Flex Test pipe

[Gjohnson7]

Hey, anyone know where I can pick up a Test pipe with flex section like this one.

http://www.projectnissan.com/shopping/pc/viewPrd.asp?idcategory=103&idproduct=4290



http://www.projectnissan.com/shopping/pc/catalog/projectsilvia/pjs-flexpipe.jpg
This one doesn't seem to be available yet.

Thanks for any info.

[Ninjabread]

You can make one for real cheap. Just order a 3 inch flex pipe off summit, and 2x 3inch flanges anywhere + 1 foot of piping just to be safe.

cheapo.

[Gjohnson7]

Hmmmm..... Not a bad idea, but I don't have access to a welder or the experience to do anything like that.

Well, here's the deal. I need this flex pipe or a normal test pipe to button up my exhaust. My car will be daily driven. I have stock motor mounts and a Nismo Tranny mount. Do you guys think I should hold out for a flex section or will I be ok running a test pipe.

[Ninjabread]

So long as you have rubber exhaust hangers, u should be fine.

My gaskets die because I'm using poly hangers so there is no play.

[Gjohnson7]

Yeah, I'm running rubber (stock) exhaust hangers. I just want to make sure I don't snap any bolts.

Sorry, this is my first time to upgrade exhaust.

[SHIFT_Slide]

Usually 99% of the flex pipe stuff hangs way too low. If you really want anything with a flex, it's better to have it custom made if you plan on having a low car. As long as the exhaust is bolted up correctly with the stock rubber hangers, you'll be fine. Ultimately you want the exhaust to be basically floating, which will help prevent cracks on after market exhaust manifolds.

[fliprayzin240sx]

Take your DP to an exhaust shop, the flex pipe is better on the dp anyways. Any muffler shop should be able to do it for less than $100.

[Gjohnson7]

Usually 99% of the flex pipe stuff hangs way too low. If you really want anything with a flex, it's better to have it custom made if you plan on having a low car. As long as the exhaust is bolted up correctly with the stock rubber hangers, you'll be fine. Ultimately you want the exhaust to be basically floating, which will help prevent cracks on after market exhaust manifolds.

Well, the car won't be that low. I was planning on running coilovers, but my budget will probably only allow springs. I believe my exhaust will be mounted right with all stock rubber hangers.

Take your DP to an exhaust shop, the flex pipe is better on the dp anyways. Any muffler shop should be able to do it for less than $100.

I was planning on taking my down pipe to an exhaust shop to have a flex section welded in, but the exhaust shops are telling me they can't touch it because I'm not running a cat.

[ThatGuy]

That's bullshit. You're paying them for a service, not their advice on emissions.

Tell them you are running a separate cat, or that it's for a track car.

[fliprayzin240sx]

So take the downpipe off the car and have em install one in there. Problem solved...

[Gjohnson7]

That's bullshit. You're paying them for a service, not their advice on emissions.

Tell them you are running a separate cat, or that it's for a track car.

The shop was telling me they could get a $10,000 fine. But I didn't think to tell them it was for a track car.

So take the downpipe off the car and have em install one in there. Problem solved...

Ok, so if I go this route. How much of a flex section needs to be welded in.
Of course I could measure when I pull the downpipe off, but I assume it's about a foot.

So, do you guys think it's worth the extra money for the custom flex section or would I be just fine picking up the test pipe and calling it a day.

[IronMonkey]

If you arent worry about emission, just take off your downpipe, weld in a section of the flexpipe and extra piping to delete your cat. No need for test pipe or cat.

[fliprayzin240sx]

They will put in a flex pipe for the same amount of pipe they cut out of it. Its not really rocket science...even Leeroy Jenkins down the street can do it.

[IronMonkey]

They will put in a flex pipe for the same amount of pipe they cut out of it. Its not really rocket science...even Leeroy Jenkins down the street can do it.

yes, but im saying if they didnt cut any pipes off and add a little more piping to it instead, then he wont have to run test pipe.

[SochBAT]

Add the flexpipe to the DP, not exhaust. Thats just retarded.

IIRC, most manifolds crack or get FUBAR is because the weight of the exhaust is placed on the manifold, without any assistance of leveling out the weight.

The flex pipe eases the weight off the manifold.

[slw240sx]

just take your down pipe to a shop in town that does fab work, most performance shops that do any fab work could knock that out while you wait providing they have a flex section in stock or you bring it.

it wont be as cheap as a muffler shop, but its a easy thing to do. even with making a good fixture to hold it in position i could do that in 30mins or less tig welding it.

[SHIFT_Slide]

Most manifold crack not only because of the weight of the exhaust, but of how its mounted. If the entire exhaust system is mounted so that it can move very little, and then you take some engine mounts that are worn and rev the engine= stress on everything. Cheaper manifolds will crack because it's the weakest part of the system.

Gjohnson7,
If you really want a flex section, buy a downpipe that already has it. The only problem with them is they hang a little to low, and since you already said you aren't going that low, it really wont affect you that much. From what you've said about the shop that you'd get your exhaust welded, I'd stay away from them. I really wouldn't even want them to weld in a flex section because chances are if they weld it with it off the car, it might be slightly off.
Who knows, it might be a sweet shop and they'd do a great job though.

[slw240sx]

for the length i normally use 4" long Flex sections, Stainless steel versions run around 50-60$

[projectRDM]

The main thing to remember is to use the primary exhaust hanger on the transmission mount. This is the first and most solid one and will do the best job at keeping the manifold from cracking under load. The rest of them should be replaced with poly hangers. Making the idea 'free floating' will load more on the manifold, because the exhaust system is basically swinging under the car.

I bought a flex section for $60 from atpturbo.com, got it welded for $30. That way you can put it where ever you need it.

[SHIFT_Slide]

When I said floating I meant it in a different way. The way the exhaust should be bolted up is so that every hanger lines up perfectly, and that you have no trouble mounting it. Just about all of the weight should be held up by the hangers, aka floating.