zliminator Posted December 30, 2005 Share Posted December 30, 2005 I've been planning to do a cowl induction for over 2 years because I saw a documentary of the 1st GTOs where they said the front hood scoop i.e. ram air was just cosmetic because as soon as the air hits the front of the hood it bounces up and creates a vacuum around the front of the hood. Now someone has just informed me that unless I'm going to be racing, then I should just stick to a ram air and that cowl ind. doesn't really kick in till I get up around 100 or so. Who's right? I was thinking I could just put some vents on the hood duct it in around the air cleaner. That would be the easiest way, I'm thinking. I was hooked on the cowl ind. mostly because of looks, too. Dan Quote Link to comment Share on other sites More sharing options...
Phantom Posted December 30, 2005 Share Posted December 30, 2005 I've actually posted on this once before. I did a ram air experiment for a mechanical engineering senior design class. I used the 340 'Cuda I had at the time as I was considering opening up the hood scoops to get ram air. The first thing I discovered - like Pontiac with the Firebird -that the inlet to the scoop needs to be moved to the leading edge of the hood to avoid the dreaded pressure curl that occurs when the air rises up over the hood. The second thing I discovered is that there is no sifgnificant contribution made by 'ram' air until you're passing the 90 MPH mark. Below that it is negligible. The third thing I discovered was that the temperature of the ambient air above the hood was about 100°F lower than the intake air behind the radiator. The additional density of the cooler air netted about a 5% gain in HP. Bottom line - the term is 'cold air intake' - any way you can get it - whether it be by cowl induction or a hood scoop. Quote Link to comment Share on other sites More sharing options...
260DET Posted December 30, 2005 Share Posted December 30, 2005 If you are using the stock Z aircleaner you could run some flexible hose forward from the cleaner through the radiator support panel. In front of that panel is a high pressure area, ideal for what you want. Alternatively some get an air box made up in place of the stock aircleaner and use a pod filter in front of the support panel. Quote Link to comment Share on other sites More sharing options...
zliminator Posted December 30, 2005 Author Share Posted December 30, 2005 It has a round type air cleaner. I was thinking of just putting some grills in the hood and ducting it around the aircleaner and be done with it. Except how do you keep the rain from getting into the air cleaner? I may just go with cowl induction. Quote Link to comment Share on other sites More sharing options...
Bartman Posted December 30, 2005 Share Posted December 30, 2005 I've been watching this post since it started because I'm wondering how to get ram air on my setup as well. If I remember correctly, the Camaro's and Trans Am's that had Ram air claimed to have more horsepower just from this option (something lke 8 - 15 hp). Am I remembering this correctly, or is it just an urban legend? I don't know if there were the same type of claims with the cowl induction. Based on what's been posted so far, it appears that your better off just getting air from in front of the radiator support (colder and higher pressure). I am also curious about rain with a ram air system and with exposed air cleaners like zliminator is talking about. Quote Link to comment Share on other sites More sharing options...
SpeedRacer Posted December 31, 2005 Share Posted December 31, 2005 Eric over at ZParts has a great shot of a V8 Z with cowl induction. http://www.zparts.com/events/wcn2002/promo/image/DCP_3341.html Cowl induction is usually the best way to go but not the easiest. Highest pressure area and of course the usual ~1% increase in HP for every 13 degrees cooler the intake charge is. The cowl area will help prevent water entry as well. BTW, I don't know who's car that is but it is REALLY IMPRESSIVE! Quote Link to comment Share on other sites More sharing options...
260DET Posted December 31, 2005 Share Posted December 31, 2005 The cowl area on a S30 is quite poor for positive air flow, just check the air flow effectiveness from the interior vents which duct air in from the cowl area. It would work but would not be the most effective solution. As for water causing a problem if the support panel area is used, if air is being ducted to a stock aircleaner just have the ducting run uphill a bit from the front. If using a pod, protect it with a vertical sheet of aluminium or whatever. Plenty of other solutions, depends how its located too. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted December 31, 2005 Share Posted December 31, 2005 Although this isn't a Z example, I will give you some recent experience I had with my 71 Chevy truck. When I repainted I needed a new hood (old one rusted beyond repair), so for only a couple of bucks more, I put on a cowl hood (more for looks than anything...just something different). The other morning I went to the store. There was a good layer of water on the truck (condensation from the evening's chill). I have a pretty good layer of wax on the truck so the water beads up nicely..... Anyways: Even at fairly low speeds (<50mph), I noticed the drops of water running up the cowl, and being drawn (sucked) pretty briskly into the air gap of the cowl induction. The droplets from the windshield cowl (part that covers the wiper mechanism) also were pulled forward into the hood gap. That experience sold me on the "working" of the cowl hood...... . . . Just my 2 c worth Quote Link to comment Share on other sites More sharing options...
Z0wner Posted January 2, 2006 Share Posted January 2, 2006 Nice truck Quote Link to comment Share on other sites More sharing options...
icice9 Posted January 2, 2006 Share Posted January 2, 2006 plus the cowl looks awsome on a Z Quote Link to comment Share on other sites More sharing options...
260DET Posted January 2, 2006 Share Posted January 2, 2006 A cowl intake would work better on a S30 if you could get it closer to the windscreen, like on the truck, that looks like it should work well. Quote Link to comment Share on other sites More sharing options...
johnc Posted January 3, 2006 Share Posted January 3, 2006 Or you can make it tall... Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted January 3, 2006 Share Posted January 3, 2006 This is the cleanest I have ever seen. I did a calculation for one of the guys I work with; he has a 67 Z28 stock eliminator. If I remember right I calculated about 10 added hp @ 100 mph around a 2.5% increase. It was a couple of years ago so; I think it was around that number. This did not account for the change in air temp. Quote Link to comment Share on other sites More sharing options...
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