turbo v8 bug, running too hot
05-14-2009, 08:50 PM
#1
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turbo v8 bug, running too hot I just finished swapping intakes (from the truck intake) and completely re-doing the fuel system properly.
I recently drove the car, and when not stomping on it, the temp stays around 175-180*, it will go up a bit after getting on it, but comes back down. My concern is i took it up on the highway for about 8 miles and the temp was right around 205* (at 65mph, ~2400 rpm, no boost) After getting off the highway, the temp would not come back down.
The engine is running ~15:1 afr when crusing, and ~11:1 under boost, i am running ~6psi boost, and 15* timing under boost. Electric fan kicks on at 180* the airtemp was ~73*
The biggest problem is most likely that the intercooler is blocking the airflow too the radiator, as I never had overheating problems before the turbo. So my thoughts were to add a large "heater core" or something in the passenger wheel-well, since I currently have the heater core lines looped together.
any thoughts?
I recently drove the car, and when not stomping on it, the temp stays around 175-180*, it will go up a bit after getting on it, but comes back down. My concern is i took it up on the highway for about 8 miles and the temp was right around 205* (at 65mph, ~2400 rpm, no boost) After getting off the highway, the temp would not come back down.
The engine is running ~15:1 afr when crusing, and ~11:1 under boost, i am running ~6psi boost, and 15* timing under boost. Electric fan kicks on at 180* the airtemp was ~73*
The biggest problem is most likely that the intercooler is blocking the airflow too the radiator, as I never had overheating problems before the turbo. So my thoughts were to add a large "heater core" or something in the passenger wheel-well, since I currently have the heater core lines looped together.
any thoughts?
05-14-2009, 09:22 PM
#2
Nice project!!!
Does your electric fan have a shroud?
Are you getting a lot of radiant heat in the engine bay? If you are, a turbo blanket on the turbine housing or a REALLY good ceramic coating might help. It looks like you have a heat shield over it now, which is probably a good start. Likewise, a good ceramic coating or exhaust wrap on the hot side tubing would probably help as well.
I would also suggest putting some sort of pusher fan on, but I am thinking that would be a last resort.
Running a heater core in the wheel well might help, especially if it could get adequate airflow over it.
Have you considered moving the intercooler? It looks like you have a short, wide space behind the license plate that might get some airflow.
-Dave
Does your electric fan have a shroud?
Are you getting a lot of radiant heat in the engine bay? If you are, a turbo blanket on the turbine housing or a REALLY good ceramic coating might help. It looks like you have a heat shield over it now, which is probably a good start. Likewise, a good ceramic coating or exhaust wrap on the hot side tubing would probably help as well.
I would also suggest putting some sort of pusher fan on, but I am thinking that would be a last resort.
Running a heater core in the wheel well might help, especially if it could get adequate airflow over it.
Have you considered moving the intercooler? It looks like you have a short, wide space behind the license plate that might get some airflow.
-Dave
05-14-2009, 09:42 PM
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I have looked into placing the intercooler behind the license plat, but have yet to find a long skinny intercooler with 2.5" inlet/outlet that would fit.
I think another problem might be lack of coolent capacity. I know the radiator only holds about 2.5 gallons, and than whatever else is in the block, just does not seem like alot to me.
I think another problem might be lack of coolent capacity. I know the radiator only holds about 2.5 gallons, and than whatever else is in the block, just does not seem like alot to me.
05-15-2009, 01:06 AM
#5
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I agree with the line of thinking others have going here. Basically get some better fans if you don't already have the best. Also are you still running the stock T-stat?
05-15-2009, 05:30 AM
#6
Most cars don't run the fan at speed. I don't think bigger fans are the answer. You need to straighten out the airflow through the radiator when driving.
I would fabricate some type of ducting to make sure any air coming in the nose actually goes through the radiator and not around it. Adding a chin pan to smooth out the turbulence underneath the car letting air out the back of the radiator might help also.
