HTT/ATS Manifolds...concrete evidence?

[Matt400]

There's another way to look at this.



There's an expansion chamber effect to be considered that may explain the reading given by DHayden's testing. If the exhaust manifold is significantly larger than the exhaust port runners (by volume) then the exhaust gases will cool as they expand into the manifold.



So it's quite likely that the EGT drop seen onthe pryo is NOT the result of any enhancement in airflow. It could be explained by the expansion of hot exhaust into a larger volume conduit. This expansion will cause the gases to be cooler, denser, and lower velocity.

Hrmm. . had not thought about that possibility at all and it sounds very possible.

So your pyro might be getting fooled by the expansion of exhaust into the larger manifold volume.

How so? maybe you are thinking if the pyro is in a runner vs down by the turbo inlet??

Likewise on the intake side. If the INTAKE manifold is a much larger volume than the piping leading up to it, then YOU WILL SEE A PRESSURE DROP.

So, it's quite likely that flow through the intake and/or exhaust haven't changed AT ALL. Rather, your means of measuring temps and pressures are being tricked by the the cooling expansion effect of a larger VOLUME-- both on intake, and exhaust.



Now, if your boost is being measured using one of PDRs Boost Bolts, then we're back to square one on the intake side.

I see, so you are assuming he is measuring boost at the intake manifold where the expansion would result in a temperature and pressure drop. Geeze. . my head hurts now but its still fun stuff.

 

[ATSDiesel]

There's an expansion chamber effect to be considered that may explain the reading given by DHayden's testing. If the exhaust manifold is significantly larger than the exhaust port runners (by volume) then the exhaust gases will cool as they expand into the manifold.

It is true that exhaust gas does cool when it expands, but the manifold does not increase the area or runner lenght enough to warrant that ammount of temperature drop. Our manifold is thicker than the stock one and casted from metal with the same carbon content as the cylinder head, making the issue of temperature a wash.

 

[Cummins Thunder]

What are you guys paying for both products?



CJ

 

[Matt400]

the manifold does not increase the area or runner lenght enough to warrant that ammount of temperature drop.

So then we are back to the original assumption that the reduced restrictions allow the turbo move more volume at a lower pressure and is where the lower EGT's are from.

 

[glhs]

DHayden;

When you measured the boost numbers, was the fitting in the manifold ( below the air horn ) or in the air horn itself?

Kurt

 

[mberry]

Ok, after reading this entire thread to this point and sleep deprivation, each and every one of you is on my "buddy" list when I get the money to get a new turbo. Okay? good. Thanks.











I need a nap. I'm really starting to hate fixing computers for a living...

 

[ATSDiesel]

So then we are back to the original assumption that the reduced restrictions allow the turbo move more volume at a lower pressure and is where the lower EGT's are from.

Their ar more ways to improve flow characteristics other than increasing size, thouth it does help.

 

[DHayden]

I had a better picture of the probes but its throwing a hissy fit and doesn't want to upload to my gallery so I'll have to use this pic. You can see the exhaust probe clearly which is almost exactly in the same location as the old one (both were/are off of #4 cylinder). You can see the boost probe but not completely clearly, it was not moved.





#ad

 

[RT66DOC]

Their ar more ways to improve flow characteristics other than increasing size, thouth it does help.

Awww, you say that to all the girls. :-laf

 

[Fishin Guide]

Their ar more ways to improve flow characteristics other than increasing size, thouth it does help.

Changing them where?



On the exhaust side through a fixed flange size?



Or on the pressure side through the stock CAC, grid heater and valve pockets??



Dave

 

[ATSDiesel]

changing the actual flow path both on the intake and exhaust. Take cylinder heads for example. The flow of the cylinder heads can be improved by just smoothing out all of the curves so that the air can move through with less drag. the flow of that cylinder head can be improved this way without enlarging the ports, their will still be a gain.

 

[Fishin Guide]

Yes, and this is especially true with a naturally aspirated engine. But, when you start compressing the flow, how do you determine what "gains" are actually there?



Let's put it this way. What does ATS do specifically to test and document increased flow at X psi?



And would you be so kind to post that information?



Dave

 

[monkfarm]

ATS seems to be after the money, not the service. I think ATS has a short term view of business. They want to grap your money. I found ATS to be crabby, short of views, and just plain ignorant when it came to human relations. I ordered their exhaust manifold (which was not predrilled for pyro (even tho a threaded hole lead me to believe that it was) and I still haven't installed my pyro (lack of time). All the (clerk?) wanted to do was take my credit card # and get off the darn phone. HTT invited me to call back to ask any questions.

 

[Matt400]

I think part of that kind of problem is growing pains. As name recognition increases the phone lines do the same, companies struggle to add people on to take calls, and those taking the calls are expected to answer questions only the engineer could answer.

Smaller companies have the tech people still available for phone calls because product and phone call volume permits it.



A way that works good for me is I will ask for the tech department if I need tech help.

If I have tech questions that would help me to make a purchase I ask that stuff on TDR where you get feedback from people using the product.

If I simply want to buy the product then anyone who can take my CC# works for me.

 

[biggy238]

I Agree on the latter half. ASK EVERYTHING on here. . Then go back and ask what you still don't know and need to find out of the company itself. You find out those little quirks that the manufacturer neglected to mention (hypothetical only).

 

[RailroadJim]

The most interesting thread yet

New guy here and this is so far the most interesting thread on the whole dang site. I've been trying to wrap my head around just how these turbo charged diesel things work in comparison to gas and a carb. especially the intake/exhaust difference, my goal is to learn the basic dynamics before starting to upgrade. Their are some very smart folks on this website and i hope more threads of this nature will emerge. I would like to hear a contribution from the HTT rep on here if possible, flow bench type numbers for each manifold would be interesting to see allthough they may not be relevant according to a few opinions posted. Thanks for the knowledge.

 

[Jetpilot]

New guy here and this is so far the most interesting thread on the whole dang site. I've been trying to wrap my head around just how these turbo charged diesel things work in comparison to gas and a carb. especially the intake/exhaust difference, my goal is to learn the basic dynamics before starting to upgrade. Their are some very smart folks on this website and i hope more threads of this nature will emerge. I would like to hear a contribution from the HTT rep on here if possible, flow bench type numbers for each manifold would be interesting to see allthough they may not be relevant according to a few opinions posted. Thanks for the knowledge.

HTT's exhaust manifold manifold actually flows slightly less than ATS. According to HTT this improves performance... . I have used ATS exhaust manifolds on all my trucks but maybe I can try and get some real dyno numbers comparing both manifolds in the near future.



Doug

 

[Fishin Guide]

That would be great Doug. I would be curious if there would be any measurable difference between the two, either on the dyno or at the track.



Dave

 

[Jetpilot]

That would be great Doug. I would be curious if there would be any measurable difference between the two, either on the dyno or at the track.

Dave,



My guess is the difference will be minimal at most..... My guess is the under 500HP crowd will benefit from the HTT and the 500HP+ guys will be better off with the ATS, providing there is any real measurable difference in flow characteristics.



Doug

 

[Matt400]

HP aside, I wonder what improvements in mpg there are if any. Reducing restrictions down stream of the turbo help mpg but what about up stream?