bobdylan Posted November 1, 2013 Share Posted November 1, 2013 So the AE82 lives again after a small issue with the fuel system, but time to move on.The idea I have with the air box is take the top half of the stock ST box off, build a custom top half that mates with the bonnet using a rubber sealer (??) so it seals tight. Have a STI style vent directly above it feeding it cool air. Have a filter mesh on the vent and run open trumpets of between 70mm and 100mm.Would that work? Any potential downfalls of this plan? Quote Link to comment Share on other sites More sharing options...
Vintage Grumble Posted November 1, 2013 Share Posted November 1, 2013 Water and crud flowing into your engine? Tho I guess the air box will have to fill up quite a way before it would eat water. Quote Link to comment Share on other sites More sharing options...
bobdylan Posted November 1, 2013 Author Share Posted November 1, 2013 Good point RE water, maybe a few little holes in the bottom then. Quote Link to comment Share on other sites More sharing options...
Bling Posted November 1, 2013 Share Posted November 1, 2013 Potential downfall is less power, but I guess its for looks and noise rather than power. Drinking water will be another downfall as mentioned. Quote Link to comment Share on other sites More sharing options...
Truenotch Posted November 2, 2013 Share Posted November 2, 2013 Drinking water isn't an issue - the engine will still run fine with a bit of water down the ports. The bonnet scoop style would work OK and is easier than other options. Quote Link to comment Share on other sites More sharing options...
bobdylan Posted November 2, 2013 Author Share Posted November 2, 2013 The st currently runs a the stock airbox with the plastic trumpets removed and a pod filter bolted up to it. Made a tad over 100KW which is disappointing. Why would it loose power? Would it not work the same as a ram air intake as its breathing cold air not warm engine bay air? Quote Link to comment Share on other sites More sharing options...
Truenotch Posted November 2, 2013 Share Posted November 2, 2013 100kw is great power for a silvertop. The best I'd seen from a standard engine was somewhere around 97. Be happy. Why aren't you running trumpets? They won't restrict horsepower at all. I don't think it would lose power from that setup - just give it a go if you're not too worried about your bonnet. Quote Link to comment Share on other sites More sharing options...
bobdylan Posted November 2, 2013 Author Share Posted November 2, 2013 Have yet to buy them and decide on a length. will run trumpets when i build the new airbox. 100KW is with the new headgasket, bt cam, exhaust and ecu. Looking at a set of kelford cams. Goal is 120kw. Quote Link to comment Share on other sites More sharing options...
kpr Posted November 2, 2013 Share Posted November 2, 2013 if the inlet in the scoop isnt massive. it will probably act like a plenum setup anyway. otherwise as truenoth says. bit of water wont hurt the engine. long as there isnt massive amounts pooling. and its clean water. +1 on that being good power for a silivertop! especially with no trumpets. which dyno was it on? Quote Link to comment Share on other sites More sharing options...
bobdylan Posted November 2, 2013 Author Share Posted November 2, 2013 The engine was dyno'd by the previous owner. It came from an ae101 gt apex which I purchased as a parts car after a nasty rear accident. He did show me the results as part of the deal. The guy lived in howick up in Auckland. I was hoping the airbox would give some positive effects. I have a spare bonnett so was going to give it a try this week. When i did the swap i removed the plastic trumpets and it seems to have improved topend a fair bit. Quote Link to comment Share on other sites More sharing options...
Bling Posted November 2, 2013 Share Posted November 2, 2013 Yeah it likely just shifts the power from the lower range, and jams it all at the top of the revs. I know this because I used to get torque steer @ 7,000rpm... (I still had trumpets, just no airbox) Don't think you're getting extra power by doing that mod. You don't, you've just sacrificed power down low and in the mid range, and shifted it up high. Not exactly ideal. Factory setup with a better air filter gave the best results overall. No trumpets at all just sounds silly to me. The torque curve will be pretty bad. If you do some more homework on the whole concept on the trumpets and the air intake, you may end up with a different view. Just randomly removing parts with no knowledge isn't exactly the best method. Your car though, so best of luck. I do suggest you do some research though, it's for your benefit. Don't take my post in a negative way. What i'm trying to say, is do your homework on trumpets rather than hoping for the best. So much information on the web in regards to trumpet lengths, so is worth a look. Which aftermarket ECU do you plan to run with the cams etc? Even messing with the trumpets would mean an aftermarket ECU could be beneficial. Quote Link to comment Share on other sites More sharing options...
