Single pump, SB 66 and 120's = 918/2000 !!!!!

What's a manual vs auto with twins race gunna prove? From a dig most any built auto will walk on me. My trucks built for sled pullin but goin to race in florida for valair
 
I know of a silver Dually that'll run ya Richard... Lol






And John, I'd really like to be a believer cuz that would be awesome numbers, but your speedtek numbers kinda make me think the floor it numbers were a fluke. Oh well, I'd really like to be proven wrong
 
smoke machine said:
Never in 5th. Always been told to pull 6th. I've bn on alota different dynos.
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The reason "other" shops tell you to dyno in a higher gear is because it makes their products shine.

If you listened to one of your pals, then they don't know how a dyno or a motor runs in the correct gearing.
 
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Yea I think Floorits dyno is more the problem then the gear.. But the gear probably fudges the numbers a little more on top of it all.
 
smoke machine said:
What's a manual vs auto with twins race gunna prove? From a dig most any built auto will walk on me. My trucks built for sled pullin but goin to race in florida for valair
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We can find us a private spot....70mph roll....whatever.
With your 918 hp you should kill me...twins or not.
 
Above 3k on any dyno the truck will make 650 all day. We tryd 5 different tunes all with in 10hp of each other. Its always done the same on a inertia dyno
 
You got it. I'm leaving Houston Wed afternoon, should be in town Thursday afternoon. Maybe we'll meet up along the way.
 
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UNBROKEN said:
Wasn't even that...was a Dyno Dynamics
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Still and inertia dyno correct?


If it wont load an engine to the point it drags the rpms down I just cant agree with any of it.

Inertias just tell me that X motor revs up at Y while turning Z amount of weight.
 
What kind of dyno is a dyno dynamics? Is it a load type dyno like a mustang that measures torque and calculates horsepower? Or is it inertia like a dynojet that measures hp and calculates toque?

I could see using a different gear skewing a mustang dyno, but I find that theory hard to apply to a inertia dyno :pop:
 
Yes, but you take a 1500 hp puller on a DJ and it does nothing. A loading dyno will show 1500. In my mind, you can purposely build a dyno queen that will show 700hp and get its ass stomped by a 600hp truck.


I dont see F1 cars using an inertia dyno, me thinks they is a reason.
 
Not to get into a dyno argument but if you aren't loading a 1500hp engine on a dj its because your roller isn't big enough to load it (most aren't for that much power).
I agree with your second point, peak power doesn't mean much if the rest of the combo lacks. Dyno's should be a tuning tool and only a tuning tool.
 
White Knight said:
What kind of dyno is a dyno dynamics? Is it a load type dyno like a mustang that measures torque and calculates horsepower? Or is it inertia like a dynojet that measures hp and calculates toque?

I could see using a different gear skewing a mustang dyno, but I find that theory hard to apply to a inertia dyno :pop:
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I agree. And as to whether the dyno was loaded or unloaded I'm gonna have to say it was loaded. As the o.p. stated he made more boost on the dyno than he does on the street. You're not going to see that on an inertia type dyno. Which also shows that the gearing manipulated the numbers.
 
Sandaholic said:
I agree. And as to whether the dyno was loaded or unloaded I'm gonna have to say it was loaded. As the o.p. stated he made more boost on the dyno than he does on the street. You're not going to see that on an inertia type dyno. Which also shows that the gearing manipulated the numbers.
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Good catch, I didn't notice that before. That .79 of the overdrive puts 918 down to a reasonable 725
 
TMONEYDIESEL said:
One of the most common differences when conducting roll-on power tests on a dyno is in the gear used during the test. Although 4th & 5th gear (depending on tranny)has been the standard, some dyno operators prefer to use a higher gear, and now 6th gear, which can distort comparisons. Power readings recorded in 6th are generally higher than those performed in 5th gear. Generally, the higher the transmission gear, the greater the engine loading and higher the power reading will be. Since the higher gear ratio slows the engine’s acceleration rate, less power is required to accelerate the rotating and reciprocating parts.
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If you're going for flywheel HP. Sure. For wheel HP, who cares. It's power at the wheel in that gear. If you are going to argue to use 5th or direct, then you need to make everyone use a common tire size and diff ratio. It's all math, the power at the wheel can be figured even with a .73 mixed in there. In the end, 6th gear provides the longest pull and will load the motor sooner.

Just because gassers do it that way, doesn't mean diesels should follow blindly. At this SS race there's a dyno right? There will be a scale? do the math for a few trucks that dyno in 6th.

On a dyno dynamics tho, the eddy current should provide enough feed back to spool a charger in 3rd. :) No so much the case on a dynojet 248

The one thing I dislike about dyno dynamics dynos with no alternator or ODBII RPM hook up is the miss match for RPM that the dyno is "calculating" and the real rpm the motor is making. This obviously directly reflects the HP number. the torque number is correct, just wrongly placed on the graph (hence the wrong hp number)

In my history here, MPH to HP calc has been very close to HP numbers dynoed in 6th, dyno jet or dyno dynamics.
 
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