Preferred Dyno Pull RPM Range w/Data

[itstock]

I chose 2500 and up, but if a dyno operator or engine builder or tuner or...most anyone (because they probably know more than me about it) suggested they start the pull later, I wouldn't think twice. On the loaded chassis dyno they started my car at what looks like 2750. I wouldn't care if they started it at 4500.

[AL427SBF]

Reset ...

As cobra replica owners with motors built to perform, tell the forum what RPM range you are interested in for Dyno Pulls to measure your engines performance.

1. 4500 up to your specified max. RPM ... 0 votes
2. 4000 up to your specified max. RPM ... 0 votes
3. 3500 up to your specified max. RPM ... 3 votes
4. 3000 up to your specified max. RPM ... 7 votes
5. 2500 up to your specified max. RPM ... 16 votes

Appreciate the participation, enough data to show most drivers would like to see how their motors build power over the drivable RPM range.

[Jerry Clayton]

Hopefully this will work
C:\Users\jerry clayton\Pictures\2013-05-03 Komet

Wellllllllll---this isn't going too good, but----this is 2 pulls on a Mustang Chassis Dyno---One with a K&N aircleaner with their extreme top and the other run with the aircleaner off but without the base plate that I like to have to smooth the airflow-there are 50 ft lbs torque and 50 hp between the horizontal lines so you can see that up to about 4200 rpm that it made about 20 hp and 20-50 ft lbs tq differance----



Sorry----but I mistyped some numbers--there are 50 hp/lb tq between the horzontal lines---differances are 10 - 20 or so on tq and 5 - 10 hp maybe 12-15 in a couple spots----- I seem to have memory of other tests where we had 8-12 hp differance but don't remember what size engine------

[ERA Chas]

Barry-you're making the same well-intentioned mistake that Brent and Jerry did. All of your experiences and knowledge have been wasted over the course of 3 pages here.
Some customers you don't want.

[Jerry Clayton]

I think that a lot of the differances in concepts come because of the differances of a eddy current chassis dyno and a water brake engine stand dyno-----the eddy current will add a controlled rate of load depending on vehicle data loaded into the controller computer----it is based on rolling and aero load of the vehicle---a water brake dyno doesn't do that--you add load to hold the engine at the rpm instead of letting it accelerate along a curve representing the vehicles dynamics-------

and then there is the inertia dynos that compute numbers based on time to accerate a weighed load( as in a big steel drum full of concrete---------

[Barry_R]

Not in any position or with any intent of questioning Jerry's data there - but 50 pounds of TQ from an air cleaner change seems like an awfully big change...

[vector1]

Originally Posted by Barry_R

Not in any position or with any intent of questioning Jerry's data there - but 50 pounds of TQ from an air cleaner change seems like an awfully big change...

If the bottom two lines are the a/f ratios, I guess that would be part of the reason plus airflow smoothing of a good base plate.

[Jerry Clayton]

I edited the post where I had mis typed---

[Barry_R]

No problem. I was trying to be "delicate" about that...

[Jerry Clayton]

I used to have a base plate that I could fasten down on the carb but someone must of borrowed it----seems like there was a consistant 8 hp differance between no cleaner and an K&N extremetop 14 x 3 unit------