ibizacupra
02-08-2002, 16:31
There has recently been a small number of people running their cars on Rolling Road Dyno's with Hurricanes, and some power readings between stock airbox cars and Hurricane'd cars have dissapointed their owners by achieving lower power figures than stock airbox cars.
I would like to explain the facts of how this can occur, but not be a problem in reality.
What is being reported tho by these owners is that on the real road (not RR dyno) the cars do pull better than stock.
The Hurricane Induction kit, can suffer more from heat and hot air draw from a Rolling Road as it breathes from low down in the front of the bumper/wing area. This area is sat very low, especially when a car is sat down in the rollers themselves. Rolling road dynos, especially Eddy brakes ones, produce a huge amount of heat in their operation and this heat rises and radiates from the rollers and the associated equipment from the pit the rollers sit in. This hot air is just where the Hurricane breathes from. The stock airbox, despite being more restrictive than a Hurricane, breathes from above the wheel arch via panel gaps by the windscreen base. There is very little hot air in this area.
When I personally dyno'd the Hurricane (and other) Induction kit, I deliberately did so using VAG-COM and NOT a Rolling Road Dyno, and datalogged both torque output, and airflow from the MAF whilst driving a 4th gear power run on real roads. In real terms this was about 30mph to 120mph with the corresponding air flow and speed whilstling past the car, intercooler, cold air feed for the Hurricane etc etc.
In real world driving, these power runs equated to a 7bhp and 8lb/ft increase, and corresponding higher MAF airflow reading, when run back to back against the stock airbox. The results logged and felt, correspond with customers feed back also, where there is a noticable increase and certainly no loss in power when driving in the real world. RR dyno's do none of our turbo's and justice due to the heat load they subject the cars to.
VAG-COM results are posted as ever for scrutiny here>> http://www.badger5.demon.co.uk/bin/std-vs-hurricane.PDF
and here>> http://www.badger5.demon.co.uk/bin/hurricane-v-std-small.jpg
An alternative I would suggest to people who might be concerned over this would be to route their cold air feed pipe along the same route as the factory airbox did. A small mod to the old feed pipes foam support would be required, to cut a larger hole for the larger Hurricane cold air feed pipe. The feeds then would remain from the same source. There is no direct cold feed up there tho, and I doubt the real world gains would be as high in this configuration, but it's a suggestion none the less for those worried about their RR dyno figures as opposed how it actually drives on the real road. Give the Hurricane cold air feed some cool air and there is no reason why it would not out perform a stock airbox configuration even on a RR. Just don't allow hot air to be sucked in on the RR. - It still sounds nice tho :p
NOTE: edit and added (6th August)
One thing which has occured to me following some customer feedback, is to allow the car to settle in and readapt to the new Induction kit. When following the instructions in the kit, the battery is removed. When reconnected the ECU will go into readapt mode and learn its settings again. During this time, the driving experience could feel quite dull as its adapting from its safe start point. (this is'nt a fault with the filter, it is the ECU adjusting) Point being give it a few miles, or try not to disconnect the battery (not always required but fiddly to install) to prevent the ECU readapting making you think the kit has dulled performance not enhanced. Don't be too hasty is my advise.
regards
Bill
I would like to explain the facts of how this can occur, but not be a problem in reality.
What is being reported tho by these owners is that on the real road (not RR dyno) the cars do pull better than stock.
The Hurricane Induction kit, can suffer more from heat and hot air draw from a Rolling Road as it breathes from low down in the front of the bumper/wing area. This area is sat very low, especially when a car is sat down in the rollers themselves. Rolling road dynos, especially Eddy brakes ones, produce a huge amount of heat in their operation and this heat rises and radiates from the rollers and the associated equipment from the pit the rollers sit in. This hot air is just where the Hurricane breathes from. The stock airbox, despite being more restrictive than a Hurricane, breathes from above the wheel arch via panel gaps by the windscreen base. There is very little hot air in this area.
When I personally dyno'd the Hurricane (and other) Induction kit, I deliberately did so using VAG-COM and NOT a Rolling Road Dyno, and datalogged both torque output, and airflow from the MAF whilst driving a 4th gear power run on real roads. In real terms this was about 30mph to 120mph with the corresponding air flow and speed whilstling past the car, intercooler, cold air feed for the Hurricane etc etc.
In real world driving, these power runs equated to a 7bhp and 8lb/ft increase, and corresponding higher MAF airflow reading, when run back to back against the stock airbox. The results logged and felt, correspond with customers feed back also, where there is a noticable increase and certainly no loss in power when driving in the real world. RR dyno's do none of our turbo's and justice due to the heat load they subject the cars to.
VAG-COM results are posted as ever for scrutiny here>> http://www.badger5.demon.co.uk/bin/std-vs-hurricane.PDF
and here>> http://www.badger5.demon.co.uk/bin/hurricane-v-std-small.jpg
An alternative I would suggest to people who might be concerned over this would be to route their cold air feed pipe along the same route as the factory airbox did. A small mod to the old feed pipes foam support would be required, to cut a larger hole for the larger Hurricane cold air feed pipe. The feeds then would remain from the same source. There is no direct cold feed up there tho, and I doubt the real world gains would be as high in this configuration, but it's a suggestion none the less for those worried about their RR dyno figures as opposed how it actually drives on the real road. Give the Hurricane cold air feed some cool air and there is no reason why it would not out perform a stock airbox configuration even on a RR. Just don't allow hot air to be sucked in on the RR. - It still sounds nice tho :p
NOTE: edit and added (6th August)
One thing which has occured to me following some customer feedback, is to allow the car to settle in and readapt to the new Induction kit. When following the instructions in the kit, the battery is removed. When reconnected the ECU will go into readapt mode and learn its settings again. During this time, the driving experience could feel quite dull as its adapting from its safe start point. (this is'nt a fault with the filter, it is the ECU adjusting) Point being give it a few miles, or try not to disconnect the battery (not always required but fiddly to install) to prevent the ECU readapting making you think the kit has dulled performance not enhanced. Don't be too hasty is my advise.
regards
Bill