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Old 10-16-2010, 03:25 AM   #1
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Default Long distance driving.

Hi guys..
I'm having a problem.

I have a 93 NA6 with a TD04 turbo custom kit, running a Celica GT4 intercooler, FM linkmk2 ECU with WB02, 550cc RC injectors, 3 core KOYO aluminium radiator with twin SPAL fans, Mocal 13 row oil cooler.

On long drives, when i hold a constant speed of 140kmh the temp via the Link shows about 96-98 deg C. When i start to head anywhere above that for sustained periods of time, the water temp starts to rise over minutes and can hit between 102-108 deg C at 160km/h. I try to be gentle on the accelerator and not build boost and keep it at 0psi or in vacuum, but i can still hear the turbo spooling away, with my rpm at abt 4500.

My question is....what can i do to prevent the turbo from spooling at such high rpm, long distance trips?

Are these worth considering?

1) External wastegate
2) external actuator
3) Change final drive (which i don't really want to cause i like the close ratio gearing on the NA)
4) change 5th Gear
5) get the 6 spd GB and diff off a NB

any other ideas? comments please?
Thanks guys

oh yes....over where i am...temperatures are usually 34-35deg c with >90% humidity
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Old 10-16-2010, 03:33 AM   #2
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Put your plastic undertray back on. Your overheating has absolutely nothing to do with the turbo, gearing, or anything else you mentioned.
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Old 10-16-2010, 04:06 AM   #3
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Put your plastic undertray back on. Your overheating has absolutely nothing to do with the turbo, gearing, or anything else you mentioned.
it is on.....
i suspect it overheats only when the turbo keeps spooling...cause the TD04 is water and oil cooled....
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Old 10-16-2010, 04:34 AM   #4
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Quote:
Originally Posted by qes78 View Post
My question is....what can i do to prevent the turbo from spooling at such high rpm, long distance trips?
A: Remove it, and place it in the trunk.

B: Remove it, and place it on the seat next to you.

C: Remove it, and place it on a shelf in your garage.

D: Remove it, and sell it on eBay.

(etc.)

Honestly, I'm not seeing the problem here. 108C is a little hotter than my engine runs, but it's not like the engine is going to liquify at that temperature. Frankly, I'm not surprised that it's running a tad warm- 140 km/h (that's 87 MPH for you Americans) is a pretty fair clip for a vehicle with all the aerodynamic properties of a spanner.


For starters, the quantity of heat which the turbocharger contributes to the cooling system is pretty trivial. And it's not as though the heat load on the CHRA water jacket is going to vary much with whether or not the compressor is doing anything- it's got a steady stream of rather hot gas flowing through the turbine housing an inch away.


If you're really worried about it, fix the real problem: the cooling system. Search around here a bit on the term reroute (or "re route") and I pretty much guarantee your problems will go away.
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Old 10-16-2010, 04:34 AM   #5
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maybe just leave your WG open
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Old 10-16-2010, 04:40 AM   #6
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Quote:
Originally Posted by Joe Perez View Post
A: Remove it, and place it in the trunk.

B: Remove it, and place it on the seat next to you.

C: Remove it, and place it on a shelf in your garage.

D: Remove it, and sell it on eBay.

(etc.)

Honestly, I'm not seeing the problem here. 108C is a little hotter than my engine runs, but it's not like the engine is going to liquify at that temperature. Frankly, I'm not surprised that it's running a tad warm- 140 km/h (that's 87 MPH for you Americans) is a pretty fair clip for a vehicle with all the aerodynamic properties of a spanner.


For starters, the quantity of heat which the turbocharger contributes to the cooling system is pretty trivial. And it's not as though the heat load on the CHRA water jacket is going to vary much with whether or not the compressor is doing anything- it's got a steady stream of rather hot gas flowing through the turbine housing an inch away.


If you're really worried about it, fix the real problem: the cooling system. Search around here a bit on the term reroute (or "re route") and I pretty much guarantee your problems will go away.
well, the interesting thing is, this is about the 2nd time the turbo has melted my aircon compressor. i wasnt worried about the temperature...unti the aircon couldnt work thereafter. I have been considering the re-route option. hmmmm
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Old 10-16-2010, 04:40 AM   #7
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run a gt40r and you should have no problem making it stay in vacuum
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Old 10-16-2010, 04:42 AM   #8
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run a gt40r and you should have no problem making it stay in vacuum
well.....im sure about that too, thanks
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Old 10-16-2010, 04:47 AM   #9
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maybe just leave your WG open
thanks for that. have u tried doing that before?
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Old 10-16-2010, 05:03 AM   #10
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if you're in vacuum and "hear" the turbo spooling but it doesn't go into boost its not really "spooling". its just spinning. probably a little faster than at low speeds but that has nothing to do with your issue.

you have a cooling problem. a logical place to start would be the cooling system.

