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Old 01-07-2013, 07:32 PM   #45
Scooby Specialist
Member#: 323379
Join Date: Jun 2012
2014 Diesel Cruze
Yamaha R6


Originally Posted by Dave D. View Post

I see your point, but many here think that track numbers are the final word in measuring engine output. Would you say that efficiency is then improved by a good track TC? That lower ET has to come from somewhere, and is clearly not an illusion.

The graph at least indicates that.
A good torque converter will improve ET by getting you immediately to your powerband.

The power isn't changed. The time it took to get there did. There's the ET improvement.

Now, a GOOD TC can (CAN NOT does) also net a few mph due to its efficiency and lighter rotating mass. But this is usually minimal if at all.

A proper stalled auto will trounce a manual of equal modification in a drag race. Not due to power being more, but optimizing the amount of time spent at or around peak power.

Gearing is significant as well. Take two identical cars, gear one to run out of rpm at the 8th mile. It will destroy the other. Now run them down the quarter mile and watch the "faster" get obliterated. It didn't make more power, it just uses it better. It won't dyno any higher, but you can feel it too. Same thing going on.

ET is far from the total picture. Traps are far from the total picture. Dynos are far from the total picture.

There's way more to racing than numbers. And a dyno graph is the last thing I'd bench race with.

Random info:
My previous car at one point dynod a pitiful 325rwhp. It had a small 3200 stall and 3.42 gears (which were no longer right for the car) It ran [email protected] one night. With a proper stall getting the car to its powerband and the gearing it needed (4000 stall/4.33 gears) it would have dropped to around 11.8 with all else being equal. And still only 325 whp. The dyno wouldn't reflect any changes except for a possible slight efficiency shift.

I know this because I had it dynod and used the dyno for what it is. A tuning TOOL. I knew exactly where my shifts needed to be, I knew exactly where I needed to stall up to. Peak power was at 5950rpm. No reason to shift any higher than 6700 rpm in 2nd gear. It's only slower to go to any closer redline with where third gear started at wot. 4.33 gears would have topped me out of third gear at the 1/4 with 26" tires. I knew 28" tires would have gotten me about 10 mph more before I needed 4.10s.

That car would have run mid-low 11s this year had I not sold it. And mostly just in optimizing power already made. (And adding some for fun.)
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Last edited by ProfessWRX; 01-07-2013 at 07:56 PM.
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