Competition Super-nice AWD Dyno in Georgia!!!!!

[jetenginedoctor]

Just thought I'd show everyone something that might be of interest. Dyno4mance in Calhoun, GA has one of our AWD dynos with a second retarder on the rear dyno bed. This dyno can test vehicles with power in excess of 3000 HP!!!!!



Here are links to some photos on their website that are well worth a few moments to look at. They've even got stadium seating and a projector screen setup for first-class dyno competition events!!!! This is a first rate dynamometer in a really great facility. Those of you in the South Eastern US owe it to yourselves to check this place out, and perhaps arrange a TDR dyno day with these folks.



http://www.dyno4mance.com/tuning/dynamometer/DynoSetup.php



http://www.dyno4mance.com/tuning/dynamometer/DynoSetup2.php



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[snowracer69]

Does the wing help when you put that yellow thing on the dyno? :-laf

 

[GatorRam]

On top of the 85+hp that it adds, it also allows you to push it up on the rollers like a big shopping cart. :-laf

 

[jetenginedoctor]

On top of the 85+hp that it adds, it also allows you to push it up on the rollers like a big shopping cart. :-laf

Heh-heh. . . . no comment. . . . :-laf

 

[DHRA]

Thanks for the information, this could be a great tool for 4wd drag racers and sled pullers to do some tuning!

 

[jetenginedoctor]

This is what Piers dyno at PDR will look like when he upgrades to an AWD setup. It's pretty incredible watching an AWD dyno test, especially when the vehicle tested is making obscene amounts of power. . . .

 

[Kernel]

Hey Brian,



I can't really make it out that good, but what kind of numbers is that ricer in the background putting down?



Scott

 

[NPloysa]

Hey Brian,



I can't really make it out that good, but what kind of numbers is that ricer in the background putting down?



Scott

Looks like, starting from the top:



153



1162



49



That's all I can see!

 

[jetenginedoctor]

That'd be 153 HP, 1162 lbs of Tractive Effort, and 49 MPH.



BK

 

[NPloysa]

That'd be 153 HP, 1162 lbs of Tractive Effort, and 49 MPH.



BK

Yeah, that's what I meant



How much torque you think? 10, maybe even 12 lb/ft!?

 

[jetenginedoctor]

Yeah, that's what I meant



How much torque you think? 10, maybe even 12 lb/ft!?

It doesn't matter. HP matters. Tractive effort matters. All engine torque dictates is how fast the engine has to turn to make a given amount of power.



HP is king.

 

[Kernel]

What is tractive effort and how does our trucks compare?



Scott

 

[CGriffith]

Thats a nice lookn' set up. I wonder if the display is still readable with a thick cloud of partially burnt #2 in the air.

All of the ricer shops I have been to don't have a good way of pulling all the smoke out of the shop. The guy at the last dyno day tried to tell me that 40ft of 3. 5" flex pipe had no effect on the engine at all, which we know isn't true.

How you all deal with the black cloud at real dyno shop?

Also I thought a mustang/constant load dyno could handle the highest of HP trucks. Why do you need a AWD dyno to get all the power to the ground?



A good wing is heated so your hands don't get cold while pushing

 

[LaserBob]

The Flex pipe at PFI slips over a piece of 4" exhaust pipe to make the connections. It is not 3. 5" flexpipe.



It will no doubt have a small effect, but 98% of the trucks ran through the pipe. Only the duals and one other (I think) did not connect up to it.

 

[NPloysa]

It doesn't matter. HP matters. Tractive effort matters. All engine torque dictates is how fast the engine has to turn to make a given amount of power.



HP is king.

HP is king for a gasser, sure. Most ricer drivers don't care about torque, but I only asked because our trucks do make plenty of torque.

 

[jetenginedoctor]

What is tractive effort and how does our trucks compare?



