[Rudy_1SS]

Good morning guys,

I did a little searching but didnt turn up the answers I was looking for.
I recently had a local shop, with a good reputation, cut out my secondary cats. Their welds were done well (i'm yet to have a CEL) but i'd like to have a more "legit" system in there. The sound with just the cat delete is nice, its louder than stock and the rumbling and popping sounds are much more satisfying but I feel the sound is a bit raspy.

http://www.phastekperformance.com/20...pipe-60606.htm

Would a system like the one in the Link sound diffrent than the cat-delete while still maintaining NPP function? It seems to me that this kit is the same thing I had done just with more piping, but for 500$ more there must be some difference. I suppose deleting the crimps may open up a lil more sound as well?
If anyone has a vid of NPP axel backed mated to this system id really appreciate it.

Thanks alot guys and have as good a Monday as possible

[Master357]

Crimps in the factory pipe do not hurt anything. Oval pipe and round pipe have the same area.

I think you have already done the smart and cheapest thing having your 2nd cat deleted.
I looked into these Borla pipes as well, but cannot stomach paying that kind of money for what can be accomplished at my local exhaust shop for a fraction of the cost.

[Rudy_1SS]

Originally Posted by Master357

Crimps in the factory pipe do not hurt anything. Oval pipe and round pipe have the same area.

I think you have already done the smart and cheapest thing having your 2nd cat deleted.
I looked into these Borla pipes as well, but cannot stomach paying that kind of money for what can be accomplished at my local exhaust shop for a fraction of the cost.

That was my reasoning also...I was just wondering if the whole system may produce a diffretn sound. It's a crazy amount of money haha, seems a lot of the exhaust systems for these cars come with a pretty steep price tag and I couldn't justify the price either.
Thanks for the reply.

[Megahurtz]

I'm in the same boat right now sorta. I don't want to cut up my factory exhaust but I want to delete my secondary cats. The Borla midpipe is the best option to retain factory AFM valve function but the cheapest I've found this version is $1100 shipped. If Tim over at EFI gets the AFM deletes manufactured and selling soon I can purchase the non AFM mid pipe for about $650 shipped, but then add on the cost of the AFM deletes which probably wont be too expensive....but still.

Maybe I should just stop being OCD and cut my factory exhaust.

[EFI Tuning]

Megahurtz,

Will you be turning off AFM in the ECM? If so, the 1st revision units are 100% viable to use and I could have a set in your hands next week. The reason I'm doing another revision is that some C7 guys would like to be able to keep AFM enabled in the ECM and still eliminate the valves. That request came in after I sent the PCBs out for fab. I am wrapping up the second revision layout today. Those units will be about 3 weeks out.

I can build up to 30 sets of the first revision units if people are interested. AFM must be turned off in the ECM though or you will get a CEL.

I have not finalized the pricing for the final version of the module set yet but if you are ok with the first revision I will price them at $100.00 for a set. I will need 7-10 days to build them up and ship them out. The final version will be priced higher than this. These initial units utilize the same connectors utilized by GM (including weather seals) and the PCB will be fully potted to ensure there are no issues with moisture.

Thank you,
Tim

[Megahurtz]

Originally Posted by EFI Tuning

Megahurtz,

Will you be turning off AFM in the ECM? If so, the 1st revision units are 100% viable to use and I could have a set in your hands next week. The reason I'm doing another revision is that some C7 guys would like to be able to keep AFM enabled in the ECM and still eliminate the valves. That request came in after I sent the PCBs out for fab. I am wrapping up the second revision layout today. Those units will be about 3 weeks out.

I can build up 30 sets of the first revision units if people are interested. AFM must be turned off in the ECM though or you will get a CEL.

I have not finalized the pricing for the final version of the module set yet but if you are ok with the first revision I will price them at $100.00 for a set. I will need 7-10 days to build them up and ship them out. The final version will be priced higher than this.

