Request: air intake temp AIT data
Thread Starter
Elite Member
iTrader: (5)
Joined: Jan 2005
Posts: 7,486
Total Cats: 372
From: Atlanta
Anybody care to post up some data/charts of the intake air temps for comparisons? Here's my latest from last week. Started at just above ambient ~32c in second gear, rising to ~58c in fifth gear at 6000rpm.
This may not be exactly what you want but it is all I can do right now (I'm at work). This is on a SC'd system. The air temp is the blue line going from 30 to 50 degrees C.
Here are 2:
The first is my final pull on the dyno, 4th gear pull
IAT is 74F at the beginning of the pull. However I poured some cold water on the intake mani and intercooler before the pull. It was mid 80s in the shop. The hottest spike at the end is 110F.

This second one is taken from a street run and is 1,2,3
Looks like I started at 2100 rpm and 96F. IAT was 106F getting into 2nd, 112F getting into 3rd, and 140F at the end of 3rd. Can you say heat soak?
The first is my final pull on the dyno, 4th gear pull
IAT is 74F at the beginning of the pull. However I poured some cold water on the intake mani and intercooler before the pull. It was mid 80s in the shop. The hottest spike at the end is 110F.

This second one is taken from a street run and is 1,2,3
Looks like I started at 2100 rpm and 96F. IAT was 106F getting into 2nd, 112F getting into 3rd, and 140F at the end of 3rd. Can you say heat soak?
Thread Starter
Elite Member
iTrader: (5)
Joined: Jan 2005
Posts: 7,486
Total Cats: 372
From: Atlanta
Just the rise is evident enough to suspect my IC is struggling to manage the demand. I just checked Stripes log (below) posted a while back and he's getting ~4c rise in temp on a full throttle boost pull from 4-7k.
Ben- your street run isn't to dissimilar to my street log. Does the MS compensate (retard IGN) for AIT increase?
Ben- your street run isn't to dissimilar to my street log. Does the MS compensate (retard IGN) for AIT increase?
Highest I've ever logged it.
61*F to 91*F full 3rd & 4th pull....went back to 61* as i cruised.

typically if I goes throughout the gears it's just a 20* delta. I also go about 5-10*F lower cruising around than at idle.
61*F to 91*F full 3rd & 4th pull....went back to 61* as i cruised.

typically if I goes throughout the gears it's just a 20* delta. I also go about 5-10*F lower cruising around than at idle.
Last edited by Braineack; Jun 17, 2007 at 11:28 PM.
That must have been a pretty cool day/night you data logged that. The highest you have ever seen is 91F? What was the outside temp?
I typically run 50F above ambient with city driving with my RX7 intercooler, and about 20F above amb. on the highway after the intercooler has heatsoaked. Heatsoaking the RX7 intercooler only takes a few 5 second pulls. Sorry no logs as I only have an IAT guage.
Ben- your street run isn't to dissimilar to my street log. Does the MS compensate (retard IGN) for AIT increase?
When closed loop boost control is active, it can reduce max boost with IAT, and also pull boost with knock.
yeah yeah, I always datalog in the mornings or after dinner. Hasn't been horribly hot out lately. I was just looking through old logs with a good boosted pull to see the MAT. Couldn't find a good 1-2-3-4-5 pull.
one thing I have noticed is, say I start the car in the morning and log, my intake temps drop as I drive. Just looked at a log, I started the car and recorded. First MAT reading was 85*, as soon as I started driving it gradually dropped to 75*. Everytime I stop at a stoplight, they rise back to 85* and then again drop to 75* as i cruise.
Thread Starter
Elite Member
iTrader: (5)
Joined: Jan 2005
Posts: 7,486
Total Cats: 372
From: Atlanta
* IC is too small - (17x6x3 core)
* Must be the Link's AIT compensation (coolant rise was <4c thru that entire 2-5 run, so it wasn't coolant comp)
* AIT compensation is too great (again FM default for crappy westside petro)
Ben - I think you could benefit from a bigger IC given your logged run thru the gears.
Scott - 6k in fifth gear = you must live near a race track :gay:
thanks for the input guys- I think I've got some direction now
* Must be the Link's AIT compensation (coolant rise was <4c thru that entire 2-5 run, so it wasn't coolant comp)
* AIT compensation is too great (again FM default for crappy westside petro)
Ben - I think you could benefit from a bigger IC given your logged run thru the gears.
Scott - 6k in fifth gear = you must live near a race track :gay:
thanks for the input guys- I think I've got some direction now
Mine is 8 x 8.75 x 3 core. 
Probably about the same size as your oil cooler. :-)