kpr Posted November 2, 2013 Share Posted November 2, 2013 cold air should get some gains. i'd try run trumpets around same lenght as stock blacktop. or blacktop trumpets. since you are running blacktop ecu. changing them on stock ecu generaly just messes with your fuel ratio's. running them short/none will give the above effect. may gain a little peak if lucky, but your overall powerband will be lower. generlly get dips and peaks in the powerband. 1 Quote Link to comment Share on other sites More sharing options...
bobdylan Posted November 2, 2013 Author Share Posted November 2, 2013 I will be running trumpets. At this stage just finding the ones I want and what length. The current setup is running the stock airbox just no plastic trumpets. When i go for my idea i am going to use trumpets. As far as ecu goes looking at a set of cams from Japan which come with a tuned ecu. Read some good reviews on it and it comes out to about $400nz plus shipping. this is the current airbox (have removed top cover) Uploaded with ImageShack.com Quote Link to comment Share on other sites More sharing options...
bobdylan Posted November 3, 2013 Author Share Posted November 3, 2013 Have bitten the bullet and purchased a set of 70mm Trumpets from T3, good deal inc shipping $220nzd. 1 Quote Link to comment Share on other sites More sharing options...
bobdylan Posted January 28, 2014 Author Share Posted January 28, 2014 Digging up this old thread. So plan is to build a box where the silvertop airbox is and make come up inline with the bonnet and have it vented to deliver fresh air straight to the trumpets. have a drain in the bottom to remove any water and put a filter on the vent. If anyone can design something using cad or offer suggestions it would be great! Quote Link to comment Share on other sites More sharing options...
kpr Posted January 28, 2014 Share Posted January 28, 2014 if cad is not your deal. make it from cardboard scissors and tape. then use as your template to build the real thing 1 Quote Link to comment Share on other sites More sharing options...
bobdylan Posted January 28, 2014 Author Share Posted January 28, 2014 The guy who will make it says he needs plans. I suck at cad. Yeah guess just make out of card and take it to him Quote Link to comment Share on other sites More sharing options...
beachlander Posted January 28, 2014 Share Posted January 28, 2014 Make it out of cardboard then make a drawing from the dimensions. Quote Link to comment Share on other sites More sharing options...
Rhyscar Posted January 28, 2014 Share Posted January 28, 2014 I think you will run into issues with not being able to fit the 70mm trumpets inside a ST airbox of any sort.. hence the whole reason why I went and build this (same trumpets as you bought); As mentioned by beachlander cardboard is your friend (and I do CAD for a living!) that's how I did it.. TBH an airbox isn't 100% neccesary for a simple setup. I ran my blacktop with open trumpets for a couple of years.. ran a short 40mm trumpet (originally wanted to fit inside standard airbox) have got a dyno plot showing naff all difference between standard trumpets/40mm trumpets with 1kw shifted from mid range to up top.. I don't like the idea of running a bonnet scoop due to the aerodynamic disadvantage. theres no point having 2-3kw more power from fresh air but having more aerodynamic resistance! with an NA car making it as slip stream as possible is the best way to go.. you will get similar gains from a well set up cold air intake with 4" pipe right up to the airbox etc and an oversized filter. I built one years ago that used a panel filter from a 3.8L commy engine curved with a massive volume of air behind the filter. Worked really well although never had that setup on the dyno. The only advice I can give design-wise is have the largest volume of air closest to the trumpets (after the filter ideally) as possible with as little restriction. I designed the carbon one to hold 30L of cold air post-filter and previous setup for 15L. Def works as after 2hrs on the dyno or after a 10 lap race you can touch the airbox and its dead cold. Quote Link to comment Share on other sites More sharing options...
Roman Posted January 28, 2014 Share Posted January 28, 2014 The Base of The windscreen is a huge catchment area for high pressure air. Which is why the air intake for the fan for the inside of the car comes from there. Using the drip tray thing as an air feed would work better than a scoop, with the added benefit of being millions less ugly. Just make sure the intake is above the high tide mark for rain haha. Quote Link to comment Share on other sites More sharing options...
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