DougieFresh Posted March 12, 2010 Share Posted March 12, 2010 Hi, I have an 83 brat, and I was wondering if I could utilize the giant space in the engine compartment for something like an electric supercharger or something. I know it's a bit jury rigged, but I was thinking about getting a backpack leaf blower, gutting out the gas motor in it, and putting in an electric motor to power the impeller and lead the piping to a customized housing for the air filter. I am getting exhaust work done, and maybe a new carb, but the airfilter housing looks soooooo restrictive. Am I retarded, or could this be beneficial? -Doug Quote Link to comment Share on other sites More sharing options...
WoodsWagon Posted March 12, 2010 Share Posted March 12, 2010 Keep the gas engine in the leaf blower, and electric motor will use up too much energy too fast to be practical. Having a 2stroke motor screaming under the hood at the same time you're accelerating would be badass! You will have to build a box around the carb that the leafblower will blow in to, so the whole carb is in a pressurized environment. Otherwise it won't work. That's called a "blow through" carb setup. There's also the old belt-driven supercharger, but that takes away some of the allure of having a leafblower under the hood, or better yet, sticking through the hood. Pull up at the drag strip, hop out, yank the pullstarter on the leafblower, and get ready to race. You'd probably win, if only for the fact your challanger would be laughing too hard to drive. Quote Link to comment Share on other sites More sharing options...
DougieFresh Posted March 12, 2010 Author Share Posted March 12, 2010 Hahaha! so true. Quote Link to comment Share on other sites More sharing options...
phantomcrooner Posted March 12, 2010 Share Posted March 12, 2010 (edited) LoL, Oh man, that's a good one, never heard of the leaf blower idea. Blow through turbo applications do work but you really have to do it just right or you will have problems. It is hard to get the air/fuel ratio correct, if you even can. They tend to lean out under full boost and high rpm's, which is why i decided to run a megasquirt setup on my Beetle. EFI with turbo is best for a daily driver, unless its a drag car only. You can dump a lot of fuel down a 4b carb with a turbo on a 2200cc vw engine in a quarter mile and not kill the engine, mostly, but it will not reliably drive to the supermarket and back. Edited March 12, 2010 by phantomcrooner Quote Link to comment Share on other sites More sharing options...
Qman Posted March 12, 2010 Share Posted March 12, 2010 We did it one night while fiddling around on the dyno. Only managed to gain 5hp on an injected EJ18. I doubt the stock carb will like being blown through either. Quote Link to comment Share on other sites More sharing options...
DougieFresh Posted March 12, 2010 Author Share Posted March 12, 2010 (edited) Haha! 5 hp is more than I would have expected. I was actually thinking about maybe using a shop-vac top assembly because it would have more "push" than a leaf blower that has to wind up pretty high, and has a super high volume at low pressure compared to the vac's lower volume and higher pressure. I'm just trying to think of a way to fill that spare tire spot because I'm going to get bigger wheels and tires that won't fit that spare anyway... Edited March 12, 2010 by DougieFresh Quote Link to comment Share on other sites More sharing options...
Qman Posted March 12, 2010 Share Posted March 12, 2010 Cams and a Weber are your answer for larger tires. I know a guy that can hook you up with the cams... Quote Link to comment Share on other sites More sharing options...
WoodsWagon Posted March 12, 2010 Share Posted March 12, 2010 We did it one night while fiddling around on the dyno. Only managed to gain 5hp on an injected EJ18. What were the specs on the leafblower? MPH of air, size of motor? You may have just not had enough leafblower to make MAD poWAH! Did you have it tightly sealed to the airbox? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted March 12, 2010 Share Posted March 12, 2010 It could be done - but you would need a large leaf blower and you would want to keep the gas engine. The draw from a big enough electric motor would kill any benefits. As for blowing through the carb - there are a lot of things that must be considered - for one the fuel pressure has to rise right along with the boost pressure in order for the float to work. You have to seal the throttle shafts, and the stock emulsion tubes aren't well suited to forced induction. Tuning is a real pain due to the different sized primary and secondary barrels. You would be much better off with a single barrel or a racing 2-barrel that has identically sized venturi's that open simultaneously (like the 38/38 DGAS, but that is too large). A friend and I have done it with a 32/36 but he is currently looking at other carb options since the DGV isn't well suited to his plan of 15 psi (currently running at 7 psi). There are a lot more considerations than I listed above - that's just a start to the issues you will have. Better, as Qman mentioned, to just swap the cam and install a nice big Weber carb. You'll have all the torque you want with none of the problems associated with forced induction. GD Quote Link to comment Share on other sites More sharing options...