Probably about the same size as your oil cooler. :-)
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
Scott's crazy, it's supposed to be 90 today. oh wait, he can't datalog with no motor.
I may try to datalog mine soon for you. I moved the filter from the turbo inlet behind the headlight. I'm curious if it'll help my hot air problem.
I may try to datalog mine soon for you. I moved the filter from the turbo inlet behind the headlight. I'm curious if it'll help my hot air problem.
well, I had to make sure the damn EBC was working as intended....it was only a 40mph zone, not too bad.
oh and fwiw, my core is 11x12x3. I've highly considered bumping up to 18x12x3, wouldn't take any work for me to adapt it and sub $150 shipped.
oh and fwiw, my core is 11x12x3. I've highly considered bumping up to 18x12x3, wouldn't take any work for me to adapt it and sub $150 shipped.
Thread Starter
Elite Member
iTrader: (5)
Joined: Jan 2005
Posts: 7,486
Total Cats: 372
From: Atlanta
my core area is 75% the size of scott's
at $150 for the big IC and your boost level, I'd do it.
Y8s- I'd be curious to see the filter position difference and what kind of compensation the hydra is doing. I wonder if Jeremy adjust your map for the better fuel.
at $150 for the big IC and your boost level, I'd do it. Y8s- I'd be curious to see the filter position difference and what kind of compensation the hydra is doing. I wonder if Jeremy adjust your map for the better fuel.
Everything Corky is saying is that 18-20" long and you've reached the max the IC can really cool....but having the extra amount of runners surely wouldn't hurt Rob. I betcha the 18x12x3 core would....well techincally, be twice the cooler.
Corky still reccomends 6-7 sq. in. of internal flow. for every 100HP.
legnth of runner x height of runner x # of runners / width of runner
my 11x12x3" bar&plate: 11 x .25 x 16 = 44 / 3 = 14.66 / 6 * 100 = 244HP * .83 = 203rwhp
your 17x6x3" bar&plate: 17 x .25 x 8(?) = 34 / 3 = 11.33 / 6 * 100 = 188HP * .83 = 156rwhp
18x12x3" bar&plate: 18 x .25 x 16 = 72 / 3 = 24 / 6 * 100 = 400HP * .83 = 332rwhp
Corky still reccomends 6-7 sq. in. of internal flow. for every 100HP.
legnth of runner x height of runner x # of runners / width of runner
my 11x12x3" bar&plate: 11 x .25 x 16 = 44 / 3 = 14.66 / 6 * 100 = 244HP * .83 = 203rwhp
your 17x6x3" bar&plate: 17 x .25 x 8(?) = 34 / 3 = 11.33 / 6 * 100 = 188HP * .83 = 156rwhp
18x12x3" bar&plate: 18 x .25 x 16 = 72 / 3 = 24 / 6 * 100 = 400HP * .83 = 332rwhp
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
lets see...
air temp trim: 0% at 30C, removing .2% fuel per 10C increase.
coolant temp trim: zeroed above 80C for now.
air temp spark trim: 0° at 30C, -9deg at 130C
coolant spark trim: 0° from 60-90C, then -1° for each 10C (130C = -4°)
(I assume -X° means less advance)
I haven't driven the car with the new filter location yet. It looks pretty bling though. It's a 90 degree 4" stainless pipe. slightly polished. :gay:
Corky still reccomends 6-7 sq. in. of internal flow. for every 100HP.
legnth of runner x height of runner x # of runners / width of runner
my 11x12x3" bar&plate: 11 x .25 x 16 = 44 / 3 = 14.66 / 6 * 100 = 244HP * .83 = 203rwhp
your 17x6x3" bar&plate: 17 x .25 x 8(?) = 34 / 3 = 11.33 / 6 * 100 = 188HP * .83 = 156rwhp
18x12x3" bar&plate: 18 x .25 x 16 = 72 / 3 = 24 / 6 * 100 = 400HP * .83 = 332rwhp
legnth of runner x height of runner x # of runners / width of runner
my 11x12x3" bar&plate: 11 x .25 x 16 = 44 / 3 = 14.66 / 6 * 100 = 244HP * .83 = 203rwhp
your 17x6x3" bar&plate: 17 x .25 x 8(?) = 34 / 3 = 11.33 / 6 * 100 = 188HP * .83 = 156rwhp
18x12x3" bar&plate: 18 x .25 x 16 = 72 / 3 = 24 / 6 * 100 = 400HP * .83 = 332rwhp
height of runner * width of runner * # of runners









tho you probably don't want any more power :gay:
