Abbey Motorsport Sprintex SC updated Dyno plots

[sw20kosh]

IAT relocation kit installed and scaled. Interested in what people think... I am not convinced it is working as one might hope. I think it is measuring heat soak of the aluminum it is siting in not the temp of the air. I could be wrong though.

Here is throttle position vs. IAT over the course of 20 min commute with some WOT pulls n such thrown in. Intercooled.

[jamesm]

gaining 70f in one pull is a lot. it would seem like the intercooler isn't working at all.

below is a sample of a wot 3rd and 4th gear pull with my turbo/fmic, for comparison.

http://www.datazap.me/u/jamesm/turbo...sample?2-3-4-5

[sw20kosh]

Originally Posted by jamesm

gaining 70f in one pull is a lot. it would seem like the intercooler isn't working at all.

below is a sample of a wot 3rd and 4th gear pull with my turbo/fmic, for comparison.

http://www.datazap.me/u/jamesm/turbo...sample?2-3-4-5

Where are you getting 70F? This is a 20 min drive not one pull. The green is throttle position. Red is IAT. There are multiple pulls there and the IAT goes from 20C to 45C (70F - 113F) over the course of the 20 mins.

See below for look at a series of WOT pulls. IAT post-blower should go up during WOT pulls where there is boost/air compression right? Nada. Something is up.

[jamesm]

Originally Posted by sw20kosh

Where are you getting 70F? This is a 20 min drive not one pull. The green is throttle position. Red is IAT. There are multiple pulls there and the IAT goes from 20C to 45C (70F - 113F) over the course of the 20 mins.

See below for look at a series of WOT pulls. IAT post-blower should go up during WOT pulls where there is boost/air compression right? Nada. Something is up.

I was referring to the log posted by mark above, not yours.

[sw20kosh]

Originally Posted by jamesm

I was referring to the log posted by mark above, not yours.

It is a 25 sec long pull on a dyno and there is no heat detected till half way through at which point it starts ramping up. It is probably just detecting heat soak of the engine too like mine is. Total speculation though.

Keep in mind that car is on a dyno and mine is on the street. That engine will heat soak much more on a dyno.

Are you running a blow through MAF? Is your MAF/IAT unit post intercooler?

[Ryan86]

I just removed my IAT as I found a wire loose on the harness, I don't know for sure but I think the car is running better without the IAT.
And no it was not due to loose wire, I happened to clean intake and came loose when I pulled plug out.

[sw20kosh]

Originally Posted by Ryan86

I just removed my IAT as I found a wire loose on the harness, I don't know for sure but I think the car is running better without the IAT.
And no it was not due to loose wire, I happened to clean intake and came loose when I pulled plug out.

Is your IAT reading from the airbox or is it relocated to the manifold (post-blower)?

[Ryan86]

The IAT sits on the manifold and the harness runs through and connects into MAF sensor.
Would this read post blower?

[jamesm]

Originally Posted by sw20kosh

It is a 25 sec long pull on a dyno and there is no heat detected till half way through at which point it starts ramping up. It is probably just detecting heat soak of the engine too like mine is. Total speculation though.

Keep in mind that car is on a dyno and mine is on the street. That engine will heat soak much more on a dyno.

Are you running a blow through MAF? Is your MAF/IAT unit post intercooler?

yes is it a blow-through maf... i never see more than 10deg over ambient ever. even after repeated runs to redline. it seems that the innovate unit is just too damn small to do the job, kinda like the old mazaspeed miatas intercooler. it's an interheater lol.

i guess the fact that it's on a dyno could effect it, but i don't think *that* much unless they have no fans at all... i mean the intake temp shot up 70+ degrees during the pull, that's no good.

[sw20kosh]

Originally Posted by jamesm

yes is it a blow-through maf... i never see more than 10deg over ambient ever. even after repeated runs to redline. it seems that the innovate unit is just too damn small to do the job, kinda like the old mazaspeed miatas intercooler. it's an interheater lol.

i guess the fact that it's on a dyno could effect it, but i don't think *that* much unless they have no fans at all... i mean the intake temp shot up 70+ degrees during the pull, that's no good.

