Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now


Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 10-18-2009, 04:56 PM   #1 (permalink)
Master EcoModder
 
Join Date: Sep 2008
Location: Fort Worth, Texas
Posts: 260

450hp Audi Monster! - '01 Tt Quattro
Thanks: 0
Thanked 0 Times in 0 Posts
Question Duct radiator into exhaust --- Possible?

Merge them before the catalytic converter, so you can seal the engine compartment completely (well, after the radiator grill) and have no aerodynamic losses from the air going everywhere and around the engine compartment... ?

This would also boost radiator efficiency since the air would be "ducted" and given an airway path- not just a "go find somewhere" around the engine compartment.

What do you think? Possible?


(Support Ecomodder.com & get rid of these annoying ads!)      
 
  Reply With Quote
Old 10-18-2009, 05:08 PM   #2 (permalink)
Master EcoModder
 
Old Tele man's Avatar
 
Join Date: Jul 2009
Location: Tucson, AZ
Posts: 430

Vibe - '09 Vibe Base (2ZR-FE)
90 day: 35.23 mpg (US)
Thanks: 0
Thanked 10 Times in 10 Posts
...exhaust volume is determined by engine RPM, while radiator air is determined by MPH (assuming all else constant)...so you're gonna encounter one heck of a "merging" problem.

...it's possible, but IMHO going to entail LOTs of duct work.
__________________
...and the Devil said: "...yes, but it's a DRY heat!"
  Reply With Quote
Old 10-18-2009, 05:13 PM   #3 (permalink)
EcoModding Apprentice
 
Join Date: Oct 2009
Location: Portland OR
Posts: 112
Thanks: 1
Thanked 2 Times in 2 Posts
on formula cars as well as sports racers (Formula car with a full body)
The ducting of the air through the radiator has huge effects on speed.

The EVO/Touring Cars all duct their air up through a tuned hole in the hood so as to take the firewall air out of play aerodynamically.

But you have to rethink engine insulation, there is a lot of stuff under the hood that needs some air flow to stay healthy. (Alternator, electronics etc)

Dave
  Reply With Quote
Old 10-18-2009, 05:16 PM   #4 (permalink)
Master EcoModder
 
Join Date: Sep 2008
Location: Fort Worth, Texas
Posts: 260

450hp Audi Monster! - '01 Tt Quattro
Thanks: 0
Thanked 0 Times in 0 Posts
Well I was thinking of a simple y-pipe with a one way valve on the radiator side so the exhaust doesn't go backwards into the radiator...
  Reply With Quote
Old 10-18-2009, 05:34 PM   #5 (permalink)
EcoModding Apprentice
 
Join Date: Oct 2009
Location: Portland OR
Posts: 112
Thanks: 1
Thanked 2 Times in 2 Posts
I think your attacking too deep, what if you just duct the radiator to its own pipe,
It would need to be about 1/4 the size of the radiator... Your radiator needs about 2000 to 4000 CFM depending on the setup. No restrictions allowed. Of course your fan choice would be key, with the right fan the pipe could be smaller...

Dave
  Reply With Quote
Old 10-19-2009, 01:59 AM   #6 (permalink)
Take me to your Earthling
 
Piwoslaw's Avatar
 
Join Date: Oct 2008
Location: Warsaw, Poland
Posts: 658

Svietlana - '05 307 SW
Diesel
90 day: 50.47 mpg (US)
Thanks: 41
Thanked 39 Times in 21 Posts
I think ducting radiator air to the wheelwells would be better, and easier. This would reduce snow buildup and maybe improve airflow in the wheelwells, which usually have lower pressure than the engine bay.
__________________
Piwoslaw's Peugeot 307sw modding thread

"You can't call yourself human if you think only of yourself."

Don't laugh at things you don't understand.

Quote:
Originally Posted by blueflame View Post
The more you drive, the less you think. Thats why I always take the bus.
  Reply With Quote
Old 10-19-2009, 03:33 AM   #7 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 4,434

Cara's Work Log - '00 Caravan
90 day: 28.21 mpg (US)

Cara - '00 Caravan Base
90 day: 29.01 mpg (US)
Thanks: 147
Thanked 70 Times in 63 Posts
You'd need a "path of least resistance" setup for the exhuast, so that it could not come back through the vent under low pressure situations.

