I needed to get my blow down tube installed and as everyone knows, the standard blow down tubes are useless since they are hard to bend and too short for our vehicles and you can't use rubble hose. I see many have used stainless braided tubing using -8an fittings but that can get costly by the time you get all the parts. The braided hose and fittings look nice but my nitrous bottle hides in the spare tire compartment so I wasn't too worried about how it looked. I read that somebody had used a flexible stainless hose that can be purchased at most hardware stores. I went to Lowe's today and sure enough, they make some decent flexible hoses thats stainless and fit right on the end of the bottle with no adapters. These hoses actually fit water heaters at the gas connectors and you can get 3' or 4' legnths coated or un-coated. I got the coated yellow 3' and paid 9 bucks! At the bottom, I'm using one of the included fittings that came with the hose and making my own bulk-head fitting by using a coupler that I bought for .98 cents and a few large washers.

Here's what the hose looks like (except mine is coated):


Total cost me a little over 11 bucks. I'll try to take some pics.

I talked the guys at the track and they said it will pass tech with no problems.

Here's the more expensive way of doing it:
1- -8 bulkhead fitting and nut
1- -8 striaght AN conn
1- -8 90' AN conn
3' -8 Braided hose
2- Washers for bulkhead fitting
Here's the part# + price.From Summit
EAR-800108:-8 straight conn-$7.75
EAR-809108:-8 90' conn-$20.95
EAR-306008:-8 3' hose-$38.95
AER-fcm2103:-8 bulkhead-$9.95
AER-fcm2103:-Bulkhead nut-$5.25
You have to supply washers.
Total=$82.25+ shipping

Hope this helps anyone that needs a blow down tube.

 

Hey thanks if you can send me picks it will help out I will be going to Lowe's tomorrow hopefully and looking for these items

 

I am pretty sure that if you are not using steel tube to vent the blow off, it has to be telfon steel braided line. The steel flex line you have shown will pop and break apart of 1500 psi. The whole purpose of the vent line/tube is for when the bottle pressure gets over 1500 psi is to relieve that pressure. If the tube/line can not handle 1500 psi, it is going to go into car.

 

But the line should not actually get to 1500 psi since one end it open to the atmosphere. As soon as the bottle vents, the nitorus would go right down the line and out of the car. The line is not really being "pressurized" (I know a little but not to 1500 psi).

 

I bet that most are using the -8an SS braided lines which are also only rated at 1500psi and I doubt the aluminum blow down tubes that you can buy from NOS and the other nitrous manufactures can not handle more than 1500psi either. Its similar to a purge. Most people are using nylon tubing for their purge systems. Those lines can't handle to hold the nitrous pressure but they can usually handle the purge which is just venting the nitrous.

Here's a pic:

I easily bent the tube so that its 90 degrees and it fits great in the car without touching anything. Unlike the braided SS line, you can bend this to conform the car and it stays that way. The silver thing is what I bought to go underneath the car and act as a bulk head fitting. The blue fitting is what you need for a NOS bottle if you need to convert to accept a blow down tube.

 

I wouldn't worry too much about pressure. The blow off cap area (installed) is about 1/8" diameter. If you run this into a 5/16" fuel line hose rated at 250psi you'll be fine.

The hose is vented to atmosphere and the pressure drop is quite substantial when exiting the blow off cap orifice.