IAT2 showing -40 in datalogs after Brass IAT Sensor install

[2019GT]

I just had the Brass IAT Sensor from Lethal Performance installed by a shop today and I noticed a severe loss of power. I datalogged it and sure enough, IAT2 is always reading -40 and even with a commanded pedal of 100% I'm only getting a max actual throttle of like 5%...

Does this sensor REQUIRE a proper tune to read properly? I noticed my gauge is still displaying Inlet Air Temperature ...

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[Ruiner46]

Whipple tune? The whipple tune only works with their IAT sensor and wiring. -40 means the tune doesn't see the sensor at all. The brass sensor takes over IAT1's wiring, so you basically took away IAT2.

 

[2019GT]

Whipple tune? The whipple tune only works with their IAT sensor and wiring. -40 means the tune doesn't see the sensor at all. The brass sensor takes over IAT1's wiring, so you basically took away IAT2.

Hey, yeah it's still on the whipple tune. Just placed the order with Lund for a custom tune. Once I swap to the Lund tune it should pick up the IAT2?

Edit: I didn't see this warning on Lethal's site, but I did find this on another site:

Works on Whipple and Roush kits that don't use Whipple or Roush calibrations. The supplied brass GM sensor replaces the Ford GT500 sensor.

*Must have aftermarket calibration to work properly. Harness is made long for universal fitment.

If I'm understanding correctly, then once I load my Lund tune I should be fine ...

Edit2: Just checked datalogs when I was N/A and IAT2 showed -40 there too. My fault for not fully understanding what happened when the brass IAT was installed. So in the nGauge datalog, I assume since we relocated the IAT sensor, then what's being logged to ACT is actually the IAT2 value.

 

[HKusp]

When you datalog the person tuning will ignore the IAT2 reading and use the IAT1 reading as it is re-purposed with that harness.

 

[2019GT]

When you datalog the person tuning will ignore the IAT2 reading and use the IAT1 reading as it is re-purposed with that harness.

I wish I knew this before but that's my own fault of course. Hopefully Lund gets the base tune over soon and the power will come back. Going WOT and barely accelerating faster than a geo prism was a strange feeling lol

 

[HKusp]

I bet it was. It could get you into a different kind of trouble than it could when it was putting the power down.

BTW, I would think you could plug the IMRC harness plug back in and unhook the breakout harness to the brass sensor until you get tuned and it should go back to what you had. Please report back the difference you feel when you do get the Lund tune installed. I am interested in how much, if any difference you notice in the "seat-o-the-pants" meter.

 

[2019GT]

I bet it was. It could get you into a different kind of trouble than it could when it was putting the power down.

BTW, I would think you could plug the IMRC harness plug back in and unhook the breakout harness to the brass sensor until you get tuned and it should go back to what you had. Please report back the difference you feel when you do get the Lund tune installed. I am interested in how much, if any difference you notice in the "seat-o-the-pants" meter.

Appreciate the tip on that, can't hurt to try.

Will do! The whipple calibration isn't bad at all. WOT shifts are soft and shifts about 7500. I was able to get a 60-130 of 6.5 video timed on one run, and 7.0 dragy on another with advancetrac kicking in the whole time from 100-130. Datalog showed throttle was restricted to about 45 for that segment. So I'm confident if advancetrac didn't kick in 6.5 is a legitimate time. Good to have some baselines in numbers before trying Lund.

 

[HKusp]

I am pretty sure you are going to fall in love all over again when you get the Lund tune. I never went with the Whipple tune because I heard that they left a lot on the table.

 

[2019GT]

I am pretty sure you are going to fall in love all over again when you get the Lund tune. I never went with the Whipple tune because I heard that they left a lot on the table.

I ran a Lund E85 tune before this and it was *completely* different than the stock tune in all the best ways! I had to run stock before installing the Whipple and that was a real reminder just how amazing the Lund tune actually was. Will definitely update here after I get the Lund tune done!

 

[2019GT]

I am pretty sure you are going to fall in love all over again when you get the Lund tune. I never went with the Whipple tune because I heard that they left a lot on the table.

Some updates, since I received my base tune and did some datalogging for Lund. First they gave me an RPM limited tune and we tested out the part throttle and idle. Then they gave me a second base tune which I figure is the same tune just without the RPM limit. We did some WOT datalogs and everything looked good they said.

I did some high level checks on the datalogs, and we're actually adding a few degrees of timing at WOT, whereas on the whipple tune they were pulling about a degree. AFR at WOT was like 0.75 which is about 11, seems fair enough.

I'll tell you this, I'm having more problems with AdvanceTrac on shifts now lol but it's not consistent. When I'm doing these tests on a closed road and it's relatively smooth then AT isn't an issue, but even mildly bumpy and I seem to have issues This tune isn't even shifting the tranny hard, but I need to datalog to see the timing and torque code on shifts when AT *doesn't* kick in so I can see if that's been touched.

It's interesting how the whipple calibration handles AdvanceTrac differently though. With Whipple, if AT kicked in it didn't *feel* like I lost power even though datalogs showed actual throttle dipped down to like 45% from peak 85%. When AT kicks in on any Lund tune I've ever had, it feels like the throttle is yanked down to 0 lol but once again I'll need to datalog and see exactly what's happening to the throttle there too.

When AT *doesn't* kick in - it's fast! I don't quite know if it's much faster than it was before, but I'm still on the base tune. I'm scheduled for a remote dyno session soon so hopefully not only will I get tuned by Lund but also get my dyno numbers?

 

[HKusp]

Hopefully they'll smooth that out as revisions come. I would certainly communicate your concerns with them.

 

[2019GT]

Hopefully they'll smooth that out as revisions come. I would certainly communicate your concerns with them.

We hit some trouble on the dyno today :/ Fuel Pressure dipped below 30psi on the first pull. Duty Cycle was pegged at about 43% and this is on brand new DW400 pump and 55lb injectors. So, going to be a bit more delayed on this lol. But I found out I'm putting down about 580hp on a mustang dyno which is way less than the 690 STD I got on a DynoJet lol. I'm curious how much gain Lund will net me from their base tune once they can actually tune it.

 

[2019GT]

Hopefully they'll smooth that out as revisions come. I would certainly communicate your concerns with them.

Made 675 STD on a mustang dyno! (With octane booster). Without octane booster made about 615.

My original dyno tune which I wasn't happy with I had made almost 690 STD on DynoJet.

Haven't read played around driving wise yet but that's a huge diff!

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