2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

KOYO vs Fluidline vs Godspeed radiators

Thread Tools
 
Search this Thread
 
Old 05-03-09, 01:19 AM
  #51  
I wish I was driving!

 
Join Date: Dec 2001
Location: BC, Canada
Posts: 5,241
Received 84 Likes on 68 Posts
Originally Posted by fc3s91
Here is one reason a dual pass radiator is better than a single pass:
The two major designs for radiators are vertical flow and horizontal flow. As far as efficiency is concerned, there is no advantage to horizontal-flow radiators other than that they tend to allow a larger core to fit into a given engine compartment. Virtually all production-based radiators are built with a single-pass design, where coolant enters from the engine into the top of the radiator and travels across the core to the outlet on the opposite side. While dual-pass radiators have been around for a long time, they are now beginning to show up in high-performance and racing applications. A dual-pass horizontal-flow radiator moves coolant across the top half of the radiator on the first pass, then directs the coolant across the lower portion of the radiator face for a second pass. One reason this works is because the velocity of the coolant roughly doubles when the coolant is forced to travel across half as many tubes per pass. This creates turbulence in the tubes, exposing more coolant to the radiator tube walls and improving heat transfer. This also presents an increased load to the water pump, which means using a dual-pass radiator demands a better water pump if the system is to take advantage of the dual-pass concept.
Thanks Robert
Laws of physics, supported by testing by the Society of Automotive Engineers > Car Craft Article
Old 05-03-09, 06:27 AM
  #52  
Cake or Death?

iTrader: (2)
 
clokker's Avatar
 
Join Date: Jan 2007
Location: Mile High
Posts: 10,249
Received 63 Likes on 53 Posts
As long as we're talking radiator theory....
Wouldn't it make sense to have the hot water enter at the bottom of the core and exit at the top?
Old 05-03-09, 09:33 AM
  #53  
R.I.P Mark( Icemark )

iTrader: (23)
 
fc3s91's Avatar
 
Join Date: Nov 2001
Location: socal
Posts: 3,912
Likes: 0
Received 1 Like on 1 Post
Originally Posted by scathcart
Laws of physics, supported by testing by the Society of Automotive Engineers > Car Craft Article
Yep that is exactly were I got it from.
Thanks
Robert
Old 05-03-09, 09:35 AM
  #54  
Senior Member

 
OutCold's Avatar
 
Join Date: May 2008
Location: Norway
Posts: 437
Likes: 0
Received 0 Likes on 0 Posts
Koyo`s for me, heard most good things about it and im running one myself.

Originally Posted by fc3s91
Here is one reason a dual pass radiator is better than a single pass:
The two major designs for radiators are vertical flow and horizontal flow. As far as efficiency is concerned, there is no advantage to horizontal-flow radiators other than that they tend to allow a larger core to fit into a given engine compartment. Virtually all production-based radiators are built with a single-pass design, where coolant enters from the engine into the top of the radiator and travels across the core to the outlet on the opposite side. While dual-pass radiators have been around for a long time, they are now beginning to show up in high-performance and racing applications. A dual-pass horizontal-flow radiator moves coolant across the top half of the radiator on the first pass, then directs the coolant across the lower portion of the radiator face for a second pass. One reason this works is because the velocity of the coolant roughly doubles when the coolant is forced to travel across half as many tubes per pass. This creates turbulence in the tubes, exposing more coolant to the radiator tube walls and improving heat transfer. This also presents an increased load to the water pump, which means using a dual-pass radiator demands a better water pump if the system is to take advantage of the dual-pass concept.
Thanks Robert

