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Discussion Starter #1
I was just curious if anyone else got these and what they sound like with the Varex exhaust. I will be putting them on in spring. If you guys are curious they are on sale now at Summit Racing and can be had for about $850-900 shipped to you with high flow cats which I think is a good deal for polished 304 stainless w/cats. FYI, you do need the Varex catback to use these headers.

https://www.summitracing.com/parts/xfo-hsvf82kitb/overview/make/pontiac/model/g8/submodel/gt
 

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I bought the full system last spring. Fitment was pretty decent, and took a bit to break in. It sounds great though, not obnoxiously loud either. Since the car is in storage for the winter, this is the only video I have.

 

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Discussion Starter #3
I bought the full system last spring. Fitment was pretty decent, and took a bit to break in. It sounds great though, not obnoxiously loud either. Since the car is in storage for the winter, this is the only video I have.
Was that pass with the valves fully open? That is the headers and full catback system right? Sounds good!
 

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Discussion Starter #5
Is it pretty quiet still with the valves closed even though it's full length headers?
 

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I have Kooks to the Varex catback. I wish I had the Xforce headers just to make it bolt on, but I already had the Kooks.

The catback did take a while to break in. It was a very deep, smooth tone at first. Now it screams above 3k rpm. Come spring, I'm going to remove the small cats that I have, we'll see how that does for sound.
 

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Discussion Starter #8
Yeah its almost like stock. With the valves open on the highway, there is a slight drone, but with them closed it's whisper quiet.
Nice, just what I'm looking for!

I get a slight drone now with the solo Mach system on the highway so I'm not too worried about it.
 

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I'll chime in. I have the Varex exhaust, but still have the factory exhaust manifolds and catalytic converters. In full open it does drone a little in the 1700-2000 range. It is not bothersome at a constant speed, but if you pull away with just enough throttle to keep it in that range through the gear shifts, it can be annoying. Closed is the same volume as stock, but a better tone. The Smart Box and app make it pretty amazing, I have it set to be closed at light throttle, 35% at medium throttle, open at full throttle. Zero drone, zero AFM noise when cruising, step into it a little and it growls, floor it and it howls and sounds great.
I've been looking at adding the headers. Did you guys get the 1 - 3/4" or 1 - 7/8" piping? Looked like the bigger piping is actually cheaper, but I don't think I need it. Did y'all need a tune? I figure it needs the rear O2's turned off since it has high flow cats, but don't really want to change my stock tune.
 

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Discussion Starter #10
The long tubes are 1 3/4", the 1 7/8" are technically "mids", but the mids will probably bolt onto other exhaust systems whereas the 1 3/4" will only bolt up to the Varex catback system.
 

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Discussion Starter #11
If anyone is looking to go to a Varex exhaust, I'm going to be selling my full system, ceramic coated full length headers w/high flow cats, and full 3" Varex exhaust with key fobs for the valves. System has about 500 miles on it and is being dismantled as we speak, I decided to go a different direction with my exhaust.
 
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