My Dyno Run

[Koz]

I took my car to MRC Performance Castle Hill today for a dyno run to determine what power my Polo is producing.

The mods performance wise are an APR chip and a SEAT intake.

My very first run was the best because everything was cold ie intercooler, piping etc and the power output dropped after the 1st run.

The first run peaked at 121.8kw @ the wheels at about 5600rpm in 4th gear. PSI peaked at 20 psi at about 3500rpm and torque was just over 320nm at about 4700rpm.

My first run pulled 140kw at the fly wheel.

My other runs where about the 116kw at the wheels which is probably the more realistic output as the figure was consistent for the other runs.

I also had a run with the air con on and showed just over 112kw at the wheels.


I am a little dissapointed as I was hoping/expecting around 130kw-135kw at the wheels.

It was good to get some figures tho for future reference.


Cheers

Colin

[DUB 20V]

nice one mate, i would have thought the polo would have got more with the ko3s turbo oh well not bad power for the little polo :)

[SoVeReIgN]

Change your downpipe & turbo intake pipe and you might hit the 130.

But remember, all dynos are different.

[MACCAA]

121.8 sounds about right.Timbo and I both were within a couple of kw with different flashes-Revo and Oettinger.Dump pipe is the way to go for 130kw.
I have dump pipe and full exhaust,Timbo has dump pipe only-and he's got more power on the same dyno.Go figure....

[Koz]

Change your downpipe & turbo intake pipe and you might hit the 130.

But remember, all dynos are different.

Yeah Im looking to get Seb to replace the downpipe shortly.

Maybe I was expecting a bit too much but was wanting to see 150kw+ at the fly wheel as quoted by APR. I suppose I may get that on another dyno.

But on the plus side I still thoroughly enjoy driving my lil rocket. :)

[Timbo]

Maybe I was expecting a bit too much but was wanting to see 150kw+ at the fly wheel as quoted by APR.

Depends on how you do the calculation back from KwATW to KwATFW and -- of course -- you'd need to be using the APR dyno ;) , but I reckon you'll find that's pretty close.

The most critical thing to remember about dynos is the deltas they show for the mods you've made: a stock Polo GTI dynos in the range 91-96KwATW, so if you have 121KwATW, you've made a 30+% gain. Most tuners are pretty bloody happy with that :)

[VW GTI]

Who could supply and fit the downpipe in Brisbane? I asked Guy and he only has the full cat-back exhaust.

[DubSteve]

Yeah thats right Timbo! Thats a good gain if you ask me also with a front mount you will hit a bit more, look at GT3 and flaps there both in the +140kw marks:)

[GT3]

Timbo has dump pipe only-and he's got more power on the same dyno.Go figure....

It begs the question - who did your exhaust? are you running high flow mufflers and cat as well? what diameter? - if you're running 3" dp and 2.5 for the remainder, that could explain it, ie too much diameter upfront with the remaining 2.5 system. Milltek and APR have found negative returns beyond 2.5" for an 'entire' system, hence why they don't go bigger.

[Guy_H]

Intake temps is what will kill you on the dyno (and on the street) - just for fun, log the intake temps you will see them peak @ around 90 deg C, and the power drops off pretty quick :(

[GT3]

The first run peaked at 121.8kw @ the wheels at about 5600rpm in 4th gear.

My first run pulled 140kw at the fly wheel.

That calculation/conversion is wrong - 122kw atw is around 150kw at fly.

[balkanac]

How do you calculate that? is there an online calculator somewhere or is it just a fomulae?

[SoVeReIgN]

How do you calculate that? is there an online calculator somewhere or is it just a fomulae?

Ah usually its
15% - FWD
20% - RWd
30% - 4wd/AWD

(Roughly - Little more for autos)

[Timbo]

Ah usually its
15% - FWD
20% - RWd
30% - 4wd/AWD

(Roughly - Little more for autos)

I wonder what the source of this is? Not disagreeing, but these 'rule of thumb' get rolled out on most car forums, and I've yet to see someone reference a good technical source.

Engineers? Discuss: :D

[SoVeReIgN]

I wonder what the source of this is? Not disagreeing, but these 'rule of thumb' get rolled out on most car forums, and I've yet to see someone reference a good technical source.

Engineers? Discuss: :D

Through experience I guess

Think about it - Your standard polo gets about 94kw at the wheels - Thats about 85% of 110kw = 15% drivetrain loss.

[mitch_gti]

for an otherwise standard GTI, 121kw ATW seems fairly accurate.

I think i remember guy mentioning 125kw atw on polo gti after APR.
4kw would be dyno error.
1.8t seems to be fairly consistant in its power output. ie everyone in standard form is getting between 91-96 kw atw (mine got 93.something IIRC)

Falcons have a variance of like 30+ kw lol.

[GT3]

Through experience I guess

Think about it - Your standard polo gets about 94kw at the wheels - Thats about 85% of 110kw = 15% drivetrain loss.

FWD cars - add 10 bhp to the wheel figure and divide the result by 0.9
RWD cars - add 10 bhp to the wheel figure and divide the result by 0.88
4WD cars - add 10bhp to the wheel figure and divide the result by 0.84

[archangel_7]

Change your downpipe & turbo intake pipe and you might hit the 130.

Hey Sovreign,

130kw is a big gain just from changing the downpipe and turbo intake... just out of interest, how would you go about doing that? parts, etc?

[Jarred]

yea it's all really confusing. but the most important, is qhat it puts out at the wheels really, since they do all the moving!

regardless, I think it's time for a few more mods my man!!

[MACCAA]

Hey Sovreign,

130kw is a big gain just from changing the downpipe and turbo intake... just out of interest, how would you go about doing that? parts, etc?

130kw is in addition to a reflash.Reflash=122kw approx.Reflash + exhaust=130kw approx.

[Timbo]

FWD cars - add 10 bhp to the wheel figure and divide the result by 0.9
RWD cars - add 10 bhp to the wheel figure and divide the result by 0.88
4WD cars - add 10bhp to the wheel figure and divide the result by 0.84
Do you have a source for that? I mean, there are any number of formulas like that which get to the same result, but what is their basis? :???:

[GT3]

but what is their basis? :???:

http://www.nitrod.com/articles/HorsepowerTA.pdf

[Koz]

By the way guys on Wednesday or Thursday I will scan my graphs and post them up for everyone.


C

[Timbo]

http://www.nitrod.com/articles/HorsepowerTA.pdf

Cool! Thanks. I also found one by a dyno operator suggesting wheel slippage on the dyno rollers is also a factor, although the maths wasn't very convincing :?

[GT3]

I will scan my graphs and post them up for everyone.

They're just dyno results, don't base your car's overall worth on them. A better question may be - do you need more power? If you do, what sort of power do you want? If you want to obtain it crudely, cheaply and easily, then there's many, many dp advocates on here. But if you want power that can be sustained, then consider options that lower intake temps. See Guy's earlier comments re what happens and think about why your peak power dropped off and couldn't be sustained.

[Koz]

They're just dyno results, don't base your car's overall worth on them. A better question may be - do you need more power? If you do, what sort of power do you want? If you want to obtain it crudely, cheaply and easily, then there's many, many dp advocates on here. But if you want power that can be sustained, then consider options that lower intake temps. See Guy's earlier comments re what happens and think about why your peak power dropped off and couldn't be sustained.

Yeah I can see were your coming from but I was just expecting a little more. In regards to the graphs I want to post them up for people to look at and tell me if its normal that the power and torque curve is all over the place like the share market and not a nice consistent curve.


C