DougieFresh Posted March 12, 2010 Author Share Posted March 12, 2010 Yeah, that sounds like a good plan. How much for those cams? Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted March 13, 2010 Share Posted March 13, 2010 Yeah, that sounds like a good plan. How much for those cams? It's a single cam on the EA81's. You do have to split open the block to get to it since it's mounted directly beneath the crank and is only accesible when you tear the engine completely down. It would be sensible to do a full rebuild at the same time since all that stuff is removed in the process anyway. GD Quote Link to comment Share on other sites More sharing options...
DougieFresh Posted March 13, 2010 Author Share Posted March 13, 2010 yeah, the only "problem" is that my engine only has 18,000 miles on it...so I really don't need to do anything to it besides easy mods. I'm getting a whole new exhaust system from the headers back. I'm going to run it through a high performance cat and muffler. I'm going with a fiberglass filled muffler so it isn't too loud. (I do a lot of highway driving) Is the stock camshaft that bad? I know I want to get a performance carb for it, any recommendations? Quote Link to comment Share on other sites More sharing options...
Qman Posted March 13, 2010 Share Posted March 13, 2010 The Weber will make significant improvements. The cam finishes the project. The cost will be around $72.50 for the torque cam. I will have to check again to be positive of the price. Lifters need to be resurfaced as well. The whole package is usually under $100 + shipping to your home. Quote Link to comment Share on other sites More sharing options...
Numbchux Posted March 13, 2010 Share Posted March 13, 2010 yea. we've joked about the leaf blower thing. But they are really only designed to move a lot of air at essentially zero psi. as soon as there's back-pressure, it would just be useless. Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted March 13, 2010 Share Posted March 13, 2010 yea. we've joked about the leaf blower thing. But they are really only designed to move a lot of air at essentially zero psi. as soon as there's back-pressure, it would just be useless. Depends on how fast you spin it. Get it up to 50,000 RPM like a turbo and it could move some air at pressure - but the squirrel cage fan inside it would probably blow apart long before you got it going fast enough. And you would be severely limited by the fan design and size - it would approach mach 1 at the outer edges of the fan at fairly low RPM's and the forces would simply shred it like a soda can in a lawn-mower. Basically if you want low-RPM pressureized air in volume you need a positive displacement pump. Like a rotory lobe (roots style) blower. GD Quote Link to comment Share on other sites More sharing options...
Yo'J Posted March 16, 2010 Share Posted March 16, 2010 If you have a garage baby 18000mi 83 brat w/o rust and a good dash and interior, don't do a darn thing with that thing! Now if its worth(less) running the trails, modding it out is a wondrous thing to do with it. Might be worth a bit. IMHO Quote Link to comment Share on other sites More sharing options...
DougieFresh Posted March 16, 2010 Author Share Posted March 16, 2010 Hahaha! Yeah, It's not perfect, but the body is completely straight, and the engine is barely broken in. There is some rust, but I'm taking care of it now. I'm going to make it look close to stock minus bigger wheels and tires. Quote Link to comment Share on other sites More sharing options...
Yo'J Posted March 16, 2010 Share Posted March 16, 2010 Cool, I love running bigger tires. I went with a rule, up and out must equal. Didn't acheve it, but, I would like nice looking rims someday. Be prepared to sledge hammer your fender-wells in front for your tires to fit and not rub. Quote Link to comment Share on other sites More sharing options...
DougieFresh Posted March 16, 2010 Author Share Posted March 16, 2010 yeah, I'm going to see if I can buy some rims that are offset enough to give me the full steering without rubbing. I know summit racing has a metric assload of different rims. I would most likely get the rims offset wide a bit, then tastfully put some black fender flares on it. I don't want huge ones, but I also don't want my tires sticking out too much... Quote Link to comment Share on other sites More sharing options...
Yo'J Posted March 16, 2010 Share Posted March 16, 2010 I m leaning towards six lug redrills so I can get cheap spare rims for seasonal tires, but, I'm DD'ing a beater roo. Totaled on the licence. 4x140 is a tough rim to source ya know. Thirteens is about it or pugs. There's spacers.... Quote Link to comment Share on other sites More sharing options...
DougieFresh Posted April 4, 2010 Author Share Posted April 4, 2010 Yeah, I actually found some six lug toyota wheels that are really nice for $60. I'm worried they may be offset quite a bit, but I figure 3 inches more width will be ok with fender flares. Quote Link to comment Share on other sites More sharing options...
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