As was said, yes, it could be done. Special care would need to be taken, though.

When I first read this, I read it as (duct radiator through exhaust) meaning: (run coolant through a radiator fitted to the exhaust pipe to cool the engine). I was all prepared to tell you why it just wouldn't work.

The added benefit of running your heated radiator airflow to the exhaust is that:
At low radiator velocity, high exhaust velocity, the exhaust will act like a siphon flow, pulling more air through the radiator via negative pressure at the back of the radiator's surface.

At high vehicle speed/low engine speed - the excess flow from the radiator, ducted smoothly into the exhaust pipe, would work to increase scavenging due to a siphon flow effect creating negative pressure on the back of the valves, increasing the pressure differential across the face of the valve as it opens.

At a high enough speed with low enough engine speed (not even extremes, here), one could experience lowered pumping losses due to the piston no longer having to apply nominal pressure to the exhaust gasses to force them out.
__________________


"¿ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

Quote:
Originally Posted by tasdrouille View Post
Because bean counters always win, that's why.
  Reply With Quote
Old 10-19-2009, 04:10 AM   #8 (permalink)
Master EcoModder
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 2,365

Blue - '93 Tempo
Last 3: 27.29 mpg (US)

F150 - '94 F150 XLT
90 day: 17.21 mpg (US)

Sport Coupe - '92 Tempo GL
Last 3: 69.62 mpg (US)
Thanks: 40
Thanked 76 Times in 60 Posts
I'm reading it as having an air duct with the exhaust pipe running within it- I mean, if you want something that has a shot at working.
__________________
  Reply With Quote
Old 10-19-2009, 04:27 AM   #9 (permalink)
EcoModding Apprentice
 
Join Date: Oct 2009
Location: Portland OR
Posts: 112
Thanks: 1
Thanked 2 Times in 2 Posts
Quote:
Originally Posted by basslover911 View Post
Well I was thinking of a simple y-pipe with a one way valve on the radiator side so the exhaust doesn't go backwards into the radiator...
Remember the air flow through the radiator is dependent on zero back pressure behind the radiator, and the air coming into the engine compartment is to cool stuff besides the radiator..

Dave
  Reply With Quote
Old 10-19-2009, 10:46 AM   #10 (permalink)
Master EcoModder
 
Join Date: Sep 2008
Location: Fort Worth, Texas
Posts: 260

450hp Audi Monster! - '01 Tt Quattro
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Christ View Post
The added benefit of running your heated radiator airflow to the exhaust is that:
At low radiator velocity, high exhaust velocity, the exhaust will act like a siphon flow, pulling more air through the radiator via negative pressure at the back of the radiator's surface.
EXACTLY what I was thinking! And that is 99% the case anyway... unless the fans are on AND you are running above 100mph lol.

I don't know how much restriction a one way valve would give though...

And I also thought about venting them to the wheel wells... but aren't we always trying to remove airflow from them with things like wheel skirts and flat moon discs? Why would we even think about adding more flow there it just contradicts everything I believe...
  Reply With Quote
Reply  Post New Thread

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Raising Exhaust 99LeCouch Aerodynamics 13 10-18-2009 06:51 AM
Mimicking Gen3 Prius Exhaust Heat Recovery Daox EcoModding Central 36 08-05-2009 03:46 PM
Does Exhaust Noise Play a Role in Fuel Economy? Metallover EcoModding Central 16 07-12-2009 10:47 PM
Civic Vx engine question. stock exhaust manifold vs. stock exhaust manifold vtecn8ive DIY / How-to 3 07-12-2009 02:07 PM
MetroMPG.com mailbag: various questions (final drive, exhaust, underdrive pulleys...) MetroMPG EcoModding Central 0 02-23-2008 09:40 PM




Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2009, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.3.2
All content copyright EcoModder.com