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We made a shelf that clipped onto the front near mesh to hold dry ice to see if it helped on my track m3
Originally Posted by Bravo at
OP - I've removed the foam molding up by the battery and brake fluid areas sealing the hood and the engine shroud along the window. This opens up a 1 x 1.5 inch space on both sides for air to move out of the bay area sooner. I also remove the front license plate holder to allow the aerodynamics of the bumper to help move air into the engine bay a little easier. Both low cost and haven't hurt my day-to-day drives. Looking at removing the radiator shroud holding the fans and replacing w/14" or 16" mishimotos. But haven't figured out the wiring just yet.
I have coolers for P/S, oil and Trans. The area in front of the radiator is just packed with the CAI, coolers and the hoses. May have to locate the PS and trans cooler lower on the bumper.
The idea of removing the radiator shroud and just have the fans is to help get all the air in the bay as possible.
Another idea might be to exhaust the hot air coming out of the PCVs to somewhere else instead of back into the upper plenum.
I removed the hood blanket and also remove the Motordyne M370 plate above the plenum. Just ideas.
So do you guys have any results from your modifications as far as coolant or oil temps before and after your modifications?
Curious where this discussion ended up. I love the motivation to tackle and manage the high heat situation with our cars.
I added an oil cooler as a precaution initially and that seemed to help drastically compared to my 370Z for track days. I then added a Mishimoto radiator and put a gasket under the cap of the coolant overflow tank to try to get rid of it spitting cooling on the track. It sealed it up perfectly, but inadvertently pressurized the coolant runoff tank and eventually sucked enough coolant out of the engine to get really hot in a hurry. I had to dump in all the coolant I had and water and burp the radiator at the track- not fun. The next track day I just cut a hole in a sponge and duct taped it to the radiator overflow cap to catch the runoff without pressurizing the tank. That seemed to work. I still had one session where I ran hot- I was running extremely fast laps and braking hard creating extra heat. So the last step was to order an Autokits X hood with vents that I think would help a lot. But they had big delays in production and offered to cancel the order for me so I did as I think I will do smaller tracks now with, hopefully less heat.
I added an oil cooler as a precaution initially and that seemed to help drastically compared to my 370Z for track days. I then added a Mishimoto radiator and put a gasket under the cap of the coolant overflow tank to try to get rid of it spitting cooling on the track. It sealed it up perfectly, but inadvertently pressurized the coolant runoff tank and eventually sucked enough coolant out of the engine to get really hot in a hurry. I had to dump in all the coolant I had and water and burp the radiator at the track- not fun. The next track day I just cut a hole in a sponge and duct taped it to the radiator overflow cap to catch the runoff without pressurizing the tank. That seemed to work. I still had one session where I ran hot- I was running extremely fast laps and braking hard creating extra heat. So the last step was to order an Autokits X hood with vents that I think would help a lot. But they had big delays in production and offered to cancel the order for me so I did as I think I will do smaller tracks now with, hopefully less heat.
I took a different approach for looks and removed the reservoir entirely. Made my own and ran clear tubing to the canister. I ended up finding out that I too made the mistake of not venting hence why I also started leaking due to bottle being pressurized.
I will create a control air leak in the bottle for expansion and replace the rad cap as I noticed that fluid goes in and out at atmosphere temp when you squeeze the top rad hose. Possible that my FISMO cap is starting to fail.
The Z gained an OEM oil cooler in 2012 because this engine runs hot. I've heard that even that one has trouble keeping up on a track so you need a beefy one. Get some racing oil (red line), and build yourself a beefy oil cooler (see DIY section - good write ups).
You can try removing the plastic where fog lights go. If you have fog lights as an OEM option, you can even run air tubing straight from the hole for extra air or cut one if you don't have OEM fog lights. Brake cooling is usually the best use for this type of mod, but if oil cooling is a priority it would be useful to run extra air or maybe even run a secondary cooler if the cost/benefit need for oil cooling is high enough.
The Z gained an OEM oil cooler in 2012 because this engine runs hot. I've heard that even that one has trouble keeping up on a track so you need a beefy one. Get some racing oil (red line), and build yourself a beefy oil cooler (see DIY section - good write ups).
You're a bit late to the party. I mentioned in the very 1st thread about 3 years ago that I have a big oil cooler.
However, it is ironic that you posted in this thread today because today I found out the reason for my recent lack of A/C is due to a cracked weld on the condenser attached to my Mishimoto radiator. I decided late last year that I was not going to track the car any more. So when my service department told me today that I could have it replaced with the OEM radiator and condenser for free under my vehicle service contract, I decided to go that route. However, this means I will now have 2 spare Mishimoto radiators and 1 spare oem radiator. Know anyone who needs a radiator?
I removed the battery and brake covers today in an attempt to address these temps and under hood pressures. I noticed that between the upper and lower grill the front has plenty of real estate for air flow, even then people complain of under hood items "overheating" meaning way too hot to the touch. The reality is that this bay is practically sealed and radiates quite a bit. Hood scoops would be the last measure but while looking at it's design any air that comes in past the the engine has no other choice but to escape from under the car.
