Velocity Stack

[DyNamiC]

A little while back, someone had a velocity stack on a HX40 listed in the classified section. I PM'd him about it but he never answered me back. It fit perfectly on the turbo and I have not been able to find one like it anywhere online. I wish I had saved the picture... Does anyone know of ones that fit the HX40?I believe the one he had was purple and made of aluminum.

 

[91-gsx]

A little while back, someone had a velocity stack on a HX40 listed in the classified section. I PM'd him about it but he never answered me back. It fit perfectly on the turbo and I have not been able to find one like it anywhere online. I wish I had saved the picture... Does anyone know of ones that fit the HX40?I believe the one he had was purple and made of aluminum.

Here are 2 links, the first link is for a 4" aluminum velocity stack. The second link is for the same velocity stack, but this auction includes an air filter that fits the 6" diameter of the stack. It has a 4" opening and expands to 6". It will net a good amount of horsepower. Later.

BLOX VELOCITY STACK 4" AIR INTAKE (aluminum) BLACK:eBay Motors (item 390080285025 end time Sep-09-09 07:28:02 PDT)

Blox Velocity Stack 4" w/ Filter (Composite Black):eBay Motors (item 350228821882 end time Aug-18-09 12:34:03 PDT)

 

[SpeedAddict62]

Did you not see my reply in the Holset thread? Since I'm lazy, I'll just repost it here.

A little while back, someone had a velocity stack on a HX40 listed in the classified section. I PM'd him about it but he never answered me back. It fit perfectly on the turbo and I have not been able to find one like it anywhere online. I wish I had saved the picture... Does anyone know of ones that fit the HX40?

Check out:

Velocity Stacks, Motorcycle Velocity Stacks, Ram Tubes, Bellmouths hand-crafted by Velocity-of-Sound.com
Very cool place, I just bought one of their podrams

Vibrant also has them:
Vibrant Performance ::.

Or you could even try something like this:
Bellmouth Starter Collar Air Handling Systems

Lastly, you can search Ebay, there are a ton of vendors on there selling Blox bellmouths.

Also, for some really good reading on why you should use a bellmouth, check this out.

 

[DyNamiC]

I have seen a couple of those already. The one this guy had fit the HX40 perfectly. It slid right over the compressor inlet, no coupler or clamps in between.

 

[SpeedAddict62]

1. Why would you want it to slip over the inlet? Wouldn't that sort of defeat the purpose of a bellmouth? The end of the compressor inlet would create a lip inside the bellmouth which can't be good for airflow.

2. What is so bad about a coupler? IIRC, the inlet is probably 4" (that is why my HX35 is). Just get a bellmouth with a 4" ID and slip a coupler on the end of it to connect to the inlet. You don't really need clamps, because it isn't pressurized. Save yourself $20 and get a 4" coupler off a diesel truck in a junkyard or something.

 

[97gstnick]

So are these things more beneficial than a cold air intake?

 

[SpeedAddict62]

Yes...read the link in my last post. CAI is just that, it intakes cold air. The idea behind a bellmouth (or any velocity stack for that matter) is that a plain pipe end is pretty poor for airflow. The bellmouth allows a smooth transition from the atmosphere to the pipe. You can still use a bellmouth with an air filter; you can buy a podram like I did, that takes a 6" filter and reduces it down to a 4" pipe diameter. It isn't quite as good as a full bellmouth but it still does the same thing.

 

[e85_4g63]

I'd say they'd make a great addition to a cold air intake, as for being as good as, IDK...

 

[91-gsx]

Just wondering if you guys thought a velocity stack would make any difference if placed after a mass airflow sensor? I have seen Jim Wolf use "Pop Chargers" on Nissan cold air intakes with a lot of improvement even though they have mass air flow sensors in the middle of their intake pipes.. Our mas airflow sensors have honeycombs that direct air, so do the honeycombs getting in the way negate any gains of a velocity stack at the end of the intake pipe? I would think that there should be gains, but I had to ask for your opinions. Thanks ahead of time for the information.

 

[SpeedAddict62]

How would you place a velocity stack after a MAF? I'm not really sure how you would implement a bellmouth on a car with a stock MAF, since the bellmouth is only really beneficial when you have a large chamber (the atmosphere) flowing into a small one (the intake pipe). You'll also see them in intake manifolds, one for each cylinder feeding off the plenum. With a hot wire MAF, it would be easy to make one, since you could just have bellmouth -> pipe -> MAF -> pipe. Since our MAF isn't designed like that though, it would be harder to do. I do see it being beneficial though, if you were able to design a bellmouth for the inlet of the MAF.

 

[dsm-onster]

Just wondering if you guys thought a velocity stack would make any difference if placed after a mass airflow sensor? I have seen Jim Wolf use "Pop Chargers" on Nissan cold air intakes with a lot of improvement even though they have mass air flow sensors in the middle of their intake pipes.. Our mas airflow sensors have honeycombs that direct air, so do the honeycombs getting in the way negate any gains of a velocity stack at the end of the intake pipe? I would think that there should be gains, but I had to ask for your opinions. Thanks ahead of time for the information.

Yes the sr20/z31/z31/etc nissan guys have a hot wire maf from the factory with NO screen. But the screen only directs flow ONCE the air is AT the maf sensing portion. Getting air to the intake pipe still means air traveling over the rim of an intake pipe. The velocity stack SHOULD still help greatly with flow just as it would at an intake runner inlet.

 

[bling5tatus]

Someone I know that dynos cars keeps a velocity stack on hand and has reported hp gains of 10% at the wheels from going from a pipe w/ no filter to a velocity stack...

so just remember that before you go trying to race people w/ no air filter on your maf, you're probably killing more power than you're gaining.

 

[91-gsx]

Cool guys. I have bought a Blox 4" velocity stack. I have already made a cold air intake that looks just like its a stock 1g air-box and intake like it came from the factory, from the outside, and even works like stock to replace filters... But... It has a ton of features that I'm going to show everybody on this forum and others really soon. I think you guys are going to love it, because I really do. Thanks for the help guys