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Joined: Aug 2002
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CEG\'er
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CEG\'er
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Hey guys, Is drivetrain loss a fixed HP number? Let's say for argument, that your car has 220 crank HP and dynos 175 at the wheels. 220 - 175 = 45 45 / 220 = 20% loss. Now let's say you increase crank HP by 40. Do you still only loss 45 HP through the drivetrain? 45 / 260 = 17.3% loss So now (theoretically) you should have 175 + 45 = 220 at the wheels. I ask because its (through my thought process  ) counterintutive. I was under the impression that 20% loss is standard. There's a dicussion over on the M6 boards about this and I want to post a reply, but I want to make sure of myself. Am I wrong and they right? I request the pleasure of information from the knowledgeable Contour Enthusiasts! Thanks.
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Joined: Mar 2001
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Hard-core CEG'er
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Hard-core CEG'er
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Haha! I was reading that thread and wondering the same thing...
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Joined: Sep 2002
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To me it would seem that the more power your put through it the more power your going to lose.
So if you increase crank hp you also increase hp loss through the drivetrain.
This is why I stopped modding my atx contour when I had it. No matter how much I put into it, I was losing a great percentage to drivetrain loss.
I could be wrong though.
"Cobb - It's not just for corn anymore!"
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no its not a fixed number, and its not a fixed percentage either. some people's cars may lose less hp through the drivetrain than others. i hear that our cars lose about 18% through the drivetrain so thats what i use. atx's are more.
say you have 100 hp at the crank, so you have ~ 80 whp, which is a 20 hp loss.
now lets say you have 1000 hp at the crank, so you have ~ 800 whp, which is now a 200 hp loss.
so no, you dont loss the same amount of hp.
Jim Hahn
1996 T-Red Contour SE Reborn 4/6/04
3.0L swap and Arizona Dyno Chip Turbo Kit
364 whp, 410 wtq @ 4,700 rpm
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Joined: Jul 2002
Posts: 206
CEG\'er
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CEG\'er
Joined: Jul 2002
Posts: 206 |
exactly. the more hp you add.. the more you lose. the percentage is different on all cars. i think he was right with saying a mtx has about 17-18% loss. normally, atx's have more drivetrain loss than mtx's.
1998 Sport Contour, A4
2000 WS6 Trans Am, M6
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CEG\'er
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OP
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I knew it! I'm going to go "own" some misinforming little b*tches!
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Originally posted by GreenNuggs:
I knew it! I'm going to go "own" some misinforming little b*tches!
Link to said owning?
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Joined: Aug 2002
Posts: 208
CEG\'er
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CEG\'er
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It is generally a percentage. If you are producing more power, it is not all progressively eaten by the drivetrain--thats just silly. If you were losing 20% before, and you produce more power, it is still 20%, its just that the actual number is higher.
00 SVT Contour: SHM LT headers, LSD, Spec Stg 3...dyno:190.3whp sold 02/04
04 Subaru Baja Turbo 5-spd
00 Camaro SS 393cid: 510rwhp/469rwtq, 11.16 @ 124.95(hit 1-2 limiter)
www.erikz.org
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Standard accepted loss with the MTX-75 on our platform is 17-18% HP and 9-10% TQ
Now you must remember you can not add this amount from the wheel power levels to make the crank HP. Mathematics just does not work that way!
You have to divide by the remaining percentage.
For instance.
190 FWHP & 170 FWTQ = 190 / 82% (or .82) = 231.7HP & 170/.90 = 188.9TQ
2000 SVT #674
13.47 @ 102 - All Motor!
It was not broke; Yet I fixed it anyway.
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This was the original post over there... Quote:
I will use a Miata as an example. We know from testing that a Miata drivetrain soaks up 23-26HP. That is a fixed loss. If I have a stock engine it will pull about 115HP on a rolling Dyno. Adding mods that increase the Engine HP another 20HP will be directly reflected by the dyno. The drivetrain still only takes 23-26 HP away. So no matter if I have the stock motor or a 240HP turbo the drivetrain hasn't changed and still only soaks up 23-26HP.
To better clarify... The drivetrain takes a FIXED amount of horsepower. In out a 6S this FIXED amount is ~60 HP. So now matter how many mods you add, the drivetrain will still take it's fixed amount of ~60 HP, leaving you with the extra horsepower.
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