In some way or fashion I'm obsessed with reducing under hood temps on the 'V'. I fully intend to redo the fender vents to extract trapped heat(and a 160degree thermostat in the future). The entire engine compartment has a perimeter hood seal. The underside of the hood (at the windshield base)outside of the seal has an area that would be suitable for ventilating......except for the fact that this is also a high pressure area (ala NASCAR induction madness 1969ish) that would effectively negate what I'm trying to accomplish as I undersatnd it no?
Reducing coolant temperature is not a good idea.
Venting is not easy to do properly on modern cars, and often leads to the opposite of the desired result. I know that there are cars with fake fender vents, that when the manufacturer tested with actual vents, resulted in higher underhood temps. So they left the fake ones for looks instead. If you are serious about lowering underhood temps, I'd check into coating or wraping the exhaust components.
Do you have heat issues now? If not, don't mess with it.
Boost_Crazy said:
Venting is not easy to do properly on modern cars, and often leads to the opposite of the desired result. I know that there are cars with fake fender vents, that when the manufacturer tested with actual vents, resulted in higher underhood temps. So they left the fake ones for looks instead. If you are serious about lowering underhood temps, I'd check into coating or wraping the exhaust components.
Can you give us an example of those cars? It would be good info to not screw up something at a later date.
irish44j said:
buzzboy said:
Do you have heat issues now? If not, don't mess with it.
this.
The supercharger retains alot of heat that I would like to extract from the engine compartment (venting while driving). The other possible solution is the Camaro ZL1 hat, larger heat exchanger, 160d thermo, cooling fans running after shutdown, retune,all of which at this time is not in the budget. So the fender vents have my attention(functiionality)......
docwyte
SuperDork
11/25/17 9:30 a.m.
Hmm, is my E36 M3 considered a "modern" car? Because adding hood vents to it consistently lowers coolant temps 10-20 degrees F.
I literally just bought a set of hood vents from Trackspec Motorsports yesterday for my 98 M3...
The 2nd Gen F-body fender vents were functional and very effective, iirc.
By removing the factory installed fender vents and replacing with a perforated equivalent and drilling holes in the hood hinge assmy's(less restrictive path to the vents) I'm hoping to see some improvement. Thanks DocWyte I'll check Tracspec...
Anecdotal evidence, but wrapped exhaust makes a huge difference on underhood temps on LS motors. A lot of the Corvette guys do it. I just couldnt bare to cover up my gorgeous Kooks headers.
In reply to Gearheadotaku :
Off the top of my head, the new Titan XD with the diesel. That example stuck with me because the faux vents are extremely fugly, and I was surprised to learn that they were intended to be functional. Testing showed that they had the opposite effect, so they closed them off.
If you need to ask, you already know the answer.
Trans_Maro said:
If you need to ask, you already know the answer.
No I don't know the 'answer' ...........I'm not engine compartment flow dynamicist nor did I sleep in a Holday inn last night. My main question is, will providing a pathway for heat to escape at the base of the windshield have an adverse effect?
Ok then.
Leave it alone.
GM pays their engineers plenty of money to turn out a decent product. If it's running at normal operating temperature, why mess with it?
This isn't 30 years ago, overcooling an engine will do more harm than good. Move the operating temperature out of the parameters that the ECU is looking for and it will compensate by giving you a less-than-optimal operating state.
Spend your time, brainpower and money on something that will actually make a difference like suspension, tires and performance enhancers. A 160 degree operating temperature is not one of those in your current state of tune.
As for the last question.
No, the base of the windshield is a high pressure area. wheel openings and under the car are the places to extract hot air.
I'll agree that there is a significant wave of heat that occurs when you open the hood on these. I use mine to hest the garage in the winter by taking it for a drive and parking it inside. Other than "it feels really warm" and "the cool CTS-V kids put in a 160", do you have an actual problem you're trying to solve?
I can't say that mine has gotten hot ever, even on track, though that might be because I'm slow. Wordmis that they make a LOT more heat with a small pulley and more boost, but I haven't read actual numbers so I don't know. The more I do this the more I worry about oil temperature rather than water temperature.
I wouldn't consider putting a lower-temperature thermostat on an engine just to reduce underhood temps. Messing with the engine's normal operating temperature is a great way to massively accelerate engine wear.
GameboyRMH said:
I wouldn't consider putting a lower-temperature thermostat on an engine just to reduce underhood temps. Messing with the engine's normal operating temperature is a great way to massively accelerate engine wear.
please explain from an engineering viewpoint ............I'm all EARS.............I've run a 160 in a small block L31 that currently has 370K+ with no adverse affects...........serve and volley
The idea is that an engine is designed to operate within a given range. My R63 has a little flashy light that tells you not to be an a-hole until the oil gets to 80C. At that point everything has thermally expanded to the right state and the oil is warm enough to flow properly and life is good. Formula 1 is the extreme end of this where you have to warm and circulate the oil to get the engine up to temp before you even attempt to start it. At the far other end is your lawn mower which gives zero berkeleys what the temperature is and you can jam it up to full throttle within seconds of starting and it doesn't care. Cars are somewhere between lawnmowers and Formula 1.
If 160 degrees is within specs for the engine it won't accelerate wear, but if draws coolant tempt outside the ecu parameters (some ecu's are looking at coolant temp to control mixture and what not to optimize emissions) then you're not doing yourself any favors. The thing is, usually we're trying to keep an engine from getting too hot, and a 160 doesn't do anything for that, because once you're at 200, it doesn't matter if the thermostat is 160 or 180 or 199, it's open all the way, so it doesn't really help you run cooler when the car is hot, it just lets the car cool down faster and run cooler when it's not under load.
I think (and this is just what I've read) that a big reason to put a 160 in the V is to physically lower the radiator temperatures so that the little tiny radiator that feeds the supercharger can be cooler and then the intake charge can be cooler and then you can make MORE POWER! This is especially true when you turn the boost up as the supercharger heats the air even more requiring even more cooling to stay within a safe range. Not really a concern on normal engines, and really only happening when the car is idling between drag runs, so not something I've ever really been concerned about myself as that's not really my thing. I suppose it could help it cool down better between autocross runs, but an extra 20 degrees of temperature isn't really the reason I'm not beating Camaros.
mazdeuce covered it, an engine is designed to run with a certain amount of thermal expansion, if you run a lower-temperature themostat then the parts won't quite reach that temperature and clearances will be tighter than ideal. And you could be doing much of your hard running at this temperature if the car's cooling system can dump the heat fast enough. On something as crude as an SBC variant, you can get away with a lot though.
A lot of systems won't go into closed loop until they get to higher temperatures nowadays.
Even my wife's old Suburban with an L-29 Vortec will stay in open loop if you put a 160 degree thermostat in it.
My E36 M3box '99 Malibu ran hotter without a hood. Venting the V is probably fruitless.
Properly located hood vent toward the nose of the car. Behind the radiator but not back toward the base.
Look at the new Vette and most GT based race cars of the last decade +
Daylan C said:
My E36 M3box '99 Malibu ran hotter without a hood. Venting the V is probably fruitless.
Yeah, that's not the same thing. Not the same thing at all.
