A couple months ago while i was out in the local salvage yard searching for parts to repair the front-end damage on my car I ran across a 1989 "no hump" flat hood in the salvage yard. My original plane was to just get the VIS vented hood, but, after finding the 89 hood, I had an idea to save it... so, i decided to snag it up.

The 1989 hood does not fit the 2.0 engine properly, The hood WILL bolt up and shut with the cam gear cover off. but, if you so much as lightly press on the hood in the location of the timing belt the hood makes contact, So cutting a slot for the cam gears is necessary.


Because this is road race/street car That i plan to put working AC in, I still wanted a vented hood! So the search for a Functional hood vent was on. After weeks of searching the web for options i decided to go with a set of Run-Cool Large high flow hood louvers, The vents are pricey for what they are, no doubt about it. but... they're made in American by Americans.



The day i took it for a test drive the ambient outside air temperature was 113*F, The pavement was 145*F My logged IAT would be between 120*F at stop lights and during pulls, it would drop down (very fast might i add) to 113* street curse/highway cruse.

The project is still in the works, I still have some work to do around the timing cover slot.

What did you use to cut such clean holes in the hood without hitting/cutting through the hood bracing? Looks great by the way, good job brother!

Outrun Talon said:

What did you use to cut such clean holes in the hood without hitting/cutting through the hood bracing? Looks great by the way, good job brother!

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Thanks, I used a jig saw with a metal blade on most of it, avoiding the hood bracing, Then i carefully used a angle grinder with a cut-off wheel to cut the sections above the hood bracing.

Good work, personally I dont like the looks of it on that car though, mby on my jeep, they look like furnace vents. The timing belt thing is pretty goofy too.

My friend wants to take the hump off another stock hood and have 2 humps both cut open in front with a grill in place. I told him just to get a CF and be done...

props for uniqueness always tho

Not bad at all! I have always wanted to do that exact same thing, but have the vent under the hood coming up from underneath, and then either spot weld it in place or rivet. I may one day get a OEM hood and do just that. I think it would look sweet esp. if the vent was painted black.

I am about to install some vents in my summit. I am curious if it will run cooler or not. my car started running hot on the highway after I installed half size radiator.
would have liked to hear back to back numbers with vents and no vents,

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94awdcoupe said:

I am about to install some vents in my summit. I am curious if it will run cooler or not. my car started running hot on the highway after I installed half size radiator.
would have liked to hear back to back numbers with vents and no vents,

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As has been mentioned before, the air will take the path of least resistance. The air will flow from high pressure to low. If there are large openings next to your radiator the air will mostly bypass it. You ought to build a shroud next to your radiator and close off any openings and make sure that the only pathway for the air to take is to go through the radiator. Then the vents will help by creating a lower pressure behind the radiator.

Good luck.

I hadnt considered the lower pressure aspect. I was looking at it from a radiated heat angle. the engine compartment is essentially an upside down cup. when heat goes in it can only go out through underside of car. there is a tremendous amount of heat radiating from the turbo. trapped in the worst spot the end of the cup. venting the hot air off has to be pretty big. all the evo cars come with nice hood vents above the turbo. its surprising to think the dsm didnt get a vented hood.

whats really amazing to me is how quickly most remove the factory CAI setup in favor of of freer flowing intake. but now the turbo is just sucking in hot air from the compartment. even at just 400whp the turbo is sucking in some ten cubic feet of air per second. I would want that air to com from outside the compartment.

I was overheating at the track and put a carbon fiber vent in my hood years back. I can see the heat radiating out of the vent when at a stop. I made more changes than this vent and the new combination caused the overheating to go away (additional things like removing the AC condenser and related parts and adding an external oil cooler).

One thing I noticed with my hood vent is the hotter intake temps of the HVAC system when in motion. It seems like I cannot get cool air anymore through the HVAC system.This makes sense because I believe it draws the air in from the bottom of the windshield. Turning the air to recirculate helps.

What ever works in the arizona heat... I'll have to get creative myself . Making the move very soon to scottsdale

Just because a vent works at a stop or even at low speed doesn't mean it will at highway speed or faster. The right way to test it is to get (forgive me I do t recall the exact name) a vacuume gauge but it measures in in of water or something vs mercury. And place it's probe in different locations, once you find a low pressure area on top of your hood where there is a high pressure area underneath at highway speeds this is the ideal location. You can use this method to assist in designing air dams and what not as well to keep / enchance a low pressure area behinds your radiator. Also ducting is key!

Example a lot of the cowl induction seen in years past worked within a specific range of speed, but when you went faster a vacuum was actually formed reducing air flow to the carburetor. Point is test before you just go cutting holes, some people have caused the air pressure to increase under there hood making it harder for air to pass through the radiator because they thought something looked like it would work.

Good point, RipperXX. Here's a helpful link that folks might find beneficial that references where to locate the vent in the hood: http://www.autospeed.com/cms/article.html?&A=113178.

wow. good info. glad you posted that before I started cutting.

94awdcoupe said:

I am about to install some vents in my summit. I am curious if it will run cooler or not. my car started running hot on the highway after I installed half size radiator.
would have liked to hear back to back numbers with vents and no vents,

You must be logged in to view this image or video.

Click to expand...

Where did you get those vents?

they are a spare set I had for my evo 1. the original hood was damaged so I saved these before scrapping the hood.

Could anyone photoshop those Evo 1 vents onto a 1g DSM?

I have a spare hood laying around for the seagull, maybe I'll craft up a vented hood! Just for the giggies

Do it!