Originally Posted by lukesdiesel

The issue is your smart ass comments.

When you dyno you want 1:1 gear ratio otherwise your scewing your numbers by using the gear ratio to produce better numbers. 1:1 or direct drive usually yields better hp while in OD usually yeilds the best torque number.

Originally Posted by Hammer

Very Incorrect...
The actual difference vetween usning O/D and Direct is not enough to even make a fuss about.In reality you want to dyno usning O/D as it will aid in the load and spool of your charger.When done in direct the run value is so short that many chargers will not be spooled thus numbers will suffer greatly.By doing your run in O/D it will best simulate the conditions that your truck see in daily manners thus giving you the best idea of how it will perform in those conditions.

Weston...
One thing we have seen many times since the Quad boxes hit the street is how poorly they perform on a dyno and how bad they sputter and break up as seen in that vid.Why anyone would buy such a product is beyond me,but,its not my money nor my truck so I guess its a deal where they get what they paid for.In ALL of the 24v trucks which I have seen dyno,from heavy hitters to daily drivers,the best all out box for these type of trucks is the TST PM3 Comp version stacked with an EZ for timing.I have seen Fred Huber(Offshoreracr),Doug Leonhard(DLeonhard) and Doug Smith(JetPilot) all go way into the high 600's(The two Dougs' both with single chargers and Fred with a B1-B2 Twins setup) on fuel alone.We have never seen a Quad box go into the 600's nor get close at any of our shows.Honorable mention for best fueling 24v boxes would go to the Edge Drag Comp and the old DD UFM Drag(Diesel Dynamics Ultimate Fueling Module,which was basically a Edge Comp).

I also agree with Dan on the dyno being a tuning tool....
I have made and witnessed many runs on all types of dynos since the craze hit many years ago.You will find that the smaller wheeled jets often inflate HP numbers greatly and usually are harder to reproduce your results run to run.The larger wheeled jets usually produce a more repeatable number and can often give you a better idea of how the street manners of your truck will be.The load versions of the various types can often confuse a owner as evehn in daily driving your truck is not loaded all the time.To me a load jet would be very useful to a owner who tows heavy or in mountains all the time or a sled puller where max load is seen from the throttle stomp until the pan's sprags hit the dirt and stop them.Those type of jets and their different tuning would allow owners to see how their trucks respond to long sustained EGT blasts and allow them to tune for the best performance with even EGT's.

I have seen runs in O/D and in direct with little change between the results.Tire diameter changes only move the graphs parameters right or later in the sweep making power and tq later in the curve.Tire and wheel weight however will change a run enough to make a difference.A lighter tire and wheel combo allows the truck to get lit faster and one which is heavy delays the runs values.I have but one issue with dynos and their numbers made and thats when someone takes the numbers made from a small wheel jet(which usually are alot higher) and tries to stick their chest out and play childrens games of mine is better than yours with a guy who has only rolled on a large wheeled jet.The numbers are what they are and people need to take into consideration the jets they run on and that no two are the same.I am the one Weston refers to with numbers that only varied 2hp from a 248C at SGS Performance to the Mid-Atlantic Diesel 248X.We just had our dyno day and had a member,Gene Peters(AKA the Geriatric Juvenile)from NJ who was on a Mustang 1750 Single Eddy load dyno the day before our fall show.To show the differences of the jets Gene made 606hp/1450Tq on the Mustang 1750 and made 635/1125 on the 248C,so which was the real number or test of the truck(both runs were made with Water Meth)?.To me both are as they both tell you what the truck is capable of in two different types of conditions.Is 1 run better than the other,nope not to me as both are very useful pieces of information if you use them as the tuning tools they are............Andy

Andy, I told Rick he needs to hit up that dyno @ Danville, you know what I mean.