You might be misunderstanding the points of my posts. I am not trying to elucidate the efficiency of the intercooler or the blower. I am trying to figure out if the IAT is reading the temp of the charge air correctly or if it is being overridden by the hot aluminum manifold it sits in. The data I have posted shows the latter where the sensor cares more about how long you have driven rather than how much boost/heat the supercharger is pumping out during WOT pulls.

If that is the case then any of your conclusions about how inefficient the intercooler is are invalid.

[King Tut]

I don't know that I have seen a good picture of the IAT sensor, but I doubt it is reading the temp of the manifold and not the air. It isn't like a water temp or oil temp sensor where it is metal and relies on contact with the water/oil. It requires air to pass over it, so as long as it is in the airflow it should be measuring the correct temp and not the temp of the metal it is screwed into.

[jamesm]

Originally Posted by sw20kosh

You might be misunderstanding the points of my posts. I am not trying to elucidate the efficiency of the intercooler or the blower. I am trying to figure out if the IAT is reading the temp of the charge air correctly or if it is being overridden by the hot aluminum manifold it sits in. The data I have posted shows the latter where the sensor cares more about how long you have driven rather than how much boost/heat the supercharger is pumping out during WOT pulls.

If that is the case then any of your conclusions about how inefficient the intercooler is are invalid.

isn't it possible that the intake charge is just heat soaking more the longer you drive? your suspicion is that the sensor is reading incorrectly? personally, i think the hot aluminum manifold is probably just heat soaking the air your taking the temp of. but who knows...

[sw20kosh]

Originally Posted by King Tut

I don't know that I have seen a good picture of the IAT sensor, but I doubt it is reading the temp of the manifold and not the air. It isn't like a water temp or oil temp sensor where it is metal and relies on contact with the water/oil. It requires air to pass over it, so as long as it is in the airflow it should be measuring the correct temp and not the temp of the metal it is screwed into.

Thanks. I'll take pictures of the sensor and the chamber in the manifold it sits in.
@moto-mike want to chime in?

[Xero-Limit]

Originally Posted by sw20kosh

Thanks. I'll take pictures of the sensor and the chamber in the manifold it sits in.
@moto-mike want to chime in?

so the issue here is that I'm guessing it is using a brass bodied IAT sensor, similar to a GM type. Until I see pictures I don't know for sure but based on a few datalogs I keep seeing the same thing. Note the attachment. This is a NON intercooled car, so temp changes will be even more abrupt than sw20kosh's.

You see several shorter WOT pulls, with barely any movement of the IAT. Only after a very long pull do you see the "IAT" climb up. Then it takes a VERY long time for it come down. This just isn't accurate to how the SC behaves. You should see spikes in temp with every application of the throttle lasting more than a second or two, but instead you see heatsoak.

I think the reason here is that the IAT sensor body is very heat conductive, sits in a heat conductive supercharger plenum, and probably gets more thermal conductivity through its body than it does from the charge air. To understand this you have to crack one of these guys open and compare to other IAT designs on OEM vehicles.

Most OEMs employ either a wire type element that is directly exposed to the air (i.e. inside the MAF). Some of the others, like the GM variants, use the bigger brass type sensor that is interchangeable with coolant sensors. Inside the brass is the same wire element surrounded in electrically insulated but heat conductive paste similar to what you put on CPUs. This transfers the heat to the wire. The caveat here is these metal sensors are put into polycarbonate intake tracts where the heat conduction is still from the air, or even metal intakes that are removed from engine heat. So that means it functions nearly as well (but more dampened) than the exposed wire sensors.

Now if you put one of these metal bodied sensors into the SC plenum such as here, with no isolation, you are going to capture more thermal transfer from the blower and engine than you will from the charge air.

Hope that explains it but the datalogs show the sensor works to measure temperature, might just be the wrong sensor for the application. Looks like bullet/sprintex did their homework on this by using the Bosch MAP sensor with IAT. That solves the problem as it employs a wire directly in the plastic MAP sensor.