AVO Turboback Exhaust

[MarcoLGT]

Mcg - thank you for the write up! It's a huge help. I purchased one of those adapters originally but cancelled before it shipped. Grimmspeed 077046 may offer better flow for this transition, but it's technically for a donut gasket to 3" flat gasket. The holes aren't slotted, so I passed. It may work, only way to know is buy it and see. Until now I never realized you cut the stock side off thw adapter, oops. Plus there are no pictures of the AVO adapter. Its like no one really makes an adapter for our car. Unless the AVO adapter fits properly, but the flow from 3" - 2.25" is not smooth.

 

Scubaboo - That gets me in trouble, a deal too good to pass up. Like right now, a GS intercooler and boost control solenoid for $805 shipped. The intercooler goes for $845 itself! Yet I must refrain...

 

So i just checked what I have (AVO 3" gasket, AVO adapter, stock 2.25" gasket). What I can see the AVO adapter should work. The extruded piece to the stock exhaust measures 1/16" bigger than 2.25" and judging from mcg_ picture/measurement that should work. The 3" gasket will need the bolt holes slotted. The AVO adapter will need the bolt holes slotted, they're drilled for a 3" flange/gasket. This was matching up to the stock exhaust gasket. And the AVO downpipe holes may need to be slotted slighty, they already are but did not match the stock gasket holes. Or one could slot out the stock flange holes on the car, but mine is rusted to hell, so I'm leaving that alone. I want the bolts to go straight in, no angle at all. Less likely to leak that way.

 

Also found the AVO adapter does not sit flush against the downpipe flange, has a slight rock to it. So either the GS 2x thick 3" gasket #076001 will work or I'll have a machine shop check the adapter and downpipe, see what they think. Last thing I want is the coating destroyed on my new downpipe. Have something else for them to do anyway.

[Scubaboo]

Marco, that sounds a lot more complicated than I remember lol, I seem to recall it being pretty straightforward with the GS parts. I havent reviewed mcg's thread yet, though.

 

That GS IC is a good deal! I'm cheap lol so I got a used Racer X IC off a member here something like 1/4 the price, I figure the GS is not 3x better right? But I may pony up for a GS or Garret if a good deal comes up.

[MarcoLGT]

Your GS adapter is already slotted. Mcg slotted his 3" gasket and used the GS slotted 2.25-2.5". He also threw on some exhaust putty and fixed his leak. Not saying that's wrong, just trying to avoid it. Everyone has their own way. Mine happens to be the longest/biggest pain.

 

There's no way I'm swinging for the intercooler, just a pipe dream. I like it because it gets rid of that pesky intercooler to throttle body coupler and replaces it with a straight one. They did actual testing on their unit. At least that's how I justify my wants, lol.

 

I tend to over think things and try to shoot for perfection, maybe that's my problem and why nothing gets finished...

[mcg_]

Mcg - thank you for the write up! It's a huge help. I purchased one of those adapters originally but cancelled before it shipped. Grimmspeed 077046 may offer better flow for this transition, but it's technically for a donut gasket to 3" flat gasket. The holes aren't slotted, so I passed. It may work, only way to know is buy it and see. Until now I never realized you cut the stock side off thw adapter, oops. Plus there are no pictures of the AVO adapter. Its like no one really makes an adapter for our car. Unless the AVO adapter fits properly, but the flow from 3" - 2.25" is not smooth.

 

No prob, man. I think the Grimmspeed 077046 or the AVO adapter are the ones you want (but I see what you are saying about the holes not slotted). I had the GS 077044 (from my 4th Gen LGT) - hence the modification.

 

So i just checked what I have (AVO 3" gasket, AVO adapter, stock 2.25" gasket). What I can see the AVO adapter should work. The extruded piece to the stock exhaust measures 1/16" bigger than 2.25" and judging from mcg_ picture/measurement that should work. The 3" gasket will need the bolt holes slotted. The AVO adapter will need the bolt holes slotted, they're drilled for a 3" flange/gasket. This was matching up to the stock exhaust gasket. And the AVO downpipe holes may need to be slotted slighty, they already are but did not match the stock gasket holes. Or one could slot out the stock flange holes on the car, but mine is rusted to hell, so I'm leaving that alone. I want the bolts to go straight in, no angle at all. Less likely to leak that way.

 

Good thinking; I wish I had thought it through this much before I attempted the job.

 

He also threw on some exhaust putty and fixed his leak. Not saying that's wrong, just trying to avoid it. Everyone has their own way. Mine happens to be the longest/biggest pain.

 

FWIW, I didn't have an exhaust leak. I'm simply read somewhere years ago to always use some gasket maker when coupling exhaust pieces and have done so ever since.

 

There's no way I'm swinging for the intercooler, just a pipe dream. I like it because it gets rid of that pesky intercooler to throttle body coupler and replaces it with a straight one. They did actual testing on their unit. At least that's how I justify my wants, lol.

 

The GS IC is damn fine piece. Much nicer looking and better fitment than the AVO....but alas, despite the discount they gave me for test fitting the IC, I never pulled the trigger. If I had cash to burn, I'd love have a tuner conduct back-to-back tunes (AVO IC v. GS IC) but, frankly, I suspect the tunes/results would be very similar as the really performance improvement are likely longer performance applications.