ramtd02

Buddy of mine just dynoed his truck, he has a BDTDw/crazy larry, and an edge EZ, pretty much same truck as me with the g56. For some reason the dyno he went too told him too dyno in 6th?? It was a mustang dyno and he put down 452/1765.....he thinks he should be closer too the 490 mark.

What kind of difference would he see in 5th gear?? I figured he would be about 480, but would he really lose 30 hp by dynoing in 6th?? We are still on Winter ULSD, but on the winter fuel i put down 507 on a mustang in 5th.

anyone have an idea of what he is really putting down?? By really i mean dynoing properly in 5th gear (direct).

TIA
Jon

ramtd02

bump

anyone have an idea??

morkable

Which dyno? When I dyno'd my truck I tried both in drive and od, worked better for me in OD.

Kevin

Luvnacumns

Maybe I'm stupid but 452 Hp 1700 in torque... Isn't the torque high????

Shane

dodgezilla04

"BDTDw/crazy larry, and an edge EZ, "and 1700ft lbs? is that a typo? if not, i need to sell my stuff and buy what he's running. i dont see how he can get quadrupple the torque. usually it is twice, not 4 times.
supposed to dyno in 5th due to the 1 to 1 ratio.

Luvnacumns

That's pretty much what I was thinking....

ramtd02

thats what the dyno sheet says.....but i was under the understanding that taller gears on the dyno yielded lower hp and higher torque.

He was on a mustang dyno at a shop here in edmonton, it wasnt GCL or sub-racing.

Just wondering what kind of hp losses are there frome dropping too 6th vs. the proper 5th?

RustyJC

Dyno in direct drive (5th) on a load-type dyno like the Mustang. This minimizes losses in the transmission.

Dyno in 6th (OD) on an inertia-type dyno like the Dynojet 246C. This places more load on the engine and helps the turbo spool harder and faster. I made 2 pulls in 5th (~325/650) and 2 pulls in 6th (347/762) to quantify this to the dyno operator.

Rusty

JD Dearden

I think dyno numbers are all a waste of time, Guys always roll in to the shop and show some graph where there PS dyno'd at 760hp or whatever than they run a 14.6 sec quarter mile whatever.

ramtd02

i fully agree, there are trucks in the low 600's that would mop the floor with a truck in the mid 700's, tuning and where the power is, is more important.

ramtd02

On the DJ, i used 5th gear, the dyno operator knew what was going on and applied the brakes too spool the turbo for me!

RustyJC

Once he came off the brakes, though, the engine would be pulling against a heavier load in 6th. Using 6th gear is equivalent to adding inertia to the dyno drum. The more inertia, the more load the engine is working against.

Try it both ways - you may be surprised!!

Rusty

acook

I like to use the track as a dyno myself.

qzilla

The problem here is that the software in the mustand dynos is made to only work with a 1:1 ratio. If you dyno in a higher gear than that the HP numbers will fall and the torque numbers will rise. IF you dyno in a lower gear the hp numbers will rise and the torque numbers will fall.

If he did not use 1:1 you can just throw the paper away.

Dynojets are not affected by gear ration because of how the do the math they can automatically correct for gear ratio.