Scott

Tractive effort is the end result of your engine's crankshaft torque, engine horsepower, transmission gear ratio, rear axle ratio, tire and wheel size, all the frictional and inertial losses from everything from the crank flange to where the tires meet the ground. It's the amount of 'push' your powertrain and chassis produce together to accelerate the vehicle or carry it up a grade. This is what a guy needs to be aware of when making tuning or setup changes on a car or truck, not crankshaft HP or torque. You want to be able to make as much tractive effort as possible, and you can do this by carefully choosing your gear ratios, shift points, etc. This is what makes your truck faster or move more weight up a higher grade with more speed.



Make sense? Think of it as you would the thrust that an aircraft engine makes. The different gears in the transmission works much the same as a variable pitch prop would. A lower angle of attack on such a prop takes a smaller bite out of the air, improving low speed climb-out performance. As the aircraft accelerates, the angle of attack is changed to take a bigger bite out of the air, increasing airspeed and high-speed efficiency. However, increasing the prop angle too much at too low an airspeed results in the prop stalling, not accelerating the aircraft much the same as your truck will lug down if you're climing a grade in too high a gear.



If you could put a big fishing scale in a chain between your truck's rear bumper and something anchored to the ground, tractive effort is what the fishing scale would read.



I know this isn't a great explaination, if I'm not being clear enough, please say so and I'll try to think of a better way of explaining.



BK

 

[jetenginedoctor]

How you all deal with the black cloud at real dyno shop?

There are a lot of ways of effectively scavenging exhaust away from a vehicle being tested. The really slick setup is a large exhaust fan pulling through 8 inch flexible duct hose with a 10 inch high-velocity axial flow fan pulling exhaust straight from the tailpipe/stack and pushing it up to the big exhaust fan. I believe this is how Piers does it at his shop.

Also I thought a mustang/constant load dyno could handle the highest of HP trucks. Why do you need a AWD dyno to get all the power to the ground?

There are more and more AWD cars and trucks on the road every day. Unless you have an AWD dyno, you can't test these vehicles without damaging the center differential/transfer case. A lot of sick-ass little foreign cars are AWD, as are a number of Chrysler SUVs with the big V-8 engines. These guys gotta have SOME way of testing, and we've provided the best way to do it.



As far as dyno'ing a 4WD truck on an AWD dyno. . . . you'll always get the best test numbers in 2-HI, but some guys really want to know what they can put to the ground in 4-HI. This is what some really heavy-hitting diesel drag racers are doing with 4WD trucks, launching in 4WD to get a better holeshot. They've got so much power, they don't really CARE that they're losing some in the transfer case and front axle geartrain!!!!! These are bad hombres, my friends. . . .

A good wing is heated so your hands don't get cold while pushing

Heh-heh. . . . . comedy gold. . . . :-laf :-laf :-laf

 

[snowracer69]

These are bad hombres, my friends. . . .

hehehe... hey, I'm part of that group now! Oo. :-laf LOL!

 

[jetenginedoctor]

HP is king for a gasser, sure. Most ricer drivers don't care about torque, but I only asked because our trucks do make plenty of torque.

HP is all you should be concerned with as well. Any engine with much HP and less torque at the crank can gain torque by means of a gearbox. Consider a modern helicopter, for example. The turbine engines that power them have shaft speeds typically 30,000 RPM. The turbine makes a lot of HP, but little torque. This speed is reduced in a gearbox on the engine, and torque is multiplied. This shaft speed is reduced again inside the main rotor gearbox, and likewise, torque is further multiplied. Think about how much torque it must take to swing those big-ole' rotor blades through the air fast enough to lift a chopper and it's payload into the air, and fly along at 200 MPH. It's all a matter of power available (HP,) and using torque multiplication by way of geartrain to put that HP into a useable form.

 

[Kernel]

So, tractive effort and gearing are related in that a change of gear can help you gain or loose a certain amount of tractive effort... am I following you right? You have a given amount of tractive effort depending on horsepower produced and depending on what sort of gearing ratio etc. you use, you are either using it or losing it through your drivetrain. Indirectly it is a reflection of torque?



Scott