Headers

[Foxrus14]

Should of went Kooks!

[Crushinator]

When you guys are ordering headers, are you just ordering the headers? What else is needed for me to do this in my garage? Will long tubes bolt right to the factory exhaust? I've only ever had headers installed on one car, and I had East Coast Supercharging put them on a Carroll Supercharged '97 C5 I had.

[D2M]

You have to order Z/28 specific headers. As far as I know ARH and Kooks are the only 2 companies making Z/28 specific headers. You will have a choice: Headers with catted connection pipes, headers with non catted connection pipes, headers only, catted connection pipes for headers only and non catted connection piped for headers only. I know that Kooks offers nicer gaskets and hardware so if you decide to buy ARH buy some MLS gaskets and dont use the ones that come in the kit.. I went with ARH only because of availability, ARH was 1 day away as Kooks was on eternal back order at the time.

[bowtieman_racin]

I ordered the 2"x3" kooks headers with ground effect x pipe and mufflers and quad tips. This kit connects directly to the headers. Only problem is the wait. It's been 3 weeks now and while I'm not in a hurry due to winter, I hope to hear something from Maryland Speed soon on shipment.

[Stephen12ZL1]

Originally Posted by bowtieman_racin

I ordered the 2"x3" kooks headers with ground effect x pipe and mufflers and quad tips. This kit connects directly to the headers. Only problem is the wait. It's been 3 weeks now and while I'm not in a hurry due to winter, I hope to hear something from Maryland Speed soon on shipment.

please review after installation

[bowtieman_racin]

Will do I'll try to take some good pictures too

[oakaro68]

Originally Posted by Stephen12ZL1

D2M tracks his car frequently with no tune and headers. I plan to do the same as the PCM can adjust fueling for exhaust only changes. The commanded AFR is the same as stock and the PCM will adjust fueling accordingly to ensure the car isn't lean or rich. I tuned out the rear 02 sensors and cat over temp but left the MAF values alone. The 1-4 skipshift was also tuned out. I need to adjust the "fan on" temps with the a/c off as I forgot to make this adjustment.

So what I'm wondering though is since the commanded AFR will be the same, but adding LT's will increase air flow will make it run a bit lean. I'm fairly confident even the LS7 is not running wide band O2 sensors and will not be able to adjust AFR when in power enrichment mode. Narrow band O2 sensors are great at adjusting at or near stoich, but not richer AFR conditions. But they wouldn't be used in the first place during hard acceleration, which makes me curious what the AFR is during aggressive driving (with a wide band).

It's nice to know some of you are running no tune and not having problems though.

[D2M]

Ever since California emission standards or Ultra Low emission standards were introduced all cars are using wide band O² sensors as the pre cat sensors. The commanded ARF will change, the OEM range of change is unknown to me however but it will be able to adapt the AFR to a certain amount. You can feel the increase in power, its a day / night difference. A custom tune will be optimal however but will kill you warranty. I dont have a AFR monitor installed but I did pull a few spark plugs about 600 miles after install and they looked exactly the same as before the install. I have since driven the car about 5K miles, track days, 25°F weather, 95°F weather with AC on, part throttle and FULL throttle.. All is good so far and it runs great with no stumbles or flat spots in the power band.

Before I purchased my set I did some research on the LTH W/O tune subject and found some ZO6 Vette guys running this setup without issues.

[oakaro68]

Originally Posted by D2M

Ever since California emission standards or Ultra Low emission standards were introduced all cars are using wide band O² sensors as the pre cat sensors. The commanded ARF will change, the OEM range of change is unknown to me however but it will be able to adapt the AFR to a certain amount. You can feel the increase in power, its a day / night difference. A custom tune will be optimal however but will kill you warranty. I dont have a AFR monitor installed but I did pull a few spark plugs about 600 miles after install and they looked exactly the same as before the install. I have since driven the car about 5K miles, track days, 25°F weather, 95°F weather with AC on, part throttle and FULL throttle.. All is good so far and it runs great with no stumbles or flat spots in the power band.

Before I purchased my set I did some research on the LTH W/O tune subject and found some ZO6 Vette guys running this setup without issues.

How is the idle? Do you still get the lope to the engine? Did it make it more pronounced or smooth it out?

Still getting a lot of exhaust popping too?

These are some of the things I definitely would not want to lose!

[D2M]

Idle is exactly the same just louder. Cold start is allot louder as well. Popping from exhaust seems to be the same it may be slightly less often but louder.

[Schlok]

Originally Posted by oakaro68

How is the idle? Do you still get the lope to the engine? Did it make it more pronounced or smooth it out?

Still getting a lot of exhaust popping too?

These are some of the things I definitely would not want to lose!

You can get more lope...you just need more cam too

[MonroeZ28]

Originally Posted by D2M

Ever since California emission standards or Ultra Low emission standards were introduced all cars are using wide band O² sensors as the pre cat sensors. The commanded ARF will change, the OEM range of change is unknown to me however but it will be able to adapt the AFR to a certain amount. You can feel the increase in power, its a day / night difference. A custom tune will be optimal however but will kill you warranty. I dont have a AFR monitor installed but I did pull a few spark plugs about 600 miles after install and they looked exactly the same as before the install. I have since driven the car about 5K miles, track days, 25°F weather, 95°F weather with AC on, part throttle and FULL throttle.. All is good so far and it runs great with no stumbles or flat spots in the power band.

Before I purchased my set I did some research on the LTH W/O tune subject and found some ZO6 Vette guys running this setup without issues.

I don't understand why you guys aren't running a tune can someone explain? I remember installing LTs on my C5Z06 and they sounded great and it felt like I had much more power. I brought my car to Corvettes of Westchester who I understood to be the best tuner around and happened to be close to where I live. I went there on a Saturday afternoon and spent like 4 hours watching this guy tune the car throughout the day. When I got back in my car to test drive it I was in shock how different the car was. The throttle response was ridiculous and the power was insanely different and crisp all the way through high and low RPMs. My point is that with headers and no tune I thought the car was very improved until I got a proper tune and realized it was night and day.

[D2M]

My reason for not getting a tune is not to void the warranty. If I still have the car when warranty expires then I may get it tuned.

[frenchsquared]

Originally Posted by D2M

My reason for not getting a tune is not to void the warranty. If I still have the car when warranty expires then I may get it tuned.

Yep, mine will get a tune and a few upgrades when the warranty is over. I want GM to fix it if it breaks on a race track.