If anything I would look at putting some type of fan/ducting in the back of the engine compartment to help move the air out of the back of the engine bay.
As for the heater core idea, there was a guy on a Z car site who swore by his heater cores in the wheel wells. If I remember right he went a little further and mounted small fans on the cores. Might have had a duct cut between the wheel well and the engine bay so it helped to further move air.
BTW, utterly awesome looking car.
I would fabricate some type of ducting to make sure any air coming in the nose actually goes through the radiator and not around it. Adding a chin pan to smooth out the turbulence underneath the car letting air out the back of the radiator might help also.
If anything I would look at putting some type of fan/ducting in the back of the engine compartment to help move the air out of the back of the engine bay.
As for the heater core idea, there was a guy on a Z car site who swore by his heater cores in the wheel wells. If I remember right he went a little further and mounted small fans on the cores. Might have had a duct cut between the wheel well and the engine bay so it helped to further move air.
BTW, utterly awesome looking car.
05-15-2009, 06:55 AM
#7
Most cars don't run the fan at speed. I don't think bigger fans are the answer. You need to straighten out the airflow through the radiator when driving.
I would fabricate some type of ducting to make sure any air coming in the nose actually goes through the radiator and not around it. Adding a chin pan to smooth out the turbulence underneath the car letting air out the back of the radiator might help also.
If anything I would look at putting some type of fan/ducting in the back of the engine compartment to help move the air out of the back of the engine bay.
As for the heater core idea, there was a guy on a Z car site who swore by his heater cores in the wheel wells. If I remember right he went a little further and mounted small fans on the cores. Might have had a duct cut between the wheel well and the engine bay so it helped to further move air.
BTW, utterly awesome looking car.
I would fabricate some type of ducting to make sure any air coming in the nose actually goes through the radiator and not around it. Adding a chin pan to smooth out the turbulence underneath the car letting air out the back of the radiator might help also.
If anything I would look at putting some type of fan/ducting in the back of the engine compartment to help move the air out of the back of the engine bay.
As for the heater core idea, there was a guy on a Z car site who swore by his heater cores in the wheel wells. If I remember right he went a little further and mounted small fans on the cores. Might have had a duct cut between the wheel well and the engine bay so it helped to further move air.
BTW, utterly awesome looking car.
you could louver the hood ro open up the body work behind the front wheels. that should help air get out and that will let more air in. Forcing the air through the rad will also help.
The heater core idea isn't as daft as it sounds! i heard about a SC C5 guy (Snitz) that had heating problems. he drove road courses so it was 20min of HARD driving. as you have to have your win dows open anyway he just turned the heating on full to try and. he saw some good temps reductions! well worth a try in my opinion.
Also do you have an external oil cooler?? heard they help out alot!
im getting a little radical now
but have you thought about a REAR mounted rad instead/aswell as the front one??? the Sweeds do it all the time and they work REALLY well! if there is room you could flat mount it in the same location as the original engine and run a fan or two underneeth to pull air through. with a bit of ducting it could work REALLY REALLY well. then you could run a BIG fornt mount intercooler to! Chris.
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05-15-2009, 08:48 AM
#8
A chin spoiler is a really good idea. Even a heavy rubber air dam mounted under the radiator should make a difference. I took the air dam off my Corvette once because it kept scraping, and the engine ran significantly hotter. These cars face a similar situation to you - big engine crammed in a little sloped engine bay. They have to get every ounce they can out of their radiators.
The air dam will allow less air to flow under the car, creating a higher pressure area in front of the car (forcing more air through the rad) and a lower pressure area under the car (pulling more hot air out of the engine bay.) A heavy piece of rubber about as wide as the rad, mounted on the lower rad support, should get the job done. You'd probably be best off mounting it to a piece of aluminum angle and then mounding the angle to your rad support. The rubber might need some sort of support to keep it from bending back too far. If you scrape it on high curbs, it's just rubber!
