I am going to be honest wit you JC I see your point but the fact that I am having to force feed you evidence of your own fucking argument and you can not see the relevance??? Dude this really makes me question everything you are saying.
You are talking about a different motor, different engine bay, different manifold. Recite a physics explanation and equations all you want.
I know for a fact with these spacers installed the car runs more consistently during back to back runs and takes a lot longer to suffer power loss due to heat soak.
I have actual experience with the advantage these spacers add. I had them on my B7 S4 and have them on the shelf for my RS4. Like I’ve mentioned I don’t believe they add 20hp, but I am convinced through my own experience that these spacers help the engine in all areas, from daily driving and sitting in traffic, to back to back passes at the strip or spirited back road driving…they more than likely prevent the loss of 5-10hp due to heat, while technically not adding anything they still provide an advantage.
What you posted was also not proof…it was really a pretty poor test. I really don’t feel like defending my stance, because if you don’t believe JHM or hundreds of our personal experiences then don’t buy these and then ask us why you car runs like shit after you make one or two hard pulls. I’m half tempted to throw my car on a dyno before and after the install and do some back to back pulls…even though JHM already did that.
You should question that because while he has good facts there applied wrong. There is over 3 feet of intake on the long runner in the intake manifold. The spacers have been shown to reduce knock vs non spacer cars and allow the intake charge to remain in a better condition both temperature and turbulence wise.
The link you put up shows a reduction in temperature in some of the examples.
Are you trying to find out the effect of something heating a volume of air? Have you performed any experimentation? Ok, so if I measure the temperature of air before something anything has an effect on it the measure the temperature of air immediately after. Then I will be able to prove if said medium had any effect on that volume of air. If you are going to argue a point. Fact>opinions proof>speculation.
Guys I am not trying to carry the torch for this guy. I am trying to point out the holes in is statement I believe the spacers do help. I was trying to show him how to follow up his opinions with facts. So we can have a productive discussion against mere speculation.
or evidence of similar test that support his arguments
And I hope you see I was backing you.
The only disagreement I would say is that turbo cars in the link or perhaps in general should be removed as they have an outside effect factor in the intercooler. To assess the range of possible Temps one we aren’t speaking on turbo cars and two on turbo cars the ambient temperature can be skewed due to its run through a possibility heat soaked or super cooled intercooler the temperature variable would become a factor. Also boost applying heat per psi would also effect the variables. Lastly the length of the na two stage intake manifold is 10 X larger runner length then on a turbo car in the one example.
To help further advance the conversation let’s understand that the gains of using spacers rises as heat raises. The hotter it is the bigger gains you see from spacers.
Oh fuck! Am I glad I joined this forum! I am in good hands. Look! numbers and charts aside, if it actually went down like Sakimano said and they drove 40 minutes, opened their hoods and the manifold with the spacers was comfortable to the touch then that is enough for me. Bought and done.
JHM testing from their spacers for the S4…
We should move this to AR
I was struck by the same thought… seems Schrödinger’s cat is still alive
…or is it?
I had to ;D
That reply was just incase anyone thought I was defending JC. Ill point out also that the temperature of any engine will vary In many ways, adding a turbo intercooler shorter longer manifold etc… All will have an effect on the temperature of the air as it passes into the intake and ultimately into the cylinders. To make claims with out any proof and talk as though they are facts will make anyone look foolish. Regardless of how well the Spacers do or do not work if you are going to make claims bring proof of your claims. The articles I posted were examples of tests that matched JC arguments. lol Ironically enough they from an audi forum if it was a corvette forum my point would have been the same that he needs to back up what he is saying with some sort proof. Provide evidence instead of speculation. Also even with the engine having a smaller manifold, with less SURFACE AREA, where a higher volume of air was moving through due to compression, the overall temps still saw a measurable drop. <----- See that its called using empirical evidence to corroborate my argument. Anyone can look at the test and see in this instance the over all temps were slightly lower with the spacer on the car.
Just saying pressure adds another variable heat being one of them.
So keeping to the actual na intake removes outside variables. Ambient Temps won’t sway in short term driving like intercooler Temps. It’s hard to determine what might have had more effect on the air the spacers or the intercooler. Also a longer runner makes all the difference in the world due to the airs exposure time vs a short intake. While the turbo test leaves much to be desired it even shows a reduction in Temps.
Now that we have resolved the cat’s state (?), I’m glad to see you two back and involved on AR. Your commentary has been missed.
Correct many variables involved. Which just extrapolated the issue. You can’t try and use science and math to prove a point unless you take into account all the variables. JC in your calculations, you did not even have a definitive proof of air speed which is in constants flux during acceleration. Nor any considerations for how conductive the manifold or air would be. Your numbers are just ramblings And guesses. 0 useable facts.
Well said.
Guys I’m half a day behind most of you, when I wake up and 20 replies have shown up, don’t kill me if I miss anything.
I would happily play the math game on that. The advertised/measured absolute temperature change of the manifold between spacers and no spacers is small. 20 degrees C isn’t going to drastically alter flow characteristics at all. If you think the difference in boundary layer turbulence is going to have a significant change in airflow characteristics on this manifold with very wide channels with a 20 degree C change I would like to see your math for that.
I would normally agree with you but we’re talking about a few millimeters of change in the runner size of the manifold. In which way do you think they would have been restricted to vary the size by such a small amount? If there’s room for spacers (there is, easily) it would have been peanuts for Audi to make the runner size this tiny bit longer. I’ve seen you call the Audi manifold a good design before, something which went considerable time into, so to argue they were somehow restricted to such a tight runner length is absurd.
[quote]Also, the whole thought process behind this post is capricious and malicious. It’s a troll job really. You perceive a number of the people on the site with whom you’ve had differences as JHM fans, and are attacking a JHM product in order to, in some way, get back at those people. That is absurd, childish behaviour.
[/quote]
Actually the subject just appeals to me. I believe I argued against these spacers over 5 years ago already.
The problem with them is, as I set out in the OP, that for all intents and purposes their precise effect cannot be reliably measured. You have to take a pretty indirect approach to figuring out what they could do, best case scenario. And the laws of physics are indicating the best case scenario is a very small gain in air mass getting into the engine. Very small. The inconvenient truth here is that the laws of physics are more reliable than human perception or “common sense”. Back to back testing is difficult as well because of the time gap between runs which means variables change and the difference we’re trying to detect is small to begin with.
[quote]Go do some testing and then present your results.
[/quote]
I will. I’ve ordered some thermocouples and I’ll pick them up when I’m in Belgium in May. There should be a JHM tuning cable there for me as well, by the way.
The mass of the manifold would allow us to calculate the energy required to increase or decrease its temperature by one degree. We know fairly accurately the mass of air moving through it. We also know the specific heat capacity of both. All we need then is accurate measurements of the manifold and head temperature in varying conditions.
At the end we will have the total amount of energy which is being transferred to the air. Thus the increase in air temperature.
The reason why we have to be this indirect and difficult is because we simply cannot do what you are suggesting on the car. We can’t put a thermocouple at the end of the runner while the car is in operation.
Let me know how you would calculate the surface area inside the manifold with any degree of accuracy…
[quote=“purpelt81,post:35,topic:7232”]
I’d need to know the volume of the manifold for the first one. Anyone want to fill theirs with water and check?
The second is too difficult to accurately calculate because surface area is a total unknown, hence why I suggest the best way forward would be to calculate exactly how much energy is being transferred (need mass and delta T measurements) and then apply that number to the mass of air and the heat capacity of air both of which are known.
So that’s my suggestion. I’ll fix a K-type thermocouple to the manifold (will try out a few different spots) and another to the head as close to the manifold as possible. We’ll do idle tests, running tests, and the rate at which the temperature of the head and manifold converge once the engine is turned off with no airflow through the manifold or over it.
Can we at least agree on the fact that whatever heating effect a warmer manifold has on the air, the effect will be largest at low rpm and smallest at high rpm?
And that whatever the delta T between the spacered manifold and the regular setup is, the change in air temperature will be only a fraction of that difference?
The other inconvenient truth is that sometimes, the human performing the math and physics can also be unreliable and leveraging the wrong variables, equations or simply make wrong assumptions, etc.
I’m not qualified to challenge any of the math or statements made here as this isn’t my field of expertise but I do know that even though math is true, sometimes, the wrong math is applied leading to incorrect results or conclusions.
In the end, both the measuring and the selection of equations and variables to be applied/used is done by a human and prone to errors.
funny enough it was longer than 40 minutes for Mistro. He drove 30 minutes just to get to my house where we met up. Despite this his was still fine.
I threw a bag of ice on my manifold and he did as well.
My ice was 50% melted in about 20-30 minutes. His was barely changed.
justincredible once did a test with a digital laser thermometer on his S4. Next time I get together with Mistro we will do the same thing when we arrive at whatever destination just so we can get an idea. We will do the same thermometer test after a few dragstrip passes in a row to see what it looks like then as well.
The bottom line for me, is that I trust the integrity of the guys at JHM. While I’m not going to pull my manifold 6 times to do before after testing, before after racing, before after dyno tests…they will. And they have.
They produce these and sell them for a couple hundred dollars. You might say that they’re just trying to sell something so they are back-proving the spacers to make a dime. This is a very good piece of skepticism to have about any company selling any product, especially in Audi tuning where the majority of the companies don’t own the cars or test a fucking thing.
However as I said, JHM’s history of testing, proving, and being fastest lead me to trust the integrity of the product. Not everyone will have that same trust. That’s likely because they don’t have 7 years of experience with JHM.
You could fill a dumpster with products that JHM binned because they didn’t work
-open element air intakes (they recommend the stock airbox after a variety of testing various designs and wasted R&D money. Stock was best straight up)
-RS4 intake manifold modifications (they recommend leaving it stock, even though they succesfully sold a $1300 manifold modification on the B67 4.2 S4. Other companies sell a $1500 manifold ‘polish’ and updated tune. You have to wonder why)
-‘ram air’ intake for the B67 S4 (they recommend leaving it stock because the cost of the product and the cost of installation and other work needing to be done didn’t warrant the modest HP gain)
They’ve tested the hell out of these cars. In fact they’re the only major tuning company in the Audi world who actually owns the cars and tears them to pieces for testing to find areas for improvement.
For me that’s all I need. For others, there is math I guess.