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We have a Land & Sea Dyno in our area.
Owner prefers to use ramp settings but some tuners have found that vehicles seem to get too much load at high rpm.
Could there be a setting that is incorrect on dyno?
Also what do you guys prefer ramp pulls or road simulation setting for tuning on dyno?
I'm not familiar with the Land & Sea dynos, however most load bearing dynos work in a similar way. If you are using the dyno to perform ramp runs, generally the dyno can be configured to allow a certain acceleration rate (rpm per second or kmh per second for example). This will define the amount of load placed on the engine. I generally try to replicate the way the car accelerates in a high gear on the road. You need to apply a reasonable amount of load to be realistic - 500 rpm per second is a pretty reasonable place to start I find.
I also use the dyno in two ways which you will see in our Dyno Tuning course, or if you have watched some of our webinars. To map the part throttle area I use the dyno in steady state where the load is varied automatically to hold the engine speed steady. You can then move up and down the load rows in the ECU using the throttle and do a great job of filling in the entire map.
To tune at WOT I use ramp runs as described above.
Hopefully this information will help.
I looked at buying a Land and Sea before opting to go for a Dynapack instead. It does work the same as most modern roller type dyno's with eddy current brakes to control speeds. As Andre has said it depends on how it's been programmed to create the runs as to how it delivers load on the vehicles. Do you know how long the runs last over what kind of rev range?
Does the ramp setting increase load as the car accelerates or does it hold a constant load?
Not sure how guy as ramp set on dyno. Will have to check it next time I carry a car.
We normally do pulls from 3000rpm to 9000rpm (mainly Hondas). When vehicle gets in the 6000rpm the load feels like it starts to increase.
Is there a set time duration on a ramp run?
Is the load suppose to remain constant through out the run?
Normally the dyno will perform a ramp through the rpm range at a fixed rate. This actually requires that the applied load varies to cope with the changing torque production of the engine.