[vince3]

I’m thinking about doing full bolt ons minus headers due to so many install,
and fitting issues with headers. It seems like they all rub or burn up your starter or main wiring harness. If you do get headers with cats, the cats melt or you have to go catless with increase noise.

https://www.camaro6.com/forums/showt...535959&page=10

This user Alpha1LE hit near 490 rwhp and another user got around 480 rwhp, then swapped to headers and didn’t gain anything. Do you think the stock cats will also melt?

If I do headers, the safest seems to be CSP headers with catless connection pipes, wrap the starter and move the wiring harness and install a magnaflow x pipe muffler where the factory x pipe is.

I know I’m rambling at bit, but any thoughts on this?

[DaveC113]

Yeah, OEM headers are excellent and long tubes won't get you nearly the gains they used to with the old log-style cast headers. Removing or relocating cats isn't a good idea, and isn't legal. Unless you're going full race car I wouldn't touch the oem exhaust.

[m6-lt1]

I can't see you getting past 450-460 whp without headers. Probably will be closer to the lower end of that number.

You don't have to worry about melting the cats. That's a ZL1/supercharged thing. That would probably happen on oem cats after a certain horsepower number (like 700-750whp is when I'd start to worry).

The fitment issues and burning wires are mainly due to using cheap headers and/or getting them installed at a shop that does not take precautions to not melt wires. I get it though, the burning of wires would be the number 1 thing I ask a shop about. I've also seen it happen on these boards one too many times. You'd think there'd be plenty of room in the engine bays of a push rod V8 but not this platform.

[vince3]

https://www.camaro6.com/forums/showt...=559372&page=3

Here is a pretty detailed post of someone who got 480 rwhp with no headers and cat deletes. Then they added catted headers and lost power.

[EliteLT1]

I did a bunch of bolt ons but haven't touched the exhaust yet. I got 462 hp and 456 lb*ft on E85. I didn't measure the ethanol content before dyno, but probably around 75%

The mods are CAI, 95mm TB, LT2 manifold, flex fuel sensor

I want to add headers and mid pipes at some point but working on suspension now

https://www.camaro6.com/forums/showthread.php?t=617315

[kropscamaro16]

headers might not add alot of power but they do sound so good on these cars especially with full exhuast i got compliments everytime i go to to the track about how my car sounds

[SSShark]

Originally Posted by kropscamaro16

headers might not add alot of power but they do sound so good on these cars especially with full exhuast i got compliments everytime i go to to the track about how my car sounds

Completely agree. I have Kooks headers with the Borla S-Type. The sound is amazing.

[ChibbMD]

Originally Posted by EliteLT1

I did a bunch of bolt ons but haven't touched the exhaust yet. I got 462 hp and 456 lb*ft on E85. I didn't measure the ethanol content before dyno, but probably around 75%

The mods are CAI, 95mm TB, LT2 manifold, flex fuel sensor

I want to add headers and mid pipes at some point but working on suspension now

https://www.camaro6.com/forums/showthread.php?t=617315

I have almost the exact same mods and am in the exact same range of HP and TQ. I did buy some Kooks 1-7/8 headers off a member mainly because they were a good deal and exactly what I was looking for. Haven't gotten around to installing yet, but looking forward to knocking that out soon. I'll have to report back here with results.

[vince3]

Originally Posted by ChibbMD

I have almost the exact same mods and am in the exact same range of HP and TQ. I did buy some Kooks 1-7/8 headers off a member mainly because they were a good deal and exactly what I was looking for. Haven't gotten around to installing yet, but looking forward to knocking that out soon. I'll have to report back here with results.

That would be a good comparison to see if headers help with when you have the supporting mods

[Megahurtz]

No competent tuner is going to lose power by adding headers to the LT1. That said, they don't provide a lot of extra peak HP. The gain is in the mid range area and they do make the car faster. But, if you don't want to deal with headers, you can still get a nice bit of performance out of the LT1.

Add a green drop in filter, port the stock 87mm TB(or get the Soler 91mm eff unit), have the stock LT1 intake manifold ported(or add a ported LT2 manifold) and add a Flex Fuel sensor. The performance gain will be noticeable with these mods.

[MT-SS1LE]

Is there any gain to be had by removing the secondary cats? I understand they were only put their to comply with California's draconian emissions rules (which I couldn't care less about).

[vince3]

2” kooks with connection pipes for $1360 or 2” speed engineering with x pipe for $800ish?

[GreyGhost702]

Originally Posted by vince3

I’m thinking about doing full bolt ons minus headers due to so many install,
and fitting issues with headers. It seems like they all rub or burn up your starter or main wiring harness. If you do get headers with cats, the cats melt or you have to go catless with increase noise.

https://www.camaro6.com/forums/showt...535959&page=10

This user Alpha1LE hit near 490 rwhp and another user got around 480 rwhp, then swapped to headers and didn’t gain anything. Do you think the stock cats will also melt?

If I do headers, the safest seems to be CSP headers with catless connection pipes, wrap the starter and move the wiring harness and install a magnaflow x pipe muffler where the factory x pipe is.

I know I’m rambling at bit, but any thoughts on this?

The only reason a factory cat would melt is if the engine was tuned poorly or catastrophic failure. You'll be fine on factory cats for a good long while. ZL1, ZR1, Hellcat, GT500, GT350, all vehicles north of 500hp on factory cats with full warranties. The Big 3 wouldn't stick their necks out if the parts wouldn't outlive the warranty period. That said, nothing lasts forever.

Don't get hung up on a number, you just end up chasing or end up disappointed.

As far as getting hung up on LTH's, if you're new to the modding game, nothing ever goes the way it should in a build. There are things you can do to mitigate heat issues from LTH's, just don't wait to have issues and take those precautions. I haven't had any issues with mine so far, maybe because I don't daily my car or because I live in a cooler area, or both. Just lucky. Who knows.

For as good as parts makers are these days, sometimes there's little flaws you have to work through. My LTH's were of the cheap kind and I had an issue with my header flange and had to spend $100 at a machine shop to be fixed so they installed properly and had a good fit. Par for the course, and small beans in the grand scheme. They work beautifully now, and a part on the car I don't even think about since it doesn't cause me problems. The increased noise is such a beautiful sound. 'Merica.

If you're going to avoid specific parts to avoid the pains of dealing with the unforeseen, you'll leave a lot of potential on the plate. With what you're doing right now, no cam and no ported heads, LTH aren't going to pay a lot of dividends. You get into a cam and ported heads, it's going to leave some of that potential on the table, but you'll still make good power and track times. Get into FI, now you're barking up a whole other tree, and a lot more of that potential gets left behind. At a certain point, the OE system will become a restriction to the point where it just won't be safe to push more boost.

If you're not cracking the seals on your engine, the OE exhaust will work just fine with what you want to do.

Originally Posted by MT-SS1LE

Is there any gain to be had by removing the secondary cats? I understand they were only put their to comply with California's draconian emissions rules (which I couldn't care less about).

No power to be had anywhere behind the manifolds. Purely exhaust tone and volume preference. If I could chain amplifiers to my exhaust and crank them to 100% I would, that's what I like. I want my Grandpa who passed away 6 years ago to know when my car starts. Goats tip over when I drive by. Karen's grab your pearls and hold the china, I turn over in Track Mode.

[ChibbMD]

Originally Posted by vince3

2” kooks with connection pipes for $1360 or 2” speed engineering with x pipe for $800ish?

My research suggested that 2" headers were a better match for the supercharged ZL1 and 1-7/8 was all you need for the naturally aspirated LT1. Bigger is not always better.