Originally Posted by LiquidZ (Post 109936)

I thought it was for allowing bending in the exhaust under engine load.

Originally Posted by kannibul (Post 109980)

Nah, if that was true, you'd have a broken engine mount. It's a fitment / something to go wrong later, device.

Originally Posted by drisko (Post 110028)

Sounds good. This exhaust is looking more tempting by the minute, especially with the weight savings.

Hope some dyno results come soon too.

Originally Posted by F.I. Inc. (Post 109893)

A very valid question!

The reason why most manufacturers use flex joints is to account for inconsistency in their production pieces. Ex: Nissan makes thousands of 370's in one year. The quality assurance on the exhaust system is probably fair at best and the flex joints allow for slight alignment variance.

We have never used flex joints in our production cat back exhaust systems for a number of reasons. Stainless Steel expands when it gets hot and flex joints will add to it like an accordion. They hinder performance by creating turbulence to the exhaust flow from the inside. They allow the system to sag as well.

We have prototyped all of our exhaust systems correctly from day 1 and do not have fitment issues. Our quality assurance is top notch and second to none. I stand behind that until the day I die! Now in some cases we use flex joints. On some of our turbocharged down pipe applications we use them. We judge each case based upon it's circumstances.

The exhaust system is bolted to the manifolds. Then it is hung in rubber. The rubber is to allow movement as to when the engine torques. See the engine is sitting in rubber motor mounts so when it torques everything bolted to it Will want to move with it. If we solid mounted an exhaust to the frame it would break when the engine torqued.

Here is some food for thought,

This is not our first car. We have over 10 high end cars that we currently have a production exhaust system for. Not one uses flex joints in the cat back. Cracking is not an issue that is common with our products especially our cat back's.

If anyone is deeply concerned about the lack of flex joints and feels they want them, We have a mandrel bender in house, we are they designers and producers of all of our products so we can fulfill any request. If you want the flex joints I will install them at an extra fee to make you feel more comfortable. I am not being sarcastic I am being serious! But, in my honest opinion they are not needed.

I will say once again, it is a valid question...

Thank you, Tony
(818) 882-2788

Originally Posted by F.I. Inc. (Post 110060)

Everything is looking on schedule for tomorrow evening. Were are shooting to bang it all out in one trip on one night.

Originally Posted by kannibul (Post 110395)

Before and after dyno, I assume?

Also, I know it might be hard to request it, but, could you also do it with FI HFC's (for a third set?)

;)

Originally Posted by kannibul (Post 110395)

Before and after dyno, I assume?

Also, I know it might be hard to request it, but, could you also do it with FI HFC's (for a third set?)

;)

Originally Posted by F.I. Inc. (Post 110425)

I know this thread is long and it even took me a minute to find it. This is originally what I wrote in reply #201:

Later this week probably Thursday night. But, we are aiming to get it all done in one shot. In the following order:

1) Stock (Baseline)
2) TDX cat back
3) TDX cat back w/ high flow cats
4) TDX cat back w/ resonated test pipes
5) Possibly- stock cat back w/ high flow cats
6) Possibly- stock cat back w/ resonated test pipes

We will get 3-4 runs with each configuration and take the average of each one. Not low stock and high cat back, that is inaccurate and it is false!

It is a Dynojet and it will be set in SAE all the way through.
The only change we will make will be the component we are testing. I will take video and sound clips as well.

I welded a wideband bung in to the stock exhaust to show all of you what the A/F numbers will be stock. I will also have A/F readings in every other configuration to show you if it leans out and how much.

Stay tuned...

Originally Posted by F.I. Inc. (Post 110772)

Off to the DYNO, at the very least I will post some numbers late tonight...