Need to relocate my IAT sensor
10-08-2010, 05:55 PM
#1
Safety Car
Thread Starter
Need to relocate my IAT sensor
I have a Honker CAI and this moves the MAF sensor up close to the throttle body. On the 01-04 models, the MAF sensor has the IAT sensor built in with it. Can I buy an '00 IAT sensor and tie into the wiring harness at the MAF? If so what is the part number?
The reason I want to move it is because of heatsoak I'm getting coming off the TB. Surely others have done this mod before.
The reason I want to move it is because of heatsoak I'm getting coming off the TB. Surely others have done this mod before.
10-08-2010, 11:50 PM
#3
Team Owner
I have an '03 C5Z with a Honker and a 5 wire MAF...exactly what performance degredation issues are you experiencing??
I may be mistaken, but I believe that the older MAF's have a smaller inner diameter. Trading one issue for another...
I may be mistaken, but I believe that the older MAF's have a smaller inner diameter. Trading one issue for another...
10-08-2010, 11:54 PM
#4
Safety Car
Thread Starter
I'm not trading the maf, just using the two wires for the iat sensor.
if you get to tuning your car you will find that with the maf sensor located so close to the TB you will get heat soak.
if you get to tuning your car you will find that with the maf sensor located so close to the TB you will get heat soak.
Last edited by printmanjackson; 10-08-2010 at 11:57 PM.
10-09-2010, 01:06 AM
#5
Team Owner
My tuner (CMS) didn't say anything about this heatsoak issue. You can always go speed density and delete the MAF...but admitedly, I don't know enough about that process to condone it.
Try Caspers Electronics for harneses/adapters...if they don't have it, no one will.
Try Caspers Electronics for harneses/adapters...if they don't have it, no one will.
10-09-2010, 07:05 AM
#7
Former Vendor
Member Since: Apr 2006
Location: Portland OR
Posts: 2,470
Likes: 0
Received 1 Like
on
1 Post
St. Jude Donor '10-'11-'12
Caspers 
Radiant heat from the tb ? the sensor must be really close. The IAT for an fbody should work fine. I've swapped them back and forth before.
Radiant heat from the tb ? the sensor must be really close. The IAT for an fbody should work fine. I've swapped them back and forth before.
10-09-2010, 08:59 AM
#8
Tech Contributor
10-09-2010, 12:52 PM
#9
Melting Slicks
Member Since: Dec 2003
Location: Near Jacksonville Fl.
Posts: 3,314
Likes: 0
Received 12 Likes
on
11 Posts
97-98 used an IAT that was mounted in the air bridge, you can use that one, you will just have to transfer the wires from your MAF over.
If I recall they are blk and tan ones on the end.
I replaced mine with a Sorensen P/N WT382P I don't think there's any difference to speek of except for mounting.
If I recall they are blk and tan ones on the end.
I replaced mine with a Sorensen P/N WT382P I don't think there's any difference to speek of except for mounting.
10-09-2010, 03:26 PM
#10
Safety Car
Thread Starter
Have you datalogged your IAT? Well if you're gonna do it, this harness makes it literally a snap.
http://www.casperselectronics.com/st...oducts_id=1108
http://www.casperselectronics.com/st...oducts_id=1108
Like I said, the Honker moves the MAF right in front of the TB and even if you are in SD, the IAT sensor still gets heat soak.
After doing some research this is a prertty easy mod.
10-09-2010, 03:27 PM
#11
Le Mans Master
Member Since: Aug 2005
Location: CA.
Posts: 5,255
Likes: 0
Received 281 Likes
on
258 Posts
St. Jude Donor '13-'14-'15
Why go thru all the trouble of re-locating the IAT sensor---Just leave it where it is---and have your tuner "tune out" all the timing deducts appropriately--- I typically will set the all the deducts up to 122*at "0"
so no timing deduction and then from 133* to about 167* remove about 60-70% of whats shown--this will leave you with around -1.5 * at 133 and up to around -2.5* at 167--- beyond 1678 i leave t be---
ALSO while in there--remove the ECT timing deducts up to 208*
PS---heat soak is a problem especially when driving around town--even on a cold day the IAT temp will read 150* and the ECM can take out 5* of timing----Most engs only have around 20* of final timing anyway so thats a 1/4 of the total---Until you drive it fast for 5 mins or so it will continue to remove gobs of timing until the IAT cools down--(if ever )
so no timing deduction and then from 133* to about 167* remove about 60-70% of whats shown--this will leave you with around -1.5 * at 133 and up to around -2.5* at 167--- beyond 1678 i leave t be---
ALSO while in there--remove the ECT timing deducts up to 208*
PS---heat soak is a problem especially when driving around town--even on a cold day the IAT temp will read 150* and the ECM can take out 5* of timing----Most engs only have around 20* of final timing anyway so thats a 1/4 of the total---Until you drive it fast for 5 mins or so it will continue to remove gobs of timing until the IAT cools down--(if ever )
Last edited by tblu92; 10-09-2010 at 03:45 PM.
10-09-2010, 08:18 PM
#12
Drifting
Funny I just saw your post and I've on many occasions had a similar thought as you.
I have a Callaway CAI also on my 03.
Regarding heat soak, it has nothing to do with the MAF being located closer to the TB due to Callaway's design. That's a good thing IMO. But now since the MAF with the built in IAT sensor is now located just above the engine side of the radiator opening the heat from the rad. simply rises up and warms up the MAF which is directly above.
