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LTX and LSXPutting LT1s, LS1s, and their variants into Third Gens is becoming more popular. This board is for those who are doing and have done the swaps so they can discuss all of their technical aspects including repairs, swap info, and performance upgrades.
Hello All,
I'm curious to know what other LS swap third gens (or just cars with "cold air intakes") are getting for intake air temperatures. My setup uses a 4" intake tube pulling from behind the headlight and my IAT's can get up to 150 degrees F when the fans kick on and start throwing hot air into the engine compartment. I'm also in Houston in the summertime, so I would consider this worst case scenario. I also think that my IAT/MAF sensor might benefit from relocating it further toward the filter to get it out of the radiator air as well. Anyone have experience here?
There are a couple threads on here for cutting a hole into the drivers side battery box and grabbing the air in front of the tire. I think that is my easiest solution unless anyone has any better ideas? https://www.thirdgen.org/forums/ltx-...-k-member.html
You can try to build a box around the filter like Detroit Speed does. That will shield it from some of the engine bay heat soak. Putting the filter through either the battery box or EVAP floor would be the best. That is what I am doing although I do not have IAT data yet. Look at LSXMatt's thread on his cooling issues. He recently made some changes to his set-up that lowered temps by 40 degrees.
Putting the filter through either the battery box or EVAP floor would be the best.
That's what I did on my 2nd gen and it lowered the IAT to a maximum of 15 deg over ambient temperature when stuck in traffic. Whenever the car is moving its right at ambient temp. That's hard data using Tunerpro and looking at the ambient temperature readout on my rear view mirror.
I played around with a lot of different configurations trying to lower the IAT, and my conclusion was that unless you get the intake end of the tube completely out of the engine compartment, youre not going to significantly lower the IAT.
[QUOTE=aggie3rdgen;6383504
There are a couple threads on here for cutting a hole into the drivers side battery box and grabbing the air in front of the tire. [/Quote]
Never really understood the thinking behind putting a filter on the end of intake pipe and sourcing air from the engine bay. Other than convenience I suppose.
This thread is finally shedding some light on the advantages of sourcing true cold air.
Thanks for posting everyone.
Thanks for all the replies. I've noticed on the newer camaro's, they grab air from the engine compartment, but a heat shield is separating the intake filter from the rest of the compartment and seals on the hood. I think this really points to the hot radiator air being a major culprit. Reading more into LSX Matt's thread on high engine temps, he moved the intake hose off the upper radiator hose, lowering his IAT's. I modified my upper radiator hose to drop it down below the intake tube and that seemed to help some, but getting the dual pass radiator and relocating the upper radiator hose to the other side will be the best solution. I'm trying not to spend $1000+ on this just yet.
I'm going to try to punch through the EVAP floor like some others have done and see if that helps. I have a strong suspicion it will. My only hesitation is driving in the rain or dare I say going through a puddle of water. Any experience with doing this mod and sucking water into the motor?
My tuner also suggested to move the MAF/IAT sensor away from the hot air so going to try that as well.
My upper radiator hose modifications. The 4" intake tube gets close to touching only where the hose connects to the radiator, maybe 1/2" - 1" of gap between the two. intake is off to show the hose modifications.
Any idea how the air for this enclosure is sourced? It might provide some insight as to how to protect the filter from water or other contaminants.
It comes from the fender. The box around seals it off from the hood and it gets the air from inside the fender. Most newer GM's do it this way, even trucks.
Here is what I did. The box draws air from the outside of the fender and the inside of the box has a ceramic liner. Done this way it is shielded from road spray. I don’t have IAT data, but the intake tube is cold to the touch when the car is idling. One thing to note, I’m in the PNW on the coast, so it doesn’t get hot here like Houston.
I like this idea a lot. I was going to put the filter down through a spectra CAI bulkhead, but I never thought about putting a box around it. I can then cut a hole in the floor for the air to be drawn up into the box.
