Dahlback Airfilter :lost power.

[DJ-ROY]

We did a test on my car and Jeffers, with and without filters, on the rollers. His car lost power with his relatively small cone filter - I think it was a k&N type.

My car, with one of the largest ITG foam filters you can get, did the same power with and without.

Was Jeffer at that RR shootout in Holland?

This test was done car with a S2ABY standard turbo so dunno what will happen with big turbo,s like Jeffers one, BTW: I wasnt there my car is in the garage :mischeif: , Jeffer wasn,t there either he is helping Cees with his engine i have heard.

[Rusty]

Sounds about right. Rolling roads just don't get the air flow that you'd like. As Paul said, would have been interesting to have data on inlet temperatures to see what was happening there. Sometimes you just fit a cone filter for the increase in inlet noise and accept that power isn't going to be as good as a properly sorted airbox with a cold feed. Depends what you're after but for 300 euros... ouch!

[Greg_S]

could also need a bigger filter on it to get decent power

[Paul Snip]

Okay, I was at that meeting.

And Lukas, with the Dahlback filter, borrowed my original filter to compare the results.

One year ago, we had a rr-meeting too. Lukas' S2 had 291 HP.
Now, with the Dahlback filter and no cats, he only had about 270 HP.
A little dissapointing.
He borrowed my original-ABY-filter, en he had his 290 HP back.

That says enough to me.

The Dahlback-filter takes too much hot air from the turbo.

Just as i had always thought. That's the reason why I never bought an open filter for my S2.

According to the owner of the tuning-service (where we had the rr-meet) only a air-box could give some more power. Open air-filters are only good for the noise.
That's my opinion too!
Cold air is what you need. Not from under the hood, but from outside the car. The perfect solution will be a ram-air intake air-box.
That's something i'm thinking about. Make one myself, or maybe buy one, somewhere.

[AAH!]

I agree to a certain extent that the Dahlback suffers from a bit of heat soak and sucking in hot air from under the bonnet, but in my experience this really only happens in slow city driving situations (and possibley rolling roads), you can feel it when you have been sitting at traffic lights and you try and pull away quickly.

I have never really found this to be a big problem as when hot it cools down very quickly in normal or fast driving conditions. Recently after a good thrash I felt the dahlbacks metal tube and it was stone cold. Although I agree a direct feed/ram-air feed would be a good option.

But worse than under bonnet heat though is driving in the south of france in 39ºc heat. That really saps the power! Bring on winter.

[martinjs]

[QUOTE=Paul Snip]
He borrowed my original-ABY-filter, en he had his 290 HP back.

That says enough to me.

QUOTE]

Yeah but did you test the car out on the road with both filter setups? I think you will have better results.

[Bibby]

I have my Dahlback shrouded in heat resistant material to screen the area from the turbo and manifold as best as possible. It's like a glass fibre material with a silver backing. It doesn't touch the filter, more shaped like an airbox.

[Sweeper]

same here, metal pipes were cold even after a good incity trashes!

I agree to a certain extent that the Dahlback suffers from a bit of heat soak and sucking in hot air from under the bonnet, but in my experience this really only happens in slow city driving situations (and possibley rolling roads), you can feel it when you have been sitting at traffic lights and you try and pull away quickly.

I have never really found this to be a big problem as when hot it cools down very quickly in normal or fast driving conditions. Recently after a good thrash I felt the dahlbacks metal tube and it was stone cold. Although I agree a direct feed/ram-air feed would be a good option.

But worse than under bonnet heat though is driving in the south of france in 39ºc heat. That really saps the power! Bring on winter.

[Erikb]

I have done some testing with my Gtech pro earlier when I just bought my S2. When I bought it I had a standard 3b airbox fitted, after a few months I decided to buy a ITG filter (BIG one) and fitted it to my standard car. I used the standard heat shield to protect the cone filter against the heat of the turbo. I dont know the exact figures but I know there was a bit of a gain with the ITG filter.

I thought about fixing a flexible pipe from the bumper to the filter, but havent done it yet.

[Jamo]

If you use an after market filter you need a cold air feed pure and simple.

Apart from the HKS and Apexi filters i've yet to see them give any better results.

Pays your money takes your choice IMHO.

[Ski]

i cannot find a way to fix a cold air feed to that area of engine, just no room at all.. anyone got any pics of how this could be done ?

[Ski]

also what is the size of the big ITG filter? i.e. size of the mount to the pipe so i can order the right one. my tiny pipercross is too small.

[Jamo]

There plenty on the forum, search for bacofoil and view this thread

http://www.s2forum.com/forum/showthread.php?t=731&page=2&pp=15&highlight=intercooler

As you can see the ITG filter is huuuge.

[Ski]

huge indeed... i'll just get a tape measure onto my pipe to find the fittings too many threads to search for the measurements

[Chris M]

i cannot find a way to fix a cold air feed to that area of engine, just no room at all.. anyone got any pics of how this could be done ?

There's loads of room My car has two cold airfeeds to the filter.