I found that after an hour of idling my IATS average at 160s @ 100degs
After the covers temps stayed in the high 140s @100degs
This means at Idle is is effecitve
I'll be riding without covers and monitoring these temps as I come up with ideas on how to make utilize this moving forward.
There is now a small gap from the bay connecting to the cowl and you can feel hot air coming out of there, I have not yet tested at high speeds but im confident on my theory.
An under hood tray should produce vacuum inside the bay and take care of the pressures however at idle it cannot possibly outperform wide openness.
Anyone without a tray can attest how much heat comes out the underneath of these cars.
That's an interesting idea. Where does the air escape from the engine bay- did you remove the rubber seal that mates up with the back of the hood on the fire wall as well or is there another spot?
That's an interesting idea. Where does the air escape from the engine bay- did you remove the rubber seal that mates up with the back of the hood on the fire wall as well or is there another spot?
I removed all the seals that seal the hood from the engine compartment. The hot air escapes from the gap created by removing these.
No more 100mph+ hood dance though I want to try the under tray to compare. If the tray does not work then this means modifications will need to be added to these covers and seals when I decide to install them back in the car.
Granted the modification will loose some of the efficacy once these covers are installed but I believe in my theory.
My biggest variable is the tray will it help or hinder. A possible theory is that the tray will lower the amount of air that goes inside the bay at high speeds however at idle is my worry since this the tray keeps the heat.
So far I'm pleased with the results just not on the looks, extremely happy that my hood doesn't bounce at high speeds.
My thoughts - it'll help with idle and low speed, as well prevent any heat from being retained in certain areas due to convection - but it won't help much at speed. Aerodynamics dictate that there will be a low pressure zone at the base of the windshield, meaning air will be pulled IN rather than being expelled at speed. It's the idea behind those big cowl induction hoods you see on some muscle cars. The high pressure zones in the front (especially right behind the front edge of the hood) do more to extract heat.
That being said - I pull off the battery and brake master covers whenever I'm at the track. The hot brake fluid saturates the cover area more quickly and means I could possibly have brake fluid boil quicker.
Yellow - size of inlet coming into the bay
Blue spray - lower speed air that has no other choice but to exit from down low.
Because hot air rises this makes it a tad more difficult to exit from the top as it would have to be pushed down, vacuumed out or lower its temperature so it can leave on it's own.
The end result for me might be modifications to these panels unless the under tray proves a substantial change which I doubt. It's possible that aftermarket ones might however I can't expect the oem to work that great since IT flexes just by looking at it.
My thoughts - it'll help with idle and low speed, as well prevent any heat from being retained in certain areas due to convection - but it won't help much at speed. Aerodynamics dictate that there will be a low pressure zone at the base of the windshield, meaning air will be pulled IN rather than being expelled at speed. It's the idea behind those big cowl induction hoods you see on some muscle cars. The high pressure zones in the front (especially right behind the front edge of the hood) do more to extract heat.
That being said - I pull off the battery and brake master covers whenever I'm at the track. The hot brake fluid saturates the cover area more quickly and means I could possibly have brake fluid boil quicker.
I can't disregard this as it has been proven however I have to regard that most of these setups are done for induction purposes and not the relieving of heat.
Today sitting in a traffic jam IATs got to 145s and ECTs in the 210s AC off.
Once I cleared the jam by 3rd-4th IATs were in 105s and ETCs 189s
Prior to this It would have taken higher moving speeds to bring these numbers down that quickly.
I want to research this a bit more just with this car only, being that the info online it's outdated, most of it involves spacers to "increase" this effect only to find out lifting the hood only lowers intake temps just by a bit. Also the shape of the G hood is different from others, That division in the middle kinda directs air to the corners and it's curved so certain parts might or might not see this cowling effect.
The VQ is one HOT engine and it's radiating effects can hinder it during track days. If at the end of the day this mod help you "cool down" faster it would have earned its place
So far it has proven itself to me as no money has been spent and even as a modification I dont foresee it will take more than just a couple of bucks and time.
I removed all the seals that seal the hood from the engine compartment. The hot air escapes from the gap created by removing these.
No more 100mph+ hood dance though I want to try the under tray to compare. If the tray does not work then this means modifications will need to be added to these covers and seals when I decide to install them back in the car.
Granted the modification will loose some of the efficacy once these covers are installed but I believe in my theory.
My biggest variable is the tray will it help or hinder. A possible theory is that the tray will lower the amount of air that goes inside the bay at high speeds however at idle is my worry since this the tray keeps the heat.
So far I'm pleased with the results just not on the looks, extremely happy that my hood doesn't bounce at high speeds.
I have a Zspeed under tray that is vented to supposedly pull some air out of the engine bay at speed. Maybe that will help you? I have not had the "100mph+ hood dance" you speak of so maybe the vented under tray is helping, or maybe I just have the rubber adjusters at the front of the hood adjusted a touch tighter.
07-29-2017, 11:17 AM