I've thought about a box but not sure there is adequate air flow for higher horsepower engines. I know firebrdo88 has run open and closed and his best 1/4 mile times are open (car runs high 9's on nitrous). I have an open element in the engine bay and the only time it gets hot is idle and driving slow, both conditions where it doesn't matter. Air temp goes down right away with any speed. One of these days I will experiment a bit with boxing out the radiator fan wash.
I've thought about a box but not sure there is adequate air flow for higher horsepower engines. I know firebrdo88 has run open and closed and his best 1/4 mile times are open.
Do you think this is a function of the box being restrictive and is it the filter element itself?
Reason I'm asking is that I'd always considered the twin panel filters in the TPI Camaro to be inadequate for any high horsepower application. Then along comes Chad Speier (Speier Racing Heads) with his modified filter lid and OEM sized filters. He says zero restriction and has data to prove it. His engine is no slouch either (although it certainly isn't a 9 second car).
Not sure what to make of it all.
Do you think this is a function of the box being restrictive and is it the filter element itself?
Pretty sure Firebrdo88 has a large filter like me that is not a choke point. I would suppose it's just ability to access needed air volume from fender....? Engine bay has limitless air to pull from of course. Maybe he's teetering on the balance point between air supply vs. air temp. I don't know if he ever knocked out the battery tray.
Soloc4,
Thanks for sharing, I like the box and the car! Are you not running a MAF?
I’ve went ahead and ordered some tubing from intakhoses.com, I should have some data next weekend to share.
I saw the ram air rework thread and like that setup also. Maybe I’ll transition to something like that eventually. I’ll need to source the stock air box as I don’t have mine anymore.
I've thought about a box but not sure there is adequate air flow for higher horsepower engines. I know firebrdo88 has run open and closed and his best 1/4 mile times are open (car runs high 9's on nitrous). I have an open element in the engine bay and the only time it gets hot is idle and driving slow, both conditions where it doesn't matter. Air temp goes down right away with any speed. One of these days I will experiment a bit with boxing out the radiator fan wash.
I have had the same concerns about air volume, but the most restrictive part of the system is the filter which is the same size as most people run, and my car is not a 9 sec. car either. The car doesn’t seem to be struggling to breathe, lack of traction is more of a problem for now.
Soloc4,
Thanks for sharing, I like the box and the car! Are you not running a MAF?
I’ve went ahead and ordered some tubing from intakhoses.com, I should have some data next weekend to share.
I saw the ram air rework thread and like that setup also. Maybe I’ll transition to something like that eventually. I’ll need to source the stock air box as I don’t have mine anymore.
Yes I have an blade style MAF on the engine side of the inlet , probably not the best location, but it seems to work.
Hey Guys,
So an update to this thread. I was able to cut a hole in the EVAP tray and relocate the air filter outside the engine bay. Using HP tuners and logging IAT's, I was able to achieve a +10 degree delta vs the +40 degree delta (IAT vs ambient temp) I was seeing before.
Hole in the EVAP tray. Used two 4" flanges, back to back with seals between the flange and the metal tray. 4" intake tube fitted up to the 4" flange. As a bonus, I'm now able to fit my washer reservoir with the filter out of the way (not pictured). Air filter clamped to the bottom 4" flange. Hangs a little low, but you can't see it when the car is on the ground. Some concerns with the front tire throwing water and road dirt/debris on the filter. I think I'm going to try and fabricate a plastic or sheet metal divider to protect it a little more.
Hey Guys,
So an update to this thread. I was able to cut a hole in the EVAP tray and relocate the air filter outside the engine bay. Using HP tuners and logging IAT's, I was able to achieve a +10 degree delta vs the +40 degree delta (IAT vs ambient temp) I was seeing before.
Hole in the EVAP tray. Used two 4" flanges, back to back with seals between the flange and the metal tray. 4" intake tube fitted up to the 4" flange. As a bonus, I'm now able to fit my washer reservoir with the filter out of the way (not pictured). Air filter clamped to the bottom 4" flange. Hangs a little low, but you can't see it when the car is on the ground. Some concerns with the front tire throwing water and road dirt/debris on the filter. I think I'm going to try and fabricate a plastic or sheet metal divider to protect it a little more.
