Custom vented hood for more cooling ?

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Mitevo7

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Dear All,

As some of you may know, i just converted a BMW E46 with 1jz engine, due to i am getting more and more familiar with the new characteristics of the car and i have been pushing it a lot. Now i've noticed, whenever i floor it hard and fast, the water temp will raise a little over the mid mark, upon slowing down, it will return to below middle. Have asked the mechanic that did the conversion, he said its very normal because its a turbo engine, when push hard thus will hot a little, plus recently the weather is crazily hot.

With skepticism, asked another mechanic which i never dealt with before, he mentioned the samething as he's thought its quite normal, however, he gave some suggestion on venting the hood and side fender for hot air to exit faster.

Therefore here comes this discussion, how effective is it to vent my car's body parts, or i should just get a low temperature thermostat and call it a day ?

Thanks,
Ken
 

gunnerzz

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Maybe...more hot air escapes thru the vent rather than recirculating back to the front of the radiator. But vent will help most when the vehicle is moving. During stationary it all depends on the radiator fan and the air temp the radiator is getting.

I rather seal the radiator area to prevent any chance of hot air from the engine bay getting recirculated to the front of the radiator.Very difficult to do but rewarding. I did that on the Kenari and aircond is much better too.
 

Mitevo7

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Maybe...more hot air escapes thru the vent rather than recirculating back to the front of the radiator. But vent will help most when the vehicle is moving. During stationary it all depends on the radiator fan and the air temp the radiator is getting.

I rather seal the radiator area to prevent any chance of hot air from the engine bay getting recirculated to the front of the radiator.Very difficult to do but rewarding. I did that on the Kenari and aircond is much better too.
My issue is when i am driving or racing it hard, the temp will creep a little higher, from what i read, 1JZ normally installed in larger Toyota cars. BMW E46 is not at the same league with Crown, may be that's why the hot air is kinda trapped in the engine bay.

Can you share some picture how you seal the radiator area ?

Thanks,
Ken
 

mADmAN

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venting the hood if done properly can reduce the engine bay temperatures via the venturi effect. will minimize radiant heat being soaked up by ur engine components.

however, i would suggest a lower temp fan switch and thermostat. so that the fan will turn on at a lower temperature and cool the water earlier. a fan shroud would probably help as well.... after thats done, u can look into the venting.
 
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Mitevo7

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venting the hood if done properly can reduce the engine bay temperatures via the venturi effect. will minimize radiant heat being soaked up by ur engine components.

however, i would suggest a lower temp fan switch and thermostat. so that the fan will turn on at a lower temperature and cool the water earlier. a fan shroud would probably help as well.... after thats done, u can look into the venting.
Dude you foreseen my actual plans, indeed i am getting fan controller and lower temperature thermostat now. I don't want the modified body to attract any unwanted attention from authorities eventhough i am legal. My exhaust note is already quite a police magnet when i drive fast lol.

Thanks,
Ken
 

Izso

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Dear All,

As some of you may know, i just converted a BMW E46 with 1jz engine, due to i am getting more and more familiar with the new characteristics of the car and i have been pushing it a lot. Now i've noticed, whenever i floor it hard and fast, the water temp will raise a little over the mid mark, upon slowing down, it will return to below middle. Have asked the mechanic that did the conversion, he said its very normal because its a turbo engine, when push hard thus will hot a little, plus recently the weather is crazily hot.

With skepticism, asked another mechanic which i never dealt with before, he mentioned the samething as he's thought its quite normal, however, he gave some suggestion on venting the hood and side fender for hot air to exit faster.

Therefore here comes this discussion, how effective is it to vent my car's body parts, or i should just get a low temperature thermostat and call it a day ?

Thanks,
Ken
Ho ho ho... this was one of the things I mentioned to you right? The 1JZ runs hot. Uprate the radiator and fan and it's limited by the flow of the engine bay. I had the same problem with my 36 sometime back and my oil temp would touch 110 at time too with the water also reaching 100. I was looking for vents until I went for the old school mechanic way of raising the hood with some washers to test my theory of poor airflow and lo-and-behold, the temperature stabilized and although it still went up during spirited drives, the heating up wouldn't be as drastic. Perhaps you should try raising the hood as a temporary measure.
 

marsha1l_v6

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i just ordered spal last week..else can share shipping cost.

im working on reducing engine bay temp as well. using low temp thermostat..and raised front hood
 

vr2turbo

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All turbo cars runs hot, especially when pushed. The turbine will be really hot, and water and oil sent there to cool that part will become very hot and when return to radiator and engine sump respectively, will spike up the temperature, that is why need engine oil cooler too.....
 

