[MAtRiX_757]

Originally Posted by jimmypop13

It is assumed unless stated these days that high flow cats still cause a CEL. Kooks green cats are the only ones I know of that don't.

And I guarantee not having AFM valves sounds like a ricer in v4 mode. You can do this test right now. Pull fuse 43. That will keep the AFM valves open in v4 mode. Go for a drive down around town and on the highway. Now imagine headers and a less restrictive exhaust. It will be even louder. Without the AFM valves, there's no big restriction to quiet it down.

Yes but the valve delete is grounding it out, not just removing it. Also Kooks Green CATs are giving another user on this forum CELs I know SOLO-PERFORMANCE used to say that theirs don't for Gen 5.

[CAMAR0STEVE]

Not sure if this video has been seen? https://m.youtube.com/watch?v=_SJJDdPA-9k Looks like they have something for us NPP guys

[MAtRiX_757]

Originally Posted by CAMAR0STEVE

Not sure if this video has been seen? https://m.youtube.com/watch?v=_SJJDdPA-9k Looks like they have something for us NPP guys

I already posted it its 2 pages back, also we know about the NPP system already. All kinds of info 2 pages back.

[jimmypop13]

Originally Posted by MAtRiX_757

Yes but the valve delete is grounding it out, not just removing it. Also Kooks Green CATs are giving another user on this forum CELs I know SOLO-PERFORMANCE used to say that theirs don't for Gen 5.

The valve delete is just keeping the electric motors happy so they think the afm valves are in place and keeps them from throwing a code. It in no way eliminates afm. AFM will still come on, v4 mode will still happen, the electric motors will still turn, just no AFM valves will be there to stop the car from sounding like a 4 banger with full exhaust

[Illmaticz]

I'm definitely interested in the axelback system.

[Stainless Works]

Thanks for filling everyone in jimmypop13.

AFM Valves or Deletes
Yes we have AFM deletes or 3" AFM valves. The factory electric motor is grounded in either case which will prevent a CEL related to the AFM.

Long Tube Header CEL
As with any changes to emissions, your vehicle will still throw a CEL related to the cats or off road pipes on any long tube header installation. A good tune will remove the CEL. Catbacks will not throw a CEL because they don't change anything related to the o2 sensors.

[Stainless Works]

Originally Posted by rotis

If I get the full catback, and then later install the SW headers- will the axle-back portion of the catback (mufflers) connect directly to the headers without modification?

It kinda looks like it would in the pictures, I just want to confirm.

Thanks!

Hey Rotis - We haven't really talked about this too much but we do have an upgrade plan for catbacks to full systems. Basically you would discard the factory manifold leads and purchase the headers, cats/off-road, and header leads separately. You would then keep your catback x-pipe all the way back.

Here's what you would need to upgrade.

Bare Headers
High Flow Cats or Off Road Leads
Header Lead Pipes
6 Clamps

This is a special order upgrade and you could purchase from us direct or have any of our dealers call us for a custom quote.

[Hyper16]

My car came without the NPP mufflers. I would like to achieve the look & sound of the NPP by upgrading the exhaust and adding quad tips. Are you going to make a quad tip axel-back for non-NPP systems? I realize the rear facia will need to be changed.

[Stainless Works]

Originally Posted by Hyper16

My car came without the NPP mufflers. I would like to achieve the look & sound of the NPP by upgrading the exhaust and adding quad tips. Are you going to make a quad tip axel-back for non-NPP systems? I realize the rear facia will need to be changed.

Nothing in the plans now. I'll keep you guys posted if we move in that direction.

[JonGSA]

I've been digging and I noticed that on the site, there's an option for axle back, quad tip for NPP AND factory connection. Is this a typo or a real version of the axle back? I have to admit i really haven't stuck my head under the rear of the car yet, but I thought there weren't any factory connections back there.

I'm looking at making my NPP system a little louder, but since the car is lease I dont want to be hacking apart the stock system. Otherwise, I'm back to looking at the cat back with factory connections so its a straightforward, damage free swap.

Thanks

[crabman]

Originally Posted by Stainless Works

Usually emissions tests check the computer for codes and then a visual inspection for cats. It varies everywhere though. In our experience you will get a check engine light, but it can be resolved with a good tune. We recommend a tune with headers because you won't maximize the performance without one.

Warranty is all on the dealer. Some dealerships will say it voids the warranty, others say it's fine. Your best bet is to buy from a dealership that does aftermarket performance parts in house. Tom Henry Chevrolet out of Pittsburgh is a good example. They sell our headers and will honor the warranty.

