yuri_Stingray

When is the CAI going to be available? What types of gains should I see if I am running their tri-y headers?

#1c6

what will not affect the WARRANTY?

RedVett1

Agreed. So it pays to know your service manager.

carpe dm

It is a Federal law; a felony.

drbozy

What is the horsepower increase with the tri-y headers

DocHolliday

I had no idea…it's crazy that something like this would actually be a federal offense.

Boomer111

Removing the cats isn't worth the hassle for the little power gain.

Plus the stink is horrible.

Same logic goes for the CAI/filter change.

Street use only.

J Christensen

As I wanted to know with the COW booster, here too, I'd prefer to get the 'tune' without the throttle booster, and then after I have become use to the header install with tune, then add in the throttle booster.

I'd like to have the 'feeling' between the two. Blended together, like I have with my Cow booster/tune, it is impossible to really separate out the difference.

SCM_Crash

Removing the cats from stock exhaust will net you maybe 5HP. Today's cats actually flow very well. Removing them from headers will gain you a little more.

In either situation, you won't feel the difference. If your car is a street car (or you just never take your car to the track), removing the cats is pretty much a bad idea.

You can bash on Cali all you want, but the emissions laws are making their way from Cali to all other states. It's only a matter of time. I know why they forbid moving the cats (and therefore made long tubes illegal), but the symptom could be fixed and headers would actually be better for emissions.

I think the problem is that car guys and the government are unwilling to come to a compromise. One wants to have all out power and ignore the repercussions and damage of doing just that, and one wants to totally limit how much damage you can cause without listening to alternatives.

However, the after market COULD in theory build long tube headers that can be made CARB legal. The reason they're illegal in the first place is because it takes longer to heat up the cats to the point that they actually do their job. If a manufacturer could come up with cats that are electronically pre-heated, then they could make a good case for legalizing the headers. Especially since installing headers actually causes the engine to work less, which in turn means less fuel is being burnt and less carbon emissions are released.

Removing cats for sound is kind of dumb, IMHO. You're sacrificing clean air for others so you can sound louder (and maybe more obnoxious). To me, making your car sound louder JUST for the sound when it means making things dirtier is a poser way of saying, "I race... But I don't actually do it. But look at me and pretend I do."

DocHolliday

Way to think out of the box Crash, well written post.

Mike's LS3

Good points! I had a 03 BMW M3 which from the factory came with a shorty headers followed by CATS. I wonder why GM does not install shorty headers for the corvette? It would be a good compromise to satisfy both the EPA and performance enthusiasts. I think it would be a great option with the NPP as an exhaust package for those who want the sound and performance.

SCM_Crash

Thanks, guys.


Actually, BMW isn't the only manufacturer that does this. Even the Mustang has come with shorty headers from the factory. I'm not sure at all why GM doesn't do this, but I can assure you that the LS7 manifolds flow better than any set of shorty headers I've seen. I picked up 13HP/13Tq by switching my C5 Z06 over to LS7 exhaust manifolds (no tune). I have never heard of any shorty headers that can make that claim.

The C7 manifolds are a slightly modified version of the LS7 manifolds. I can imagine that GM has put very good flowing exhaust. They'll never be as good as long tube exhaust, though. And that really is a shame.

I wouldn't mind picking up a few ponies here and there, but I won't do it at the detriment to everyone else. 30HP is hardly noticeable for my uses. I don't think my car will make it to the track more than 3 or 4 times a year, so I'm not going to drive around without cats just to hardly notice a difference 3 or 4 times a year (if I even notice it at all).

TrevorVette

Hey guys i can vouch for the pfadt tune. Installed it on my car and the throttle response down low is .. Wow. Big difference.

I manage a service department for a GM dealer in California, won't mention here for obvious reasons, but I had my guy check to see if they would spot if there is a tune loaded.

Unfortunately, I have to report here that it can be seen by GM. My service tech pulled up information in our GM portal that explained what to look for as far as flash rom write/erase/rewrites.

I flashed back to the stock tune as per Pfadt's software. The flash rom now showed 4 flash CVN rewrites.

I flashed to the Pfadt tune and now the CVN count was 5. Also, on his scanner showed an error code that he looked up and said there was a PCM MISMATCH error when looking up the code on our knowledge base.

Once again, spent another 20 mins to write to stock as I was hoping there was a glitch, and low and behold my count is up to 6 now with the restored factory tune. The history is as plain as day. There are time stamps on all writes to the PCM. He showed me everything - so just know if you want GM to fix any major issues under warranty, don't mess with the PCM or you will leave guys like me no ammo against the fight with GM to cover you. Tread carefully. I'm a cool guy about things, but I wouldn't risk my career and my dealerships relationship with GM just to turn the cheek and help out a guy who modified their car. No offense, but I need to feed my family and most other guys will feel the same way IMO.

For now, I love the tune and it's too late now. I'm stuck with a better performing car (yay!) but even I wouldn't be in a good position if I have motor and/or drivetrain issues and need to file a warranty claim with GM.

TrevorVette

And and FYI- when your car is in for warranty issues and GM gets involved, engineers now have us use a new piece of software that we plug into your car and technicians grab a "system state" image file of your PCM. The new PCM's store a lot of data apparently, and techs now save this image and drop the file on a company Dropbox where they analyze the software. Consider your PCM a blackbox that Gm can use against you for warranty claim reasons.

fraub

bump

13brv3

If you had a spare PCM, can they tell if you've swapped them in and out? In other words, will the PCM SN history be recorded in any of the other modules? How about an hour counter that would differ from the rest of the car?

Thanks,
Rusty

C7Z51_2014

No, I spoke with the Service Manager, nice guy. He's says when the car is hooked up, the data goes to GM and if a tune is detected, GM voids the warranty in the system. Nothing the service manager can do to prevent it.

That's why I KEEP asking is anyone having this tune has been to the dealer to see if, in fact, GM detects the tune. Thus far, no one has indicated they went to the dealer and all is clear.

daixloxbmw

Thanks for the info TrevorVette! I think this needs to be stickied or at least posted as its own thread so everyone is aware of it.

J Christensen

Trevor,

Excellent info. I have a Cow booster with a little bit of a thrown in 'tune', however, thinking of needing to keep my 4 year aftermarket warranty, I purchased the COW booster et al on a separate PCM, and pulled the OEM one for backup.

Reading your info confirms how picky and able the digital PCM's can work for us, or against us.

I wonder where on the PCM the 'counter' number and date info is kept/logged, and or if it is digitally located some other place in the cars system, and if it can be located and written to OEM?

Can the PFADT folks solve this writing issue for a 'clean'/untraceable install/uninstall of their tune, other than for the owner's written paper notes of when they installed/uninstalled? If it's on the PCM, PFADT ought to be able to 'read' the old and original OEM 'count' and date/data, and write that 'setting' info back to the PCM when their tune is installed or uninstalled, letting the owner maintain PCM change in their paper file.

PFADT can you all do this?

J Christensen

So for 'standard' visits to GM, say oil changes, buzzing molding on the front windshield, etc, GM would not need to check the PCM status? Or is it a standard now for GM to check each time the car is in their shop?

I agree, good sticky info, both for here, C7, and also for C6 forum.