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Arttu

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Posts posted by Arttu

  1. 17 hours ago, badger said:

    Same turbo and does similar.  Mine starts boost about 3500rpm, stays at about 10psi for ages but doesn't hit 1 bar until 8-9k. (14psi spring and I do get boost creep sometimes). I'm sure it used to build boost a lot quicker but I'm questioning that. 

    To those that know, would a softer, say 6psi spring and a digital boost controller alter that characteristic letting the controller cap the limit higher, i.e 15psi etc? 

    Sounds like the wastegate is opening already at 10psi and then there is boost creep at higher rpm.

    A boost controller should help building boost faster. It will help to keep the gate closed until you hit the target. But it can't help with the creep, if the gate can't flow enough to keep the boost down then the controller can't do anything to lower the boost.

    Any way, if you feel that the turbo is spooling up slower than it should it's good to check carefully all possible exhaust and boost leaks. Especially exhaust leaks will affect a lot on spool-up.

  2. I think your boost drop is actually boost spike ;) It's probably caused by the wastegate actuator in combination with your boost regulator. Maybe the actuator has more volume so when the gate starts to open it needs more air through the regulator before the gate is properly open and that causes delay. And if the actuator has softer spring you need to turn the regulator more close which slows down the reaction too. You can test it without the regulator and see how it works then.

    Gradual boost building might be just a feature of the turbo but that's hard to say without detailed data. One explanation could be that the VF23 has bigger A/R turbine side. I think my VF34 behaves more or less same way. It starts to build little boost pretty early, slightly above 3000rpm. But it needs quite much more rpms to reach full boost, over 5000rpm for 1 bar. So there isn't any violent kick at any point, it just pushes harder and harder as the revs rise.

  3. A couple of notes:

    -24VAC from the generator wires sounds low. Usually the spec is something like over 50VAC @ 5000rpm. It might be a good idea to verify this.

    -If the battery voltage is always over 13V when the engine is running you can't drain the battery empty while riding. So apparently voltage drops lower at some conditions.

  4. Sensitive topic, oil discussions may get pretty long and heated :P Maybe even the Rules mention something about them...

    Yes, synthetic oils can improve lifetime of the turbo, especially if you use longer oil change intervals or run it hot regularly. On the other hand many people claim that the clutch won't work well with synthetic oils or they are generally bad for old bike engines. Personally I haven't noticed these problems nor see any technical basis for them. Assuming that you use oils that are suitable for wet clutches (JASO MA classification). Car oils, esepecially "energy conserving" ones might be a different story.

    • Like 2
  5. MTC seems to have 81mm turbo pistons with advertised 10:1 compression. Maybe that could be lowered enough by machining some dish on the piston and increasing the squish to upper end of working range?

    Busa pistons could be one option too. If I recall correctly what others have told here stock Busa pistons in oil cooled engine result about 9.5 compression when the deck height is adjusted to minimum. So turbo pistons could end to that 8-8.5 range, maybe.

    • Like 2
  6. 8 hours ago, Gixer1460 said:

    Not exactly a budget build anyway! I wonder which bit is still / remains Suzuki produced ? xD

    In the video he mentioned the headlight with cowl, tail light and engine cases. Apparently minus the cases now... The frame was also "technically stock with some modifications" :D

  7. I have currently about 11:1 compression ratio on my air cooled GSX. I have boosted it up to 1.2 bar on E85 without issues. I have water injection for charge cooling but I have run it also without water on dyno and haven't noticed any issues. So it's more for peace of mind I would say. I have also full flex fuel setup but I haven't run this engine version on gasoline yet.

    Before the latest engine rebuild the compression was about 10.5:1 and that I run on gasoline too. Boost on gasoline was limited to 0.5-0.6, lowest that my internal waste gate allows.

    So in your case I would probably aim for 9.5-10:1 compression. That should allow moderate boost on gasoline, especially if you use charge cooling. And on E85 it should be good for over 1.5 bar.

  8. 1 hour ago, george 1100 said:

    A lot of US high performance car parts are made in China and have proven to be on par with US made. They have the latest and greatest manufacturing technology that embarrasses the rest of the word. Bottom line it comes down to quality control. They can and will make anything you want, good, mediocre or shit. 

    Exactly. I think the biggest difference compared to western manufacturers is that many Chinese companies will happily make shit if someone wants to buy it. More established companies usually refuse to do that to protect their reputation.

  9. 5 hours ago, Reinhoud said:

    What I can find the Maxpeeding is between 3 and 4 times cheaper then Carillo's.

     

    This would be something I wouldn't have the guts to take the risk, suspension or a turbo failing is mostly very annoying, if a conrod fails there's a lot more damage..

    Hmm... Just for reference, if we see US prices for Busa rods: CP-Carrillo - $1150-1430, Wossner - $900, Maxpeeding - $480. So about 2-3x difference. I can imagine getting some decent quality with that money if it's manufactured in cheaper location and some of marketing and profit overhead is cut away. In comparison Maxpeeding turbos start from $100 which is about 10x difference to genuine stuff so I highly doubt you can get anything decent for that cheap...

    But naturally everyone must do their own choices and select what kind risks they want to take with their money. And I completely agree that risking with connecting rods is, well, risky. However, I know that these Maxpeeding rods have been used a lot also on pretty high power bikes and I haven't heard about problems any more than with brand name ones. So I think in this case the risk is fairly low.

  10. 6 hours ago, Reinhoud said:

    I was looking at car parts not too long ago, turbochargers and suspension, that's when I heard about the brand. It was that cheap that raises questions. The reviews weren't good.

