poor dyno result why?

[FL00DY]

dude

line both cars up Side by side

see what happend in real world situation

if your dead even then the dyno is crap and wrong

if your better than even better


but really dynos are more or less (in my opinon) a means of diagnosis

What many people dont see is how the cart actually reads

how it translates in to usefull power.. where it produces power etc etc etc.

Ie a dyno wont really read actual drivability

some cars produce more power and evenly earlier on in the revrange thru the timing etc.

which in real world terms translates to a better option

unless you fancy driving it like a honda to get the max power out of the last few hundred RPM..

failing that..

ditch your exhaust and see what happens

also!!

another factor people never take in to account on dynos is TYRE PRESSURE MAG WHEEL SIZE etc

in my GTI.. i ran 130kw with my 16 inch wheels on..

put some 18" wheels on and ran 122kw


really to make a comparable dyno sheet you need to account for all variables.

ie use one set of mags and tyres on 4 different cars if you wish to compare them

but then you have to maintain atmospheric pressure and the current temperature as at the duration of the initial run!

if this doesnt make any sence sorry.. im half asleep.

Wow, some paragraphs would make this so much easier to quote

Ditching the dyno and dragging both cars is as useless as the dyno IMO. You will still have roughly the same amount of variables, diff rubber, maybe diff size rims, drivers skill level and as has been said; how differently both cars have been driven. Dyno's and drags are only really useful if only ever run on the same dyno, and used to compare your mods one after the other. I know a MCS that has used the same dyno for 6 or so runs over the years and it's great for him to see what each mod has made (or lost) him. But if you start comparing different cars, you'll drive yourself nuts

[Guy_H]

Jason,

The only way to tell (and I just spent 3 weeks solid running cars on a dyno in the UK) is exact data logs out of the cars.

We were in Manchester doing the calibrations on the big turbo kits & fuel pump files for the 2.0T's and a car, even though strapped to the dyno & left overnight made 30hp different the next day with no changes.

You have an unknown flow in your intercooler (could be causing huge pressure drop? never been measured?), you have 53,000 km's on a car (so your MAF is probably tired) - If you had have hooked Vag Com up to each Polo there & watched intake temps & Timing pull & Boost, I think you would see the exact difference between each Polo (and from that you could also gauge what fuel was being run in each car too!).

If you had the time to do it (takes a lot of time), you would really know.

Seeming your unknown variables, I would be pretty happy with the run!

Sorry I couldn't make it there - looks like it was a good fun day!

[GT3]

I only pulled 120.9kw atw and I have the APR remap, APR downpipe and TIP (1.3 less than Rhys with just the remap).

I wouldn't read too much into that, too many variables, and I wouldn't have massive expectations from your downpipe. I systematically dynoed with the same dyno/operator with every mod. FYI, the only mod that made zip difference on the dyno was the Forge TIP.

[ranton-inc]

Wow, some paragraphs would make this so much easier to quote

Ditching the dyno and dragging both cars is as useless as the dyno IMO. You will still have roughly the same amount of variables, diff rubber, maybe diff size rims, drivers skill level and as has been said; how differently both cars have been driven. Dyno's and drags are only really useful if only ever run on the same dyno, and used to compare your mods one after the other. I know a MCS that has used the same dyno for 6 or so runs over the years and it's great for him to see what each mod has made (or lost) him. But if you start comparing different cars, you'll drive yourself nuts

yes

exactly right

sorry about the spacing its a habit to hit enter after each line.

[Mischa]

id say the downpipe and tip do jack all and the other 1.something kw's is just a degree of error or slight differences in tolerances in the engine.

[velly_16v_cab]

i think it has already been said in this thread but so many things can change the out come of the power output.

wheel size, larger rims will give lower ATW figure.
wheel alignment - i suffered with this before giving low reading ATW but correct @ flywheel
Air temp - a run later in the day with higher air temp will drop a reading
Engine soak - a HOT engine will also be down on power.

did you have a flywheel reading?

[VW GTI]

id say the downpipe and tip do jack all and the other 1.something kw's is just a degree of error or slight differences in tolerances in the engine.

Any reasons behind your theory?

[jasn78]

hey guys thanks for ur respones on this issue gives me plenty to look at and guy yeah its not that im saying the car is slow cause i know it isnt more just wondering y such a difference than mine and a polo gti with just flash

[Guy_H]

Blue ones are always the slowest

Next time get a red one

[jasn78]

yeah guy but blue looks the best and looks are more important lmao

[Flaps]

flaps really no point getting it dynoed somewhere else is there? as i am wanting to compare apples to apples not oranges (if i went to a different dyno i wouldnt know what some1 elses polo is putting out) whereas i do know what other polos are putting out on that one

and ben this polo definetley has not been babied

I said this because there are so many poor results. The K04'd Polo didn't get in the 140's when Guy's red one pulled 150 something with supposed problems getting the power down

Also from the video and some of the photo's why are some cars run with the bonnets down?