A dealer can do nothing if a high dollar part breaks because the warranty resides with GM and possession is 9/10s of the law. The way it works is the dealer is authorized to make most less expensive repairs on it's own hook. They simply submit the paperwork and get reimbursed for parts and labor, that labor usually is reimbursed back at a tabled rate. On more expensive repairs the dealer cannot get reimbursed for labor or parts until a regional rep from GM comes in to look at the car. That rep does not sell cars, he does not care about repeat business, he works for GM and his job is to guard the gate. You can think of him like the terminator, he absolutely has no mercy, cant be bargained with, etc. If he says no the dealer cannot get reimbursed for labor and must come out of pocket for parts to fix the car. Most of us will not be good enough customers for the dealer to decide to come out of pocket unless the cost is low but that regional rep didn't show up in the first place because it was going to be a cheap fix.

So lets say this happens to you, you spit a valve for example. That dealer cant fix it until the rep comes in and signs off but when he does he refuses the warranty coverage on GMs behalf after seeing your shiny new headers. This refusal will be based on the legal concept that GM is not required to warranty a configuration they did not sell you and when you changed power levels you changed the engine to a configuration that GM didn't sell and hence is under no obligation to warranty. At this point the dealer can either decide to fix it out of their own pocket far more likely will tell you that they are very sorry but they tried everything they could but GM refuses to budge and they're not going to be able to do this work.

You can now jump up and down, yell, spout M&M act, makes no difference. GM has your warranty coverage in their possession and you can't do jack about it until the end of what may be a very long process. At the time of refusal you are either staying broke down or out of pocket, take your pick.

I've followed an M&M action to its conclusion. I won. The M&M act allows for the recovery of fees but does not guarantee them, I did not recover my fees. I'm saying this because many people say you can fight and get your fees, you may, you may not. Invariably people start saying on these forums that they have to prove the modification caused the failure but in reality what ends up happening is you have to prove that whatever they said is false, otherwise it stands because they are in possession of the warranty and to get it you have to show cause as to why they should give you what is in their possession. It sounds crazy but think about, if your neighbor builds a fence that encroaches on your property you cant just go to court and say "Liar Liar pants on fire", you have to show a plat map, survey, some proof that the fence location is incorrect. It's the same principal here.

On one of my vettes the trans started leaking and it was just an O-ring on a shaft seal. The headers I had on the car in no way had anything to do with that but I was worried nevertheless when I took it in. The trans would have to be dropped to repair and that is what triggered the rep inspecting my car. He made no grief whatsoever about the headers and they did the repair under warranty. What would have happened if it was an automatic and I had blown it, don't know but it probably wouldn't have been good.

I'm not preaching to anyone here, I've modded every fun car I've owned so I'm not saying don't do it. I'm not complaining about SWs selling these parts, that's their business and I'm glad to have all these smart people making the have more fun parts for our cars. I do think that people should be aware of what they are getting into though and go in eyes open when they make mods that may jeopardize their warranty. The saying over on the corvette forum is that anyone who mods their car should be capable of and willing to be their own warranty station. Mod smart and it's unlikely to come to it but it's good advice anywhere.

[bpang1234]

I'm primarily looking for a system that does the following:

1. Retain NPP functionality - switch from quiet profile to loud profile.
2. Retain OEM to near OEM decibel level in Tour Mode...so I can take phone calls.
3. Achieve better than OEM sound in Sport & Track Modes...no drone in highway cruising.
4. Avoid any weird ricer noise due to AFM.
5. Ultimate horsepower/torque gains are not necessary.

Would the Axleback be my best ticket?

[jimmypop13]

Originally Posted by bpang1234

I'm primarily looking for a system that does the following:

1. Retain NPP functionality - switch from quiet profile to loud profile.
2. Retain OEM to near OEM decibel level in Tour Mode...so I can take phone calls.
3. Achieve better than OEM sound in Sport & Track Modes...no drone in highway cruising.
4. Avoid any weird ricer noise due to AFM.
5. Ultimate horsepower/torque gains are not necessary.

Would the Axleback be my best ticket?

I would think the header/x-pipe combo and keep the stock axleback would be the best choice. The stock NPP muffler seems to be much quieter in tour mode than the SW NPP axleback. I'm hoping they will find a way to make a future version quieter in tour mode. Also be sure to get the AFM valves when ordering the header/x-pipe combo to avoid the 4-cylinder mode and get the high flow cats as that will quiet it down just a touch more.

I ordered this combo myself but it hasn't arrived yet. Unfortunately it will probably not be until May before I get it installed

[Emeru]

Any dyno numbers yet ? Interested in seeing a dyno sheet for the full setup.