[avarshav]

So, my car is a bone stock SS 1LE. I'm looking to more or less keep it that way, but I do want get headers and hi flow cats. From the research I've done, most of the noise restriction is up there, and I plan to keep the NPP exhaust and not do the axle back (for now). So, I'm really looking for just the sound right now, letting it open up and scream. That's my goal for now, let her be loud, but lets not cut her open just yet....



I am NOT doing a build right now. and I am NOT going to do a tune. I'd like to keep my warranty intact for now. I believe that in order to get the best out headers, I need a tune, but I'm just not going to go there right now.


so that's the crux of my question. If I'm just doing headers and highflow cats without a tune, will I pick up any power gains at all? or worse, will I lose power after the mod without a tune? I'm thinking without a tune the computer probably makes adjustments to balance out and effectively eliminate any power gains?



and while I'm on the subject, any recommendations for headers and high flow cats? any big difference between 2" or 1 7/8? brand recommendations?

[CHASLT1]

Just doing headers will kill the warranty... I have had AR and Kooks headers on my Vettes. Make sure they are coated as that helps a lot for heat and they won't rust.

[sage85z28]

Yes do the headers, I put ARH 2 inch headers with high flow cats and their 3 inch X pipe into the stock NPP and I love it! I did tune the car though after the install for best gains. I obviously did drive the car before the tune and had no issues. I picked up 37 RWHP with my exhaust install, however I don’t feel as though it was all the headers that gave me such a big gain. I feel the exhaust enhanced all the other mods that I have had done, but numbers are numbers the power can be felt in the seat.
Also even though you said you don’t want to void warranty I highly recommend the BMR engine mounts, they free up a TON of room.

Here is a link to how it sounds
https://youtu.be/E-MDIyLtV48

[ST1LE]

You will pick up gains, but it won't be a lot at all. A secondary cat delete is an option that gives you what you want, but it is cheaper and no tune needed, will give you just sound like you want.

[avarshav]

Originally Posted by CHASLT1

Just doing headers will kill the warranty... I have had AR and Kooks headers on my Vettes. Make sure they are coated as that helps a lot for heat and they won't rust.

the issue of warranty has been litigated time and time again. a dealer cannot void your warranty for a defect unless the modification you made has clearly caused the defect. so it is a matter of risk versus reward.



by installing headers, i figured my worst case exposure is losing warranty on the exhaust system. uh. ok. I'm ok with accepting that risk and that a set of headers will not blow the motor.


once you do a tune, any unrelated motor defect could potentially be voided under warranty due to you having a tune.



so it is simply a risk calculation. I would calculate the risk of warranty issues to be less with a set of headers and no tune, and higher risk of warranty issues once you add a tune. We can litigate the issue back and forth but ultimately is just a calculation of risk one has to take.


there's always time for a tune when I come closer to end of warranty, at that point in time, I'll have my game plan figured out for the car. but now, i'm just interested to see what headers with no tune gets me....

[avarshav]

Originally Posted by sage85z28

Yes do the headers, I put ARH 2 inch headers with high flow cats and their 3 inch X pipe into the stock NPP and I love it! I did tune the car though after the install for best gains. I obviously did drive the car before the tune and had no issues. I picked up 37 RWHP with my exhaust install, however I don’t feel as though it was all the headers that gave me such a big gain. I feel the exhaust enhanced all the other mods that I have had done, but numbers are numbers the power can be felt in the seat.
Also even though you said you don’t want to void warranty I highly recommend the BMR engine mounts, they free up a TON of room.

Here is a link to how it sounds
https://youtu.be/E-MDIyLtV48

cool... how long did you drive it with no tune? you feel any gains without the tune?

[avarshav]

Originally Posted by ST1LE

You will pick up gains, but it won't be a lot at all. A secondary cat delete is an option that gives you what you want, but it is cheaper and no tune needed, will give you just sound like you want.

if you do the secondary dat delete, does that cause a check engine light?

[s346k]

i ran a 17 ss 1LE that has kooks long tubes, hf cats, no secondary cats and a cai cai. stock tune. it ran dead even with my car when it was stock. id say no gains power wise and honestly it was not noticeably louder than my car.

edit: he has no CEL.

[Joshinator99]

Originally Posted by s346k

i ran a 17 ss 1LE that has kooks long tubes, hf cats, no secondary cats and a cai cai. stock tune. it ran dead even with my car when it was stock. id say no gains power wise and honestly it was not noticeably louder than my car.

edit: he has no CEL.

No surprise. Adding headers with no tune will gain virtually nothing. Our torque-based ECM means if you don’t tune for your mods, it simply reduces spark or closes the throttle to keep your output at what it thinks it should be (at or very near stock HP rating).

[Joshinator99]

Originally Posted by avarshav

if you do the secondary dat delete, does that cause a check engine light?

No it does not. Unless you manage to get an exhaust leak during the process, then you will get a CEL.

[CHASLT1]

I gained 28 hp on a 2006 C6 with the LS2 with headers and tune and around 37hp with a 2013 C6 with the LS3 on headers and tune. If you do headers then be sure to get a tune for the best gains.

I gained 29hp with a 2010 5.3 Colorado with just a tune alone. My tuner said the Vettes were tuned more hot vs the trucks from stock.

[sage85z28]

Originally Posted by avarshav

cool... how long did you drive it with no tune? you feel any gains without the tune?

I drove it a couple days like that, I wasn’t driving it real hard during this time as I wasn’t sure if I could hurt it in anyway. I wanted to just get it though a couple heat cycles and double check torque specs, clamps etc etc.

[JSH]

The small hp gain is not worth the cost if that's the only mod you're making.

[Fraxum]

OP you can run LTs without a tune, you will get CELs but you will need a code reader to turn them off. Or you can just leave them on.

You will get the full 15 RWHP. It's a PIA install. Not like the 2 hour job on the 5th gens.

I added LTs on my 16 SS with NPP but hated the high pitch sound. No LTs for my LT1. On the other hand you can add about the same amount of power by just adding an LT2 intake manifold, no tune needed. Then you can do what you want with the exhaust level after the stock triY shorties. Fit a CAI or even a Chevy CAI CAI to get even better sound. The Lt2 IM might also add a bit of intensity to the sound letting more air through the engine.