I just received my Flowmaster american thunder dual exhaust kit in the mail and realized they dont include any down pipes!

The car I am installing them on is a 66' fastback with a 289 and stock exhaust manifolds. I figured this would be no problem to get so I drove down to Smyth and they looked through their books but couldn't figure out what downpipes I need and said to look around online. So since you guys have been helpfull in the past I decided to come here first.

Well anyhow, anyone else put H pipes on a stock 289 and know what kind of downpipes I would need to get?

 

Well darn it, I got shot down. Called Summit (where I ordered the kit) they said most people put them on cars with headers and have the connecting pipes custom made then refered me to flowmasters tech department. Called flowmaster and they said the same thing that I would still need the pipes bent, but refered me to a site that makes pre-bent downpipes. Went there and they are still developing the ones for Fords...

Grrr. I figured having a stock car I wouldn't have any trouble hooking up an exhaust kit... guess not.

How hard would it be to bend these pipes myself you think? I have a pipe bender Like this one and a mig welder. Never used the pipe bender yet though so I dont know what its capable of. :/

 

You need them to be mandrel bent. Take your kit to an exhaust shop and have them make you the pipe and then connect it all up by welding everything together.
Also, TylerDru went through this a week or so ago and solved it by buying the pipe somewhere. PM him to see what he used.

 

do u really want turn downs??? im assuming they are just long and coming straight out the back right now, correct??? might wanna think about some nice tips......that option always give the extra little "bling" and u wont have fumes and as much vibration right underneath you....my friend has turn downs on his firebird and if ur not moving at a good clip your sucking up a lot of smoke.

 

I had long tubes. Take that kit back. and let an exhaust shop do it. You will spend about the same without all of the headache. Your kit is made for headers not stock manifolds.

 

Well at this point since its gotta be custom anyways I may as well just get headers.

What kind of performance increase would you think headers would have over stock manifolds? I'm not a huge performance freak I am just curious from the standpoint of if headers are more of a cosmetic bolt on or if they will actually make the car noticeably perform better and sound better. Sorry if thats too silly of a question, i'm more into body work and paint than the mechanical stuff.

 

I bought the same kit you did at the beginning of this summer. I have a 289 with tri-y headers. I installed what came in the kit my self then took my car to an exhaust shop to have them make the pieces from the header collectors to the h-pipe. It was $100 to have them do it. Soaring, not one shop in a city of 90,000 did mandrel pipe bending. I thought that was wierd but oh well, they didnt have to make any sharp curves or anything so nothing was restricted. I have pictures of the final install Marxus if you'd like to see them.

You will notice a considerable amount of power gain with headers, especially in torque. Anything is better than stock manifolds.

shifteasy, by turndowns I think he means the pipe from the manifolds to the h-pipe, no the turndowns that go behind the mufflers.

 

yeah I would love to see pictures of them installed since tri-y is one of the header types I was thinking I might get.

$100 to make those parts isn't too terrible I spose, I figured you would have to have them put the whole assembly in. As long as I can do everything but those couple parts I guess thats worth it.

 

From the front to back. I have an oil leak, thats why everything is so dirty and a plastic baggy melted on the h-pipe. [:@] But you can see the pieces they made. Not very long pieces, labor is what kills the price.



Middle of car to front


rearend with stainless steel tips! Man I love those things.

 

With the exhaust you bought headers will make your car sound really good (IMO i have a very similar set up) And you will gain a few HP nothing that will be really noticible i dont think.