Drivetrain Project "Low IAT"-Intake Manifold Cooling
K-huevo and big howe, I completely agree with you as far as testing. As mentioned before: I don't even know if it works! I started this project with the idea of cooling the intake manifold without messing up the flow under the IC: shield. With that came the tilt as I needed space under the IC and I figured flattening the "S" the air has to make ,wouldn't hurt ether. Then I saw Bart's scoop on his car and thought it could be tweaked a bit, thanks to composites, one thing kept leading to another and I kept "sculpting" the thing.The reasoning veered more toward minimizing heat soak, therefore completely separating the IC circuit from the engine bay.I could extend the duct over the engine and dump the air over the exhaust,while it would work on a moving car, at idle, the flow would reverse itself ( hot air rises). Venting through the hood became "De facto". I'm aware of the aero problems in this area of the hood, clever louvers design+ vortex generators (kill the boundary layer!
) maybe some fences, could turn this area into a air pump at speed and just a natural (hot air rises) thermal vent at idle. If nothing els it will be a trick windshield de-icer in the winter.
) maybe some fences, could turn this area into a air pump at speed and just a natural (hot air rises) thermal vent at idle. If nothing els it will be a trick windshield de-icer in the winter.
K-huevo and big howe, I completely agree with you as far as testing. As mentioned before: I don't even know if it works! I started this project with the idea of cooling the intake manifold without messing up the flow under the IC: shield. With that came the tilt as I needed space under the IC and I figured flattening the "S" the air has to make ,wouldn't hurt ether. Then I saw Bart's scoop on his car and thought it could be tweaked a bit, thanks to composites, one thing kept leading to another and I kept "sculpting" the thing.The reasoning veered more toward minimizing heat soak, therefore completely separating the IC circuit from the engine bay.I could extend the duct over the engine and dump the air over the exhaust,while it would work on a moving car, at idle, the flow would reverse itself ( hot air rises). Venting through the hood became "De facto". I'm aware of the aero problems in this area of the hood, clever louvers design+ vortex generators (kill the boundary layer!
) maybe some fences, could turn this area into a air pump at speed and just a natural (hot air rises) thermal vent at idle. If nothing els it will be a trick windshield de-icer in the winter.
) maybe some fences, could turn this area into a air pump at speed and just a natural (hot air rises) thermal vent at idle. If nothing els it will be a trick windshield de-icer in the winter.
I'm not sure if I'm looking at it differently from everyone else. To me, the stock IC is ideal for steady state and light spirited driving. It lacks in capacity and flow when using the throttle hard. While everything helps and has it's merits, I've tried getting bigger chunks of temp back with things I've played with. That being said, if a good product came out that I could just purchase, I'd probably be at the front of the line, as I wouldn't have to put any time in, just bolt it on and go.
Keep it up, I'm sure everyone is happy to see someone trying new things on the car.
Longboard
Why? Talk about heat soak, temps inside the intake manifold will be higher than ambient (ice charged W/A not withstanding), not only is the IM subjected to convective heat, it draws conductive heat from the head, don’t forget the IM plenum is where boost develops with a roots SC; the IM needs air too.
Joined: Mar 2005
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From: Westerly, RI
From the first page of this thread...
...and let's not forget why DrPhil and myself started this whole thing with the IMD...
...Insulation is a double-edged sword: it keeps heat out, but it also slows heat dissipation. I'd think that once a nice source of cooling air is found then the manifold should be un-insulated to allow for maximum heat dissipation. To be honest the only place I have a lot of insulation is the air box, since there is considerable heat transfer into the box especially in traffic and stop-start driving.
Partsman's mod reminds us to think air flow, always a good idea!
Partsman's mod reminds us to think air flow, always a good idea!
Originally Posted by DrPhilGandini
"All the work we've done to cool the air intake with CAIs and fancy ICs is being undone at the manifold just before the air enters the cylinders."
Why? Talk about heat soak, temps inside the intake manifold will be higher than ambient (ice charged W/A not withstanding), not only is the IM subjected to convective heat, it draws conductive heat from the head, don’t forget the IM plenum is where boost develops with a roots SC; the IM needs air too.
I understand your concern. I left the front, sides and back open. They are not covered. The front of the IM has a heat-sink attacked to the face which get air blow directly onto it. After the air hits it it them exit to the sides away from the IM.
Joined: Mar 2005
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From: Westerly, RI
Why? Talk about heat soak, temps inside the intake manifold will be higher than ambient (ice charged W/A not withstanding), not only is the IM subjected to convective heat, it draws conductive heat from the head, don’t forget the IM plenum is where boost develops with a roots SC; the IM needs air too.
EDIT: which he just posted above.
I am not insulating (as in wrapping) the IM. No no!! I' m just trying to insulate the IC system from all sources of radiant heat and still provide a good flow of air to the IM. Sorry if it didn't come out this way.
In the overall, heat generated (or retained) by the intake manifold is small potatoes compared the ability of the intercooler to remove heat from the charge air. The act of insulating/isolating the IC from radiant heat also deprives the IM from a topside breeze, mostly a subordinate concern. I understand, just thinking out loud, carry on.
