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About rerb

  • Birthday 04/03/2003

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    Maine, USA.

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  1. Hi, yesterday I had some free time and ran some tests. With my exhaust (Vance and Hines muffler on 2.5" pipe) fitted, I saw 12 psi in first, 13 in second and beyond. Afr in boost was around 11. I did 3 runs and got the same result. I took it off, and there was a massive world of difference. I was hitting 14 psi in first, 15 in second, and I saw it tickle 16 in 3rd before I browned my pants and let off mid wheelie. Afr was around 11.5 - 12. Same thing, did 3 runs and used a gopro to verify what the gauges were reading. So obviously less exhaust = more power. A lot more. I assume the backpressure is putting resistance on the turbine wheel, choking it out. This would make sense as it's a larger turbo. My question is am I stuck with a loud bike to run these numbers, or has anyone figured out a setup where a muffler doesn't affect boost as much? Would a smaller turbo be choked out less? I also have a thought that maybe the leaner running from less exhaust adds to the power. Just food for thought here, anyone with a muffler please chime in and tell me what you've found, thanks. I know the Vance and Hines one is pretty quiet, maybe there's a higher flowing one that works well here? Thanks.
  2. Well I'm partly an idiot. I took another look today and noticed the wastegate actuator actually managed to get stuck against the frame, propping it open about 1/2 of the way. I guess boost pressure was enough to open it fully, but on the return the friction must've held it in place somehow, I have no clue. Readjusted the mount and now it clears by a few hundredths, bike runs a lot better now. Still not sure how that even happened unless the manifold sagged with the weight of the turbo
  3. Yep, I was off by a hundredth whoops. I went smaller on the ring gap for forced induction because my motor has never gotten hot before, and it's a very cool climate around here. Depending how my bore looks this winter I might go bigger, but so far no problems. I do have a larger piston to wall clearance though, .005". No signs of piston slap yet even though my machinist warned me about it
  4. I ran .14 inches on the top ring, so about 3.6mm
  5. When it was running great I didn't lol. That's how I knew something was up. I could lift the wheel in 3rd but now it stays down in all gears Doing a lot of headwork this winter and hopefully switching over to a td04, what would you guys recommend for a td04 capable of 250 hp? I see 14t is a common choice but not sure.
  6. Think my turbo blew a seal, started spewing oil into the charge line. I'll check compression too but I think there's crossover between the hotside and coldside because just the day before it was a total rocketship. Motor feels the same before boost but I'll still check compression.
  7. Hi guys, my bike has seemed a lot slower over the last few days. I've noticed if going wot from first into top of second, I'm only building 10 psi. (Wastegate set to 14) This is with +1 -1 longer gearing BTW. This seems low, and the bike feels a lot lazier too. In 3rd to 4th I can tickle 13. My current suspects are small boost leak, boost controller, or failing turbo. When I disconnect the charge pipe before the plenum with the bike running and cover the side that connects to the turbo housing with my hand, the bike dies. If I blow into the plenum, it comes out of the pipe that goes from the compressor to the plenum. I thought it would go through the turbine side of the turbo, not the compressor side. Is this a sign of a fucked seal? Thanks.
  8. Sounds like just what I need. Sadly that means dropping money on a new manifold, but it'll be worth it
  9. update? I have busa pistons in with the shaved down valve pockets
  10. ooh that curve looks very nice. May I ask why you went with a 20g as opposed to a smaller turbo? Looking into it, getting an ignitech CDI seems cheaper and better than a dyna2000, something I want to do this winter. How big of a pain was it to install? the dyna seems very simple without the need of a custom triggerwheel, and lets you keep kickstand switch function. Are you running stock coils too?
  11. I see on DW holeshot performance they have "factory drop in cams" that sound a lot like their gsxr cams. Anyone have experience with them?
  12. Yeah, I had only a dump pipe at the time so nowhere for the sniffer to sit. It's on my list to get another dyno run in for sure. But as far as the cams though, if it will help me make more peak power without more boost, I'll gladly do it. It might not be necessary for 250, but with a ported head, I just don't want to push more than 13 psi for reliability concerns.
  13. Was barely running, all those bog makes are from 8-9 afr. Put smaller mains in, huge power boost just from fixing the mixture a bit, but haven't had the chance to dyno it again. Dyno operator said he's noticed that the dyno reads about 10 hp less than you'd feel on the street because of air velocity, not sure if true or not.
  14. That makes sense. I actually had mine dyno'd and peak power was at 9k, then sharply fell off. Sounds like a replacement set of stock cams is best for me.
  15. Thanks, thats the source of the turbine housing pattern I was looking for. Unfortunately I can't find a ball bearing version thats still in production, so I'm going to swap over to an exhaust manifold built for the housing of the VF series turbos.
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