Someone else might be able to chime in on how much clearance to leave between the ground and the air dam.
-Dave
The air dam will allow less air to flow under the car, creating a higher pressure area in front of the car (forcing more air through the rad) and a lower pressure area under the car (pulling more hot air out of the engine bay.) A heavy piece of rubber about as wide as the rad, mounted on the lower rad support, should get the job done. You'd probably be best off mounting it to a piece of aluminum angle and then mounding the angle to your rad support. The rubber might need some sort of support to keep it from bending back too far. If you scrape it on high curbs, it's just rubber!
Someone else might be able to chime in on how much clearance to leave between the ground and the air dam.
-Dave
05-15-2009, 07:50 PM
#11
05-15-2009, 07:58 PM
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I am liking the more holes in the hood idea.
I am trying to envision what is happening, especially at higher speeds it seems, and I figure that the air inside the engine bay is at a slightly higher pressure(since it is having a hard time leaving the engine bay) than the air trying to enter through the grill, causing that air to simply bypass the grill. Which would leave nasty hot air in the engine bay with no circulation.
It pains me to have to cut more holes in the hood, since I like the almost factory look. But If I do add some holes, how many would be enough? A couple 6x6" sets of louvers maybe?
I am trying to envision what is happening, especially at higher speeds it seems, and I figure that the air inside the engine bay is at a slightly higher pressure(since it is having a hard time leaving the engine bay) than the air trying to enter through the grill, causing that air to simply bypass the grill. Which would leave nasty hot air in the engine bay with no circulation.
It pains me to have to cut more holes in the hood, since I like the almost factory look. But If I do add some holes, how many would be enough? A couple 6x6" sets of louvers maybe?
05-15-2009, 08:07 PM
#13
I agree on the air out statement, but don't underestimate the power of good ducting to move the air where it needs to go. I saw a 20* F temp drop on the highway in my car (200 down to 180) with just a small amount of ducting to force air from the intercooler into the radiator, instead of around it. 20* F is pretty huge.
So air out, and ducting on the frontside and you should be golden. FWIW I have a 19x16" single pass radiator with a Taurus fan cooling my turbo 5.3 and I stay under 185* F no matter what I throw at it.
So air out, and ducting on the frontside and you should be golden. FWIW I have a 19x16" single pass radiator with a Taurus fan cooling my turbo 5.3 and I stay under 185* F no matter what I throw at it.
05-15-2009, 09:03 PM
#14
If you don't want to put holes in your hood, I would seriously consider putting an air dam below the radiator. It is extremely critical on Corvettes and I think I remember the supercharged F-body guys saying the same thing. That air dam will force more air through your radiator, but mostly pull more air through your radiator and out of your engine bay. It creates a lower pressure area under your car (and your engine bay) and pulls air out.
Plus it's a pretty cheap and relatively easy solution, that will not be seen since it's under the car. All you need is a piece of angle, a strip of rubber and 10 or so nuts and bolts. Looking at your project you are no stranger to custom fabrication!! Unlike the holes in your hood, if you decide it's not working, you can just take it off and be back to square one.
If you drill holes in your engine bay, I bet that after you get up to speed (where your problem seems to be), air will be flowing from the top of your hood, through the holes, into your engine bay, and then out the bottom of the engine bay. The pressure area on top of your car is generally higher and the pressure under your car is generally lower. The air will flow towards the lower pressure.
I'm not guaranteeing this will work, but I'd give it some serious thought.
-Dave
Plus it's a pretty cheap and relatively easy solution, that will not be seen since it's under the car. All you need is a piece of angle, a strip of rubber and 10 or so nuts and bolts. Looking at your project you are no stranger to custom fabrication!! Unlike the holes in your hood, if you decide it's not working, you can just take it off and be back to square one.
