Header observation/question

[d_adams]

I'm in the middle of a repair/mod job on a set of Ti-Force headers.

Somewhere along the line, they got chopped up so I'm building replacement mufflers, brackets, etc. for it.

As received.

Now, my question is, why would it be choked down like this to 1.5" when the rest of the pipe is 2" almost all the way? This is right before the crossover x-pipe.

 

[TooFst]

Does only one of them get smaller?? IMO that pretty much defeats the purpose of equal length headers right??? Sorry not much help but those are on my list and pretty courious my self...

 

[theMelvster6]

Does it clamp on there or above where it's 1.5"? that almost appears a reduction to keep some back pressure in the main part of the header...possibly to help low end torque because the header tubes are much bigger than factory...just a thought. I would think 2" primaries is quite large unless there was some extensive motor work done.

 

[williegoat]

Reversion dam, or a means of increasing flow velocity?

 

[d_adams]

Backpressure is not a good thing, velocity is, at least when it comes to exhaust. Everything on this one is spring retained, the fit is pretty good.

2" exhaust might be a bit much for a stock xb12 motor, it's not too much on a 1125 though.

If the engine has been modded, then the 2" could be a big gain, but with a 1.5" restriction, it puts it back at the xb9 stock size. It could be a reversion cone, both pipes have one and they appear to be pretty close to equal length. Velocity may have already been lost by going to 2" right off, then hit the 1.5" cone, I don't know what it would do to the flow for sure. I've not run across any tuning info on these, much less a dyno chart showing what they're capable of.

 

[Miami78]

I'm really excited to see how these turn out...

Maybe keep the taper there for now, then later down the road (maybe when I hit 50k miles) when I do the 88ci conversion it can be opened up to the full 2"?

 

[freak2180]

It's prob tO add back the lost torque from the free'er flowing header/muffler combo. Kinda like the gaterbuell torque fix on the jardines.

 

[theMelvster6]

Ti-Force PDF

＊The middle pipe flair can be removed by cutting the spot welds of the mid pipe flair for use
with big bore and racing engines. However fuelling adjustment will be required. (Pic 5)

They call it a mid. pipe flair but it doesn't exactly say why it's there or what it for.

I'm curious myself...I'm always learning

 

[snrusnak]

I think it's just there to provide some restriction in the exhaust because the 2" primary tubes are too big for an xb engine. It isn't really the best way of doing it but if it were 2" the whole way there would be a big loss in velocity. Maybe that restriction helps keep velocity up...?

I'd think it'd be much better to just have 1 5/8" or so primary's the whole length.

 

[d_adams]

The middle pipe flair can be removed by cutting the spot welds of the mid pipe flair

It's not spot welded, it's all the way around.

Stock xb9 headers are 1.5", xb12 is 1.75" and going up beyond 1.88" typically would need engine work (on an xb) to be useful. I guess a turbo with 2" would be ok to run, but I've never messed with them.

 

[snrusnak]

So are you wondering if you should cut it off?

Personally if there's no major work done to the engine I'd leave it. If it's a 12 with intake, tune, muffler or more then probably cut it off...

 

[Miami78]

Dean, I'll send you an email, but I think we should leave the flairs on. And the O2 bungs look good, I've found plugs for them.

 

[d_adams]

Ok, should get something done early next week. Finishing up a couple of other things this weekend.

 

[d_adams]

I wonder how this is gonna work out on the 9.