bgh831 Posted March 7, 2007 Share Posted March 7, 2007 So here is something I have been pondering and wonder if I'll find any awnsers or opinions out here. I fell in Love with Subarus a while back and it only gets better. Here's the question. If a guy wanted to rear mount and use a 6 speed gear box and all the other running gear, is it as simple as getting reverse cut ring and pinnion gears cut to make it function(besides and electrical sensor gears). It seems odd that it would be that easy but after alott of thought it really does seem that it would go that easy. USMB ROCKS! Quote Link to comment Share on other sites More sharing options...
nipper Posted March 8, 2007 Share Posted March 8, 2007 come grasshopper take a lesson or two from the VW people. There are a few ways to solve this. One method has been to get reverse ground cams. Another method is to use a VW rear engined transmission. Gteeing a reverse cut gear will not change the direction, it wil just change the thrust surfaces. Someplace in the driveline you will need two gears contacting each other to reverse direction. This can be done at the tranny or at the rear suspension. Neither of these solutions are cheap. I have been toying with (keep in mind im an engineer so my toying is someones else finished design) putting a 2.5 in the business end of a corvair. Volkswagon (and porche) engines rotate in the same direction as front engine cars. This was one of the reason you can do all sorts of fun things with them. You could also flip over the transmission (though i dont see how). When they used corvair transxles in a VW they flipped the axles. Corvairs, the "front" of the engine is actually where the transmission is, and the rear is where the fan belts are. Another issue with running the engine backwards, is that the transmission may not like it. The gears are cut to minimize noise and for ease of shifting with the drivetrain rotating in one direction. Reversing that MAY dramatically alter the driveability of the car. Most engines really dont care what direction they run in. Just the direction of the starter cranking dictates which way it spins. WHen cars had distrubtors, it was possible to have the timing so far off, that there would be a backfire, and it would run backwards. Now with variable valave timing, it may make a differnce (but from what i can tell im not seeing it). You do need to modify some things though if you want it last: On applications where twin inboard engines are used, one engine typically rotates in the opposite direction to offset the prop torque generated by the second engine. Rebuilding a reverse rotation inboard engine requires a number of changes, including polishing the crank in the opposite direction as usual, using special oil seals with reversed flutes to prevent oil leaks, reversing pistons and rods left to right, and installing a cam with a special reverse rotation profile. From what i can tell, only the Cam and Crank positin sensors may have to be flipped over, everything else shouldnt care. I am sure that this has been done by someone (not with a subaru, but something other then a VW or olds conversion). nipper Quote Link to comment Share on other sites More sharing options...
bgh831 Posted March 8, 2007 Author Share Posted March 8, 2007 Interesting, So you think it would be a signifigantly dificult project to run an WRX Drivetrain complete Arse backwards in a rod or Sandrail project? Quote Link to comment Share on other sites More sharing options...
nipper Posted March 8, 2007 Share Posted March 8, 2007 well if you make it a mid engine, point the engine in the proper direction, no. If you want AWD, yes. Just did a quick look, and it seems the prefered tranny for a sandrail is the VW, since its overbuilt and simple. we love google http://www.halfbakery.com/idea/Backwards_20AWD_20Sandrail nipper Quote Link to comment Share on other sites More sharing options...
bgh831 Posted March 9, 2007 Author Share Posted March 9, 2007 Well that was just a thought about the same thought I had. At least I now know that I didn't have an original idea. Quote Link to comment Share on other sites More sharing options...
nipper Posted March 9, 2007 Share Posted March 9, 2007 Well that was just a thought about the same thought I had. At least I now know that I didn't have an original idea. Sometimes thats a good thing, it saves alot of cost and frustration nipper Quote Link to comment Share on other sites More sharing options...
Hodaka Rider Posted March 9, 2007 Share Posted March 9, 2007 Volkswagon (and por>S<che) engines rotate in the same direction as front engine cars. This was one of the reason you can do all sorts of fun things with them. You could also flip over the transmission (though i dont see how). When they used corvair transxles in a VW they flipped the axles. Actually, all you have to do is flip the differential over inside the trans. Works great! PS: fixed your horrendous spelling of Porsche. Not sure if the rest of my spelling is correct, but people have been killed for spelling Porsche wrong. Not really. Quote Link to comment Share on other sites More sharing options...
nipper Posted March 9, 2007 Share Posted March 9, 2007 me talk funny, or is that spell funny (pain pills and poor typing not a good mix). I have heard differnt opinions on flipping the differential. It really depends on the use of the vehical. As a toy it is probably fine, but it tends to change the thrust surfaces location. Now your giving me ideas on my awd corvair project, bad bad bad nipper Quote Link to comment Share on other sites More sharing options...
bgh831 Posted March 10, 2007 Author Share Posted March 10, 2007 yeah or that rear engine fiberglass rod project. hummmmm Quote Link to comment Share on other sites More sharing options...
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