Cooling for road racing tech article

3380 Views 36 Replies 10 Participants Last post by Eric, Jul 26, 2001

Andi

Discussion Starter · Jun 25, 2001

I just finished writing up this little tech article on cooling issues and fixes for road raced MKIVs. The link is:
http://www.boostaholic.com/supra/cooling/index.html

Regards,
Andi

1 - 20 of 37 Posts

Eric

· #2 · Jun 25, 2001

Andi,

Great write-up. I wouldn't ditch the stock oil cooler. It gets coolant after it goes through the radiator, so the coolant is going to be cooler than the oil. They don't put much heat into the cooling system either. It has the side benefit of heating the oil up faster on cooler days, and keeps the Greddy from overcooling under those conditions, which is a concern with air/oil coolers.

I used to run a small flexible spoiler under my Talon to get more air into the radiator behind the FMIC like you and Jeff are doing. It seemed to help. The only problem with the way you're doing it is that might be a low pressure area where you have your opening since it sits behind the little stock spoiler. The little flaps you left hanging should help though.

I'm probably just going back to the SMIC myself. It's hard for me to justify the cost of a FMIC and Fluidyne for the improvements I saw on my car.

98tts

· #3 · Jun 25, 2001

I remove the insulation under the hood no problems at all with paint.
My turbos generate a lot of heat. I let park after a hard drive i can see radiating from the hood.
Would love to get a TRD hood But I drive my car everyday in the summer. Worried about driving in the rain with that hood.

Kevin Hoare

· #4 · Jun 25, 2001

What about removing the weather stripping seal along the back side of the hood by the front windshield? Would this allow more airflow through the engine bay?

Oh well, just read your webpage and realized it was one of the first things you mentioned!

RE: VEILSIDE HOODS

I was surfing around one day and found a webpage where the guy had a Veilside hood installed, he said the fit was perfect. Here are some pics from his website. I was thinking of getting one of these hoods as well.
http://freehosting1.at.webjump.com/4925096e3/su/suprabilis-webjump/veilside.htm

[ June 25, 2001: Message edited by: Kevin Hoare ]

Eric

· #5 · Jun 25, 2001

Originally posted by Andrew Aksyonov:
<STRONG>Andi,
I've read your article and it mentioned that you chose the 10 row oil cooler because the 16 row wouldn't fit as easily... can it be done at all? I got the 16 row one, and I too do not want it in front of my radiator, should I sell it and get the 10 row or is there a way to stick it into the same place as yours?

Thanks,</STRONG>

If you have a Greddy FMIC (and probably other FMICs), the 10 row is the biggest oil cooler you can fit upright because the IC pipe limits how low you can mount it. The 10 row just barely fits. You might be able to fit a 16 row if you tilt it.

Eric

· #6 · Jun 25, 2001

Originally posted by Kevin Hoare:
<STRONG>What about removing the weather stripping seal along the back side of the hood by the front windshield? Would this allow more airflow through the engine bay?

Oh well, just read your webpage and realized it was one of the first things you mentioned!

[ June 25, 2001: Message edited by: Kevin Hoare ]</STRONG>

Actually, I don't think this would help. The area at the base of the windshield is a high pressure area, so air won't get pulled out from under the hood. Many cars have had backward facing scoops that draw air from that area for that reason.

$upraMan

· #7 · Jun 25, 2001

Originally posted by Eric:
<STRONG>If you have a Greddy FMIC (and probably other FMICs), the 10 row is the biggest oil cooler you can fit upright because the IC pipe limits how low you can mount it. The 10 row just barely fits. You might be able to fit a 16 row if you tilt it.</STRONG>

I have HKS type R FMIC. I guess I'll see if there is a way to rig it in there and if not, trade with someone for a 10 row. Tilting might work also, I think Porsche and Ferrari's radiators come tilted from the factory so there is probably some advantage running a larger cooler tilted than a smaller one mounted straight.

$upraMan

· #8 · Jun 25, 2001

I forgot to mention a couple of other cooling "tricks". Many people that are running FMIC cut the front bumper where the Toyota logo is to allow extra air straight into the radiator. I've also seen a few pictures of Japanese Supras where the high beam on the passenger side is cut out to let cool air through -- should be good for cooler intake temps and some ram-air effect, but also to keep things cooler under the hood especially when the rear rubber seal is removed to allow the hot gases out. Also TRD makes a cooler thermostat for our cars $75 from Jeff Watson, and if that's not enough take out the A/C!

