[tnspd]

I love my ZL1 1LE but it is way too quiet for my taste. I bought a set of ARH headers with high flow cats for a great price. It goes back to just before the OEM muffler. Can I install them now and drive the car around for a few months before I get the code tuned out or will the install require I get the tune shortly after the install?

[sengli]

Wow I definitely think this Gen6 car is a lot louder than my previous GEN5 cars, even my C6. Loud around these parts attracts the laws attention way too quickly

[TDS]

My vote is tune at the same time as install

[BMWM.D.]

I think you’ll be safe if you wait, but you’ll probably get a check engine light eventually due to lower than expected cat efficiency.

The Gesi ultra high output cats offered by Kooks (and ARH) are supposed to be effective enough to prevent it. ARH offers the same Gesi cats as an option, but it is a $500 upgrade. They don’t advertise them, but will build you a system with them upon request. I ended up going with Kooks since I was able to get them with the Gesi cats for significantly less cash.

Although I’ve already started tuning my car, I’ll probably see if/when I get a code from the cats. Just out of curiosity.

[Marko]

My Camaro SS in Sport mode is very loud and I’m very happy

Just as loud as my 03 Cobra with Flowmaster catback

[conradsteph]

Also had ARH headers with Cats installed with OEM muffler (along with upper pulley change). Had tune with install. Tune was worth the money - no bog, no skip shift, and sound is priceless. Lots of talk about warranty worries - depends on how you use your car and how many miles you plan per year. If your warranty worries are driving you instead of you driving the car, you bought the wrong car.

[Can'tHave2MuchHP]

Get it tuned.

[BMWM.D.]

I don’t think his dilemma was to tune vs not tune — more of whether or not it would be okay for a few months. Personally, I think it’ll be fine.

I do think the warranty paranoia phenomenon is a little strange though. I’d think most people who can afford a $60k+ car wouldn’t be financially stressed if they had to pay for a repair out of pocket. Maybe I’m wrong in assuming that, but my warranty isn’t high on my priority list. Honestly, I don’t want the dealership working on my car period.

[tnspd]

I do plan to tune once I get my CAI delivered. Which will be around February/March. I was just wondering if I could go ahead and install the headers until the CAI gets here. I run the car at HPDE events and the occasional daily drive. So the tune will not be aggressive at all.

[Can'tHave2MuchHP]

You can run no tune on the headers for daily driving purposes but I highly recommend spirited driving or tracking is put on pause until the tune is done.

When you change headers, especially without changing anything else, you change the back pressure and balance of the exhaust flow even though the computer still runs the engine like it has stuffed manifolds and cats. This often causes the engine to run rich or heaven forbid lean, and can cause more knock/pulled timing.

[ARS1]

I will be doing a full system on my 1LE but only a catback until I get some miles on the car. I agree they're way too quiet from the factory and I will be doing a full Stainless Works Headers back, No Cats w/ Tune but I'm not tuning the car until at least 1000 miles. Right ow I'm at 250 miles but it needs to be louder NOW!!! Once I get some miles on it then I will do the headers, cam, tune etc...

Everyone should be getting rid of the factory "Pancake" exhaust they slapped on these cars before headers...

[tnspd]

The system I got will replace that pancaked part of the tubing.

[swizlstik]

I didn’t risk it. Had mine tuned at the time of install.

[BMWM.D.]

Originally Posted by Can'tHave2MuchHP

You can run no tune on the headers for daily driving purposes but I highly recommend spirited driving or tracking is put on pause until the tune is done.

When you change headers, especially without changing anything else, you change the back pressure and balance of the exhaust flow even though the computer still runs the engine like it has stuffed manifolds and cats. This often causes the engine to run rich or heaven forbid lean, and can cause more knock/pulled timing.

I’ve never done any back to back testing to see the effect of headers on lambda value, but I wouldn’t expect much. Any increase in scavenging should result in increased measured airflow. For this reason, I’d expect it to run pretty close to where it should at WOT.

My experience tuning headers vs manifolds has been that the headers can safely handle more timing without knock retard. I’m not sure if this is because measured boost usually drops, or some other reason — but it’s what I’ve seen on my own stuff. So again, I think you’d be safe with the factory timing tables.

Obviously, it’s a good idea to log with a wideband to see what’s going on. With how rich my car was running on the dyno the other day (stock w/ Roto-Fab intake), I wouldn’t be at all worried about adding headers to it.