That would make the intake and output of the radiator on the same side?
Old 05-03-09, 09:39 AM
  #55  
R.I.P Mark( Icemark )

iTrader: (23)
 
fc3s91's Avatar
 
Join Date: Nov 2001
Location: socal
Posts: 3,912
Likes: 0
Received 1 Like on 1 Post
Originally Posted by scathcart
You haven't proven anything wrong, you aren't comparing identical cores, one with single pass, and one with dual pass.
Actually you are wrong, I have had a single pass koyo in the pass and by far the dual pass radiator cooled better. I also saw temps were more stable.
Thanks Robert
Old 05-03-09, 09:57 AM
  #56  
R.I.P Mark( Icemark )

iTrader: (23)
 
fc3s91's Avatar
 
Join Date: Nov 2001
Location: socal
Posts: 3,912
Likes: 0
Received 1 Like on 1 Post
Originally Posted by atticus_jay
this is helpful thread... how did you wire your E fan? possible diagram?
I used a flexalite variable speed controller. http://store.summitracing.com/partde...5&autoview=sku
I also use a 3300 cfm fexalite fan. http://store.summitracing.com/partde...5&autoview=sku

Installation:
http://www.flex-a-lite.com/auto/180-99180.pdf

Thanks Robert
Old 05-03-09, 10:11 AM
  #57  
R.I.P Mark( Icemark )

iTrader: (23)
 
fc3s91's Avatar
 
Join Date: Nov 2001
Location: socal
Posts: 3,912
Likes: 0
Received 1 Like on 1 Post
Originally Posted by scathcart
You haven't proven anything wrong, you aren't comparing identical cores, one with single pass, and one with dual pass.
Look, Im not going to get into a engineer war because Im not an engineer. I can only tell you what my finds were by my datalog and gauges. I have a Apexi pfc that I can datalog off of. Also have a Mechanical gauges that tell me temps before the thermostat. So i have one temp before the thermostat and after the thermostat. You can take alook at my pics on my album and you will find Im not your average person on this forum.
Thanks Robert
Old 05-03-09, 11:31 AM
  #58  
Rotary $ > AMG $

iTrader: (7)
 
jackhild59's Avatar
 
Join Date: Apr 2005
Location: And the horse he rode in on...
Posts: 3,783
Received 24 Likes on 23 Posts
Originally Posted by fc3s91
One reason this works is because the velocity of the coolant roughly doubles when the coolant is forced to travel across half as many tubes per pass. This creates turbulence in the tubes, exposing more coolant to the radiator tube walls and improving heat transfer.
Yes. At the cost of reduced coolant flow-fewer # per minute of coolant at higher efficiency.

Is (Higher efficiency*fewer#/min) > (Lower efficiency*greater #/min)?

Someones gotta do the math to know for sure.

But if the real world usage with accurate data collection says it works well, then it *does* work well.

Originally Posted by fc3s91
This also presents an increased load to the water pump, which means using a dual-pass radiator demands a better water pump if the system is to take advantage of the dual-pass concept.
Thanks Robert
With higher head pressure comes higher horsepower requirement at the water pump shaft. How much? We don't know.

We are going to see increased water pump pulley slippage with this setup if the increased head pressure is significant

And BTW, if the designers increase the tube size to mitigate pressure increase, then much of the advantage of the dual pass is lost.

That all being said, the unit looks pretty nice. I like the bung placements for temp sensors.
Old 05-03-09, 02:34 PM
  #59  
I wish I was driving!

 
Join Date: Dec 2001
Location: BC, Canada
Posts: 5,241
Received 84 Likes on 68 Posts
Originally Posted by jackhild59
Yes. At the cost of reduced coolant flow-fewer # per minute of coolant at higher efficiency.

Is (Higher efficiency*fewer#/min) > (Lower efficiency*greater #/min)?

Someones gotta do the math to know for sure.

But if the real world usage with accurate data collection says it works well, then it *does* work well.



With higher head pressure comes higher horsepower requirement at the water pump shaft. How much? We don't know.

We are going to see increased water pump pulley slippage with this setup if the increased head pressure is significant

And BTW, if the designers increase the tube size to mitigate pressure increase, then much of the advantage of the dual pass is lost.