    I have also heard that Maxpeeding turbos are crap. And they are so cheap that they just can't be good. Their rods aren't that cheap in comparison.

    • Like 1
  11. 9 hours ago, johnr said:

    page says theyve a max rpm rating of 7000 to 9000 rpm doesnt the bandit motor redline at 10k?

    I guess that's just copy-paste from some car rod description. Those rpm / power ratings for the rods are a bit funny in general too. There are so many variables affecting on what the rods can take so it's impossible to tell such limits for the rod itself...

  12. I'm not an expert on carb tuning but I recall that usually you can't find OEM stock needles from any public needle charts. Apparently they are custom made for manufacturers. So this means that comparing the stock needles to aftemarket ones can be slightly challenging...

    Maybe you can try to measure the ones that you have now and find the closest match from published charts. After that you can use the charts to find suitable tuning options.

  13. 5 hours ago, Reinhoud said:

    I could, but I don't have a clue how much difference in size makes a difference in AFR.

    As above, I think you won't find that info anywhere... By measuring them you will at least know if the change would be in the right direction or not.

  14. They should be quite good stuff. If you want to be extra sure get the ends measured and use genuine ARP bolts. They claim to have ARP 2000 bolts but I have heard here and there that they are fakes. Not sure what's the truth.

    This year I have tuned a GSX-R1000 drag bike with those. No problems at 400hp level.

    • Like 2
  15. Well, if the ignition box reads removed sensor as "full throttle" then you won't notice anything else than maybe increased fuel consumption. And apparently this is the case usually since I haven't heard about any problems either.

    But if the ignition box happens to read it as "closed throttle" when you are actually on full throttle then your pistons will probably notice it... I once measures timing curves from a SV650 which also has a TPS with carbs. In that case added timing on part throttle was pretty serious, 15-20 degrees if I recall correctly.  So better to pay at least some attention when removing the sensor. For example leaving the sensor connected but hanging free on the wires might be a bad idea.

  16. For ignition side troubleshooting it's good to keep in mind that cylinders 1 & 4 and 2 & 3 share the same coil.  So if another cylinder of the pair works then the problem can be only somewhere between the coil and spark plug.

    Is that non-running cylinder completely dead or just "mostly dead"? Like if you put a new plug there will it get any black soot or does it stay completely bright? Or can you notice any heat on the exhaust runner?

    • Like 1
  17. 9 hours ago, TLRS said:

    Any overlap in valve timing? Afaik normal for n/a application but less suitable for boost, at least I think I read it somewhere?!

    I also thought it was good to have cams that work early and spool turbo early. Then tune the rest of the graph with boost?

    Pretty much all bike cams have some overlap. Effect of overlap on boosted engines depends a lot on setup. If the turbo is sized properly so that exhaust pressure doesn't get much higher the overlap works pretty much like on N/A engine. So some overlap is beneficial. Low / no overlap can be good if exhaust pressure is high like on many stock(ish) turbo cars.

    • Like 1
  18. 11 hours ago, rerb said:

    Wow, glad to know. Whats limiting me is probably the afr which is fairly rich, but my power tapers off far sooner than the other charts of stock cams show. Next season I'll spice up the tune a little and maybe turn down the meth and see what that nets me. I had some issues with the APE head nuts coming loosing causing the head gasket to shimmy around a little, I'll probably pop the head off and inspect too. I have busa pistons but also shaved the cylinder a mm for extra compression so it's still fairly high.

    Under 11 AFR numbers start to be at the region where you may get rich misfires. And since misfires cause false lean reading on lambda you might be even richer in reality. So yes, tuning it a bit leaner would be also my first suggestion. Also too high water/methanol injection rate can cause misfires or just power drop in less severe case.

  19. I have never done back to back comparison where only the cams were changed. But I have tuned various oil cooled turbo build, with Bandit cams, GSX-R cams and aftermarket cams. By this far I haven't seen any clear connection between the cams and power curve shapes, or power numbers. Which is slightly odd since the cams should make difference and I have seen that also in real life with some other engines. I guess that other variables in these oil cooled builds just have been more significant.

    A couple of examples:

    Bone stock B12 engine, never opened as far as I know. Mitsu TD05 turbo, E85 fuel, 0.9bar boost.

    kuva.thumb.png.4b62a6d986dff11b838069812ef8e77a.png

     

    GSX-R1100, 1216cc turbo pistons, ported head etc. Some other Mitsu TD05 variant, pump gasoline, approx 1.0 and 1.2 bar boost.

    kuva.thumb.png.3f96bc2047c4d11789b5ff117cb3827f.png

     

    Funnily that stock B12 engine has been hard to beat in boost / power ratio :P I guess the main reason is higher compression ratio and better combustion chamber shape compared to other builds.

    Any way, if you now get around 240hp at 19psi I think the cams aren't the first thing on the improvements list.

    • Like 1
  20. Have you tried to swap #2 and #3 plug wires already? That should cover pretty much all the electrical faults. And that starting spray into non-running cylinder carb throat is worth of trying too if you haven't done that.

    I think at this point all remote diagnosis starts to be pretty much blind guessing. But sometimes that can help too...

  21. It's for igintion timing. Most likely it adds timing for low throttle. Improves fuel efficiency and maybe emissions too.

    I guess the ignition box is designed so that it reads full throttle position if the sesnor is disconnected and therefore uses safer full throttle timing. But if I would use such system without the sesnor I would ensure that by connecting the signal wire to 5V wire. Or leaving the sensor there and locking it to full throttle position. 

    • Like 1
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