irf Posted November 1, 2008 Report Share Posted November 1, 2008 has anyone used and set one up before?what i'm trying to achieve is 0.9bar up to about 4k and then 1.2 or 1.3 bar after that. three apparent problems1) on the face of it i do seem to have achieved the target boost but while it says 0.9 bar on the gauge the car seems to like surging a bit.2) gearchange sees a spike up to about 1.5bar. AFR is at about 12 but would rather get rid of this spike.3) seems a bit intermittent. if i start from low down say, 2k, from 4k sometimes it goes ballistic and hits 1.3 bar, sometimes it doesn't. if i were to start at say 3.5k, it does what i want it to do.any help much appreciated guys. Link to comment Share on other sites More sharing options...
volvo500bhp Posted November 1, 2008 Report Share Posted November 1, 2008 has anyone used and set one up before?what i'm trying to achieve is 0.9bar up to about 4k and then 1.2 or 1.3 bar after that. three apparent problems1) on the face of it i do seem to have achieved the target boost but while it says 0.9 bar on the gauge the car seems to like surging a bit.2) gearchange sees a spike up to about 1.5bar. AFR is at about 12 but would rather get rid of this spike.3) seems a bit intermittent. if i start from low down say, 2k, from 4k sometimes it goes ballistic and hits 1.3 bar, sometimes it doesn't. if i were to start at say 3.5k, it does what i want it to do.any help much appreciated guys.Hi Irf Fancy seeing you here did you see my pm on vpcuk ?? I know someone that will be able to answer this for you ;-)Russ Link to comment Share on other sites More sharing options...
irf Posted November 1, 2008 Author Report Share Posted November 1, 2008 hello russ tell me more please! Link to comment Share on other sites More sharing options...
volvo500bhp Posted November 1, 2008 Report Share Posted November 1, 2008 hello russ tell me more please!Leave it with me ;-)Russ Link to comment Share on other sites More sharing options...
irf Posted November 1, 2008 Author Report Share Posted November 1, 2008 if i could afford your rates i would!! :lol: Link to comment Share on other sites More sharing options...
volvo500bhp Posted November 1, 2008 Report Share Posted November 1, 2008 if i could afford your rates i would!! I ment i have just asked a mate for you We are not that expensive Russ Link to comment Share on other sites More sharing options...
JCviggen Posted November 1, 2008 Report Share Posted November 1, 2008 Are you using the target boost / self learning option or manually setting the duty cycle in 500rpm increments? Link to comment Share on other sites More sharing options...
irf Posted November 1, 2008 Author Report Share Posted November 1, 2008 apologies Russ, truly no offence intended!JC, doing it manually. off the top of my head i've got the boost set at 1.2 bar all the way through. the duty is set at 40%. at the switch point i've got it going up to 90%. Link to comment Share on other sites More sharing options...
JCviggen Posted November 1, 2008 Report Share Posted November 1, 2008 I think you need the curve to be more progressive. At least that's what I have found to work best. Your boost has a hard time getting to 1.2+ coming from 40% DC up to 4000rpm. The 90% DC is then giving you the boost spike after shifting at high revs.I find 0.9 bar also very low, did you put weaker rods in your car? I would say max 1 bar @ 3000 but after that take it to 1.2-1.3 straight away. That will probably mean starting off with the duty cycle at 55-60 and gradually increasing. I think 90% should only be used once you get to either 5.5 or 6K. The steps in between require a lot of testing and fine adjustments. Sometimes adding or subtracting 1% off the DC makes a noticable difference already.If you floor it at 2K its going to be hard to avoid any spiking. Solution : don't floor it at such silly revs and keep one eye on the gauge in your dash when you feel the boost hit.You can use the boost limiter function as well but its hidden, sort of. What you need to do is program both boost and duty cycle per RPM.Example :< 3K - BST 0.9 - DC 503500 - BST 1.2 - DC 554000 - BST 1.3 - DC 584500 - BST 1.3 - DC 655000 - BST 1.3 - DC 725500 - BST 1.3 - DC 806000 - BST 1.3 - DC 90Its just an example so don't take my values as good for your application, it needs fine tuning but thats the general principle. One more thing about the boost limiting : when you put BST to for example 1.0 kg/cm² it will not have a hard limiter at 1.0. Instead it will cut in when you overshoot it by a significant enough margin. Say you get to 1.1 or 1.2 then it will catch it, but 1.05 it would be OK with. Link to comment Share on other sites More sharing options...
JCviggen Posted November 1, 2008 Report Share Posted November 1, 2008 Oh, here's a vid where the DC is displayed as well : http://users.telenet.be/JCviggen/24082008014.mp4 I noticed here that the AVC-R 'fills in the blanks' so to speak, it increases duty cycle in a linear fashion between 2 set points. Link to comment Share on other sites More sharing options...
irf Posted November 1, 2008 Author Report Share Posted November 1, 2008 thanks JC, i'll have a play on my next day off no edit button anymore?fwiw the weird thing is i don't get a boost spike when i floor it from 2k, quite the opposite! but i'll try and be more progressive and see how it goes, thanks very much. Link to comment Share on other sites More sharing options...
irf Posted November 9, 2008 Author Report Share Posted November 9, 2008 just in case someone else fits one, reads this thread some time later and would like a conclusion, i turned feedback speed off and learn gear off and it's got rid of the surging. still very minor bits i'd like to play with but seems very good at the moment :) Link to comment Share on other sites More sharing options...
550 Posted November 9, 2008 Report Share Posted November 9, 2008 How do you get the learn gear to work... is your speed correct?As far as I know there is no way to get a proper speed reading. :-(With my S70 (1998) when I floor it in second gear my boost overshoots like CRAZY! Link to comment Share on other sites More sharing options...
Wagoneer855 Posted November 9, 2008 Report Share Posted November 9, 2008 With my S70 (1998) when I floor it in second gear my boost overshoots like CRAZY!Watch out for that, most of the bent rods I've heard of happened with flooring it in 2nd (in that dead spot where you can't quite kick down to first but it's too low for 2nd). I have to watch that a lot with my LPT. I've spiked up to 17psi at 2500rpm before since my MBC is set to wide open in hopes of holding some boost in the top-end I've fiddled with my wastegate actuator and MBC way too many times, just can't help it in cold weather sometimes. Link to comment Share on other sites More sharing options...
irf Posted November 9, 2008 Author Report Share Posted November 9, 2008 How do you get the learn gear to work... is your speed correct?As far as I know there is no way to get a proper speed reading. :-(With my S70 (1998) when I floor it in second gear my boost overshoots like CRAZY!my speeds out but as i said above i've turned the gear learning off and the feedback speed off. Link to comment Share on other sites More sharing options...
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