track day testing adds confusion to cooling issues
#61
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i was looking around for some ideas on moving my oil cooler today and ran across this:
i looked for a pic like this when we were talking about heat extraction in another thread and all that i saw was the rx7 one people throw around. this is a bit more relevant, but not as cool as aero cow.
i looked for a pic like this when we were talking about heat extraction in another thread and all that i saw was the rx7 one people throw around. this is a bit more relevant, but not as cool as aero cow.
#63
Myron, I have no problem believing that unshrouded fans are less efficient than shrouded fans, but what you need to understand is that it's still not enough. You missed Hustler's point - if you are driving the car hard enough to relax the turbo hardware (i.e. significantly faster than SM record), you cannot keep it cool with fans. I tried about 3 years and 80whp ago to use a set of shrouded fans to pull air through the intercooler to keep the car cool, and it resulted in catastrophic overheating almost immediately (<2 laps). If you expect to keep the car cool, you need to feed it air from the front of the car, and by the time you move enough air through the core to actually do the job, the fans and shroud are a restriction. (CLTs on my turbo car drop with increased speed).
I need to be very clear here: our radiator is not comparable to the FM or BEGi units. The only radiator on the market that has similar features to our radiator is Springfield Dyno's radiator, at ~$600/unit. Our radiators have two cores, unlike the FM/BEGi units, and this makes a world of difference when it comes to keeping things cool.
#65
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+1. How fast are you going, Myron? I gave up on fans when myt car was ~270whp and ~7sec/lap faster than SM. It's now got sheetmetal ducting and a small fan for idle and was 350whp and 11sec/lap faster than SM when it last ran.
#66
If you didn't know, my Miata is a full street car; interior, a/c, etc... It's right around 250 whp @ 12 lbs boost with 100 octane fuel. My fastest time around BW 13cw is 2.03 which I believe is 3 seconds under the SM record. I usually average 2.08-10 during a 20 min session. With a better driver, I'm sure it's capable of a 1.59. I just don't have the ***** to push it that hard....yet.
#67
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It's crazy, it's like in Texas no shops in the DFW area actually want to work on a car. Taking 2 weeks to bother getting back to me to give me an idea if if they can do any work on my car for me or what it might cost. Then you have to argue with them over what parts you chose to use. Take this for instance, its been over a week since i contacted this company to ask them about swapping the rad, ducting it for me, and moving the oil cooler.
He finally gets back to me and this is what he has to say:
Thankfully, Trey is going to help me out in a few weeks after his car is sorted. This guy looked at my car at the track a few months back, and quoted me a price including spal fans, reroute parts and labor of about $1000. now he says labor only is going to run me that much. Hustler needs to start his own shop, such a chasm in DFW for people that know WTF they are talking about, don't want to crap on what you want to do, and actually act like they care about your business.
He finally gets back to me and this is what he has to say:
Shane,
You are going totally wrong in your setup. A thinker radiator is Not as efficient at cooling. More volume of water does slow down the Initial heat up time, but once the heat is up, its less efficiencient at removing the heat. Look at it this way, as air flows through the radiator it absorbs heat and rises as it exits. By the time the air flow gets toward the rear of the radiator it is no longer removing heat with cooled air. Hot air is now taking that last bit of heat with it dropping the efficiency down further. This goes the same for intercoolers, thinker is not better at removing heat.
The reroute request will be your biggest improvement. I still prefer dual fans especially for anyone who is driving on the street. The oil cooler setup can run behind the bumper in the fender well area.
Estimating cost Shane is difficult because it is all custom work. We can do as you requested and a guess might be 12-14 hours at $65 rate. The reroute kit is $299. Let me know if we can help.
You are going totally wrong in your setup. A thinker radiator is Not as efficient at cooling. More volume of water does slow down the Initial heat up time, but once the heat is up, its less efficiencient at removing the heat. Look at it this way, as air flows through the radiator it absorbs heat and rises as it exits. By the time the air flow gets toward the rear of the radiator it is no longer removing heat with cooled air. Hot air is now taking that last bit of heat with it dropping the efficiency down further. This goes the same for intercoolers, thinker is not better at removing heat.