6UE5t

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nah.. get a fan with a higher CFM. More blades doesn't mean anything la.
I think it should. Just compare ceiling fans with 3 vs 5 blades. Replacing the motor with more powerful one of course is even better.
 

vr2turbo

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I think it should. Just compare ceiling fans with 3 vs 5 blades. Replacing the motor with more powerful one of course is even better.
Reading your reply, made me google, then saw this......lol

Fewer Blades Mean Less Drag. Many believe that the more blades your fan has, the cooler it is, but it isn't secret that industrial style and commercial fans usually only have two or three blades. ... When a fan has fewer blades, there is less drag on the motor and it can go faster and move more air more efficiently.

Looks like stronger motor is better.....
 
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6UE5t

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Reading your reply, made me google, then saw this......lol

Fewer Blades Mean Less Drag. Many believe that the more blades your fan has, the cooler it is, but it isn't secret that industrial style and commercial fans usually only have two or three blades. ... When a fan has fewer blades, there is less drag on the motor and it can go faster and move more air more efficiently.

Looks like stronger motor is better.....
Makes sense so need to pair with stronger motor as well.
 

Mitevo7

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Ho ho ho... this was one of the things I mentioned to you right? The 1JZ runs hot. Uprate the radiator and fan and it's limited by the flow of the engine bay. I had the same problem with my 36 sometime back and my oil temp would touch 110 at time too with the water also reaching 100. I was looking for vents until I went for the old school mechanic way of raising the hood with some washers to test my theory of poor airflow and lo-and-behold, the temperature stabilized and although it still went up during spirited drives, the heating up wouldn't be as drastic. Perhaps you should try raising the hood as a temporary measure.
We will try with cooler temp and fan controller at lower temp, but that will mean work the fan quite regularly. I might need to look an M3 side fender with stock air vents that can let the hot air escape from the side. It's more stealthy and low profile.

Thanks,
Ken
 

Mitevo7

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All turbo cars runs hot, especially when pushed. The turbine will be really hot, and water and oil sent there to cool that part will become very hot and when return to radiator and engine sump respectively, will spike up the temperature, that is why need engine oil cooler too.....
Well said, lots of coolers need to be installed then if i want to drive like i stole it. For now i only able to drive it hard for short period of time before seeing the temperature creeps over mid point.

Thanks,
Ken
 

Mitevo7

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Folks, anyone got contact where i can get reasonable vented hood for the E46 ? If i have to, i will need a fabricator to fabricator one from a spare hood i bought.

Thanks,
Ken
 

Izso

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Folks, anyone got contact where i can get reasonable vented hood for the E46 ? If i have to, i will need a fabricator to fabricator one from a spare hood i bought.

Thanks,
Ken
I thought you wanted low profile? hahaha.. buy the vents off Lazada and give to the fab guy to cut a hole in the hood and mould it in. But before you commit to cutting holes, why not just lift the hood for testing purposes and see if that works. If it works then you know for sure it's just a venting issue and start chopping that hood.
 

Mitevo7

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I thought you wanted low profile? hahaha.. buy the vents off Lazada and give to the fab guy to cut a hole in the hood and mould it in. But before you commit to cutting holes, why not just lift the hood for testing purposes and see if that works. If it works then you know for sure it's just a venting issue and start chopping that hood.
Hehehe, i am going for low profile and functional venting. I can go with another style of venting as long as i can draw the hot air out. We actually drove without hood once at very fast RPMs, temperature stays still ! Therefore can quite confirm we need some vents on the hood.

Thanks,
Ken
 
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vr2turbo

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Well said, lots of coolers need to be installed then if i want to drive like i stole it. For now i only able to drive it hard for short period of time before seeing the temperature creeps over mid point.

Thanks,
Ken
Turbo engine need oil cooler, my stock VR engine already equip with one......
 

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