Open Doug Thorley Headers & Broken Stock Exhaust Manifold Bolts

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Chiggy

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there say they are made that each cyl pulse exits at the perfect timing. also i would advise anyone doing header install is to remove the spark plugs. cracked spark plugs suck.

I am collecting parts quickly and plan on setting aside some spare cash for the nickel and dime stuff like gaskets and fluids. I'm going to do a cam, lifters, timing gear, pushrods, rockers, intake gaskets, valve cover gaskets, plugs, wires, headers, and a tune all in a weekend. I just have to pick the cam and rockers, everything else is just going to be isn't much of a choice.
 
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digitalfiend

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Do they make a direct bolt on for an 05 or do I just buy the kit for the 08 and have the exhaust shop modify as needed?

It seems that it's only 08 and up. Before I bought them I called Doug Thorley and specifically asked them if it would fit my 2004 Tahoe as a direct bolt-on, and they confirmed it was a direct bolt-on. Since dealing with the fitment issue is behind me I'm mostly over this, except for the extra money I didn't plan on spending at the exhaust shop. At the time I was quite peeved when I learned that their answer on the fitment wasn't aligned with reality. On my 2004 Tahoe they did rub on the body right underneath the floor of the driver's foot area...but that was easily cured with some 'massaging' with a sledge hammer.

Despite the fitment issues they're still gorgeous headers that look every bit of being well designed and well built, so I can still happily recommend them.
 
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digitalfiend

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But how do they sound.!!

Well, if you don't connect the y-pipe and drive it with open headers exiting just in front of the driver and passenger floor, then it sounds beautiful - especially at wide open throttle. I have a stock cam and engine and I couldn't believe how much my bone-stock Tahoe engine screamed with open headers. I swapped a T56 into my Tahoe a few months ago and going through the gears with open headers is so loud it's almost violent, but it's violent in a good way that makes Prius drivers pee themselves when you blow by them. On my way to the exhaust shop to get the y-pipe welded I passed a Prius and I couldn't stop laughing.

As far as how it sounds after connecting the modified y-pipe to my stock exhaust system, it is barely noticeable while being really quiet and stealthy. I was aiming for a stealth sound as much as possible so I like it. It has a nice presence when it's idling and running, but it's quiet enough that I can drop the hammer and not catch the attention of the local law enforcement.

Even better than the stealth sound is the increase in power. It's not like a supercharger or a shot of nitrous, but I have lots of extra power in the low and mid RPM range. Increasing the low and mid power is the biggest reason I went with 4-2-1 headers. Unfortunately, I couldn't tell you about any improvement in mileage because I can't keep my foot out of the throttle. It's loads more fun to drive fast and hard. :) Once I get the lead-foot out of my system I'll post MPG updates.
 
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digitalfiend

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I'm fabricating a new true-dual exhaust. I've removed the tail pipe and stock muffler and I'm running open headers temporarily - they're open just after the y-pipe for now. They sound BEAUTIFUL! This doesn't quite do the sound justice, but here it is for anyone interested:

[yt]vLkJYFZqFQI[/yt]
 
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digitalfiend

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Neighbors gotta love you.

lol

Yeah, the whole neighborhood will hate me if I don't get the exhaust done soon. ;) I just want to leave it like this though...it's sweet music to my ears. Unfortunately the deep bass and drone are too extreme for daily driving. Then there's that "noise violation tax" that I'd have to pay the local law enforcement.
 

Tahoewhat

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Dont sound too bad w/ open headers honestly. But yeah, appears to be a quiet neighborhood. Just dont do any 4am start ups and you should be good. lol
 

2000Tahoe

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JennaBear have a 2000 Hoe and would love to put headers on any recomend's also i live in a non smog stat so Thanks and the header install looks good

Dan
 

JennaBear

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Definitely LTs, brand would depend on what you want to send.

Sent from a jelly bean.
 

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