Long awaited open/closed hood scoop temp testing

[JeremyH]

Got a nice thermal temp gun for christmas so finally got around do doing some testing of the open hood scoop mod I did years back.

To see info on this mod and how I and others have done it look here:

http://www.s197forum.com/forum/showthread.php?t=22443&highlight=scoop

(on mine I left the stock honeycomb in place and opened up the back of it)

I will do another run this summer on a hot day as well and add it to the thread later on.


Intial conditions for todays "wintertime" test. 45 degrees outside. Let the car warm up to 190 degrees before testing (where my high speed fan kicks on). I then drove for 15 minutes on the same route before each test which involved a mix of city and highway driving. Then I came back home immediately opened the hood and took the temps with engine still running.

Run 1 - Hood scoop taped shut.

Turbo compressor cover

Intake pipe

Thottlebody

Intake manifold

Fuel rail

Run 2 - Hood scoop open.

Turbo compressor cover

Intake pipe

Thottlebody

Intake manifod

Fuel rail

So results for "wintertime" 45 degree day test are:

-----------------------------Closed Scoop-------Open Scoop---------Difference-----
Turbo compressor cover------ 141.5 -------------- 115.5 ------------- -26.0
Intake pipe------------------- 98.0 --------------- 78.5 ------------- -19.5
Throttlebody----------------- 85.0 --------------- 68.5 -------------- -16.5
Intake manifold--------------- 101.5 -------------- 87.0 ------------- -14.5
Fuel rail---------------------- 114.0 -------------- 106.0 ------------- -8.0


So big difference! And overall average underhood temps were 13 degrees cooler with the scoop open. Not bad for a free mod.

 

[retfr8flyr]

Not seeing anything for Run 2 - Hood scoop open.



Earl

 

[JeremyH]

Not seeing anything for Run 2 - Hood scoop open.



Earl

Wasn't done posting yet lol. Results and comparison table are up.

 

[retfr8flyr]

Understood. lol

Very interesting results, it will be fun to see what a difference it makes when it's 90 outside.


Earl

 

[JeremyH]

Understood. lol

Very interesting results, it will be fun to see what a difference it makes when it's 90 outside.


Earl

I knew this mod has to help as even on a cold day like today I can see heat waves pouring out of the scoop just sitting still idling in the driveway. Glad to finally get some data on it. I look foward to the summer test as well.

I suspect the biggest benfit is not letting heat gather in the top of the bay and heatsoaking everything when driving and when coming to stops etc. Letting cool air in while driving may have a lesser effect etc.

 

[retfr8flyr]

I know my cowl hood made a big difference with mine. Like you I can see heat waves pouring out from the cowl area all the time, doesn't make a difference on the outside temps. I know you don't believe in them but the turbo blankets also made a difference on mine.


Earl

 

[JeremyH]

A blanket is fine for a water cooled turbo as there less chance of hurting the turbo with the water cooling, the blanket of course will keep heat out of the engine bay but coating the turbine housing inside and out does a better job imho. It forces the heat into the down pipe and out of the engine bay via the exhuast vice the blanket just catching it and trying to hold it in the space between the turbine and blanket, then the heat still has to escape and go some where eventually ie engine bay or back into the turbo.

Here are some interesting results I got with the temp gun today after doing these tests. The turbine is the hottest thing to "touch" (as far as being able to hold my hand on the longest) but if I hold my hand right over it I feel no heat and the gun only reads it as being 80-90 degrees while everything else is much hotter, if I hover my hand over the down pipe I can definetly feel the heat coming off. Thought that was pretty interesting.

Chra of turbo (water from the block is around 150-160 degrees coming in when the car is warmed up and around 200 coming out)

Turbine cover coated inside and out.

Downpipe (coated on outside only and wrapped)

Also no picture but my outside coated only ceramic headers measured around 250 on each runner.

I would like to do some direct swap testing of outside coated only piping and then inside and outside coated piping like me and Bobby and have been doing. I think there is a real difference there as far as keeping heat in and letting it go out the exhuast.

 

[S197MustangGT]

very nice! if mine had a factory scoop I would do the same!

 

[Bobby]

Good mod

 

[05stroker]

If you get time you might want to remove the fac rad cover and retest. With my cowl hood I can see my grill! LOL
Nice results either way!

 

[BlueDevil]

Well done, Jeremy!
I'm considering a blanket for my kb inlet (ST 4" metal inlet, not the plastic kb one). Thoughts?

 

[Nickoli]

If you get time you might want to remove the fac rad cover and retest. With my cowl hood I can see my grill! LOL
Nice results either way!

I would think that part will help direct air through the radiator rather than over the top of it. That could cause water temps to go up if removed...

 

[05stroker]

I would think that part will help direct air through the radiator rather than over the top of it. That could cause water temps to go up if removed...

That is how mine has been since it was completed this year. No issues in cooling here.

 

[JeremyH]

Well done, Jeremy!
I'm considering a blanket for my kb inlet (ST 4" metal inlet, not the plastic kb one). Thoughts?

I'm under the thought that the actual temp of the inlet pipe isnt that big of a factor for iat's as its pull through rather quickly so not sure how much wrap would do for you as it will still heatsoak. But I have seen people do the reflective heat tape which will keep the pipe cooler longer as well. Its not pretty though lol

 

[JeremyH]

I would think that part will help direct air through the radiator rather than over the top of it. That could cause water temps to go up if removed...

That is how mine has been since it was completed this year. No issues in cooling here.

Its not just a cosmetic cover is what I thought as well. Its actualy called an air diversion plate/cover something like that and keeps air from going over top of the radiator and forces it to go through the core. I dont see any benefit from removing it really.

 

[05stroker]

Its not just a cosmetic cover is what I thought as well. Its actualy called an air diversion plate/cover something like that and keeps air from going over top of the radiator and forces it to go through the core. I dont see any benefit from removing it really.

Understood and I do understand the design. I am just saying I havent seen any temp issues with it removed.

And the up side is, I can see out my grill through my cowl opening. Were there is light there is air. LOL

 

[JeremyH]

Right, but its just air splashing through the grill and up and over the top of the radiator and into the engine bay, so my point is your sacificing a little cooling on the radiator (however little that may acutaly be) whats the gain? Besides it being cool to see daylight from the cowl to the grill lol

Like I've mentioned on this hood scoop mod, its not that im letting cooler air in that makes the difference imho its that im allowing hot air to escape easier in the hottest spot in the engine bay right up top where heat rises so less heat soak on stuff where heat normal stays trapped. etc.

 

[05stroker]

Right, but its just air splashing through the grill and up and over the top of the radiator and into the engine bay, so my point is your sacificing a little cooling on the radiator (however little that may acutaly be) whats the gain? Besides it being cool to see daylight from the cowl to the grill lol

For me its simple, if there is no effect on cooling and less under the hood temps then that is a plus IMO.

 

[Memphis 05]

Understood and I do understand the design. I am just saying I havent seen any temp issues with it removed.

And the up side is, I can see out my grill through my cowl opening. Were there is light there is air. LOL

Running the same in my car. Radiator cover off and I have not seen any temps above 195. On the highway or in traffic. Btw I am running a auto enter temp gauge to measure these temps. But would like to see if it does help or hurt

 

[05stroker]

Running the same in my car. Radiator cover off and I have not seen any temps above 195. On the highway or in traffic. Btw I am running a auto enter temp gauge to measure these temps. But would like to see if it does help or hurt

I think any air moved through the engine bay while the car is moving is a plus , as long as the cooling dosent suffer.