That all being said, the unit looks pretty nice. I like the bung placements for temp sensors.
Lower coolant flow will always cause lower heat transfer from the block into the coolant. Localized boiling and hot spots are always the result, which can lead to engine water seal failure, and increase the cahnces of pre-ignition and detonation.
Old 05-03-09, 09:01 PM
  #60  
Rotary $ > AMG $

iTrader: (7)
 
jackhild59's Avatar
 
Join Date: Apr 2005
Location: And the horse he rode in on...
Posts: 3,783
Received 24 Likes on 23 Posts
Originally Posted by scathcart
Lower coolant flow will always cause lower heat transfer from the block into the coolant.
True statement.

Originally Posted by scathcart
Localized boiling and hot spots are always the result, which can lead to engine water seal failure, and increase the cahnces of pre-ignition and detonation.
Overreaching generalization, Engineer. If you haven't measured it, you don't know.

You know this better than most.

Originally Posted by jackhild59

Someones gotta do the math to know for sure.

Is there an echo in here?
Old 05-03-09, 09:49 PM
  #61  
R.I.P Mark( Icemark )

iTrader: (23)
 
fc3s91's Avatar
 
Join Date: Nov 2001
Location: socal
Posts: 3,912
Likes: 0
Received 1 Like on 1 Post
Well I just got back form the track and results were better than I expected. Temps on my datalogit were no more than 95c. On the temp gauge read no more than 195 deg. Oil temps were great 210 deg or less. My oil temps had decreased. All around temps were good.
Thanks Robert
Old 05-03-09, 09:50 PM
  #62  
R.I.P Mark( Icemark )

iTrader: (23)
 
fc3s91's Avatar
 
Join Date: Nov 2001
Location: socal
Posts: 3,912
Likes: 0
Received 1 Like on 1 Post
This was also tested at Califorina speedway doing 12 laps.
Thanks Robert
Old 05-04-09, 02:15 AM
  #63  
Full Member

 
Sandbagger's Avatar
 
Join Date: Feb 2007
Location: Socal
Posts: 123
Likes: 0
Received 0 Likes on 0 Posts
Okay, I've read through this thread a few times and I am confused with what everyone is debating.

The OP asked a very straight forward question, "how does the GodSpeed Rad compare to Koyo and Fluidyne?"

2 members have stated from personal experience that the GodSpeed radiator has improved their water temps (lower and more stable). So to me it appears that the GodSpeed unit is a good purchase and is more affordable compared to other bolt-in units on the market.

As I continued down the thread, it seems that the topic has changed to the advantages and dis-advantages of single pass and dual pass radiators.

Each type has their own benefits, when CONSIDERED as part of a COMPLETE SYSTEM.

Now it is great to talk about ideal situations and how things are supposed to work. But it in the real world there are outside variables that will change these calculations and all we can do is make adjustments to suit our personal needs.

Is a single pass radiator a good design?

Is a dual pass radiator a good design?

The answer to both these questions is YES, given a properly designed system.

Now let's look at the stock system; single pass, non-cross flow (not ideal).

Will a cross flow be an improvement over the stock unit? Probably, because it promotes a more uniform heat transfer than the stock unit; vs. having one side of the radiator hotter than the other because the coolant has to travel diagonally across the core from inlet to outlet.

What about a dual pass system? Yes, as proven by 2 members using the GodSpeed on their personal cars.

I have to say that I was very apprehensive about a no-name company's product. But after today and witnessing it first hand, I have to say I was impressed.

I am the co-driver for FC3S91's car and after a hard day autcrossing in 90 degree weather at Cal Speedway; plus driving on LA freeways with the A/C on full blast, I never saw the water temps exceed 195 degrees. It was nice not having to wait as long for the car to cool down between runs! Which is outstanding once you take into account that Rob's car puts down over 360 @ the rear wheels on R compound tires. Not to mention that 3 boost happy drivers were behind the wheel!

