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Hello. I'm new to this forum. I have a 2000 Camaro Z28. I've got a defective right bank cat. Instead of replacing it, I'm having both of them removed and the engine retuned at a dyno speed shop. Question is, if money is a constraint, is there really a huge advantage to running LT headers over using the stock LS1 manifolds? I've read an extensive Super Chevy article hat suggested that it is critical to have headers that are tuned to the application or you'll lose hp and low end torque. (Bigger isn't always better)
Are the stock manifolds really restrictive over LT headers? BTW, I will be adding an SLP cold air intake set up before having it tuned. What can I expect to gain keeping the stock manifolds with Cats out, Slp cold air added and the retune vs. using LT headers? Thanks for weighing in on this in advance.
Thanks Killer Z. What would I gain in hp and torque in running the LT's over just running stock manifold. The car will receive the SLP cold air intake and a performance tune in either scenario I go with.
really depends on the car. its not unheard of to get well over 20WHP and tq accross the board. really depends on how your car is right now. if your car's factory tune is off you can expect to see more. if i remember there have been cars gaining close to 40whp because factory tune was off dramatically. do you have a catback now?
Plan your weekend around it and I hope you cuss cause if you don't you will be by the time you are finished. Expect to find settled motor mounts and headers hitting everything cause motor settled. So plan on a set of poly mounts ahead of time
I would be concerned with something else because cats should last the life of the car. Is it the factory plugs and wires? MAF dirty? Did you change the upstream O2s or just downstream? If the upstream are reading rich or lean it can cause the PCM to add more or less fuel causing the cats to fail, or just be a false reading and your cat is fine.
Long tubes all the way, you have to get air in and out, long tubes not only reduce back pressure but help scavenging, where the exhaust pulse from 1 cylinder pulls the exhaust out of the next cylinder, giving even more exhaust flow, and more power. Just get a mail order tune for the long tubes, no need for a dyno tune since so many tuners have dyno tuned long tube cars they will just send you the file and you save $200-400. You can expect 20-40rwhp just from long tubes, a lid and a tune, and better fuel mileage since more HP means you don't have to apply as much throttle to move at the same speed.
Ok, I have gotten the Speed Engineering, 1-7/8 primaries, headers. However, they don't have any egr connections, only O2 sensor ports. What do I do with the emissions pieces from stock manifold? My Camaro is a 2000 model.
Also, if I don't have a dyno shop tune, where and what do you recommend for a mail order tune? I've heard it's much better to have it done locally on a dyno.
10-25-2015, 12:01 PM
Stock LS1 Exhaust Manifolds vs. LT Headers 