Yeah I'll try and find the spreadsheet, but I simply recorded inlets from the scan guage at various speeds, from memory 90mph saw 8C above ambient with 70mph seeing 6C, at normal curising speeds it sat at around 5C above ambient.
Having looked at many datalogs of TC's in the inlet tract, I just want to pass on an observation since many folks are looking at inlet temps. The IAT from the TMAP is notoriously bad at giving accurate data. Unless you have achieved steady state, cruising at a steady throttle load for 1 minute or longer, the reading is usually quite off. During fast transients, it can be off a lot, sometimes more than 40F( I can't remember the most I've seen, and I'm to lazy to start looking through logs).
Just some food for thought, I'm not questioning anyones data, but the TMAP is not your friend in observing differences in testing parts.
Just some food for thought, I'm not questioning anyones data, but the TMAP is not your friend in observing differences in testing parts.
My little dose of LITHIUM
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From: Albuquerque New Mexico
Dr Obnxs has long made claims regarding the inherent inaccuracies of the TMAP sensor--especially its hysteresis.
I'm willing to buy it because I can't prove otherwise, and I think it does limit its use for testing. That said, long term experience with the TMAP might still be valuable for drawing general conclusions about trends.
I'm willing to buy it because I can't prove otherwise, and I think it does limit its use for testing. That said, long term experience with the TMAP might still be valuable for drawing general conclusions about trends.
Most definitely, I'm not trying to stifle anyone's research. Just wanted to shed some light on what folks are working with. If trying to measure differences of a few degrees, I'd say by my experience, all bets are off.
If I can find time soon I'll post some data to show the discrepancies.
If I can find time soon I'll post some data to show the discrepancies.
My little dose of LITHIUM
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From: Albuquerque New Mexico
I replaced the sensor just a while ago, and it's pretty well insulated from the manifold. I think the problem is that the actual probe is just not a "fast response" unit. The stability of readings in steady state suggests that it might be reading temperatures accurately -- and remember it's used by the ECU to adjust fuel and timing parameters -- but as big howe says, it's perhaps not useful for measuring small changes in IATs.
OE IC already done....
The atached thumb has already been done using the OE IC & no mod to the OE scoop. This does give some improvment.
Carbonized design brings this mod to a higher level ++++++++
AS long as there is no positive presure under the IC - see above.
The T-MAP is, as Dr Phil says, good for a general comparison over long periods of time. However for smaller changes for tuning, R&D - the T-MAP is way to slow. The ECU needs to see EGT, which happens much faster than IAT, to make adjustments. The MAP sensors, 2, adjust to an average of what they see. Yes they do work in harmony, up & down O2, but, ultimatly, it's the upstreame O2 that needs to save your engine.
Carbonized design brings this mod to a higher level ++++++++
AS long as there is no positive presure under the IC - see above.
The T-MAP is, as Dr Phil says, good for a general comparison over long periods of time. However for smaller changes for tuning, R&D - the T-MAP is way to slow. The ECU needs to see EGT, which happens much faster than IAT, to make adjustments. The MAP sensors, 2, adjust to an average of what they see. Yes they do work in harmony, up & down O2, but, ultimatly, it's the upstreame O2 that needs to save your engine.
Joined: Mar 2005
Posts: 3,989
Likes: 1
From: Westerly, RI
Having looked at many datalogs of TC's in the inlet tract, I just want to pass on an observation since many folks are looking at inlet temps. The IAT from the TMAP is notoriously bad at giving accurate data. Unless you have achieved steady state, cruising at a steady throttle load for 1 minute or longer, the reading is usually quite off. During fast transients, it can be off a lot, sometimes more than 40F( I can't remember the most I've seen, and I'm to lazy to start looking through logs).
Just some food for thought, I'm not questioning anyones data, but the TMAP is not your friend in observing differences in testing parts.
Just some food for thought, I'm not questioning anyones data, but the TMAP is not your friend in observing differences in testing parts.
What can I use to monitor IATs in real time?
Most definitely, I'm not trying to stifle anyone's research. Just wanted to shed some light on what folks are working with. If trying to measure differences of a few degrees, I'd say by my experience, all bets are off.
If I can find time soon I'll post some data to show the discrepancies.
If I can find time soon I'll post some data to show the discrepancies.
On a side note...I appreciate everyone's contribution to this thread. Thanks.
Partsman "I remember reading a post from you in another thread(somewhere on here) about our "lazy" TMAPs.
What can I use to monitor IATs in real time? "
You need to work backwards, use the upstream O2 if you can read the EGT with your instrument. Take the delta IAT - T-MAP - delta EGT O2 then extraplate the IAT in real time. I can't give you a formula because each ( brand instrument ) measures a little differently..... Other than that I'm sure someone has installed a better sensor in the intake ( not replacing the OE T-MAP ).
What can I use to monitor IATs in real time? "
You need to work backwards, use the upstream O2 if you can read the EGT with your instrument. Take the delta IAT - T-MAP - delta EGT O2 then extraplate the IAT in real time. I can't give you a formula because each ( brand instrument ) measures a little differently..... Other than that I'm sure someone has installed a better sensor in the intake ( not replacing the OE T-MAP ).
