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Can a garage fake a dyno run??



  Clio Dci100 Dynamique
Is it possible for a 'sour grapes garage' to deibratley understate power figures??

I took my little DCI to a company with a rolling road and they told me 79.1 bhp at the wheels & 119lbs per ft.

They asked if i wanted them to do me a remap which i didn't accpet cos it was cheaper elsewhere.

I got the map done another company and went back to the same guys rollers and he said it was only 85 bhp at the wheels!!! and 138lbs

Erm, clearly wots going on??? a full custom remap gettin me an extra wot 6HP?? lol gimme a break

My cars substantially faster since i had it mapped, but it seems to me that since i didn't do it at this guys company he told me lies about the figures! could that be tru??

If so wot can i do about it?

Also a little suspicious was that it quotes my peak torque (138lbs according to him) @ something like 4300 rpm!!!!

Surely thats wrong, don't diesels produce all their torque at around 2000?

Plse advise
 
  Clio Dci100 Dynamique
Also come to mention it, it seems to hav a cut off line of some sort...
I'l hav to try and find the bit of paper, i don't i threw it away but may wel hav done cos was cross...

Wen he did it i watched the screen and the bhp soared and all of a sudden at 85bhp became a sraight line? like a heart monitor wen the guys dead lol

Shouldn't it tail off?? not go straight?

Any ideas anyone?

Ive had this car previously dyno'd at 130bhp but not with them
 
  guess, but yal be wrong
Also come to mention it, it seems to hav a cut off line of some sort...
I'l hav to try and find the bit of paper, i don't i threw it away but may wel hav done cos was cross...

Wen he did it i watched the screen and the bhp soared and all of a sudden at 85bhp became a sraight line? like a heart monitor wen the guys dead lol

Shouldn't it tail off?? not go straight?

Any ideas anyone?

Ive had this car previously dyno'd at 130bhp but not with them

i was going to say that you should take it back, get him to do it again and watch the screen to see what i says.

as for it tailing off, that should happen because as the horsepower builds up it will struggle to reach its top hp,

can't think of anything else to help you with
 
  Corsa 1.3 CDTI
Also a little suspicious was that it quotes my peak torque (138lbs according to him) @ something like 4300 rpm!!!!

Surely thats wrong, don't diesels produce all their torque at around 2000?

Plse advise

Don't they produce torque low down but HP further up the range and maybe that's what he was on about ?
 
  FF 182, K5 GSX-R1000
Quite easy to manipulate figure on a dyno run. Ambient temperature used to be a favorite but even joe public spots that these days. Check power/torque crosses at 5250rpm.

As for the power holding, this could be due to a limit of some description within the engine.

6bhp is a reasonable gain, but more importantly the rest of the power band may be more impressive. Dont believe you can get those sorts of gains from exhausts/filters on most engines, no matter what they claim.
 
  Hondata'd EP3 Type R
BHP Figures are for Bragging rights, I'd ignore them, You say the car feels much faster and better drive, So IMO its a result.

I'm sure you could tune and tune and tune for a higher BHP figure, ?But the car wouldn't drive as nice and could infact feel slower!
 
  Clio Dci100 Dynamique
Quite easy to manipulate figure on a dyno run. Ambient temperature used to be a favorite but even joe public spots that these days. Check power/torque crosses at 5250rpm.

As for the power holding, this could be due to a limit of some description within the engine.

6bhp is a reasonable gain, but more importantly the rest of the power band may be more impressive. Dont believe you can get those sorts of gains from exhausts/filters on most engines, no matter what they claim.

Ive found the before and after tests so i'l scan and post them tonite.
Can't find my best one which is annoyin but i'm sure its hoarded away somewhere lol, if you get a chance to compare both graphs please do, the torque curve looks very different
 
  Clio Dci100 Dynamique
ok, can someone tel me how to do this...
I wanna upload the pics so they show on the screen not just as links to photobucket, or do u reckon that would be better? :s
 
  Hondata'd EP3 Type R
Go to the main page of your album when you are logged in and you get all your thumbnail pics up. Copy and paste teh code in the box that has something like this in:

url]
and paste that here, Without the spaces
 
  Hondata'd EP3 Type R
dont suppose you got a bigger one? Try clicking the image so its big, Right click on it, go to properties, copy the adress URL, and paste that in between the img brackets
 
  Clio Dci100 Dynamique
Thats very clever! :)
Can anyone help me compare these 2 graphs? I'm convinced the new one is waaaaay wrong...

Full custom Dci remap, only 6 bhp more at the wheels?
I know its wrong cos my acceleration times are much faster than they were & with all of 6hp u wouldn't really notice
 
  Clio Dci100 Dynamique
If the car feels better after the remap does it matter what the numbers say?

wel i know its silly but it does to me...
My brother has the same car and he got another 30bhp out of his clio so why can't i get more than 6? :( thats why i reckon its all a con cos i didn't use that mans company for the remap so he delibrately made it look like i got hardly any gains from it :(

Am i being paranoid?
The stats and figures just don't add up
 
  M2 Competition
To be fair rolling roads are rubbish mate. Unless you do back to back tests on the same roller on the same day with the same tyre pressures... etc etc, they wont tell you much.

Can you just do a 0-100 run on an empty road with your brother, see if your cars are on par with each other? Put your mind at ease.
 
  Scirocco GT 210
No. :S More like 7 or 8 at the fly.

So there is hardly a difference between atw and atf? I suppose if you worked % then it might be right...I was thinking of the old ad 10bhp and divide it by .9 lol

Chris

I was working out what difference to the flywheel an extra 6 bhp at the wheels would make, which is about an extra 7bhp.

Yes I was working with percentages (18% FWD loses). lol Then again, even your method works out at 7bhp too.

Example (using your method).

A car has 100bhp at the wheels. (100 + 10 /0.9) flywheel = 122bhp.

Car gets chipped and gains an extra 6bhp at the wheels.

Now 106bhp at the wheels. (106 + 10 /0.9) flywheel = 129bhp.

129bhp minus 122bhp = 7bhp.
 
  Clio Dci100 Dynamique
Yeah it should, thats why i wanna know wots going on with these results...surely the guy just understated the power cos i didnt giv him the business...my bro spoke with a guy from angel tuning yesterday who said that sometimes business competitors can do that to try and trick you into using them instead
 
  CS Dungeon
Between £300 & £400 ish Dave

What did it make on the rollers where it was re-mapped?

Take it to another RR for another run and see what it makes this time
 
  FF 182, K5 GSX-R1000
To be fair rolling roads are rubbish mate. Unless you do back to back tests on the same roller on the same day with the same tyre pressures... etc etc, they wont tell you much.

Can you just do a 0-100 run on an empty road with your brother, see if your cars are on par with each other? Put your mind at ease.

Thats your best bet. Those two graphs cant really be compared, both are horrid to work out whats going on!

27deg aint to bad if it was a warm day. If they input it high (position sensor somewhere warmer) then the corrected figure will over read.

Edit; if you really want to see the difference you could replot them on excel ontop of each other!

Just glancing at the torque curves, its got a really good gain across 2500-4200rpm, 30lb/ft in places. You'd notice that as quick a bit quicker :)
 
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that particular type of rolling road is well known to produce low numbers.
the most important thing in RR tuning is the operator and how well they set the car up - the road is just a tool.

it's not Powerstation is it?
 


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