If you drill holes in your engine bay, I bet that after you get up to speed (where your problem seems to be), air will be flowing from the top of your hood, through the holes, into your engine bay, and then out the bottom of the engine bay. The pressure area on top of your car is generally higher and the pressure under your car is generally lower. The air will flow towards the lower pressure.
I'm not guaranteeing this will work, but I'd give it some serious thought.
-Dave
I am liking the more holes in the hood idea.
I am trying to envision what is happening, especially at higher speeds it seems, and I figure that the air inside the engine bay is at a slightly higher pressure(since it is having a hard time leaving the engine bay) than the air trying to enter through the grill, causing that air to simply bypass the grill. Which would leave nasty hot air in the engine bay with no circulation.
It pains me to have to cut more holes in the hood, since I like the almost factory look. But If I do add some holes, how many would be enough? A couple 6x6" sets of louvers maybe?
I am trying to envision what is happening, especially at higher speeds it seems, and I figure that the air inside the engine bay is at a slightly higher pressure(since it is having a hard time leaving the engine bay) than the air trying to enter through the grill, causing that air to simply bypass the grill. Which would leave nasty hot air in the engine bay with no circulation.
It pains me to have to cut more holes in the hood, since I like the almost factory look. But If I do add some holes, how many would be enough? A couple 6x6" sets of louvers maybe?
05-16-2009, 06:55 AM
#15
You don't want the openings in the hood to be at the very back - that is a high pressure area at speed and it will work against you.
Depending on how the hood is attached, you can put some washers under the bolts to get yourself a gap at the back just to see how that works, even though it is not ideal.
Depending on how the hood is attached, you can put some washers under the bolts to get yourself a gap at the back just to see how that works, even though it is not ideal.
05-16-2009, 07:21 AM
#16
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I agree on the air out statement, but don't underestimate the power of good ducting to move the air where it needs to go. I saw a 20* F temp drop on the highway in my car (200 down to 180) with just a small amount of ducting to force air from the intercooler into the radiator, instead of around it. 20* F is pretty huge.
So air out, and ducting on the frontside and you should be golden. FWIW I have a 19x16" single pass radiator with a Taurus fan cooling my turbo 5.3 and I stay under 185* F no matter what I throw at it.
So air out, and ducting on the frontside and you should be golden. FWIW I have a 19x16" single pass radiator with a Taurus fan cooling my turbo 5.3 and I stay under 185* F no matter what I throw at it.
Comes with a built in shroud, moves a ton of air. (2 speed)
I had one on my 02 Jeep Grand Cherokee 4.7 v-8 mudder.
It had a overheating problem before, but not after.
Quick fix, or at least worth a try before cutting into the hood, specially if you don't want to cut it.
http://cgi.ebay.com/ebaymotors/1994-...Q5fAccessories
http://cgi.ebay.com/ebaymotors/RADIA...Q5fAccessories
http://cgi.ebay.com/ebaymotors/RADIA...Q5fAccessories
This last one is the one I used on my old jeep.
http://cgi.ebay.com/ebaymotors/TAURU...Q5fAccessories
Temporary or permanent fan mounts I used
http://store.summitracing.com/partde...5&autoview=sku
Sweet car by the way.
We've got to see some videos of it after you get this cleared up.
05-16-2009, 10:45 AM
#18
In addition to using a flexible spoiler on the bottom of the car to direct the air up and through the radiator, I'd also try to seal the top of the radiator to the bottom of the hood, to prevent air from going around the radiator.
The air has to have a path to exit the radiator. What does it look like from the bottom? Is there enough air flow space behind the radiator?
Instead of cutouts on the hood, how about on the panels between the fenders and doors? (think 70's Trans Ams)
Engine oil cooler and transmission cooler...where are they installed?
The air has to have a path to exit the radiator. What does it look like from the bottom? Is there enough air flow space behind the radiator?
Instead of cutouts on the hood, how about on the panels between the fenders and doors? (think 70's Trans Ams)
Engine oil cooler and transmission cooler...where are they installed?