Thank you,
Tim

Hi Tim,

I would like to keep AFM fully functional. I'm trying to squeeze as much power out of my car without hurting fuel mileage (excluding E85) and without making the car insanely loud. I've been down that road in my 2011 Z06. It was an amazing car but I need to make sure I don't go crazy like that again on a daily driver.

Currently I think I'm going to do the EFI ported TB and Intake, E85(already own the DMS kit thanks to your work), and then possibly the Borla midpipe to delete my secondary cats. I want my car to be louder but I also want to retain the near silent sound in Tour mode. I will be doing all of the work and tuning myself with HP Tuners and a wideband. I probably pickup HP Tuners this month. Kind of waiting on a couple of payments to come through that I am owed.

With that said, my job has me super busy right now so I am in no rush. I won't be able to action on any of the parts I would buy until after the Holidays so I plan on picking up a part here and there. I appreciate all of the work you've done and I have certainly been (almost) silently reading and observing so that I make the best choice in mods vs cost vs daily drive-ability. If I decide on the non AFM Borla midpipe I'll be picking up your AFM delete boards.

[EFI Tuning]

Sounds good! I'm going to put the first revision on the website today for anyone that does not need AFM to be enabled. If you need AFM to remain enabled in the ECM the second revision will be ready in about 3 weeks.

Tim

[EFI Tuning]

I've updated the website.

http://efi-tuning.net/efi-tuning-afm...te-module-set/

I will keep the $100 price until I have no more units of this revision.

Tim

[Rudy_1SS]

Originally Posted by Megahurtz

I'm in the same boat right now sorta. I don't want to cut up my factory exhaust but I want to delete my secondary cats. The Borla midpipe is the best option to retain factory AFM valve function but the cheapest I've found this version is $1100 shipped. If Tim over at EFI gets the AFM deletes manufactured and selling soon I can purchase the non AFM mid pipe for about $650 shipped, but then add on the cost of the AFM deletes which probably wont be too expensive....but still.

Maybe I should just stop being OCD and cut my factory exhaust.

I agree, its a lot of money. Maybe a bit OCD to be honest haha, I've cut the exhaust of a few cars but something about it feels sorta cheap. Im a believer of "you get what you pay for" and for most things it holds true, but it's always hard to tell with exhausts if you've never heard it in person.
Maybe its just brand recognition but had a feeling that a midpipe/pipe kit would be superior to a muffler shop weld in. (Not that they wouldn't have to weld the Borla part on to the stock axel back actually)

[Megahurtz]

Originally Posted by Rudy_1SS

I agree, its a lot of money. Maybe a bit OCD to be honest haha, I've cut the exhaust of a few cars but something about it feels sorta cheap. Im a believer of "you get what you pay for" and for most things it holds true, but it's always hard to tell with exhausts if you've never heard it in person.
Maybe its just brand recognition but had a feeling that a midpipe/pipe kit would be superior to a muffler shop weld in. (Not that they wouldn't have to weld the Borla part on to the stock axel back actually)

I like the idea of being able to restore my car to 100% factory. Cutting the factory exhaust is a crap shoot on how its done as well. I've seen some pretty hacked up jobs that some do not realize they reduced the flow beyond what the secondary cats did.

There is only one or two CORRECT ways to do the secondary cat delete on the factory exhaust. One way you have to get a 2.75 inch pipe, flare each end about 3/4" to slip over the factory exhaust. The pipe then needs to be an inch longer than the section that was cut out. Then you slip both ends of the pipe over the factory exhaust and weld it with at least a 1/2" in overlap. This will keep any slag out of the exhaust path from the MIG weld. And it will also keep from creating a ridge inside the flow path as well which could affect sound negatively. the second way would be to find a professional welder that would remove the exhaust from the car and TIG weld a 2.75" pipe in while keeping the specifications very precise.

So my OCD struggles with the idea of actually finding a shop that will do it exactly the way I want and cleanly vs just forking out the cash and knowing the Borla pipe is in there. I do not like anything half assed. I've been through many builds to know that if you try to cut corners you will end up paying for it in the long run.

