Hey everyone, its been a while since I posted on here, but I have a question. I am having issues with boost hesitation(sounds like a blowoff valve letting off) at speeds around 68-75mph. At 75-80 under boost it doesn't happen, just seams to happen when I'm not in the boost in high gear on the highway, just cruising. I just recently installed a AFE intake, and it seems like that might be the issue, but why? Any ideas or something I can check? Truck is stock except for the intake and DPF back exhaust(no muffler).Thank You, Rob

 

i do not think the afe is causing it but you should take the pos afe off, trash can it and go back stock with a psm kit. sounds like a problem with the he351ve variable controller parts.

 

Whats the PSM kit? And is it just a coincidence that this started right after I put the AFE on, almost like its getting too much air and releasing it.

 

Mine did something like that after I installed my S&B intake and the truck was stock. After doing the deletes and Smarty though, I have never seen it back since... I'd take the intake off or better yet, do the EGR, DPF/NOX deletes and Program it...

 

That makes sents to me, kinda like I said about it almost seems like its getting to much air. With your programmer it needs as much air as it can get, but stock its just not asking for all that, but getting it. Unspent has to go somewhere so its releasing it. Do our trucks have a blowoff valve, or something like that?

 

it does not get more air with the afe. it gets less especially if you have the afe stage2. i know with the K&N the sensor location would cause big problems. the afe is not much better than a k&n could be the same problem. a psm kit you drill a hole in the stock air box and install a adapter, a length of 4" tubing to bring cold air in the bottom of the box. you can save money by getting the parts from home depot, that is where the phrase home depot kit came from. the afe filter is poor compared to stock, the oiled filter is worse and can ruin turbo if over oiled, the oiled filter gums up the sensor, the air box lets hot expanded air in reducing turbo volume, the afe filter holds a fraction of dirt a stock filter will and a stage 2 does not have straightening vanes in the tube. the 6.7 tube is a very efficient design. most uninformed people think that all of the things in the tube is for noise reduction, it is not. by the way it works as a side benefit it reduces turbo wine. the straightening vanes in the tube along with the silencer ring reduce side shear in the compressor side of the turbo increasing turbo efficiency.

 

Great, thanks for the response. I'm going to put the stock box back in right away and grab the PSM. Appreciate it guys.

 

Carl48, What or how do you base your info on the AFE not getting more air than stock? Not trying to start a war just really interested in learning since I run one also and have zero problems. Thanks for your time on this.

 

in the air box the stock filter has many times more surface area than the afe and also has less swirling of air entering the tube, this is what causes the sensor problems. the afe box is metal with open top that lets the air be expanded before entering the tube. think about this for a minute, if the turbo can compress say for example 100 cfm if there is 20% denser air in the stock over the afe you get 20% more air to the manifold. this is the reason i recommended the psm kit for the stock. besides doubling the intake area opening it picks up the denser air near the ground rather than the hot air like the afe. the stock tube is a engineering marvel. i can not believe the amount of time and expense they went to with it. take it apart and look closely at it. the tongue in the middle completely removes any swirl caused by the turbo or filter box and directs it in the center of the turbo. if the tube was open like the afe the hurricane action on the air caused by the turbine causes the air to enter the compressor and try to go to the sides of the housing rather than into the wheel for compression. turbo manufactures call this effect side shear. look at the tongue, baffles and walls, they have dimples like a golf ball to reduce drag the list goes on, i think every time i look in one i find something i did not catch before. i am not very good at explaining things i get to technical and loose most people, i hope this helps some