe. Thanks, you can do this, a Colorado winter is a perfect time.
 
Re: Mechanical Supercharger

What does "without W/M" mean?

You mention 'mechanical superchager'. But aren't all supercharges mechanical, being driven from a belt / chain directly from a pulley. Versus a turbocharger that derives its power from exhaust gases.

Just trying to figure out the meaning.

Edited: Post some more info on the viper itself. Those cars just REEK sexy.
 
Re: Mechanical Supercharger

Lots of different terms for the same thing. Blown has originally meant supercharger, but lots of slang including mechanical, huffer, blown, etc. There are as many different versions of superchargers and turbochargers out there also, like the amount of lobes on the supercharger the length of the lobes, whether they have a slight twist or even vortex style that is lower profile literally air coming in at one end and coming out the bottom on the opposite end. you have belt driven, gear driven, belt driving gears that spin the supercharger faster like a paxton. Don't even get me started on the numerous different version of cooling the charge and the supercharger. As to turbocharging you can have blow through (old school) intercooled, intercooled with liquids like water and methonal etc. turbocharging has come leaps and bounds in the last 10 years or so with variable vanes to spin up turbo's into boost faster (makes a big turbo appear smaller allowing fast spool up) diesels love em' and you really can never get enough air (to much) in a diesel only not enough. Fingers tired must get food....

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Strickland</div><div class="ubbcode-body">What does "without W/M" mean?

You mention 'mechanical superchager'. But aren't all supercharges mechanical, being driven from a belt / chain directly from a pulley. Versus a turbocharger that derives its power from exhaust gases.

Just trying to figure out the meaning.

Edited: Post some more info on the viper itself. Those cars just REEK sexy.</div></div>
 
Re: Mechanical Supercharger

yeah, those variable vanes were coming out right about the time I got bored with my GN. I remember see the numbers that some of these turbos were putting out compared to the TE44 I had.

Nothing like running 26 PSI at the track on 110 Octane, or 18 on the street with pump gas. Pushing the edge.

Oh the days...I do miss that car. I just don't miss working on the damn thing.
 
Re: Mechanical Supercharger

All above correct.

Mechanical means turning off the crank..or operated mechanically. Not all superchargers are "mechanicals" as in; running one off of exhaust pressure is not. Mechanicals are "off the line" meaning they wind up right from the start unlike a turbo charger (also a supercharger) that has to wind up to kick in farther down the rpms. Mechanicals are old school, think dragsters, but running two (2) on board laptops and a VEC means that the curves are near perfect. We go therefor we are. BMWs for breakfast, Ferrari and Porche for Lunch.
 
Re: Mechanical Supercharger

If yours is Steel grey that has to be a 2000 as that was a one year color. That is the same as mine execpt mine is the ACR and yours has the charger. I might talk to you again this fall and see how yours is doing. I would really like to do something to mine. One of my customers has a 1400 HP twin turbo Viper that I still havent gotten a ride in. Take care and enjoy.
 
Re: Mechanical Supercharger

Sean, not at all, to some "lambda" is a life's persuit.

In a standard gas engine there is a perfect mix of air and gas, that ratio is most efficient at what is called "lambda". lambda is achieved when 14.7 lbs. of air is mixed with one pound fuel. The target, constantly being adjusted for engine load and other engine and driving conditions in the lambda is just that, 14.7. For those of us that want to see if in closed loop our cars are operating at lambda, we can. We do this by using the oxygen sensor that samples at a much higher rate then those found in stock Vipers. Stock Viper's Oxygen sensors are narrow band sensors, guys/gals that want to more accurate view their engine's ability to achieve lambda in closed loop operations rely on gauges driven by wideband sensors. As load changes, so does the require A/F (Air Fuel) mix. It would be incorrect to assume that simply having a wideband sensor and wideband gauging your car is going to allow one to properly address all issues surrounding closed loop operations. We also need a high-quality software interface (program) to the ODB2 found in our GEN2 vipers. I have one, it plugs into the drivers left hand knee location of the OBD2 fitting under the dash. I can directly look into the PCM's operations, especially the adaptives and make sure they fall within a specified range of the stock PCM operating throughout closed loop. In open loop, well that is where the fun starts and that is where two more computers kick in. There is of course more on this subject, lots more, but there you have a very simplified begining.

