Hyperboost or Bailey's?
 

Does anyone know if there is a difference between Forge Hyperboost DV's and Bailey's?

Oh, and does anyone have a preference between BMC and K&N air filters?

Re: Hyperboost or Bailey's?
 

We are the NA importer of the Bailey valve, so I have a biased opinion. :) They have proven to be a great product.

Just for kicks on Thursday we did a before and after dyno on a stock 996TT X-50 using the BMC. We picked up 5 wheel horse power. Not too shabby.

We have never dynoed the K&N so I can't comment.

Hope this helps.

Every bit counts mike.. I've got both a K&N and a BMC and the filter/cloth element is remarkably similair so I doubt there's much if any difference.

How can you pick up any horsepower gain with a DV changeout? I can understand a throttle response increase, but not a power increase!

Explain the engineering on that one to me if you can.

I don't think mike meant he gained horsepower from the DVs. I understood him saying he got 5hp from the BMC filter...

Well you can pick up some power if your factory plastic DV have failed. Other than that no you will not pict up any power from the Bailey's, but sence they are made from metal not plactic like the factory DV you don't have to worry about them failing.

While I do believe Mike (honorable guy), and also believe you get a little more hp from an air filter, I don't think you should count the 5 hp stated as an accurate number. On our cars, a 5 hp difference is well within the variability on a typical chassis dyno with no changes. In order to see a change (any change) clearly it needs to fall outside of the repeatability variability of the dyno process and 5 hp doesn't make it. Again, yes it's probably there but you have no confidence in that specific number.

Tim-

The dynos were all within 45 minutes of each other. We did 3 pulls stock and then did 3 pulls with the filter.

The second session produced higher results. I'd say it's a winner.

This is not our first dyno. We had a 2 wheel drive Mustang for 6 years prior. We have seen some cars show better results than these with a filter while others have posted a loss.

Re: Hyperboost or Bailey's?
 

Not really - as long as you go aftermarket (Forge, Baileys, etc) then you'll be fine. I have hyperboosts in my S4, mainly because the shop I used was a hyperboost dealer. I'd have been just as happy with any other aftermarket DV from a reputable company.

The Hyperboosts are a little unwieldly in size, so if form factor is an issue, you may want to go with one of the ones that is specifically designed to fit in tight spaces (I think there are now Baileys designed just for cramped spaces, but I can't remember off the top of my head). No matter which way you go, you're better off than the plastic OEM pieces. If you put a blowoff valve in and then hold your hand over the valve exhaust, you'll be amazed the amount of air that has to get pushed out. I wouldn't trust that amount of pressure to a flimsy plastic valve with a cheap spring/diaphragm.