Dahlback Cone - A lil test

[ericd]

Old dahlback setup in place, cone got clear airflow as cone butted up against headlight aperture where the airbox trumpet originally fitted
[ATTACH]17006[/ATTACH]

[ericd]

Used this monster 200mm rear facing HKS filter after the dahlback, fed cold air by the airbox internal pipe and trumpet from behind headlight, ran cool and I'm sure it was a contributing factor to getting 340 at the weston RR meet

tn_dscf0287.jpg

[ericd]

I've ran this setup for 2 years now, HKS 150mm filter + 3" custom elbow which pushes the filter into the wing area and away from the heat, (the pic is a bit misleading the filter sits right up to the wing), fed cold air by 4"" ducting connected to the original airbox trumpet at the rear of the headlight (see bottom of pic), using the original trumpet with ducting connected practically gives you the same rammed air effect that the airbox gets, just cut the ducting to length and you can direct it wherever you want, excuse me for hijacking the thread , but us Scots like to experiment

tn_dscf0370.jpg

[Rusty]

No. 2 looks pretty sweet there Eric.

It all seems relevant to me!

[EspenW]

Paul: get a digital thermometer with a long lead and place the probe at the top of the filter. Then you can measure charge air while on the move. Then do the same thing with the airbox (probe placed in side the airbox.

The heat shield will reduce heat soak while stationary, because it reflects heat radiation. However, when on the move, the engine will suck air, and create a vacuum in front of the filter, thus suck superheated air past the heat shield.

Former owner installed a shielded open filter on my RS. On a 14deg ambient day, I measured 45-60 degs at the top of the filter.

People have measured a 20hp loss when back-back testing Dahlback vs standard box..
Noise will do strange things to even a fine calibrated butt dyno..

[S2central.net]

It was my intent to log IAT with VAGCOM on some runs - I just wanted to know what the noise was like - somebody wants one for the noise. I can see how on a dyno that such a setup would suffer cos of heatsoak, but I do think with decent cold feed ducting and perhaps a better - multilayer heat-shield that the heatsoak effect could be minimised.

Paul

[EspenW]

It was my intent to log IAT with VAGCOM on some runs - I just wanted to know what the noise was like - somebody wants one for the noise. I can see how on a dyno that such a setup would suffer cos of heatsoak, but I do think with decent cold feed ducting and perhaps a better - multilayer heat-shield that the heatsoak effect could be minimised.

Paul

True, dyno test w/o proper airflow will make things even worse, but drag style standing starts, from traffic lights, etc, will also cause a major disadvantage for a open filter. Autospeed tested pressure losses in the S4 intake and found that losses through the airbox/filter were minimal:

http://autospeed.com/cms/A_0629/article.html?popularArticle

(read all 5 articles)

[Rusty]

Paul, IMO a modified / drilled airbox sounds A LOT better than the sucky cone filter. Mines as close as an airbox will ever get in noise to a cone filter but it's more growly and doesn't fart like the cones do on part throttle. I'm chuffed anyway.

[s2driveruk]

Andy, go record a clip for us to judge

[Bram]

Just mod your ABY box to 120mm inlet like I did, and put a K&N filter in. Not too noisy and enough cold air coming inside the box.

The pic shows the standard inlet tube

[Bram]

And now chop that old intake tube out and make room for the tube that is pictured on the right

[s2driveruk]

What were the AFRs like? Looks like boost leak time to me, same as my 273 run on teh MRC map.

Was running rich...pretty sure

[Bram]

Fits just tight underneath the filter, but flow must have increased a bit

btw; I shortend the tube a bit further, so little less obstruction of the filter is there currently than you see in the picture

[Bram]

And finally a nice big airduct hole in the front of the car as far as possible away from the hot turbo

[troman]

@Bram (ressurecting this old thread)

Where did you buy that 120mm duct?