Cool, exactly like my set up except I went to the battery area on the passnger side and relocated the battery to the trunk (a double benefit).
It's bad news to put the air filter by the tire. I once had a supercharged C4 Corvette with the filter in front of the tire. Got dirty as hell and took water spray. I'll never do it again.
What might work better is leaving the filter on top of the tray but boxing it in so that it can grab air from the fender and opening you made. Might even want to put a fine mesh screen over the hole to help capture water droplets.
I agree about being by the tire would pick up a bunch of debri..I’m planning on doin something similar and maybe building a box.. does anyone make a cold air box for our cars ? I’m going to try cutting the whole first to see if this helps lower iat’s if not I’m going underneath
Last edited by 91z28 98ta; 07-18-2020 at 12:55 PM.
Hey Guys,
So an update to this thread. I was able to cut a hole in the EVAP tray and relocate the air filter outside the engine bay. Using HP tuners and logging IAT's, I was able to achieve a +10 degree delta vs the +40 degree delta (IAT vs ambient temp) I was seeing before.
Hole in the EVAP tray. Used two 4" flanges, back to back with seals between the flange and the metal tray. 4" intake tube fitted up to the 4" flange. As a bonus, I'm now able to fit my washer reservoir with the filter out of the way (not pictured). Air filter clamped to the bottom 4" flange. Hangs a little low, but you can't see it when the car is on the ground. Some concerns with the front tire throwing water and road dirt/debris on the filter. I think I'm going to try and fabricate a plastic or sheet metal divider to protect it a little more.
Spectra makes the flanges and this is exactly how I am going to run mine. I will shield it from the tire though. If I cant, the filter will be in the engine bay with a box around it and get the air through the same hole.
As for water & debris, I'll make the divider between the wheel and the filter and keep a close eye on the filter condition. It does concern me, but I'm glad to hear others are running it with no issues. Long term plan will be to switch to the ram air setup or build a box.
Beutiful air set up. Thinking about tunnelling the filter over and underneath just like that. Had something similar in my 1995 Trans Am. Loved it. Filter did get dirtier faster then normal but I drove that car to the ground.
Questuion @aggie3rdgen = I see you kept the magic orb? AKA your vacuum ball? Was that necessary for the HVAC as clearly you dont need for Cruise Control right? I'm about 95% done with my LS Swap and getting the final little vacuum lines hook up so I can get the HVAC going again. BUT dont have that ball any more and wondering if its needed??
The HVAC air blend doors are operated by vacuum from the engine intake manifold. Problem is the engine doesn't make enough vacuum under heavy throttle, causing the blend doors to move to defrost position. Everything will go back to normal as soon as there is enough vacuum again.
The vacuum ball and check valve regulates vacuum when the engine is under heavy throttle. You need the check valve or the vacuum ball will be rendered useless.
Questuion @aggie3rdgen = I see you kept the magic orb? AKA your vacuum ball? Was that necessary for the HVAC as clearly you dont need for Cruise Control right? I'm about 95% done with my LS Swap and getting the final little vacuum lines hook up so I can get the HVAC going again. BUT dont have that ball any more and wondering if its needed??
I am not using the vacuum ball in my car. I really only have a problem with the HVAC during extended WOT where the vents will revert back to the defroster. As soon as I am off the throttle it goes back to how it is set. For regular driving/cruising it works fine without the reservoir.
Beutiful air set up. Thinking about tunnelling the filter over and underneath just like that. Had something similar in my 1995 Trans Am. Loved it. Filter did get dirtier faster then normal but I drove that car to the ground.
Questuion @aggie3rdgen = I see you kept the magic orb? AKA your vacuum ball? Was that necessary for the HVAC as clearly you dont need for Cruise Control right? I'm about 95% done with my LS Swap and getting the final little vacuum lines hook up so I can get the HVAC going again. BUT dont have that ball any more and wondering if its needed??
It was my understanding (as Qwk has stated also) that the vacuum ball helps with the door actuators, so I left it. I had to relocate it toward the front of the EVAP tray to make room for the filter. There are two holes up there that work well for this on my car.
07-10-2020, 09:40 AM
