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Crazed Cone Chaser
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Discussion Starter #1
I just got my car's gas system tuned as I am heading to canberra tomorrow, the guy called me and told me the extra things that had gone wrong and also told me that on gas my car is making a huge.....wait for it......70rwkw.

My engine must be just about cactus, since the stated power figure is 120kw at the flywheel, it couldn't possibly loose 50kw through the drive train could it?

Paul.
 

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Australian Ford Member
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1,120 Posts
Don't know whether you've done mods, but from memory I'm pretty sure ULP XF 4.1 EFI was 122kw flywheel (carb =99), so maybe it's not a problem.
 

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Crazed Cone Chaser
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Discussion Starter #3
The books that I have read state that the XF ULP EFI is 120kw.

I wouldn't have thought that you could lose so much through the drivetrain. 50kw is almost half the total power.

But i guess that it could be right considering that I dont know the peak kw at flywheel on gas.

oh well.

Looks like I might have to speed up my turbo-straight-LPG setup then.

Paul.
 

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Australian Ford Member
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You might be right about 120 v. 122. I might be thinking of difference between 99kw carb and EFi which appears to be about 21kw on those figures. It's around 120 flywheel anyway.

I don't know the formula for rw to flywheel, but as a rough estimate I've used 9/14 on basis of some dyno figures I've seen and that comes to about 109kwfw, which means less power loss in drivetrain but also less fw power.

Is there an accepted formula for rw to fw and vice versa?

Would gas and problems that have been found account for any loss?
 

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Crazed Cone Chaser
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Discussion Starter #5
Gas would probably account for some of the losses.

I'm not sure if the dyno run I was told about was pre-tune or after, I will find out later.

either way 70rwkw still sounds like nothing.

I just have a question which I dont know if you'll know the answer but, if 160hp = 120kw would 320hp = 240kw?

Paul.
 
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(\/)ADXF said:
I just got my car's gas system tuned as I am heading to canberra tomorrow, the guy called me and told me the extra things that had gone wrong and also told me that on gas my car is making a huge.....wait for it......70rwkw.

My engine must be just about cactus, since the stated power figure is 120kw at the flywheel, it couldn't possibly loose 50kw through the drive train could it?

Paul.
Not happy, Jan........
 

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Crazed Cone Chaser
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Discussion Starter #8
my baby's a manual.

last dyno run was 74.1rwkw.

I'd say that the gas is the biggest factor in the power figure, cause you can feel such a difference on petrol.

cant wait for the turbo, just hope the authorities will let me drive it. :)

Paul.
 

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T5 Expert Operator
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6,540 Posts
Well as a guide the Tickford dedicated gas engine makes 142kw and thats with Tickford tuning from the factory. So thats 15kw loose from the standard motor. These after market gas installation would loose more kw's IMO.
So i reckon your engine is A OK, making 74kw at the wheels.

121kw for the EFi XF is on petrol with gas your lookin at around 105kw. Yeah turbo would be the go. :nuts: :nuts:

As a guide an EF putting out 157kw at the engine with 35% driveline loss estimate will make around 102kw at the wheels. I got a tiny winy bit more than that. :D :D
 

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T5 Expert Operator
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(\/)ADXF said:
Gas would probably account for some of the losses.

I'm not sure if the dyno run I was told about was pre-tune or after, I will find out later.

either way 70rwkw still sounds like nothing.

I just have a question which I dont know if you'll know the answer but, if 160hp = 120kw would 320hp = 240kw?

Paul.
Yes 320Hp = 240kw. Mate depends what your comparing to. Obviosly some of the V8 guys will be makin figures like 130kw+ at the wheels. But for an XF it's pretty decent. Don't forget the weight of the XF is relatively lighter than say an EF-EL.

As a guide a VT Commodore S "hello Hobbes" is making 98kw at the wheels. :p :p
 

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Your making around 100Kw at the engine or so from my calculations. In my opinion it sounds about right for an old XF on gas. Is the motor original?
 

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Australian Ford Member
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Paul

Your figures aren't that bad. The 3.9 mpi is 139kw but it only puts out mid to high 80kw rw, so it's losing about 50kw too.

A kilowatt is about .76 of a horsepower, so just multiply hp by .76 to convert, or just do it mentally at 3/4 of hp figure for pretty accurate estimate.
 
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