Now the real test will be at the end of the month, when the car will be on the infield running 30 min. sessions, all day long. If the GodSpeed holds up to this and maintains the same temps as today, I'm sold on the unit and will confidently say that it will work on any street driven FC with a proper functioning cooling system.
Old 05-04-09, 05:30 AM
  #64  
B O R I C U A

iTrader: (14)
 
KNONFS's Avatar
 
Join Date: Mar 2001
Location: VA
Posts: 5,480
Received 35 Likes on 29 Posts
Originally Posted by J-Rat
All were installed correctly, all failed at the seam.


Not trying to steer people away from the Koyo, just throwing out what I have seen. I wouldnt buy one.
Mine failed at the cap base/mount
Old 05-09-09, 05:05 PM
  #65  
I'm charming
iTrader: (9)
 
kevyn_rx7's Avatar
 
Join Date: Apr 2009
Location: Dayton, Ohio
Posts: 474
Likes: 0
Received 1 Like on 1 Post
i'm curious to know how the godspeed rad's are holding up for you guys. if all is well i'm going to buy one soon.
Old 05-12-09, 09:49 AM
  #66  
Junior Member
 
ZoominFD's Avatar
 
Join Date: Apr 2009
Location: Philadelphia
Posts: 27
Likes: 0
Received 0 Likes on 0 Posts
I wouldn't suggest a Koyo, they are made by little girls.


http://www.koyorad.com/company.html
Old 05-12-09, 09:57 AM
  #67  
R.I.P Mark( Icemark )

iTrader: (23)
 
fc3s91's Avatar
 
Join Date: Nov 2001
Location: socal
Posts: 3,912
Likes: 0
Received 1 Like on 1 Post
Originally Posted by kevyn_rx7
i'm curious to know how the godspeed rad's are holding up for you guys. if all is well i'm going to buy one soon.
Okay, I've read through this thread a few times and I am confused with what everyone is debating.

The OP asked a very straight forward question, "how does the GodSpeed Rad compare to Koyo and Fluidyne?"

2 members have stated from personal experience that the GodSpeed radiator has improved their water temps (lower and more stable). So to me it appears that the GodSpeed unit is a good purchase and is more affordable compared to other bolt-in units on the market.

As I continued down the thread, it seems that the topic has changed to the advantages and dis-advantages of single pass and dual pass radiators.

Each type has their own benefits, when CONSIDERED as part of a COMPLETE SYSTEM.

Now it is great to talk about ideal situations and how things are supposed to work. But it in the real world there are outside variables that will change these calculations and all we can do is make adjustments to suit our personal needs.

Is a single pass radiator a good design?

Is a dual pass radiator a good design?

The answer to both these questions is YES, given a properly designed system.

Now let's look at the stock system; single pass, non-cross flow (not ideal).

Will a cross flow be an improvement over the stock unit? Probably, because it promotes a more uniform heat transfer than the stock unit; vs. having one side of the radiator hotter than the other because the coolant has to travel diagonally across the core from inlet to outlet.

What about a dual pass system? Yes, as proven by 2 members using the GodSpeed on their personal cars.

I have to say that I was very apprehensive about a no-name company's product. But after today and witnessing it first hand, I have to say I was impressed.

I am the co-driver for FC3S91's car and after a hard day autcrossing in 90 degree weather at Cal Speedway; plus driving on LA freeways with the A/C on full blast, I never saw the water temps exceed 195 degrees. It was nice not having to wait as long for the car to cool down between runs! Which is outstanding once you take into account that Rob's car puts down over 360 @ the rear wheels on R compound tires. Not to mention that 3 boost happy drivers were behind the wheel!