Andi

Discussion Starter · #9 · Jun 26, 2001

I'm not sure how big exactly the 16 row cooler is, you'll have to get the car on a lift and see if it'll fit anywhere perhaps with custom brackets.. I'd've never thought we'd fit my Setrab power steering cooler under the Greddy oil cooler but we managed to shoe-horn it in there.. so you neverk now.

Good luck,
Andi

Originally posted by Andrew Aksyonov:
<STRONG>Andi,
I've read your article and it mentioned that you chose the 10 row oil cooler because the 16 row wouldn't fit as easily... can it be done at all? I got the 16 row one, and I too do not want it in front of my radiator, should I sell it and get the 10 row or is there a way to stick it into the same place as yours?

Thanks,</STRONG>

John H

· #10 · Jun 26, 2001

Could melt or did melt? Big difference there. I've had mine removed for 2 summers here in TX. It gets HOT here! My paint is perfect even on the underside of the hood. If your reasoning was true, the paint on the shock tower under the hood right by the turbos would have melted long ago. It gets a hell of a lot hotter there then on the hood. My hood has never been even close to being too hot to touch from underhood heat. Although when I had my black Supra TT and it sat in the sun all day I couldn't touch that hood with a glove on it was so hot!

Have I convinced you yet?

The insulation is mearly sound insulation. I heard someone say once that it offered fire protection because it would drop and smother out an underhood fire. If you have an underhood fire to that point. You're pretty much $#@!#@$

regardless. Maybe it wouldn't have caught on fire if it wasn't so hot in the first place?

John Hein

Originally posted by Grant:
<STRONG>Andi, someone on the list mentioned that removing the sound insulation could cause the paint on the hood to overheat and possible melt.</STRONG>

Grant

· #11 · Jun 26, 2001

I said could

I'm just repeating what I've heard, I thought I should say something just in case.

Why did you remove it? Is it a lot louder, lighter?

Andi

Discussion Starter · #12 · Jun 26, 2001

Thanks for your advice Eric. John Hein also just sent me some more suggestions that I could do.. I'm going to post them on the tech article asap.

Andi

Grant

· #13 · Jun 26, 2001

Eric, there was a guy on the list who said he was almost done in devoloping piping for the 2 stock ICs idea. He just made the measurements and ordered pre-pent piping from somewhere. Problem was he had to fabricate a end tank for one side of it. Supposedly it was almost done, but I haven't heard from him in a while. Oh well I'll just stick with the stock sidemount, my IC is always cool to the touch after racing.

Andi

Discussion Starter · #14 · Jun 26, 2001

Originally posted by Andi:
<STRONG>Thanks for your advice Eric. John Hein also just sent me some more suggestions that I could do.. I'm going to post them on the tech article asap.

Andi</STRONG>

I just updated the page with some new suggestions (scroll down to the bottom). The most interesting and easy free mods that I really think would work are:

- remove the sound insulation on the underside of the hood. This would allow more heat to radiate through the hood, and would give a weight savings to boot. Sounds like a winner.

- remove the engine under-cover behind the radiator. This also sounds like a winner -- the low pressure zone under the car at speed would suck air down and out of the engine bay, and from the radiator.

What do you think? Would these mods (more so the 2nd one) help?

Andi

Grant

· #15 · Jun 26, 2001

Andi, someone on the list mentioned that removing the sound insulation could cause the paint on the hood to overheat and possible melt.

greensoup

· #16 · Jun 27, 2001

Besides sound insulation I believe in any turbo car it is also there to prevent paint damage (like on RX7s) where the sometimes extreme heat from the turbo engine can (in theory, maybe not in practice) cause the paint to peel over time.

I don't believe removing the under tray on the car is a good idea. The under tray is what helps create the vacuum underneath the car a high speeds. A full on race car will have an undertray covering the entire bottom of the vehicle.

If you really wanted to cool the car/engine run a abflug style hood. With that style of duct it should draw air through the radiator and front mount intercooler (in theory).

G

· #17 · Jun 27, 2001

Originally posted by Eric:
<STRONG>Actually, I don't think this would help. The area at the base of the windshield is a high pressure area, so air won't get pulled out from under the hood. Many cars have had backward facing scoops that draw air from that area for that reason.</STRONG>

Hey, how's it going Eric?

This is something the Z community has considered also. I'm no aeronautics engineer, so I'm having trouble seeing the lower part of the hood being a high pressure zone. My thoughts are that it's low pressure while about mid windsheild, you've got higher pressure from air deflecting off the hood/bumber.

Can you explain this a bit more? One of the Club Z guys has already done this, but hasn't really seen any benifits/loses, but then again, he hasn't really done any finite coolant temperature measurements.

