Air Filter flow

[Roberto]

Not sure if this has been tried, but here goes.

It has been said that the standard air box is best, but a mushroom head looks so much better.

The question is has anyone put a decent vent behind a mushroom head to assist with good clean, fast and hopefully cool air?

If so has it made a difference?:pimp2:

[mpau009]

Not sure if this has been tried, but here goes.

It has been said that the standard air box is best, but a mushroom head looks so much better.

The question is has anyone put a decent vent behind a mushroom head to assist with good clean, fast and hopefully cool air?

If so has it made a difference?:pimp2:

I think the issue with the pod filter setups at least at the NZ dyno day, was that with a 20degree ambient temp, that the gains in easier flow, were offset by sucking the hotter air from the engine bay. I think the point most of those threads were trying to make, is that unless you are going to go the whole way, and build a sealed cold airbox, then the benefits arent as good as you might expect.

The dyno operator suggested that the ecu was likely retarding the timing, i would imagine something to do with the increased air temps possibly encouraging knock?

The other side of those discussions was to do with the suggestion that the Karman Vortex type of MAF that these cars run might not like a turbulent airflow that non standard airboxes can create.

But if you're keen to do some testing, i would be interested to see the results.

[Kieran]

The other side of those discussions was to do with the suggestion that the Karman Vortex type of MAF that these cars run might not like a turbulent airflow that non standard airboxes can create.

Yeah, if it's badly designed, you'll suffer for it - if you want to see how much these units need good smooth airflow - remove the standard airbox and try revving the car with the maf exposed to fresh air.

I know Wirdy and I think Spirit's cars have HKS Super power flow mushroom filters - these are designed not to fritz the MAF, and both of them rigged up a cold air feed. I believe Wirdy said it kept his filter foam cleaner - but I don't remember him commenting on performance - though given the ambient temps inside a VR-4 engine bay, I'd be amazed if a cold air feed didn't help.

[Roberto]

I have the same HKS Super power flow mushroom filter.

Using the existing Feed to the old air box, but it was the idea of a vent in line with this air path nearer the windscreen behind the filter that was playing on my mind.

So instead of using possibly trapped warmer air, it would have a free flow of air which would hopefully be cooler. I'm happy with how the car is running with the HKS, just thinking aloud.

Not sure if this avenue has really been tried yet.

[BraindG]

ive got a 4inch Pipe feed from fog light to the front of my hks filter, downside... filter gets mankey black!

unfortunately I cannot comment on performance increase as this mod was done with a wealth of other things, but it would be silly to assume that there would be no increase, cold air from anywhere will help. a 4 inch flexi pipe, imho brings more cold air that the tiny entrance to the standard box set up - to do proper testing you would need a clear bonnet, and use smoke of some sort to see direction of air... I suppose.. but still logic tells me that with the correct vent for hot air to escape from under bonnet, and cold air feed directly in front of filter there can only bring positive results.

I admit, from a standing start, there will be some hesitation while the hot air is sucked in before the movement, and thus cold air starts arriving - but it must be far superior that the standard box set up... I just cant get my head around the fact that people say its better.. the input is just so small, how's it supposed to get all that air - ok, not hot air can get in, but again.. under load, and forward momentum why would it ?

Perhaps something like this, with feed from fog light will be better, but not the standard set up.. nope i cant get it.

http://www.knfilters.com/news/news.aspx?ID=450

Although, ive jsut read this http://www.strikeengine.com/car_air_filters_induction_kits_information.html - jurys open

/shrug..

[bradc]

I don't beleive there is much point in putting in a pod filter to replace the standard cold air intake, unless you're going to have some form of ducting setup, and ideally have it sealed, like Rhys's intake or my new setup with a sealed box.

As mike pointed out there is also the problem of the pod filter screwing up how the air is supposed to flow into the MAF, which could cause the car to run rich.

[Kenneth]

The standard intake setup is good for 320HP without modification if you do exhaust and intercooler. I reckon it will do more easily if you get the turbo intake pipes flowing nicely. (namely the front one)

I think it was Marcus who did some vacuum measurements and found that the standard filter and intake gave very little resistance anyway.

My advice would be to leave the standard intake and spend your money on something more useful. A decent exhaust system really makes the VR-4 come alive.