I'll bet everyone has a different idea on this one but here goes:
I use the Donaldson for these reasons:
Easy to install in the factory position.
Breaths above the shroud-behind factory grills where there is plenty of cool air and no water. (usually)
TPIS has a cover that the directions say to cut the shroud, but you don't have to cut the shroud to use it (on the Z06), just find a way (I did) to prop up the lower corners next to the bumper about 1" so the cover is not totally flat. This lower portion next to the bumper down there is the coldest and closest to the grills.
This will give you additional breathing clearence under the cover on the top portion of the fliter, the whole filter is in a wedge shape, it doesn't sit flat on the shroud anyway, it sits above it by an inch or two, the upper corners will still install as directed.
It will have plenty of room around it (between the filter and the cover) and will shelter it from side rain from the open grills and the hood rain (hoods not sealed) or car wash water (from when you raise the hood to dry the edges).
This is as close to the factory set-up as you can get and still breath plenty of cold air with no deep water injestation problems from under the shroud and no heat radiating from the a/c condenser area.
All cool, bumper air, all sheltered, from all sources of heat and water.
This works for the Z06 because it has the functional grills with the constant cold air feed.
The filter will have plenty of breathing room all around it, breath plenty of cold air and be sheltered from all water and heat sources, just like the factory.
I think, there are alot of downside issues covered here for factory fit and finish appeal.
You could get more flow with less restrictive medias. (Not that this one is restrictive, just that some are designed for almost nothing but flow and maybe sacrafice some filtration charactoristics for race use).
Don't think your getting enough air for track use for some reason?
Run a 3" collapsable seal across the radiator on both sides of the cobra head and take 5 seconds to remove the cover for full exposure and put it back when your done.
You shouldn't have hot air as long as the frontal area is sealed off from the majority of heat expansion, again use the functional grills the factory gave you.
The radiator should have the 3" seal across it anyway, to defer the heat from expanding into that area.
I'm actually surprised the factory didn't put one there. I know I've seen them in other applications, I just don't remember where!
An IAT test on the scanner should confirm all the temperature assumptions, I'm going to do one pretty soon.
In my opinion the only thing that could be better is atmospheric pressure/Ram air.
But that's my opinion, and this IS an arena, I mean forum :lol: and that's why we're all here. To compare notes.
Good luck which ever set-up you choose CRUZMISL, the car's a blast anyway. :cheers: (Blast...CRUZMISL, I made a funny) :lol:
I love my Blackwing. Just picked up a cold-air box for the Donaldson from Nate @ Xtreme Motorworks. Hope to get it installed in the next few weeks. Not driving much in the winter. Colorado= Ski season! But I agree w/ previous comments, there are several very good products on the market. I am very interested in the Halltech line. Take some time and research this forum in the advanced search. There have been several threads on this topic. Good luck!
Currently have a blackwing on with carbon fiber air bridge. It
seems to work good. Just do not use cold air cover with the
blackwing by cutting shroud as directions say to. On my 01
this caused severe surging. Nate at Extreme said he would
take the cover of the market, this was about two months ago.
I have covered the hole in shroud with cardboard waiting for
new shroud from Nate. Surging is gone with hole covered. Must
be very turbulant air and maf sensor can't get reading. I still
have screens on maf. Anyway vararam is due in on Wednesday!
I for one think there are benifits to useing the stock air box and K&N. When someone looks under the hood, they look and see no mod's, and think thay found a "mark" There is better "all weather" protection, than any of the after market systems. My ET's show that I am not giveing very much, if anything up. I do have a 02 cover in the garage waiting for spring.(still looks stock) Ric
The cover has to be completly sealed. The cause is a variant in air temp. The pure cold air is supplemented at times with hot air form underhood. Not a problem til you introduce the extreme cold air from below, once this is done the warm air must be kept out. The flucuating MAF signal is due to the hot then cold then hot. Not turbulence.
Once the cold air is stabilized by the seal, the surging is gone. The system is going lean, rich, lean, rich due to the hot air.
The "covering the hole fix" is from stabilizing the hot air it had before, the functional front grills change temp. much slower if you were to watch the IAT readings.
Once you go that cold with the hole in the shroud any sudden hot air throws it lean and bucks or surges.
Mine surged pretty hard until sealed, and it took a few mock-ups to get it all, but it does work well once your done. I was seeing IAT's well over 116 at 60 degrees ambient while idling at a long light and now they are back down while idling. 56 degrees divided by the SAE standard, 7 degrees = 1% HP is a total of an 8% loss in HP off the line until evacuated when the grills start working again.
Even being conservative at 450 flywheel with mods thats 36 HP.
I hate to ruin the party but most intake sellers locating the intake to get cold air are getting more than half their gains from the decrease in air temp, not their "high flow".
Even GM jumped on that bandwagon, hence the first real functional grills in a long time. They knew they were sandbaggin the numbers once the car got upto speed and evacuated the frontal area. Place a couple of HIGH flow fans RIGHT AT those grills with the hood closed on the dyno and I'll bet those stock stand still numbers change from around 355 to 365-370, when you test it leave the hood open until right before your run to try simulating your high speed run as much as possible, you want that front end evacuted and that IAT down at ambient where it is at speed. That would come out to around 425 flywheel while at speed (w/13% loss ratio @370, 355/.87=408). In the Spring air. Yea baby! Think about that.
My system is working well, IAT is stabilized (cold) and I used alot of adhesive backed foam tape of diiferent demensions to seal each and every corner, top to bottom. The bottom of the cover also needs to be drilled and push riveted to the shroud, this is very important in the sealing process so a flater seal is acheived to the shroud. The front/bottom/lower end of the Donaldson is the hardest as it sits about 2 inches above the shroud due to the conical design where it bolts to the bumper on those posts. Stacking the foam tape is required down there. I'm using the TPIS cover, which I'm pretty sure our vendors are selling for the Balckwing.
The worst thing you can do is cut the hole too big, you loose sealing surface. Don't follow the cover directions. Cut it to just under the media size. I'll have to measure the hole size that's best and repost, it's smaller than you think.
Good luck Vara-Ramers and don't forget you should have the same sealing issues for hot vs. cold.