If you run on another brand of dyno and get the same result then there is something wrong with your car. Process of elimination...

[Sharkie]

Dyno Day Results from a Polo GTI perspective

IMO the Dyno was running about 4-5kw low on the Polo's compared to the averages achieved around the country to date. This could be due to a number of factors and I'm not going to speculate as to why. Sufficient to say that a number of the (other) cars there ran higher numbers only weeks before either on the same dyno or on different ones.

Interesting also to note that the FMIC Polo's all ran 3 runs with a slight increase in power for each consecutive run whereas the std IC cars all dropped slightly in power with each consecutive run.

Ralphk 139.5kw
APR ECU
K04 Turbo
APR FMIC
APR Exhaust
Stock intake (std TIP, std intake, std air filter)
Stock diverter
Lightened flywheel
LSD
16" Std rims
=> Stock intake could be a severe restriction with the K04. Breathing properly could liberate another 5-10kw.

Eddy 130.8kw
APR ECU
Stock turbo
APR FMIC
APR Exhaust
Custom intake (Forge TIP, SEAT intake, K&N air filter)
APR R1 diverter
Lightened flywheel
LSD
16" Std rims
=> I was expecting about 135kw from this setup.

Sharkie 127.6kw
APR ECU
Stock turbo
Custom FMIC
Stock Exhaust
Custom intake (Forge TIP, SEAT intake, K&N air filter)
Custom diverter
Std flywheel
16" Std rims
=> I was expecting about 133kw and will dyno again on another dyno with the exact same setup.

[-Polo GTI-] 122.2kw
APR ECU
Stock turbo
Stock IC
Stock Exhaust
Stock intake (std TIP, std intake, std air filter) - presumed did not check
Custom BOV
Std flywheel
17" aftermarket rims - tyre size would be interesting to know.
=> This setup is known to run about 125kw with 16" rims on Dyno's all round Oz

Tosspot 120.9kw
APR ECU
Stock turbo
Stock IC
Custom Exhaust (APR downpipe)
Custom intake (Forge TIP, std intake, std air filter)
stock diverter
Std flywheel
17" VW optional rims - tyre size would be interesting to know.
=> Was driven straight onto the Dyno from a 15min run from home. 3rd run was around 118kw, heatsoak the likely culprit.

Jasn78 120.3kw
Oettinger ECU (Alex assured me the file used is the same as the APR file)
Stock turbo
Custom FMIC
Custom Exhaust
Custom intake (Forge TIP, SEAT intake, BMC air filter)
APR R1 diverter
Std flywheel
17" Aftermarket rims
=> I was expecting about 130kw, similar to Eddy, either that exhaust is the culprit or more likely a boost leak somewhere.

Shaneth 88kw
Stock ECU
Stock turbo
Stock IC
Stock Exhaust
Custom intake (Forge TIP, std intake, std air filter)
stock diverter
Std flywheel
16" Std rims
=> Std Polo's should do on average 93kw and its widely accepted that the Forge TIP does not add power, merely help the breathing at higher RPM

Based on [-Polo GTI-] & Shaneth's figures I'm guessing the Dyno ran 4-5kw low on the Polo's.

All in all at least it compared the Polo's to each other under the same conditions.

Time to arrange another Dyno day .... ?

[fuzion]

very strange results indeed!

this was flaps car @ sydney dyno day with a bad batch of fuel and teething problems on GIAC http://youtube.com/watch?v=XZ7_NgaEKW0

IMO find a decent reputable Dyno Runner (MDX/Mainline seem to be the most consistent or if you want your want 'im happy' readings you can always try a Dynodynamics Dyno)

sorry to hear the disappointments! but as said its more based on what you've improved on and spent your money on to gain (this case eek?) .. book a few of you into the same dyno operator somewhere else on an early morning run and see how you all go but giving yourself 2-3 hours to let the car cool down so your all even whilst running and bonnet ups as flaps said!

[Eddy]

Blue ones are always the slowest

Next time get a red one

Hoyhoy.
.......................WHAT....................... .....

[99gti]

very strange results indeed!

this was flaps car @ sydney dyno day with a bad batch of fuel and teething problems on GIAC http://youtube.com/watch?v=XZ7_NgaEKW0

IMO find a decent reputable Dyno Runner (MDX/Mainline seem to be the most consistent or if you want your want 'im happy' readings you can always try a Dynodynamics Dyno)

sorry to hear the disappointments! but as said its more based on what you've improved on and spent your money on to gain (this case eek?) .. book a few of you into the same dyno operator somewhere else on an early morning run and see how you all go but giving yourself 2-3 hours to let the car cool down so your all even whilst running and bonnet ups as flaps said!

That's a good result for the polo. These were run in 3rd gear on that day from memory wern't they?