Intake temps

[Insidious Surmiser]

Paging all major league pricks. All the guys that know far too much to not be assholes about it. (I think IJ is one of the few who at least tries not to be an asshole)

Anyhow, simple question. At high speeds (3,000+ rpm) how much of a chance does the intake charge have to heat up when moving through the upper intake? (over turbo, engine, into manifold) I know the intakes on the 7m's like to get very hot, but it seems that there is FAR greater surface area in the charge air cooler. If I had to guess I'd say that the upper intake temp has little effect on heating IAT's when the air is moving so fast, and across considerably less surface area compared to the FMIC.

I've been trying to dig up information on this, on really any vehicle, but I've had little if any success.

 

[Nick M]

You are right. It doesn't really matter. What matters is the head is bolted to the block, and the manifold is bolted to the head. And the block gets hot. And the aluminum that is bolted to the block transfers heat rather quickly compared to cast iron. There is also coolant lines that run to the throttle body to keep the intake charge consistent in temp (warm).

And to stop any chance of a misfire, the air and fuel mixture is compressed.

 

[Insidious Surmiser]

Hm, ok. I'm'll have a talk with my tuner/friend, but undoubtedly, the consensus will be the same.

Thanks for the input.

 

[Suprapowaz!(2)]

What is your tuner/friend telling you? He's recommending to go ffim in order to tune it right?

 

[IndigoMKII]

I know you can keep the intake down a few more degrees if you do some steps to keep engine bay temps down. There's a gasket that helps prevent heat transfer between the head and the intake. http://store.driftmotion.com/static/i-heatshieldinggasket7m.php You could always bypass the throttle body coolant lines, not sure if this will have ill effects or not. You can always wrap the cold side of the intercooler piping and fab up heat shields for the manifold, you can go a step further and have the manifold/downpipe ceramic coated.

If you're referring to heated air from the intake manifold reaching the IAT if the IAT is in the pipe before the throttle body, it can't. With the vacuum from a running engine, the air is always traveling into the engine. I'd be more worried about the intake manifold itself heat soaking the things around it.

 

[3p141592654]

Most of the temperature issues are from the compressor itself. At 18 psi boost pressure and 80F ambient temp 75% compressor efficiency, the output from the compressor is 287F. At that point, your intake pipes are cooling the charge! The IC assuming decent efficiency can get that down to maybe 120F, which is still pretty hot.

 

[jake8790]

^ Good info, would never have guessed the charge air would be that hot!

 

[Nick M]

You could always bypass the throttle body coolant lines, not sure if this will have ill effects or not.

I suppose it has a useful function, otherwise Toyota engineers would not have wanted it. Don't you think?

 

[jake8790]

Icing the throttle blade under humid conditions even in above freezing ambient temps.

 

[Insidious Surmiser]

What is your tuner/friend telling you? He's recommending to go ffim in order to tune it right?

no, certainly not. I'll talk with him on wed. morning when I go to look at a 88 hardtop he's got. (don't like my 89 targa) Word from his mouth was that the stock manifold will make 600whp, as well as the stock TB and 2.5" pipes. My power goal is 400whp, although I'm almost certain I'll end up over 500whp (using AEM EMS + 58mm borg warner t4)

I suppose it has a useful function, otherwise Toyota engineers would not have wanted it. Don't you think?

You'd think so. From what I understand it's useful for people in the FAR north, but in the more temperate climates, I really believe it's pointless. That's what I've gathered from a lot of owner's input, though.

^ Good info, would never have guessed the charge air would be that hot!

indeed.

 

[7M4EVR]

I suppose it has a useful function, otherwise Toyota engineers would not have wanted it. Don't you think?

Just like an oil pump that doesn't sit low enough in the pan, and head gasket bolts not torqued enough? I get what your saying but its somewhat annoying to constantly see you experienced guys saying things like this without providing at least a brief reasoning behind the comment.

If nobody ever challenged things that the engineers designed we wouldn't have a reason for aftermarket modifications in the first place. Without pointing fingers ive seen a lot of engine bay shots or build threads from the experienced guys that show either highly modified or deletion of much of the stock functioning systems on their cars, but then preach don't touch it.

I understand you have to be careful about what you say and speak to the majority of the community or there would be a ton of us newbies out there blowing our cars up, but maybe you guys could keep an open mind and give an alternative suggestion or explain why/why not it can/cant be done. I think we could all benefit from that!

 

[3p141592654]

He figured you were conversant in the Joule–Thomson effect.

 

[Insidious Surmiser]

Icing the throttle blade under humid conditions even in above freezing ambient temps.

ok, I understand now, but I'm still curious why no one I've ever heard of bypassing the coolant lines there (myself included) has had a problem with this? curious, that's all...

 

[jetjock]

Icing the throttle blade under humid conditions even in above freezing ambient temps.

Because there's such a pressure drop due to Bernoulli as in carbs. Not. So says this major league prick...

 

[IndigoMKII]

I suppose it has a useful function, otherwise Toyota engineers would not have wanted it. Don't you think?

I said you could but I didn't know what problems it could cause. The only thing I can think of would be a constant temperature applied to the casing but with the engine running and the engine bay warm, wouldn't there already be a constant temperature applied anyways?

Do the JZ series manifolds have a coolant line inside the throttle body? Sethrons FFIM doesn't have a coolant line in the intake.

 

[Nick M]

From what I understand it's useful for people in the FAR north, but in the more temperate climates, I really believe it's pointless.

Do you think International trucks put heater grids in the intake manifold after the intercooler in just northern climates? The air has to be heated to vaporize the fuel and burn it. This is why it is compressed to very small area in the first place. The coolant is for constant temps, not to hot, not too cold. If you have too much heat, power is lost. Not because hot air is less dense, because of pre-ignition. The heat is a good thing for burning the fuel. But too much makes it burn early while still on the compression stroke.

The best thing you can do besides extrude hone the manifold is, nothing.

Just like an oil pump that doesn't sit low enough in the pan

Says who?

and head gasket bolts not torqued enough?

Yep, you could say they dropped the ball on that one. As did Mitsubishi, Ford, Chrysler, Honda...anybody running an iron block and aluminum head.

I get what your saying but its somewhat annoying to constantly see you experienced guys saying things like this without providing at least a brief reasoning behind the comment. If nobody ever challenged things that the engineers designed we wouldn't have a reason for aftermarket modifications in the first place.

You are emoting. Nobody says you have to buy the car. You want a hot rod? Pony up the money. I have gotten tired of the nonsense, when it doesn't quit. Even after being shown. Like EGR causing detonation. When it reality it causes a slight misfire that you can not even detect.

 

[Nick M]

Do the JZ series manifolds have a coolant line inside the throttle body?

The 1MZFE Camry cylinder head out flows the 2JZGTE. Stop using fake qualifiers to determine legitimacy of a concept.

 

[IndigoMKII]

The 1MZFE Camry cylinder head out flows the 2JZGTE. Stop using fake qualifiers to determine legitimacy of a concept.

I'm not trying to use fake anything for any legitimate reason, merely trying to understand the purpose why some manifolds have it and some don't.

 

[3p141592654]

2JZ-GTE has a heated intake, if anyone cares.....

 

[figgie]

Of course,

ALL that for not if you are running a "cold air intake" and ingesting copious amount of preheated air that passed through the radiator!!! even hotter temps at that point.