Intercooler efficiency, lets discuss air temps

[turboglenn]

NOw i'm not going into airflow,vs. air temp, pressure drop ar anythign like that. I want to just get some basic info together from some of you guys/gals that can monitor/log your intake air temps.

As an example i'll throw mine out there

t3/4 turbo 57 trim, busher old style front mount ( the trianlge loking one with the endtanks both pointing to the pass side. I believe it's 24x8x3.5 and 2.5'' IC piping.

On colder days in the 40's and below i see almost no heat gain, it may go from 41 on start up to 50 or so on a long hard pull at 18-19psi.

On Hot days. 85+ with humidity in the 70% range most of the time ( if not higher) I go from about a 95* temp. And after a a few repeated third gear pulls im only getting 127-131 ( sometimes a TAD higher, but not by much)

In all examples of my temps, I figure idle temps are higher because of heat soaking of the piping, manifold, tb and IC from engine and outside heat. My IAT sensor is in the intake elbow for teh throttle body.

what are some of your guys readins on various situations?

 

[viperlp01]

I know on my stock side mount and stock t-25. 15 pounds on wot on a 30 degree day im reading 59 degrees. I need a FMIC . I know my temp on like a 80 degree day was like 68 degree.

 

[turboglenn]

^^ did you get that last # wrong? it says you got cooler on a hotter day. Maybe you meant 168?? Alos are these #'s from after a hard run?

 

[2gGSX]

Most DSMs do not have IAT sensors on their cars unless they're running a standalone or some other SD setup, so you might not get a huge response from people about this.

 

[99gst_racer]

I know on my stock side mount and stock t-25. 15 pounds on wot on a 30 degree day im reading 59 degrees. I need a FMIC . I know my temp on like a 80 degree day was like 68 degree.

John, those numbers were from a datalogger, I assume? And you still have the stock 2G MAS, correct?

If so, then those numbers are pre-turbo, and pre-intercooler, so they won't offer any help for testing intercooler efficiency.

 

[turboglenn]

Can't you put an IAT in the TB elbow ir IC piping with DSMlink? And also with the GM MAF and MAFT??

 

[tkelly27]

Can't you put an IAT in the TB elbow ir IC piping with DSMlink? And also with the GM MAF and MAFT??

No, it uses the IAT to determine the density of the incoming air. As the turbo changes the temperatures you'll get different densities. The GM MAF uses a hot wire unit which I don't think uses an IAT.

Even if you did get those setup, you'd only be getting one of pre or post IC temp reading. To get the mathematical efficiency you need the tcoming in, the t coming out, and the t of the ambient air

You get the higher reading when you idle because you're not getting cool air circulating through the engine bay, where your IAT is picking up the temp from.

 

[turboglenn]

just use ambient as your base air temp. S long as you've got a CAI your reading shouldn't be far from ambient anyway. Air temps for density are best measured right before teh TB after evey other part of the system has heated or cooled it to some degree. I plan on routing a 2nd IAT rught after the turbo , before the intercooler to see how much it's cooling it down and the difference at different road speeds.

 

[turbosax2]

Can't you put an IAT in the TB elbow ir IC piping with DSMlink? And also with the GM MAF and MAFT??

Yes, you can put an IAT sensor in the TB elbow and log it through DSMlink. The sensor is purely used for logging, not for reporting temps to the ecu.

 

[viperlp01]

Ya you are right. I was using a logger. But how come on a cold day i still get way above freezing numbers??

 

[turbosax2]

Ya you are right. I was using a logger. But how come on a cold day i still get way above freezing numbers??

I know my temp on like a 80 degree day was like 68 degree.

That part makes no sense. Is that a typo?

 

[viperlp01]

i don't know why eather but that was the numbers that i was throwing. I was driving when i got these numbers. The pre turbo temps will be sometimes lower than outside temps right. That is what a cold-air intake is for. I just can't figure out the temps on a cold day. Is my motor warming the air before it enters the intake. Im not lying either, none of the numbers are typos. Im not a weather man so i can't guarentee the outside temps but i know that the air temps from ym logger are accurate

 

[2gGSX]

Yes, you can put an IAT sensor in the TB elbow and log it through DSMlink. The sensor is purely used for logging, not for reporting temps to the ecu.

There was a big thread about it, but it's sort of a PITA. You have to use a GM MAF and clamp baro/intake temp, then use the intake temp input with a very specific IAT sensor which they developed an algorithm for (each thermistor type IAT is different and thus requires a different formula).

 

[turbosax2]

There was a big thread about it, but it's sort of a PITA. You have to use a GM MAF and clamp baro/intake temp, then use the intake temp input with a very specific IAT sensor which they developed an algorithm for (each thermistor type IAT is different and thus requires a different formula).

My brother and I actually already wired an AEM IAT into his DSMlink since he has a gm maf setup. It wasn't that hard really.

 

[Steve93Talon]

There was a big thread about it, but it's sort of a PITA. You have to use a GM MAF and clamp baro/intake temp, then use the intake temp input with a very specific IAT sensor which they developed an algorithm for (each thermistor type IAT is different and thus requires a different formula).

You dont need to have a MAFT, you just need an open input. On a 1G, the only free input is EGR temp, and most people use it for logging a wideband. On a 2G, you can use MDP and rear o2 so you can log more than one thing. Another thing you can do force open loop and use the front o2 input to log something.

 

[turboglenn]

. The pre turbo temps will be sometimes lower than outside temps right. That is what a cold-air intake is for. I just can't figure out the temps on a cold day. Is my motor warming the air before it enters the intake. Im not lying either, none of the numbers are typos. Im not a weather man so i can't guarentee the outside temps but i know that the air temps from ym logger are accurate

The air before the turbo is always going to be about the same as ambient. At least thats the cold air intakes job, to get you the closest to ambient temps. But, being that the piping is in the engine bay it can be warmer by the time it hits the turbo. It exits the turbo HOT, goes into the IC and gets cooled, then it can only be re-heated through the UICP,TB and intake and head ports. You just want to keep it as cool as possible before the valves to get as dense of air as possible.

i'm looking for how much the air is heated ( by asking size of turbo and boost level) and then how close to or above ambient the air is when intering the intake mani. Giving me the base # i'm looking for about how efficient your IC is in intake temperature control

 

[2gGSX]

My brother and I actually already wired an AEM IAT into his DSMlink since he has a gm maf setup. It wasn't that hard really.

You dont need to have a MAFT, you just need an open input. On a 1G, the only free input is EGR temp, and most people use it for logging a wideband. On a 2G, you can use MDP and rear o2 so you can log more than one thing. Another thing you can do force open loop and use the front o2 input to log something.

I don't think it was the fact that there wasn't an open input so much as each input has a different pull-up and pull-down ground. The main sensor talked about in that thread was the GM (Delphi) sensor, and the algorithm they made was tailored to the 2g IAT input pull-up and pull-down resistances. It isn't terribly hard to figure out other systems' algorithms through experimentation, but the 2g IAT circuit is what the one they worked out. Here's the link to the thread: DSMLink User Group Forums

I'm not trying to stop anyone from hooking one of these up if that's what it sounds like!

 

[turboglenn]

I was mearly asking for those that can moitor ( and do) to post up their temps after the IC after pulling a long gear or running up through 3rd or 4th, what size turbo and what intercooler

 

[GVR4592]

Random FMIC information with a little turbo info mixed in..... - Page 2 - Buschur Forums

 

[turboglenn]

GVR4592, thanks. Their "standard" is what i'm running. IT's cool to see that we both have very similar #'s as far as heat rise in the system with the same IC.