Now the real test will be at the end of the month, when the car will be on the infield running 30 min. sessions, all day long. If the GodSpeed holds up to this and maintains the same temps as today, I'm sold on the unit and will confidently say that it will work on any street driven FC with a proper functioning cooling system
Old 05-12-09, 10:02 AM
  #68  
Rotary $ > AMG $

iTrader: (7)
 
jackhild59's Avatar
 
Join Date: Apr 2005
Location: And the horse he rode in on...
Posts: 3,783
Received 24 Likes on 23 Posts
Originally Posted by jackhild59
Is there an echo in here?
Yes, there is an echo in here!
Old 05-12-09, 02:12 PM
  #69  
Junior Member

 
PwnedurFace's Avatar
 
Join Date: Sep 2006
Location: WV
Posts: 26
Likes: 0
Received 0 Likes on 0 Posts
I was thinking about getting a godspeed front mount and radiator
Old 05-12-09, 05:17 PM
  #70  
Registered User
iTrader: (1)
 
CorkSport's Avatar
 
Join Date: Aug 2002
Location: Vancouver, WA USA
Posts: 1,761
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by LaSkt9
corksport is cheap butttt you have to buy the shroud too which makes it around the same price as the koyo... i had the same questions a while ago i went fluidine love it
You don't have to use the shround we made with our radiator. The shroud is just for people who want to keep the stock fan. With the radiator core being as thicker than stock we wanted to give people an extra option instead of going electric.

Derrick
Old 05-15-09, 01:21 PM
  #71  
Driving RX7's since 1979

iTrader: (43)
 
HOZZMANRX7's Avatar
 
Join Date: Aug 2001
Location: So Cal where the OC/LA/SB counties meet
Posts: 6,096
Likes: 0
Received 8 Likes on 8 Posts
To answer one question regarding dual pass with stock fan

I have a Koyo Dual Pass in my S5 TurboVert using the stock fan shroud and fan. All that is needed is some minor trimming along the lower part of the fan opening. This is because the thicker radiator moved the shroud slightly up and toward the fan resulting in the fan being slightly inside the shroud at the bottom rather than behind it. A grinder wheel works very well for this.

You also need to do a little trimming around where the lower radiator hose mounts.
Old 06-18-09, 08:16 AM
  #72  
PedoBear

iTrader: (4)
 
nycgps's Avatar
 
Join Date: Jun 2006
Location: Bye NYC. you SUCKED!
Posts: 1,429
Received 1 Like on 1 Post
can I just "not" install the shroud back ? its probably gonna kill the airflow.

just wondering.
Old 06-18-09, 10:12 AM
  #73  
R.I.P Mark( Icemark )

iTrader: (23)
 
fc3s91's Avatar
 
Join Date: Nov 2001
Location: socal
Posts: 3,912
Likes: 0
Received 1 Like on 1 Post
You need the shrouding because it help with the coolong. So to answer your guestion No!
Old 11-09-09, 09:01 PM
  #74  
Too Many Questions
 
lonetlan's Avatar
 
Join Date: Jan 2009
Location: Claremore, Oklahoma
Posts: 737
Likes: 0
Received 0 Likes on 0 Posts
So, its been awhile and there isn't a follow up on the "infield 30 minute runs", with the godspeed radiator; I'm almost sold, if this post is answered by the tester(s), that would be cool.

To the people who said that their radiator failed, were exactly did it fail on the core and what were the conditions? An answer to this would be cool also

I'm amazed at how impressive you guys/gals debate skrills are! Its like Einstein vs. Bohr!
Old 11-09-09, 09:19 PM
  #75  
I'm charming
iTrader: (9)
 
kevyn_rx7's Avatar
 
Join Date: Apr 2009
Location: Dayton, Ohio
Posts: 474
Likes: 0
Received 1 Like on 1 Post
i'm also looking for some reviews... but i'm really considering just biting the bullet and buying a new fluidyne


Quick Reply: KOYO vs Fluidline vs Godspeed radiators



All times are GMT -5. The time now is 09:45 AM.