HellaFab

Do any of you guys that run your cars with half rads duct the front end?

I just removed the AC from my EM1 and it left that gaping hole where the air would just bypass the radiator. Im not boosted so i doubt there would be much cooling issues but I want to hear what you guys do.

IDK if non-ac cars came with a duct from the factory or not.

Matt

dirty19

iTrader: (1)

You shouldnt experience any cooling issues at all.
Now would be a great time to upgrade to a full rad to make cooling better.

JW racing

Go with a full size rad

rice_classic

If you have the possibility to run a full rad, then do that.

Assuming you cannot then you need to consider the fact that the air will always take the path of least resistance. Therefore you need to create shrouding or dams so that air cannot flow around, below or above the radiator and is forced to then flow through it. This will greatly improve the efficiency of the radiator.

modusmortis

Or go with the honda solution. Civics that didn't come with ac from the factory had a block off cover where the condenser goes. 74149-sr3-000
Part 8 in the diagram here.

lsturbo33

Very cool find there sir. It is a good price too.

known

iTrader: (1)

Its a good idea to cover that gaping hole there with a full size rad or a block off.

We put an aluminum pan on an ITB car and he gained 2-3 mph just based off that on the straights.

That area being open creates a pocket and extra drag.


Nice oem piece, I wasnt aware of it. I have mine filled with a large oil cooler that covers most of the opening.

spAdam

iTrader: (1)

I used to have a few of those that I saved when we installed the A/C kits at the dealer. The lower models (dx and such) didn't come with it so we had to install the kits on every new one that came through. Pretty sure they've all been thrown away by now, I haven't seen them around the garage in years.

dirty19

iTrader: (1)

If not a full size rad the head to your local hardware store and get a piece of sheet metal.
No sense paying 90.00 for a piece of plastic.

spAdam

iTrader: (1)

Holy crap they want $90? Now I really wish I saved them!

dirty19

iTrader: (1)

Part number 7 right?
http://estore.honda.com/honda/parts/...++50&dl=207651

89.00
A piece of galvanized sheet metal a couple bux....
You had a small fortune in plastic plates man!

spAdam

iTrader: (1)

Dammit.

dirty19

iTrader: (1)

keep your eyes peeled ... if you find a few you can sell them for half that used?

spAdam

iTrader: (1)

Its a possibility.

Anyways, in the interest of keeping this discussion on topic, I've actually thinking on this subject a little bit for a while. It seems to me, based on the fact that the air is going to take the path of least resistance, that we can do some work to increase the efficiency of the radiator.

For one thing, these slim fans that I see a lot of people using are crap. The fans don't do much above 25mph or so (that's totally an anecdotal comment, I've never personally logged it) but when they are needed they might as well work. The stock shroud is a good design, but if an aftermarket fan is required, it should have a shroud imo. The Fluidyne setups look really nice even though I don't have any personal experience with them.

I think there could also be something to be gained from making sure that the radiator is the only way for air to get through the grill area. Instead of just putting a piece of sheet metal or plastic over the condenser opening, I'm thinking a piece that sits in that area but a little forward of the radiator, with a right angle bend that sits along the left side of the rad. One along the right side of the rad running up to the gill opening and around the top with some foam tape to fill the gaps should seal the deal.

Kind of recessing the radiator in this "box" will help pile up and slow down the air here. You want high density, slow moving air over the radiator so that it has time to transfer as much heat as possible to as many air molecules as possible. Without presenting any math (I know some of you guys are very resistant to equations), faster moving air is, by nature, less dense... meaning less stuff in the same space.

Also, since you're mechanically piling up the air in front of the rad AND heating it as it goes through, you should be creating a decent pressure differential on the back side that will help create the necessary mass flow over the fins.

It seems to me, that maybe with the exception of big K-motors and FI setups, that you should be able to get plenty of cooling out of a (2 or 3core) half rad with a little creativity without the weight penalty of a full rad. At some point if and when I get my bucket off of jackstands I'd really like to log inlet and outlet temps at the block water necks so I can get a legit number for the engine's heat rejection rate and see how much cooling we actually need.

Or am I over-thinking this? Should we all just go full width and move on to the next problem?

chargeR

Pretty sure it's part number 8 in that diagram as modusmortis mentions above, so it's only $31.57. For the effort of cutting something else to size and fiddling about until it fits I'd get the Honda part, but I am lazy like that and like things to fit properly.

spAdam

iTrader: (1)

Yeah its #8. Guess I should have looked at the pic. #9 is the fender liner.

89ssgti

exactly it's part number 8 in the diagram.
Mine was still there and I trimmed the bottom part for the oil cooler

jdmcivicracer89

running half rad without blocking off the ac condensor hole will have some heating issues. my em1 would always creep up to the hot and id have to let off on a road course to let the temps go down. all the air would bypass the radiator. blocing it off does help but why not invest in a full core oem replacement or best yet adual core full size radiator. i went with full size dual core and never had a heat issue again. i think the radiator is one of the good idea investment if road racing.

JDMEMone

I make some out of carbon that I sell out here in Utah for about $50 that i run on my track car, i was having cooling issues as well with a aluminum half rad and that fixed my problems!

Battosai84

The block of plate seems to be work on the similar heat issues I had with my half size mishimoto. Already had plans to do some ducting, looks like i have to get it rolling quicker than i thought.

Anyone have a picture of that OEM block of thingy?
and
Anyone some good pictures how to duct the radiator?

JW racing

Make a smaller entrance hole and seal everything inside off. The reason we want to slow the air down as it enters the radiator is to increase the pressure difference across the radiator. Slower air = higher pressure. The only way air moves from one place to another is by creating a pressure difference.


http://ecomodder.com/wiki/index.php/...IntakeDuct.jpg

http://www.fivestarbodies.com/index....product&id=275

http://www.fivestarbodies.com/index....product&id=461

spAdam

iTrader: (1)

I think that pic you linked is straight out of one of the Carroll Smith books. (Maybe he and Korff shared illustrations?)

dirty19

iTrader: (1)

Full rad call it a day.. Better cooling and no need for a cover.
relocating the lower mount is only a 30 min job with a welder, and a spot welder drill bit.

BlueTeg

iTrader: (2)

For those running turbo setups, it's not that easy since the manifold and/or turbo housing prohibits us from running the full length radiators....

dirty19

iTrader: (1)

Well theres a curveball I didnt see coming.
Your only option is to work within your limitations.
I dont have an answer for that one unless you want to run one of those rywire "in grill" radiator support deals.

The big problem is to get as much cooling from whatever you can fit in there.
More fans, or a hood with a front vent in it like the afterhours automotive hood vent.