LANCER wrote on 07/06/10 at 04:54:13:DO YOU HAVE A PHOTO OF YOUR ENTIRE EXHAUST ?
IS IT A RAASK UNIT ?
IF NOT, WHAT ? WHAT TYPE OF BAFFLE ?
IT'S A NICE FAT PIPE
It's mostly all homemade Lancer.
Here's what I bought to start with.
http://www.eautoworks.com/product-Magnaflow-274322.htm The piece I bought above has almost exactly the same center radius bend as the stock header.
I went to Orielly's auto parts and picked up a 2.5" to 2" reducer.
I started with the reducer and welded a ring to it for the manifold clamp to fit against. Had a chunk of thick pipe that I sliced a ring off for that. Fits very well. All in all I just pieced it together using the piece I bought above and went to the exhaust shop and got some more 2.5 inch exhaust pipe.
In that very first weld right where the reducer meets the 2.5 inch I made a restrictor plate. Took a flat washer with a 2.5 inch diameter and drilled a 1-3/4" hole in it. Not sure why I did that but I guess I was thinking that since I ported out the exhaust to about 1-3/4" That I should have something as far as back pressure goes.
Here's where things get interesting. From everything I know about motorcycles and engines it tells me I need some sort of baffle to get enough back pressure to make it run strong. I originally really liked the sound without any more restriction. But before even riding it I had convinced myself that I was gonna need something. So I spent the better part of a day making different baffles and sometimes just different sized flat washers to slide in an out on a rod to adjust for sound. Didn't like the sound of anything I tried. Well after all that I just decided to take it out for a drive without anything but the restrictor plate that I had originally welded in. Wholly crap!!!! Couldn't believe how strong it was running. Even the low end torque was great. I put it in first gear idling up the street just letting it pull itself at an idle and rolled on the throttle as fast as I possibly could and it would almost spin. I couldn't roll the throttle fast enough to make it cough or anything. Then I took it out on the road and it would pull so good that I decided not to go with anymore to restrict airflow for back pressure. It still had a little puff puff puff sound to it at an idle that I didn't like but thought I was just gonna have to live with it. Well after looking at the pipe for a while I thought I'd cut a slash cut at the end and it would make it look a little better. Well I did that and It took the puff puff puff out of it.
With the air filter set up and the mostly free flow exhaust I now have a 55 pilot with the bleed holes and 170 main. The spark plug looks perfect. I'm at somewhere between 1.5 and 2 turns out on the air mixture skrew. Still stock on the white spacer. No backfires at all ever. I did cut a little length off of that spring on the side with the small cover before I ever put the thing together. I had it bored to .5 over also. I'm at 17/50 with the sprockets which gives me pretty close to stock gear ratio. It'll pull really strong to 85 really really quick. After 85 it still pulls up to about 105 but it takes a couple miles to get there. Gonna gear it down and see if it'll pull a little better on the top end of things.