Love the discussion people.

I used to always think a front mount intercooler would be suicide, but with so many Supras with it, I was amazed that it could hold up and nobody complained. Apparently, most of them don't track them like Eric, and I can see now, the Supra doesn't really have a super human cooling system, but actually bleeds like the rest of the sports car arena.

Eric

· #18 · Jun 27, 2001

Originally posted by LeeDarzycki:
<STRONG>Hey, how's it going Eric?

This is something the Z community has considered also. I'm no aeronautics engineer, so I'm having trouble seeing the lower part of the hood being a high pressure zone. My thoughts are that it's low pressure while about mid windsheild, you've got higher pressure from air deflecting off the hood/bumber. </STRONG>

Lee,

What I know about aero stuff wouldn't fill an index card, but I'm basing my statement on the fact that auto makers have used that location for air intakes for the motor on some cars (older F-bodies and Corvettes off the top of my head), and it is almost universally used as an air intake for the ventilation system. You get airflow through the vents on cars even with the fan off at higher speed, so it pretty much has to be a high pressure area IMO.

If you want to get air out from under the hood, the best solution is to put a backwards facing vent on the hood similar to what Lancers have on the first 1/3 of the hood or so.

<STRONG>
I used to always think a front mount intercooler would be suicide, but with so many Supras with it, I was amazed that it could hold up and nobody complained. Apparently, most of them don't track them like Eric, and I can see now, the Supra doesn't really have a super human cooling system, but actually bleeds like the rest of the sports car arena.

</STRONG>

Heh. Actually, the cooling system on a Supra is awfully good stock. I've run at Thunderhill on a 110F day, and the temp gauge didn't even wiggle with the stock IC. Back in my DSM days, I would have been pulling into the pits after about 10 minutes to cool off. I don't have any cooling issues on sub 80 degree days with the FMIC either. I'm actually surprised it isn't a bigger problem than it is. The core on a Greddy FMIC is absolutely huge, and 4" thick, so it presents a significant restriction to airflow. If I had gotten much more power out of it at the dragstrip, I'd be tempted to just live with it since the car recovers really fast if you just back off for a little while (like a 1/4 of a lap). However, the stock IC is very efficient for a stocker, and free, so I'm probably just going back to it.

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decooper

· #19 · Jul 13, 2001

Ok,Guys...here's some more stuff to add to the cooling puzzle.
I'm currently running as follows:
Stock twins
HKS oil cooler/HKS FMIC typeR
Bruce Nomura rad/intercooler block-off
Fluidyne Rad w/19-21 lb Stant cap
Water Wetter/distilled water
Spal Electric fans
MVP cool air box w/ a 5"air duct coming in from the lower brakeair duct
No thermostat-just a restrictor
heat shield in front of the hard pipe by the
tracking system
Temps will get up to 110c+ by the end of my 20 min this is w/ the car running 1.2-3 bar boost in 90-95 degree weather(Willow Springs/Buttonwillow ca)
Next step is the TRD hood....install underway as we read this)
Dan Cooper(RPS is my tuner...very nice!!!)
97 tt6spd(stripped...but still fat bastard)
HKS type R blowoff
HKS 3puck clutch
HKS VPC
HKS GCC
G- force OBD 1 ECU
Greddy profec B
GreddyAirinx
Unorthodox access pulleys(only)
RMM downpipe
Intrax Coilovers-200/400 fr ,1000/900bck
Cusco strut supports
Apex-i super meg-dunk exhaust(silly)
Porterfield brake pads-race
Motul brk fluid
Kumho Victoracer 17" 275fr/315bck
IO port roll bar(chomemoly 14 pnt cage next year)
Sparco seats/5pnt harnesses

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Eric

· #20 · Jul 13, 2001

Originally posted by decooper:
<STRONG>Ok,Guys...here's some more stuff to add to the cooling puzzle.

Spal Electric fans
Temps will get up to 110c+ by the end of my 20 min this is w/ the car running 1.2-3 bar boost in 90-95 degree weather(Willow Springs/Buttonwillow ca)
Next step is the TRD hood....install underway as we read this)
Dan Cooper(RPS is my tuner...very nice!!!)
97 tt6spd(stripped...but still fat bastard)
</STRONG>

DECooper? are you really D.B. Cooper in hiding?

Put the stock fan back in! BTW, have any interest in doing a small group event at Buttonwillow in early Aug? Should be as much track time as you can stand. Are you doing wheel to wheel stuff now?

Eric

[ July 13, 2001: Message edited by: Eric ]

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