At a stand still with fans off I've got to believe the built in IAT would heat soak quicker at this location vs the stock location with the large plastic rad. shroud sheilding the IAT from the rad. heat.
But on the flip side, with the hood closed, the underhood temps are probably equally hot all over the engine compartment. So which location is better regarding the heat soak of the MAF (IAT) ???
But when moving, and since the Callaway is a CAI (cold air intake), I would think that IAT sensor would cool off way quicker then the stock location of the IAT sensor with all that ambient air temp flowing through it. It would be interesting if someone did an actual comparison test on this subject.
So for me I still prefer my Callaway setup.
From a tuning standpoint high engine coolant temps have the large affect on ignition timing being reduced especially with the stock timing tables. High inlet air temps (IAT's) have a large impact on the car's fueling as well.
Yes a little tune tweeking is necessary.
So these are my thoughts on your subject...hope this helps a bit???
I have a Callaway CAI also on my 03.
Regarding heat soak, it has nothing to do with the MAF being located closer to the TB due to Callaway's design. That's a good thing IMO. But now since the MAF with the built in IAT sensor is now located just above the engine side of the radiator opening the heat from the rad. simply rises up and warms up the MAF which is directly above.
At a stand still with fans off I've got to believe the built in IAT would heat soak quicker at this location vs the stock location with the large plastic rad. shroud sheilding the IAT from the rad. heat.
But on the flip side, with the hood closed, the underhood temps are probably equally hot all over the engine compartment. So which location is better regarding the heat soak of the MAF (IAT) ???
But when moving, and since the Callaway is a CAI (cold air intake), I would think that IAT sensor would cool off way quicker then the stock location of the IAT sensor with all that ambient air temp flowing through it. It would be interesting if someone did an actual comparison test on this subject.
So for me I still prefer my Callaway setup.
From a tuning standpoint high engine coolant temps have the large affect on ignition timing being reduced especially with the stock timing tables. High inlet air temps (IAT's) have a large impact on the car's fueling as well.
Yes a little tune tweeking is necessary.
So these are my thoughts on your subject...hope this helps a bit???
Last edited by bcseitz; 10-09-2010 at 08:25 PM.
10-09-2010, 08:35 PM
#13
Drifting
Oh, and yes some tuners have had great results with locating the or a remote aftermarket IAT sensor out into the front facia of the car which is not affected by the engine compartment heat.
Also I've seen some aftermarket sensors located right into a FAST intake right behind the TB to cure the heat soak issue as well.
No arguement here, It's been proven that the IAT sensor would be better served in a cooler location! Do a search on the subject on HPTuners forum.
Sorry I can't help you with the electrical connection changes though. I'm curious as well.
Also I've seen some aftermarket sensors located right into a FAST intake right behind the TB to cure the heat soak issue as well.
No arguement here, It's been proven that the IAT sensor would be better served in a cooler location! Do a search on the subject on HPTuners forum.
Sorry I can't help you with the electrical connection changes though. I'm curious as well.
10-09-2010, 08:39 PM
#14
Safety Car
Thread Starter
I have been tracking the incoming temps and they do drop some but not as much as you would think on a warm day. I did a test Friday afternoon and it was in the high 80's. My car stays around 185* and the IAT was running in the mid 90's. I turned the car off and watched the IAT rise to 125* in about 10 minutes time. I started the car and started driving. The temp came down to 100* but that was it. The result of this test was the IAT came up about +5* and never went down and this will affect the tune on hotter days. It's not that the incoming air temp changed because it didn't. It's the sensor that didn't read it right because of the heat soak.
I have seen this several times and it depends on the outside temp as to how far it will drop. Sure I could go in and change the tables in the tune or just move the sensor. If you have a Honker CAI, this places the MAF up close to the TB and that's where the heat is coming from. Just go put your hand on the TB and you will see.
I have seen this several times and it depends on the outside temp as to how far it will drop. Sure I could go in and change the tables in the tune or just move the sensor. If you have a Honker CAI, this places the MAF up close to the TB and that's where the heat is coming from. Just go put your hand on the TB and you will see.
10-11-2010, 08:26 PM
#15
Melting Slicks
LPE sold a kit to do that.
Last edited by Greg_E; 10-11-2010 at 08:31 PM.
10-13-2010, 11:43 PM
#17
Team Owner
10-14-2010, 11:52 AM
#20
I've debated this point before. It's obvious that the heat from the radiator/fan assembly will heat soak the MAF housing when placed just before the TB (right above where the fans pull in hot air). When I switched to a 5 wire 85mm MAF (to clarify 97-00 used the 75mm MAF and separate IAT) I saw a very noticeable drop in IAT. This was in the stock location just behind the filter.
Some will question which is more accurate. My thoughts are that the aluminum and plastic of the MAF housing will absorb the heat and create a false, higher, reading (the heat from the housing heats the sensor element). The air which is moving quite fast will not be in the intake long enough to absorb the ambient heat to a significant degree. Making the temp reading earlier in the intake tract more accurate to what the engine is actually seeing.
Some will question which is more accurate. My thoughts are that the aluminum and plastic of the MAF housing will absorb the heat and create a false, higher, reading (the heat from the housing heats the sensor element). The air which is moving quite fast will not be in the intake long enough to absorb the ambient heat to a significant degree. Making the temp reading earlier in the intake tract more accurate to what the engine is actually seeing.