Ever the pessimist, I wasn't going to believe it until I saw it and today I had the chance to do just that!
http://www.pipercross.net/fastroad/products_venom.aspIgnore the red pipe, the kit we tried today was all tasteful black and by far the most OEM looking off-the-shelf CAI i've ever seen. It also took less than 10 minutes to fit. They've made a special effort to make it match the existing finish of the plastics in the mk4 bay.
The victim was a 2001 1.8T GTI (AUM) - Ben's old motor, so we knew it was a 'good un' and was put back to standard when he sold it other than a remap and DV, so we could get a fair test on a standard motor rather than use my loony 1.8t
We did a session of 3 dyno runs and a held load test with the car in 4 different states of tune. After each session the engine was allowed to cool until the inlet manifold was cold to the touch, IAT reported 21 degrees at idle and the coolant was at 40 degrees then warmed to 84 degrees at the start each batch of testing. The man from Pipercross looked upset when the numbers came up on the rolling road computer, his face was priceless. But I'd been watching the data and knew there was a lot more to the story, and anyone who has been to the R-Tech workshop has probably had the lecture on average horsepower vs. peak horsepower. However here are the peak figures for you to chuckle at!
Stock filter/airbox and stock mapping. - 160 bhp
Stock filter/airbox and Spec 1 mapping.- 210 bhp
Pipercross venom and stock mapping. - 161 bhp
Pipercross venom and Spec 1 mapping. - 210 bhp
Looks pretty pointless, no? To be honest it's what I was expecting, especially with an engine/ecu that i know so well. Our VW's are too well designed to be tricked into making more peak power with air filters, the ecu knows all the time exactly how much load is being worked and will compensate within it's efficiency to always hit the same numbers. Peak numbers are pub talk, how you get there.. the average figure, is what makes a quick car.
Average bhp between 2200rpm and 6800rpm was increased by about 5bhp with the CAI, whether remapped or not, and that's a lot for a simple bolt on air filter.
While Nick was showing the slightly-happier-by-this-point Pipercross dude how the average bhp is calculated by the sportdyno software I went away to find in the logs what was going on to cause this change. It didn't take long to see what was going on once the intake air temperature and measured air mass graphs were overlaid.
With the Pipercross kit installed, the intake temperatures reached were decreased by as much as 9°C compared to the stock airbox on power runs and as much as 15°C under held load. That's maximum stress, the equivalent of towing a caravan up a steep hill at 5500rpm in 4th gear. Ambient air temps were between 5 - 8 °C all day thanks to the blizzard. The more efficient burn (particularly in low revs) was allowing a bit more punch between 2000 - 3500 rpm thanks to the ecu adapting timing which gave the boost in average bhp, and as an added bonus (ME7.5 ecu's only for this next part.. sorry AGU boys
) once approaching peak the fuel injection was being altered to suit and fuel consumption was noticeably decreased at high revs!
I'm not sure you can even buy these intake kits yet, but
we're giving one away on Jan 10th at the charity day
see the shows and events section for details.
I'll be getting one for my own 1.8T to do some longer term testing to see if it's worth making changes in my map to suit the lower temps, and also run it against a not-so-standard airbox with some topheristic DIY modifications. I'm quite looking forward to seeing how it behaves on what is probably the most bonkers 1.8T remap ever to be produced in the R-Tech office
We're also going to borrow a standard-ish AGU for a day to see what it does on a less complicated ECU.
I realise i've baffled on about stuff that probably is of no interest to most of you so i've gone back and put the important bits in bold text