The reroute request will be your biggest improvement. I still prefer dual fans especially for anyone who is driving on the street. The oil cooler setup can run behind the bumper in the fender well area.
Estimating cost Shane is difficult because it is all custom work. We can do as you requested and a guess might be 12-14 hours at $65 rate. The reroute kit is $299. Let me know if we can help.
Thankfully, Trey is going to help me out in a few weeks after his car is sorted. This guy looked at my car at the track a few months back, and quoted me a price including spal fans, reroute parts and labor of about $1000. now he says labor only is going to run me that much. Hustler needs to start his own shop, such a chasm in DFW for people that know WTF they are talking about, don't want to crap on what you want to do, and actually act like they care about your business.
#69
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There's more than one school of thought on how to build a car...TSE, 949, myself and many others have chosen the types of designs that looks like something you see in ALMS or Grand-Am. Most people don't want to take the time or money to do it right up front. It's a lot easier to bolt fans to a radiator than take the time to explain Bernoulli's principle and spend more money on plastic for ducting than you would for inefficient fans.
#71
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Fans are not the answer. Ducting the nose is the key. Ducting Ducting Ducting! It does not have to be 100% water-tight sealed, but it should be 95% sealed. Coroplast, ABS, and aluminum tape are your friends. Use cheap wooden chopsticks and corrugated cardboard to make a poor man's profilometer to get the right shape for the bumper and wherever else. The idea is, ALL air that comes in through the nose inlet HAS to pass through the radiator. ALL OF IT. No fan, unless it is something insane, will push as much air through the radiator as proper ducting.
Is the ducting horse dead yet? Several of us have been beating the crap out of it for awhile now. Tough little bastard to kill.
Last edited by ZX-Tex; 01-30-2013 at 07:02 PM.
#76
I fall in the "small fan, duct the rad., get a bigger rad." group. It works, its great, it puts you at ease.
the bigger radiator = less efficiency thing is bullshit. Just look at all the race cars around. That last bit of thickness still helps since there is no way the air and radiator are at the same temps.
the bigger radiator = less efficiency thing is bullshit. Just look at all the race cars around. That last bit of thickness still helps since there is no way the air and radiator are at the same temps.
#77
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Was it GeneSplicer that used that weird bathtub liner thing for his ducting? Whomever it was, it looked pretty effective. I seem to remember Dem768 or 99mx5 or one of the guys rocking an EFR had some great ductwork pics in their build thread. (I think I've got pics of Crusher and Super or Nemo without their noses, but if I post them Emilio and the 949Racing BruteSquad will hunt me down and kill me.) ZX-Tex's description above is accurate. Steal some election signs and get to work!
#78
Thanks! My radiator is not huge, about the size of a stock Miata one but it is a duel pass 4 core Griffin supposedly good for 600 hp.
I’m running 2 fans, neither of them worth much and no ducting at all. On the street it never gets over 195 but in a 60 second autox it jumps to 225. By the end of the 3rd run in 20 minutes it was 250.
I’m running 2 fans, neither of them worth much and no ducting at all. On the street it never gets over 195 but in a 60 second autox it jumps to 225. By the end of the 3rd run in 20 minutes it was 250.
#79
Yes, Genesplicers build has the bathtub liner. It was the inspiration for my build. I will see if I have any pics, but doubtful.
Found some and took some. There is ducting from the mouth to the bottom of the radiator, and a separate "tray" that bolts to the lip and runs back to the front subframe
See the radiator hose in the pic below going to the radiator. The pan that connects the radiator to the nose is bolted to the fan brackets on the radiator and extends forward below it.
Found some and took some. There is ducting from the mouth to the bottom of the radiator, and a separate "tray" that bolts to the lip and runs back to the front subframe
See the radiator hose in the pic below going to the radiator. The pan that connects the radiator to the nose is bolted to the fan brackets on the radiator and extends forward below it.
Last edited by fooger03; 08-19-2013 at 06:12 PM.