Prior to about 1986, big assed supercharged rigs were tuned for their high rev performance profiles. When you coasted to a light or drove slowly, your rig would sound like crap. That sound was the lugging sounds some of us remember growing up with. Now, throughout the whole rpm range we acheive a perfect balance. I actually cut 60% larger injectors back to stock levels when driving around normally. When I get on it, those same 60% larger injectors deliver more gas than would ever be possible with stock injectors. 15 years ago, that would have been magic.

Here for your enjoyment is a 1,000hp supercharged rig without computerized tuning. Set up to run well at high rpms, you can hear the surging and lugging at idle and low rpm. The young man you will see at the end of this video (brown jacket) is the kid that grew up to build this Viper engine. He knew more at 16 about engines that most men know at 50. If it goes....he knows. No, that is not me, that is one of the greats of the big rig makers, Big Al, 9,236 supercharged engines and counting.

http://www.youtube.com/watch?v=La0Fqb5uzFA&feature=related

Now, before somebody screams we are off rifles here. You would be surprised at the number of excellent rifle makers that come from the skill set and tolerance sensitivity found in racing engines. Everyone at Nemesis did, in fact David Ives first built IC circuits (computer chips, astonishing tolerances) before being dragged into the heavy duty race world.
 
Re: Mechanical Supercharger

In a modern vehicle perfect lambda or Stoichiometric is actually not desired in a modern vehicle as it will "load up" the catalytic converter. Ideally you will want a rapid fluctuation of the air fuel rate and of course perfect lambda "1.0" is perfect Stoichiometry and that will very from 14:1 based on the fuel being used as an example methanols will have "less air" a lower first number because methanols are an oxygen rich hydrocarbon. perfect lambda also may not be the perfect design parameter either as Chrysler in the early days experimented with lean burn designs "they were a pain in the ass to be honest" and Honda has played around extensively with lean burn and often run as high as 22:1 and Mitsubishi has a vehicle out I remember was almost 25:1. This often is mistaken in thinking it will raise NOX emissions but it actually is very helpful in reducing them. As to horsepower a lot of magic is used to get the burn right in drag racing when you "set em' up right" you can burn a gallon and a half or more of nitro per second and 3000 cubic feet of air and each cylinder is on the verge of hydraulically locking! With a couple of magnetos you can run as much as 50 amps continuous to each spark plug! Most depending on altitude humidity, temp etc. will run approx 7:1 AFR nitro in a cylinder burns about 7,000 degrees F.
 
Re: Mechanical Supercharger

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RollingThunder51</div><div class="ubbcode-body"> boosting us up to just short of 650hp.
</div></div>

very nice work but I am suprized it is only 650 hp my '68 single 4 barell made about the same hp.
3500 pounds ran 10.20 in the quarter
 
Re: Mechanical Supercharger

TM, what you say is absolutely true. But, I thought too much for the uninitiated. As you say, Lambda numbers are actually targeted to intake compression variables as well. In open loop, I target about 12.2 in this rig. Still, when we go back to closed, we actually do revert to an injector recalc that drives it up to 14.7. As to the cat issue, proper cats take 14.7 all day long without an issue. I added a log above.

The 650 number was the tipping point for us without introducing the w/m variable. Remember, in this rig we are already breaking tires free when accelerating at highway speeds. As Strickland stated above, if you take this too far, you can spend all day under the hood...not necessarily to keep running, but at this level one ends up knowing when things are right or wrong and one wants it right 100% of the time. 650 horses that did well at 35mph or 200mph is a thing of beauty.
 
Re: Mechanical Supercharger

The cats do require the above and below lambda to make them work properly as the NOx, CO, and HC need differing levels of "richness" and oxygen to "scrub" or release compounds to perform the change to O2, CO2, and H2O. The best cat efficiency is a very rapid fluctuation of approx 20% above and below 1.0. Your ride looks great and It sure is a lot of fun to take them for a spin. Nothing like the pull of a nice big V8 with a supercharger that can really make em grunt down on the low end. Or the tunnel you see when up at 200 plus. been there a few more times than I care to admit.
 
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TM, V10...with its odd firing sequence and a whinning supercharger is surreal.
 
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I only had traction issues if I lifted before nailing it at freeway speeds. from a standing start I could hook it up in less than 1 car length with the street rubber and some fancy clutch work.
 
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I've already been there and done that...both EVO and Shovel, take my advice, not worth the effort and expense for anything other than the strip. A complete PITA.