[Rudy_1SS]

Originally Posted by Megahurtz

I like the idea of being able to restore my car to 100% factory. Cutting the factory exhaust is a crap shoot on how its done as well. I've seen some pretty hacked up jobs that some do not realize they reduced the flow beyond what the secondary cats did.

There is only one or two CORRECT ways to do the secondary cat delete on the factory exhaust. One way you have to get a 2.75 inch pipe, flare each end about 3/4" to slip over the factory exhaust. The pipe then needs to be an inch longer than the section that was cut out. Then you slip both ends of the pipe over the factory exhaust and weld it with at least a 1/2" in overlap. This will keep any slag out of the exhaust path from the MIG weld. And it will also keep from creating a ridge inside the flow path as well which could affect sound negatively. the second way would be to find a professional welder that would remove the exhaust from the car and TIG weld a 2.75" pipe in while keeping the specifications very precise.

So my OCD struggles with the idea of actually finding a shop that will do it exactly the way I want and cleanly vs just forking out the cash and knowing the Borla pipe is in there. I do not like anything half assed. I've been through many builds to know that if you try to cut corners you will end up paying for it in the long run.

Pay now or pay later haha.
Yea they did an awful hack Job on a GTI I had.
Plus I'm sure the 2 3/4 pipes sound better anyway.

[M12LRV]

I was interested in going this route. But I think I'm going to go with the Blackheart version. It's exactly the same thing but about $300 less.

https://www.holley.com/products/exha.../705013120RHKR

[StateOfMind415]

Originally Posted by Rudy_1SS

http://www.phastekperformance.com/20...pipe-60606.htm

Would a system like the one in the Link sound diffrent than the cat-delete while still maintaining NPP function? It seems to me that this kit is the same thing I had done just with more piping, but for 500$ more there must be some difference. I suppose deleting the crimps may open up a lil more sound as well?
If anyone has a vid of NPP axel backed mated to this system id really appreciate it.

Yes, the sound will change. You will get a smoother and slightly louder exhaust note. Sounds sweet above 2k RPMs, while WOT sounds vicious and loud!

The main reason why I choose the borla x-pipe was to delete the secondary cats, while still being able to revert back to the factory x-pipe whenever I need to. I bought high quality 2.75" band clamps that connects the x-pipe to the stock NPP muffler. Also, in Borla's R&D with the C7, they found that 2.75" diameter pipes has better overall performance advantages compared to 3" if your staying relatively stock.

Check out some of my sound clips...
Cold start in Ice/Snow mode:
Cold start in Sport mode:
Highway cruising:

[Megahurtz]

Originally Posted by M12LRV

I was interested in going this route. But I think I'm going to go with the Blackheart version. It's exactly the same thing but about $300 less.

https://www.holley.com/products/exha.../705013120RHKR

Are you sure this bolts up to the factory NPP system? It's 3 inch piping and mentions that it mates the the Hooker axle back system. I've never been a fan of Hooker products anyhow so I guess it does not matter. If I'm going to spend that kind of $$ I'm going to get the Borla midpipe. It's 2.75 inch and Borla is top notch quality.

Originally Posted by StateOfMind415

Yes, the sound will change. You will get a smoother and slightly louder exhaust note. Sounds sweet above 2k RPMs, while WOT sounds vicious and loud!

The main reason why I choose the borla x-pipe was to delete the secondary cats, while still being able to revert back to the factory x-pipe whenever I need to. I bought high quality 2.75" band clamps that connects the x-pipe to the stock NPP muffler. Also, in Borla's R&D with the C7, they found that 2.75" diameter pipes has better overall performance advantages compared to 3" if your staying relatively stock.

Check out some of my sound clips...
Cold start in Ice/Snow mode:
Cold start in Sport mode:
Highway cruising:

I like the way it changes the tone. It definitely sounds a little more refined than just chopping off the secondary cats from the stock exhaust. It actually reminds me of how my C5 Z06 and C6 Z06 sounded with the X pipe. I think you've made up my mind. I'm going to go with the Borla midpipe.