Long Tube Header Nightmare

[Big AP]

So I drop my truck off last week to have DNA Headers installed (I will never buy again, I’ve learned my lesson)

 

The mechanic cannot get anything to line up, has to dent headers to fit, slip joints leak, Y Pipe does not line up, it’s a nightmare. Guy gets back to me 6 days later with a nearly $1400 Bill. He was supposed to dyno tune the truck but says he just did a street tune. One day later I have check engine light on and get this sound. 
 

Very frustrated, I have a near mint 2016 Sierra Z71 with 48k miles that sounds like it’s going to fall apart. The performance upgrade was very underwhelming as well.

 

What would you guys do/think I should do? 

[Big AP]

I have attached a video of the sound. At 3000RPM there is a god awful grinding sound 

Edited June 4, 2021 by Big AP

[langston1726]

Videos aren’t working. Most likely hitting frame under load. I haven’t heard much about DNA headers on the newer trucks but I’m pretty sure they along with a few others are made you know where. Not to rub salt in a fresh wound but for $1400, you’re almost at what a set of Kooks or an ARH system would cost. 

Edited June 4, 2021 by langston1726

[Big AP]

No ****** Sherlock

Edited June 4, 2021 by Big AP

[langston1726]

I’m sorry. What type of response were you expecting? Take them off and put the manifolds back on. Sounds like fitment is a problem unless you plan on beating the areas in where it’s rubbing. Keep up that attitude though. It will take you places. Btw your videos still  aren’t working. 

Edited June 4, 2021 by langston1726

[DeePa]

Go back to stock. You’re not the type who can deal with truck mods 

[Big AP]

Didn’t mean to get off on the wrong foot fellas, I’m just frustrated. I’m taking it back and hoping he can make it right. I’ll show you guys the final product. Apart from the headache and disappointment with these headers, the sound is great and the truck is mint.

[pokismoki]

i just kept the stock manifold as they keep the power band lower in the rpm , I dont like revving a truck to make power, I would recommend cut out the flapper and cut out the California 3rd cat to free up the flow. then activate the Power enrichment function, and install an e85 sensor, then tune out the TCC function in 1-4th gear. this will make you smile for alot less money spent.

[M1ck3y]

On 6/4/2021 at 8:09 PM, pokismoki said:

i just kept the stock manifold as they keep the power band lower in the rpm , I dont like revving a truck to make power, I would recommend cut out the flapper and cut out the California 3rd cat to free up the flow. then activate the Power enrichment function, and install an e85 sensor, then tune out the TCC function in 1-4th gear. this will make you smile for alot less money spent.

 

Actually long tube headers boost low-mid range and shorties boost high rpm power. Its the same principle as short intake runner's making higher rpm power. The longer the runner/tube the longer it take's for the pressure wave to reach the valve. So when the engine is operating at high rpm the wave wont have as much time to make it back. Generally speaking intake's are tuned to the 3rd or 4th wave; meaning that the wave will bounce back and forth 3 or 4 times before the valve opens. On the intake side your looking for the positive pressure wave to push air into the cylinder, exhaust side your looking for the negative pressure wave to draw the exhaust gases out. And potentially pull fresh air into the cylinder during valve overlap. Valve timing and runner length are critical in order to make this happen.

 

Also in case anyone is wondering, the stock air intake resonance chambers are designed around this same principle. It will apply positive pressure at the intake manifold inlet, at a target rpm range. In this case its low-mid. Wot an aftermarket air intake will make you more top end power. But the factory intake has so much jam in the low-mid range its nuts, I don't need wot anymore. lol. 

 

I know you didn't ask, but there's a lot of misconception's on the internet about what does what. 

 

Edit*

 

I should point out that there is exceptions to this. Long tubes can make high end power. Comes down to which wave /rpm they're tuning for and packaging constraints.

Edited June 15, 2021 by M1ck3y