I would like to see it as well...thanks for posting.
I remember reading a post from you in another thread(somewhere on here) about our "lazy" TMAPs.
What can I use to monitor IATs in real time?
I would be interested in seeing the data...thanks for posting.
On a side note...I appreciate everyone's contribution to this thread. Thanks.
I remember reading a post from you in another thread(somewhere on here) about our "lazy" TMAPs.
What can I use to monitor IATs in real time?
I would be interested in seeing the data...thanks for posting.
On a side note...I appreciate everyone's contribution to this thread. Thanks.
A data point for everyone to think about:
2nd gear -7100RPM - Full throttle - 86F ambient
IC inlet 325F
IC out 209F
Manifold (TC next to TMAP) 184
TMAP 143
It's no wonder the car pulls timing and looses power on 15+psi of boost and 184F inlet temps.
The TMAP's time averaging does not provide accurate data unless it has stabilized for some time. Even after a hard on-ramp run, it takes around 30 seconds for the TMAP and the TC to be within 10 degrees of each other. Given enough time, the two readings will be within 1F on my system.
Joined: Mar 2005
Posts: 3,989
Likes: 1
From: Westerly, RI
I drilled holes in the horns, before the IC, after the IC, and right next to the TMAP. Then installed 1/16" exposed TC's to the center of the air stream. The TC's go into an Innovate data logging system.
A data point for everyone to think about:
2nd gear -7100RPM - Full throttle - 86F ambient
IC inlet 325F
IC out 209F
Manifold (TC next to TMAP) 184
TMAP 143
It's no wonder the car pulls timing and looses power on 15+psi of boost and 184F inlet temps.
The TMAP's time averaging does not provide accurate data unless it has stabilized for some time. Even after a hard on-ramp run, it takes around 30 seconds for the TMAP and the TC to be within 10 degrees of each other. Given enough time, the two readings will be within 1F on my system.
A data point for everyone to think about:
2nd gear -7100RPM - Full throttle - 86F ambient
IC inlet 325F
IC out 209F
Manifold (TC next to TMAP) 184
TMAP 143
It's no wonder the car pulls timing and looses power on 15+psi of boost and 184F inlet temps.
The TMAP's time averaging does not provide accurate data unless it has stabilized for some time. Even after a hard on-ramp run, it takes around 30 seconds for the TMAP and the TC to be within 10 degrees of each other. Given enough time, the two readings will be within 1F on my system.
Conversely, I have data that shows after much hard driving, then lifting the throttle and cruising for a period of time, the air heating up as it goes around the horn. This appears to be because the IC cools faster than the outlet horn under light load.
I can also force this to happen, as the W/M system will drastically cool whatever is downstream and this can have a residual effect on the air for a short time thereafter.
This leads into a side-shoot of the heat soak, even if you have a "good" IC, whatever that may be, everything downstream of the IC can have a big effect on the air entering the motor.
Just depends on how the car has been loaded, it's one of those items that's interesting to watch. After long steady state driving, the IC and outlet horn will get close(relatively) to the air temp flowing through them. Hammer the throttle and because the horn is cool, the air can continue to lower in temperature as it goes though the horn.
Conversely, I have data that shows after much hard driving, then lifting the throttle and cruising for a period of time, the air heating up as it goes around the horn. This appears to be because the IC cools faster than the outlet horn under light load.
I can also force this to happen, as the W/M system will drastically cool whatever is downstream and this can have a residual effect on the air for a short time thereafter.
This leads into a side-shoot of the heat soak, even if you have a "good" IC, whatever that may be, everything downstream of the IC can have a big effect on the air entering the motor.
Conversely, I have data that shows after much hard driving, then lifting the throttle and cruising for a period of time, the air heating up as it goes around the horn. This appears to be because the IC cools faster than the outlet horn under light load.
I can also force this to happen, as the W/M system will drastically cool whatever is downstream and this can have a residual effect on the air for a short time thereafter.
This leads into a side-shoot of the heat soak, even if you have a "good" IC, whatever that may be, everything downstream of the IC can have a big effect on the air entering the motor.
things are not always as they "appear" with intercooler testing
My little dose of LITHIUM
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From: Albuquerque New Mexico
Honestly, all the years of my IAT obsession have been far more educational about how my car works, or doesn't work, than effective in producing more HP. As all who post on this thread can attest to, while tinkering with ICs and FADs and IMDs and TCs and insulator doohickies is a whole heck of a lot of fun, in the end a turd is still a turd!
Trust me, even though Ive only driven a couple of miles with my new "cam of many names"--(having installed it this weekend), it produces an effect far greater than all my intake mods put together. haha
Back to polishing...
Trust me, even though Ive only driven a couple of miles with my new "cam of many names"--(having installed it this weekend), it produces an effect far greater than all my intake mods put together. haha
Back to polishing...
wow that's some "get off your but " work right there thx . this would to me suggest that a system like a water cooler intake being more linear in it's heating and cooling would be more tuneable ? seems it'd be more predictable anyway .



Right on.



