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Discussion Starter #1
What are you guys seeing on an 1/8th mile pass? I ask because I installed a Holley Sniper EFI system this winter so for the first time ever I have a reading of Manifold Air Temp. Problem is I am not sure how well that sensor works.

I run about 10 PSI and use water/meth injection. My data logs show a 5 degree or less change in MAT for the run. I'd sure be happy if that were accurate but I can't believe my IAT does not increase more than that.

Honk if parts fall off shared a log with me and his was similar. Very little change so I suspect the Sniper MAT is just very slow to respond?
 

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Change the sensor if you can’t trust it.
The tune and motor survived, so all is good.
Read the spark plug for specific tune advice.
 

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My experience with the GM type AIT sensors was that they were just too dang slow. Temps would read maybe 75 degrees hotter, but the pistons were destroyed. 25lb's boost with E-85 and water meth, 400 sbc. When I added the air/water intercooler, my tune was the same, but the pistons/heads now survive. So much for E85 not needing an intercooler! I'm reluctant to trust AIT sensors.
 

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Discussion Starter #6
I guess I just thought it would move more than it does. For example, on a pass last night the air temp was mid 80's. engine temp about 170*. I data logged 90 seconds which is from the time I cranked it in the staging lanes, did a burnout, made a pass then turned off on the return road. For the entire 90 seconds the MAT only varied from 116 to 128*. During the run itself it went from 121 to 127. You can't even see/tell where the water/meth comes on.

I just see guys talking about high 100s to low 200s intake air temps but I guess it is due to them running a lot more boost?

I am running a Holley Super Sniper and the MAT is built into the throttle body somewhere so not sure where it is picking up the temp.
 

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Heres a log from a 34psi pass with the Holley MAT sensor .

Its right around 70 when it leaves and 120 at the stripe . So 50 degree temp rise in apox 8.7 secs

This is with ice , turning the pump on after the burnout .

I didnt think it was that slow to respond , slow but not THAT slow. I mean you can see the temps start to go down right after I lift .

Sensor is in the hat above an Accufab 4150 TB

[/url]boostmap by David Cedoz, on Flickr[/IMG]
 

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Which MAT sensor are you using? GM has two types (that I have used). One is a sealed unit which is also used for water temp. The other is an open-end, you can see the thermistor hanging there in the breeze. I doubt that one would be good for boost though, besides, the body of it is designed to push into a rubber grommet, it does not thread in.

The open-ended one is FAST! I use them on my NA cars, drop at least 22* on a pass (1/4 mile).

The closed-ended one is SLOW! I forget how slow, but it was kinda useless, that is why I am using the other one.

I honestly do not know of any thermistors that can be put in a pressurized tract and stay-put. There could be some out there, since I never needed one I have not looked.
 

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My IAT sensor is in my lower intake (think fox body mustang); so my numbers will be a little higher than if it was in the discharge tube. This is a 1/4 mile pass (9.88 @ 140) running on Q16. I'll try to post an image, but you might have to click on the link to see it:



http://www.pikasfilm.com/copleymovie.com/Magic/SmallPics/365Pics/10.15.16/Run2_9880.jpg

I have an A/W IC and run ice in it. This is at 14 psi boost.

The green line on the bottom graph is IAT.

The dolts now running YB are blocking private servers for pics. And so, we all lose...
 

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Discussion Starter #12
I definitely don't have that sensor. The Sniper has everything self contained in the throttle body. I actually have no idea how they pack the ECU, 8 fuel injectors, MAP and MAT sensors in there. You really can't see any of them.
 

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Discussion Starter #17
I have a 14 GPH nozzle pre-blower then 2 x 3 GPH nozzles in the hat. Spraying 65% water/35% meth.
 

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Question: What would be considered an efficient A2A intercooler temp rise? Just installed a 6" Bell core on my car and on a 10psi street pull the temps went 5 degrees above ambient temp. i am going to go to the track tonight and test it with double that amount of boost, but what is considered an efficient A2A intercooler?
 

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A2A on a dragstrip is basically a heatsink. It never has an opportunity to reach equilibrium. That's why A/W works so well on a dragstrip. Easy to get below ambient with ice; at least the core itself. The amount of heat we're dealing with is insane - just contemplate melting 10-15 lbs of ice in 10 seconds.
 

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I find that IAT over 160* and the power falls off.Threw more boost at it with no gain other than 200*.
2nd gen hemi with a stage 3 bds with 6lbs of boost. I am going to a small plate system and shoot 5o HP on each,that should lower the iat by at least 100*
 
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