Temp readings from under your hood..Then before and after with intake spacers

[Justincredible]

We all know the 4.2L motor runs Super hot and this can cause some issues. I thought I would take some temp readings on not just our car but 2 others after a 20min drive threw down town Chicago.

The 2 other cars were a 2007 A4 TFSI and a 2007 F150. The idea was to test the intake area the valve covers and the inlet temps before the throttle body.

There were some obvious issues in the comparison due to motor design but this was for reference only. On all the tests the S4 Had the higher readings for all the temps. The important ones to me were the temps before the intake manifold. The A4 has a plastic type of intake so the temps were going to be lower due to the design and location of the intake tube and throttle body location. Our S4 has the intake going over the 170+F Valve covers where there was No place on the A4 or the F150 that had the same temps.

First pic here is of the throttle body right after the intake elbow. You can't see all that well in the pic but I put small pieces of heat tape to try and stop from getting surrounding heat readings. So the reading on the Actual throttle body is 133F




The next pic is of the oil filter and the back of the intake manifold. you will see its 158F.



The last one was important to me. This is part of why so many believe there is an issue with the open element. This is a temp reading from the general Area where you would have the intake Even with a good barrier there is the most heat in this area if you moved more from the Valve covers towards the cylinder head/air box Gap obviously the Temps increased quite a bit. Average was about 175F



The last place was closer to the Air meter and intake rubber elbow. Much unlike the ford and the A4 in witch didn't have the intake track going over the almost 175F degree part of the motor this seemed to be something that may be a place of interest. The intake temps were hard to pin down the exact temp cause the intake spans over a area where you have temps that range from 190-175.

If you do the coolant bypass and the intake spacers you are definitely going to dump a ton of heat out of the intake track. They definitely seem like a good idea considering the surrounding temps.

So I thought I would do the intake testing on the spacers I got from JHM. I was going to wait but I just decided to put them in and see the temp difference. This temp reading is after a hard run, with no cool down and a quick road side temp reading BEFORE THE SPACERS


This next one is WITH the JHM spacers in. I noticed that the new intake manifolds seem to have a heat resistant coating on the bottom. So I put some heat barrier tape on, to try and help keep even more heat out. This temp reading, is AFTER the JHM intake spacers and a Pretty hard run with the car, with the same test area and reading AS quick as possible after opening up the hood.


Depending on how you drive the car and what conditions you are in, the intake spacers Really do knock out some heat from the intake. The test I did, I tried to keep the car under hard acceleration with almost no long straights that might bring cool air in from the speed the car is traveling. The intake spacers, Obviously make more of a difference between hard driving and Easy driving with the temp difference between with and with out. Even with easy driving I noticed a 20F drop in the temps Over not having the spacers in.

The spacers How ever don't help once you turn off the car. The intake will still get the slow heat absorption from the motor. So if you are at the track you will need to keep the Ice on the intake while you are in the pits with the motor off. How ever if you keep the motor running and constant air flow going threw the intake you are good.

Over all I think its a great Idea and mod for the money. Any time you can get heat out of the intake that is a good thing.

[cabracco85]

Nice write up justin.

[audis4b6]

excellent write up....

[ALWAYS4UDI]

how much of a pain was this process? did you follow jhm's video?
i plan on having the manifold powder coated, so i'd like to do these while it's out.

p.s. thanks for the info!

[Devitan]

how much of a pain was this process? did you follow jhm's video?
i plan on having the manifold powder coated, so i'd like to do these while it's out.

p.s. thanks for the info!

That's what I did. If the manifold is out this process takes an extra minute or two. It is really easy and I can vouch that it has been really effective.

[ClayFighter]

thank you so much for performing these tests and sharing your results!

[AudiOso]

Very good write up Justin... thanks for the info!

[joeycuccaro]

Good write up Jason, thanks for taking the time to do this.

So were concluding the JHM spacers take about 20 degrees off the engine temperature?

[Justincredible]

Thanks guys for the kind words. Im very happy to share with you guys I always get excited to help as so many of you have helped me. Glad to be part of this great groupe of guys.

Average driving you are going to see yes about a 20-30deg drop. While hard driving is going to yeld better results. I have been taking temp readings at some local meets and its odd some cars seem to run hotter then others But regardless The intake spacers definitly create a strong heat barrior. The out side temp also seems to heat up the intake even more. I remember getting much hotter readings last year in 80deg temps.

Im actually working on seeing what I can do to cool off the over all motor bay temps. The Temps at the air meter are Crazy high and Im rigging up a way to take intake temps. But we will see

In the end You can feel a difference in power for sure. But with no hard data I didn't want to talk too much about that and try to keep it more on task with Actual results.

[antic]

Great writeup! Thanks!

[yakendo]

Another great & thoughtful post, Justin! Thank you!

[ieatfishburitos]

Justin did you calibrate your temp reading instrument to NIST standards between measurements?


Just kidding! Excellent work, nice info to have.

