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Does replacing the stock bellows tube make any difference in prformance?

What do you use to replace it ? Are there any aftermarket parts to replace it?

i doubt you'll notice anything substancial. But it does smooth the flow of air through that section before it goes to the intake manifold.

Your best bet as far as replacing it would be to buy a full cold air intake which would come with the section to replace the bellows tube. They can be had on ebay shipped to your door for like $40

This has been debated several times. If you actually remove your stock bellows tube, and feel inside, you will be surprised. It's much smoother than it looks from the outside.

and helps give the intake tract a lilttle bit of flexibility, so that the couplers don't work themselves loose

Some standard (non-magnum) 2.0L neons came with a hardpipe (steel) as a bellows tube (i think around 2004.5 M/Y). These have rubber couplers on either end. While the steel pipe is 2.5" across, the couplers restrict down to less than 2" across. This bellows tube is very restrictive; well, actually only the couplers are restrictive.

The other bellows tube found on the neon is an all rubber hose (same construction for magnums and non-magnums, just different size/shape/length). These have a pleating to allow flexibility. While the inside is smooth, there are still "pockets" formed by the pleating. This causes some pressure differences that restrict flow, but not as much as the aforementioned "hardpipe" bellows tube and its restrictive couplers.

I think someone on the dot org a few years ago dynoed a 2whp difference between a stock pleated bellows tube and an aftermarket tube (I think the only mod was a CAI and he just swapped the bellows tube around while still using the fenderwell piece to measure the gain/loss.)

Bottom line is that if you are going to get a fenderwell CAI, get one that replaces the bellows tube. If you want to retain the stock airbox, it doesn't pay to change the stock bellows tube.

My $0.02...

Or if you want, you can do what I had to do in a pinch and just couple the TB right onto the IM. I didn't have any measureable differences between that and a piece of steel pipe, but I did notice a 3 or 4 kpa difference between that and the stock bellows tube.

Just curious if there was anything to be gained by replacing the bellows tube. I want to keep my stock air box since I did the PVO hood mod on my SRT-D hood. I also closed the turbo cooler ducts so that more air diverted to the air box. The 2nd gen stock box isn't a bad design, allot better than the 1st gen DOHC hot air box on my 99 Expresso.

At one point I had replaced just the bellows tube and noticed no real gains as far as the but dyno goes. You would be better off with a K&N drop in or the equivalent.

My AEM intake came w/ a hard pipe to replace the bellows, but I didnt really notice a difference, since I replaced that and the intake at once.

Some standard (non-magnum) 2.0L neons came with a hardpipe (steel) as a bellows tube (i think around 2004.5 M/Y). These have rubber couplers on either end. While the steel pipe is 2.5" across, the couplers restrict down to less than 2" across. This bellows tube is very restrictive; well, actually only the couplers are restrictive.

Every 2GN Non-SRT came with a bellows tube, 2000-05 #4891274AB....
The bellows tube is designed to provide a flexable joint between the solid mounted airbox and the constantly rocking engine. As for a bellows tube replacement for gains, nothing a but dyno will notice but an actual dyno will. If you replace the bellows tube with a piece of pipe you are actually increasing the plenum area wich will either increase or decrease performance depending on the application.

^^^ This is the non-#4891274AB bellows tube. The Neons I've seen them on have been late m/y 2004. I'll see if I can get the part numbers sometime. I've worked on several and noticed that they were kinda weird, but they were marked with chrysler part numbers and pentastar logos.

I don't know why but I've seen them on several. Its one of them weird Chrysler things. kinda like how most 2005's got black power steering caps. Same part number, but different caps.

^ That looks aftermarket to me. I guess we'll see once you get the part numbers, abd BRR can look it up.

If you are not going to get a CAI(useless other then noise anyways, loose some weight and it does more for you), dont worry about the bellows tube and spend money on something else. One of the best mods for these cars in the UDP.

that is an interesting tube.