Thread: Power Loss through Drivetrain

There isn't a formula, Dyno's are mythical power figures and way to easy to fudge, they are a tuning tool and only good for comparison figures, I.E. you gained 15% mor HP, even different gear selection change the HP figure

Only way is an engine Dyno

I am no mechanic but I do know cars lose power as they age "depends on how well they have been looked after equals how much power they lose." In other words a well looked after example would have not lost as much power as a car that's been abused. 95 Disco 12 year old car I would have thought this is about right.

One of the mechanics should be along soon to put more of a tech spin on this.

Your figures are good..

The landy constant driveline is a power hungry beast..

We engine dynoed my V8 then fitted it and ran it on a chassis dyno...

More than 55% driveline losses...

Originally Posted by rovercare

There isn't a formula, Dyno's are mythical power figures and way to easy to fudge, they are a tuning tool and only good for comparison figures, I.E. you gained 15% mor HP, even different gear selection change the HP figure

Only way is an engine Dyno

That wont change HP figures much. Power is torqueXangular velocity. with bigger wheels, or a diff gear, angular velocity increases, but Torque decreases. They are usually pretty accurate.

Originally Posted by tombraider

Your figures are good..

The landy constant driveline is a power hungry beast..

We engine dynoed my V8 then fitted it and ran it on a chassis dyno...

More than 55% driveline losses...

Imagine how a freelander with the 1.8 feels! lol atleast there is less to lose. :P

[QUOTE=beforethevision;623488]That wont change HP figures much. Power is torqueXangular velocity. with bigger wheels, or a diff gear, angular velocity increases, but Torque decreases. They are usually pretty accurate.

[QUOTE]

When we Dyno'd the mini sprint on one Dyno it registered 110hp at the back wheels at 8500rpm in 2nd gear, went to another dyno as the other was too far to travel and nothing had been done to the engine but we wanted to start playing with the jets and had only done 1 race in between and same 2nd gear 8500rpm was 121hp before changing anything.....

Engine dyno'd with the same set up was 113hp but considering that there was very little drag on the driveline and the tailshaft was only 8" long and the gear box only had 1st and 2nd gear we thought the 110hp would have been closer to the mark.

Chassis Dyno's are not to be relied upon, as Rovercare said, they are a tuning tool only.

Originally Posted by beforethevision

That wont change HP figures much. Power is torqueXangular velocity. with bigger wheels, or a diff gear, angular velocity increases, but Torque decreases. They are usually pretty accurate.



Imagine how a freelander with the 1.8 feels! lol atleast there is less to lose. :P

Spent much time on a dyno? try 20-30Hp atleast differences for different gears and tyres

Spent a few, yeah :P Albeit one chassis dyno, with the same 13" wheels, but running similar maps with similar weather getting within 2 or 3 HP. Even after changing drive sprockets not seeing more than 5-10%.

But no, i havent had a chance to 'get around' as far as dynos go.