[V8weight]

Thanks guys for the kind words. Im very happy to share with you guys I always get excited to help as so many of you have helped me. Glad to be part of this great groupe of guys.

Average driving you are going to see yes about a 20-30deg drop. While hard driving is going to yeld better results. I have been taking temp readings at some local meets and its odd some cars seem to run hotter then others But regardless The intake spacers definitly create a strong heat barrior. The out side temp also seems to heat up the intake even more. I remember getting much hotter readings last year in 80deg temps.

Im actually working on seeing what I can do to cool off the over all motor bay temps. The Temps at the air meter are Crazy high and Im rigging up a way to take intake temps. But we will see

In the end You can feel a difference in power for sure. But with no hard data I didn't want to talk too much about that and try to keep it more on task with Actual results.

Here's what someone on the RS6 forum has come up with to lower under hood temps on the RS6
http://rs6.com/forum/showthread.php?t=17474

[Silver B6 S4]

Nice write up again! Thanks for the info.

[cabracco85]

*kawf* *kawf*

A slotted hood would help with the heat. But to get one that looks good might be the problem. i do like the one in the pic though. Not sure how it would look painted though. any details on that hood?

[poopypants]

Anyone pulled those stupid weatherstrips off? i noticed that they contain majority of the heat in the engine compartment.

[cabracco85]

Anyone pulled those stupid weatherstrips off? i noticed that they contain majority of the heat in the engine compartment.

I havent did that on my car, i wonder if they will help let the hot air get out of the engine bay. I will have to do some tests. Do they hold the hood any? or are they just there to keep the engine bay sealed up?

[oripaamoni]

*kawf* *kawf*

damn b-rad you are everywhere!

[poopypants]

I havent did that on my car, i wonder if they will help let the hot air get out of the engine bay. I will have to do some tests. Do they hold the hood any? or are they just there to keep the engine bay sealed up?

So far i think they keep the bay sealed and clean. I yanked them off and realized how much more air flow can squeeze in there to do some further cooling. When i park, heat radiates out of that plastic mesh near the wipers. The weather hasn't been too bad out here in SoCal, but my car doesn't heat soak as bad as it used to. But then again, summer hasn't begun yet. Just a thought. I thought the pulling of the weather strips would have been an obvious fix from the heat.

[ClarkSJ]

In my TT, you can get a readout of IAT (intake air temperature) with a VAG-COM or a ScangaugeII. Does the 4.2 have a similar sensor? I may hook my Scangauge up and take a look.

[Justincredible]

You can log the intake temps but much UNlike the tt 1.8T RS6 and 2.7T the 4.2 uses the MAF for the intake temp readings. This is why Im working on getting a intake elbow fitted with a MAF sensor to test more.

[cabracco85]

So far i think they keep the bay sealed and clean. I yanked them off and realized how much more air flow can squeeze in there to do some further cooling. When i park, heat radiates out of that plastic mesh near the wipers. The weather hasn't been too bad out here in SoCal, but my car doesn't heat soak as bad as it used to. But then again, summer hasn't begun yet. Just a thought. I thought the pulling of the weather strips would have been an obvious fix from the heat.

Are you worried with all of that heat it might melt the plastic? Is there alot of heat that you can feel radiating out? Did you pull off the front and rear one?

[Bravest NY S4]

good shit justin....!

[Tugboatguy]

Did you take a temp reading off the rubber intake elbow?

[Justincredible]

Did you take a temp reading off the rubber intake elbow?

I did and this was what I was kinda talking about with the openelement conversation the other day when some A4 guy came in and told me to shut the F up... Bottom line is we have a serious issue that makes our cars Way different when it comes to the inlet pipes and intake track. As for me to make the case that if you don't have a 4.2 your input is not helpful as far as the intake advice is concerned. The intake tube and area around it is over 100deg more then on any 1.8 or 2.0.

So to better answer the question. I did But I'm going to do more testing to get the definitive results as to whether I'm getting a heat reading from the actual temp of the elbow or the heat from the general area. The Rubber elbow is one of the areas I think we should try to shield more heat from. Ive been looking into this for a while now but after all the intake drama with people from other platforms telling me how math is the answer to all the issues and that a pipe is a pipe on a boat or car. I think Ill just keep that info to my self. Best to say ITS seriously hot in the elbow area and a small shield wouldn't hurt there

[jaybquick@JHM]

Nice write up. Saved me some time that I would have spent doing such a thing.

Thanks.

[cabracco85]

Nice write up. Saved me some time that I would have spent doing such a thing.

Thanks.

I 2nd that, i was going to do a write up aswell but you beat me to it. Good job justin

[ClarkSJ]

Just an FYI, I have been reading intake air temps this week using my Scanguage. I can confirm that they run just a few degrees above ambient (usually 4-6 degrees, at most 10 degrees) when the car is moving. So the stock intake is pretty good and drawing in cold air, as many have said.