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Old September 22nd 2010, 13:23
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Wally Wally is offline
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Join Date: Nov 2002
Location: The Netherlands
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Quote:
Originally Posted by 70Turbobug View Post
If I read the log correct,your max boost was 1,46 bar?
Not really: that point was just where the cursor was at that moment. More random therefore. Boost was about 1.0 bar at 4K, then climbing further to just over 1.7 bar at around 5K, then tapering to 1,5 at 6K and further down to 1,4 bar at 7K.
On the road, in 4th, 1 bar is reached at 3600 rpm if its not too hot outside.
Just follow the horizontal lines on the y-axis at the right. The scale is there. If you can read plots, it shouldn't be too hard to see what is reached when
Quote:
What springs are you running now? Do you think that your valves were beginning to float?
Quote:
Originally Posted by Wally;
The ripple after 6200 rpm is valve starting to bounce of the seat imo...
I use the Berg dual springs with Ti retainers. I will try to install my CB650's over winter. That will sort that out.

@Sandeep: I think every motor is different and maybe I have restrictions elsewhere, but boost is tapering despite my EBC set at closed-loop... so I suspect my 8cm² turbine (~0,63-ish I think) is just too small for these kind of hp. My back pressure readings kinda confimed this imo.
For an even bigger engine like your comming 2413cc, I would surely get the 0,82 A/R if you had free choice. You may loose some spool as opposed to the 0,63, but you already got that covered by the 200cc's more you have over mine...
I also looked heavily at what Subaru owners use (hence my DOM3 I got off a us Suby owner) and this combined with my current experience, I would surely get the 82 for your 2413cc. Our engines are just more responsive by themselves somehow I think.
You don't want to know what my next turbo/turbine size will be...

Last edited by Wally; September 22nd 2010 at 13:46.
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