When your *** hurts do you go to the dentist?
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Old 10-16-2010, 05:49 AM   #11
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Sorry, maybe I wasn't clear:

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Your overheating has absolutely nothing to do with the turbo, gearing, or anything else you mentioned.
If you overheat in boost, it's because your cooling system is inadequate. I can hammer around a road course doing 350whp 5th and 6th gear pulls at 16+psi in 90+ degree heat for 25 minutes straight and I have zero problems keeping the car cool. If you cannot do 100-150mph twice in a row without overheating, your cooling system is inadequate for your power level. If you cannot exceed 5in.hg of vacuum without the temps creeping up, your cooling system is broken.

In amurrican units, at 87mph your temps are 205-208F. This is high - it shows you either have a coolant pressure leak, your core size is inadequate, or you have improper ducting. With a 190F thermostat you should be sitting between 190F and 200F on the street, regardless of speed. At 100mph, the temps climb to 215-225, this is also high.

Your temps should DROP at speed, not rise. I had temps fluctuating between 210 and 220*F every lap at WSIR last weekend - the lowest temps were at the end of the front straightaway, ~154mph. Highest temps were exiting the slowest portion of the track (midrange 4th gear, 60-90mph). Temps would slowly drop as I accelerated away from the slow section (80 to ~140mph, slowing to ~100mph for turn 9, then back to ~154 entering turn 1). This is with a Trackspeed 76mm radiator, 14" Spal curved-blade fan, no shroud, front end fully ducted, extraction hood, reroute, gutted thermostat.

Last edited by Savington; 10-16-2010 at 06:03 AM.
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Old 10-16-2010, 06:39 AM   #12
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Originally Posted by 18psi View Post
if you're in vacuum and "hear" the turbo spooling but it doesn't go into boost its not really "spooling". its just spinning. probably a little faster than at low speeds but that has nothing to do with your issue.

you have a cooling problem. a logical place to start would be the cooling system.

When your *** hurts do you go to the dentist?
what else in the cooling system should i be looking at besides the reroute....
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Old 10-16-2010, 06:41 AM   #13
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Originally Posted by Savington View Post
Sorry, maybe I wasn't clear:


In amurrican units, at 87mph your temps are 205-208F. This is high - it shows you either have a coolant pressure leak, your core size is inadequate, or you have improper ducting. With a 190F thermostat you should be sitting between 190F and 200F on the street, regardless of speed. At 100mph, the temps climb to 215-225, this is also high.
Sorry, could i trouble you to elaborate on the ducting portion?
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Old 10-16-2010, 07:16 AM   #14
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Do you have A/C and do you use it? My guess is yes, which may explain your overheating issues.
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Old 10-16-2010, 07:24 AM   #15
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Sorry, could i trouble you to elaborate on the ducting portion?
Take some detailed photos of the mouth of your car. Specifically of the areas around the intercooler. My car has two main chambers - approximately 75% of the air goes through the intercooler, then through the bottom half of the radiator. 25% of the air bypasses the intercooler and travels through the top half of the radiator. The two chambers behind the IC are separated so the air that goes around the IC can't get behind the IC and restrict its flow.

If you were to winch your car up vertical so the car was perpendicular to the ground, and then pour water into the mouth, would most of it go through the radiator or around the radiator? Air is like an un-trainable dog - you have to constantly trick it into doing what you want or else it's going to just go do whatever the **** it wants.
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Old 10-16-2010, 12:20 PM   #16
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Do you have A/C and do you use it? My guess is yes, which may explain your overheating issues.
yes i do....and i do use it....
but for this particular run, the top was down and the a/c was off....
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Old 10-16-2010, 12:23 PM   #17
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Originally Posted by Savington View Post
Take some detailed photos of the mouth of your car. Specifically of the areas around the intercooler. My car has two main chambers - approximately 75% of the air goes through the intercooler, then through the bottom half of the radiator. 25% of the air bypasses the intercooler and travels through the top half of the radiator. The two chambers behind the IC are separated so the air that goes around the IC can't get behind the IC and restrict its flow.

If you were to winch your car up vertical so the car was perpendicular to the ground, and then pour water into the mouth, would most of it go through the radiator or around the radiator? Air is like an un-trainable dog - you have to constantly trick it into doing what you want or else it's going to just go do whatever the **** it wants.
i get what you mean. does this also mean that u use a shroud for your radiator fans? would you be able to show some pics of your shrouds so that I can figure out how i can customize one for mine?
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Old 10-16-2010, 12:41 PM   #18
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Old 10-16-2010, 12:55 PM   #19
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thanks very much. i suppose the function is very much like the original plastic under belly tray?just that it extends to the front of the car?
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Old 10-16-2010, 12:59 PM   #20
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thanks very much. i suppose the function is very much like the original plastic under belly tray?just that it extends to the front of the car?
No, it seals up the air from the "mouth" so its forced through the heat exchangers. Singapore's humidity doesn't help you too much, but I think you can get the job done with this ducting. If not you can buy a TSE radiator.
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