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I was on the fence on headers. My go to Vette Mechanic said that if I was into HP, headers alone is not worth the $$$. Other engine upgrades with air intake and possible trans upgrade with a professional tune would be in order. The $$$, around $10K+. Sooooo, I decided I like the ride as is. But your choice.
It’s well known headers add power to these cars. My concern is the possible noise and added heat in the cockpit. I’m ok with the benefits and cost of headers, but I don’t want to regret potential loss of interior comfort.
consider the following and chime in…
2004 coupe; 3.90, m6, ls7 clutch.
For me, 400ish RWH would be the sweet spot for a daily driver…and I don’t drive much. Would a cam and tune get me there ???
Headers alone not worth it.
Cam only LS1 is typically good for 40-60 rwhp. The MN6 baseline rwhp varies from about 290 to 310. So without ported/upgraded heads or headers you aren't going to see 400ish rwhp with just a cam. If you do... the dyno is generous.
With a 228/228/112 cam, BBK shorty headers, Blackwing intake and Stage 2 West Coast #241 cylinder heads my first MN6 build made 390rwhp and 378rwtq on A&As dyno. Moderate CA temps that day.
Second build with 232/236/113+ cam, same heads, Vararam VRB2 and Kooks 1 7/8th headers car made 418rwhp/398rwtq on 2nd Street Speed in Perkasie PA dyno. Hot as F and humid that day.
It took the cam+heads+longtubes to break into the 400+ wheel horsepower range on reputable dynos.
Cammed NA cars love the 3.90 or 4.10 gear set. Mine was great with both.
Last edited by Johnny Hardcore; Sep 22, 2021 at 07:28 PM.
Cam only LS1 is typically good for 40-60 rwhp. The MN6 baseline rwhp varies from about 290 to 310. So without ported/upgraded heads or headers you aren't going to see 400ish rwhp with just a cam. If you do... the dyno is generous.
With a 228/228/112 cam, BBK shorty headers, Blackwing intake and Stage 2 West Coast #241 cylinder heads my first MN6 build made 390rwhp and 378rwtq on A&As dyno. Moderate CA temps that day.
Second build with 232/236/113+ cam, same heads, Vararam VRB2 and Kooks 1 7/8th headers car made 418rwhp/398rwtq on 2nd Street Speed in Perkasie PA dyno. Hot as F and humid that day.
It took the cam+heads+longtubes to break into the 400+ wheel horsepower range on reputable dynos.
Cammed NA cars love the 3.90 or 4.10 gear set. Mine was great with both.
Great info on hp results! What, if any, effect on interior noise/ heat?
Great info on hp results! What, if any, effect on interior noise/ heat?
Interior noise was always on the high side with the Borla Stingers and Billy Boat Bullets I ran with those builds. One was with Bassani x-pipe and the other Kooks off road xpipe.
I heat wrapped the xpipes but with the torque tube and trans literally at your side the heat inside the car is always a bit much. I didnt notice whether or not the LTs caused any increase in interior temps. It's always been warmer than I would like.
One thing I did do that made a slight difference was I installed the C5 knee bolster pad. Which raised my right leg off the center tunnel just enough to not get baked by the heat coming from the center of the car.
Last edited by Johnny Hardcore; Sep 22, 2021 at 08:05 PM.
Post script...the sound the car makes with a set of Longtubes and an xpipe through a good exhaust is worth every bit of money spent and increased interior "noise". Like music to my ears.
Post script...the sound the car makes with a set of Longtubes and an xpipe through a good exhaust is worth every bit of money spent and increased interior "noise". Like music to my ears.
I agree - a good exhaust setup transforms the sound of these cars in a very good way. It moves the note up significantly, especially as you get to redline, retaining the large-displacement v8 rumble but adding a lot of "sports car" in place of "pickup truck" sound.
It's expensive, though. Exhaust systems just cost a lot if you want something reputable, that sounds good. Oh, and most cat-back exhausts will make it drone at ~1500rpm.
There are various reasons to do it, especially weight savings, and breathability improvements, but overall it's mostly a matter of taste except for those who are doing a lot more than just an exhaust (and are also doing a proper tune) to take advantage of the practical benefits.
I agree - a good exhaust setup transforms the sound of these cars in a very good way. It moves the note up significantly, especially as you get to redline, retaining the large-displacement v8 rumble but adding a lot of "sports car" in place of "pickup truck" sound.
It's expensive, though. Exhaust systems just cost a lot if you want something reputable, that sounds good. Oh, and most cat-back exhausts will make it drone at ~1500rpm.
There are various reasons to do it, especially weight savings, and breathability improvements, but overall it's mostly a matter of taste except for those who are doing a lot more than just an exhaust (and are also doing a proper tune) to take advantage of the practical benefits.
Agreed. In the mod game the proper tune is essential. Tuning is not a reccomendations...its a requirement. Nothing to consider as it must be part of the build when using power adders like headers, heads, cam etc..
The OP is running 3.90 gears in his MN6. Which both the 3.90 and 4.10 gearsets keep the MN6 at just the right RPM levels when cruising at legal highway speeds in 6th that will keep the car out of the dreaded "drone zone". Tested and proven with personal experience. Gearing is essential for many reasons. The improvement in mitigating drone is one that's often overlooked..
Depending on your goals, and what you like, LT headers can certainly be worth it. If you're worried about heat, you can wrap and/or ceramic coat the headers. There are also aftermarket tunnel plates that are specifically designed to insulate the cabin from the added heat. You can also install additional insulation in the cabin if you really feel like you need it. Frankly, engine bay temps are a bigger concern than cabin temps. As for noise, most find that headers make their car sound better. However, that is a purely subjective thing. You might like it, you might not. What isn't subjective are the HP gains. However, those gains will vary depending on the rest of your setup. For example, I have an A&A supercharger kit, and a Z06 Ti exhaust (along with other mods). In my case, long tube headers with x-pipe, and an updated tune would give me around 40 more WHP. To me that's certainly worth the cost. As I already mentioned, there are multiple options for dealing with the heat.
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