sp838 Posted January 6, 2015 Posted January 6, 2015 Anyone here done it? Tips, tricks, words of advice or caution? What coils are you using? What did you do to retard the spark, was it mechanical or was it done with the ECU? Very curious to hear about your experience with this. Thanks!
sp838 Posted January 6, 2015 Author Posted January 6, 2015 ok, just found this in the How To which is pretty helpful: http://www.v11lemans.com/forums/index.php?showtopic=15835&hl=%2Bdual+%2Bplug The main issue I am concerned with is how to retard the spark. It does sound from this post that the spark can be delayed in the ECU. Is this something that can be done with the Guzzi Diag software? Should I get the myECU? ECU wizards, care to shed some light on this?
czakky Posted January 7, 2015 Posted January 7, 2015 You can definitely change ignition timing in guzzidiag.... That's the extent of my knowledge.
Meinolf Posted January 7, 2015 Posted January 7, 2015 Hi, you can change the ignition map of the ECU with programs such as Tunerpro. Download the map using 15M-reader, change the values and upload the new map with 15M-writer. While I don't have any advice how much and in which areas (rpm/TPS) the ignition should be changed, it definitely should be retarded. Cheers Meinolf
sp838 Posted January 7, 2015 Author Posted January 7, 2015 thanks guys. gonna download the software and mess around to familiarize myself with it. I have a PCIII, the fueling was tuned on a dyno so not worried about that yet. just need to retard the spark by 8°. I'll probably need to bring it back for another dyno session after installing them anyway. Now I am wondering if I should pop some higher compression pistons on as well, while I have the heads off...
Meinolf Posted January 7, 2015 Posted January 7, 2015 Hi, a uniform decrease of 8° at all loadpoints probably won't work. Instead of going for new pistons you can achieve a compression of ~11 by taking 1mm of the the cylinder heads and shortening the the cylinders by 0,5mm. This would also give you a decent squish area, which the standard setup doesn't have. Cheers Meinolf
luhbo Posted January 7, 2015 Posted January 7, 2015 Hi, a uniform decrease of 8° at all loadpoints probably won't work. ... So, instead, what would work then? Hubert
Meinolf Posted January 7, 2015 Posted January 7, 2015 Hi Hubert, it depends. Not having done and tested an ignition map for a dual-plugged V11 with a 15M (my following thoughts are partly based on the current understanding of the 15M, other ECUs. Especially those with closed-loop, are a different topic) I would tend to follow past experiences. Dual plugging of twins brought the biggest benefits to those designs (for example the old LeMans1-5 or BMW R90S) which used a raised piston dome to achieve high combustion, which resulted in an ineffective design; larger surfaces leading to higher heat dissipation and a convoluted combustion chamber. At that time a rather rich mixture was (legally) possible, so the negative influences could be countermanded by just richening the mixture. A rich fuel-air mixture ignites better and burns faster. The combustion chamber of the V11, using a semi-spherical design, and the quite flat piston are actually quite good for a 2 valve head. However, at the time of design of the V11 emission values became a design-critical factor. Which lead to leaner mixtures, which lead to much higher pre-ignition values than the old designs with raised piston domes and rich mixture needed. Given that adjusting the mixture by changing the respective maps, based on AFR readings readily available using relatively cheap equipment from Zeitronix or Innovate, is possible now I would start of with a ignition curve which is similar to the old LeMans. Which at WOT is actually close to the 8° which sp838 (I do wonder why so many hesitate to use a name instead of a nick) suggested earlier on. But at intermediate rpm/settings, where one would strive for a mixture less rich than the one desirable at WOT, the pre-ignition could be closer to the original map. It gets a bit more complicated at low rpms. At and close to idle the ECU uses a formula to change pre-ignition, based on the ignition maps. The differences I have noted are close to or bigger than the pre-ignition of the old Le Mans, so I would start of with the original ECU values. Does that make sense? I haven't yet come across an ignition map from one of the tuners such as DAES or Dynotec modified for dual plugs. I'd be happy to get one. Cheers Meinolf
luhbo Posted January 7, 2015 Posted January 7, 2015 As long as sparks were battered out mechanically the 8° retarding were quite common IIRC. Once he has the software he can build and compare different maps. That's just a toy, and playing around with it is part of the game. About the maps: did you ask Paul for instance? Hubert
gelos Posted January 7, 2015 Posted January 7, 2015 For more compression you can mount head gasket from Breva 1100 1st serie, part nr.GU03022055, metallic stuff, 0,8 mm thinner then V11 gasket, shortening the the cylinders no more necessary. 1
Zooter Posted January 7, 2015 Posted January 7, 2015 Do you get much more midrange torque out of modding the cylinder heads like this?
moto fugazzi Posted January 7, 2015 Posted January 7, 2015 I've been thinking about dual plugs for a while now. Last summer, I talked to someone that had Mike Rich pistons in his V11 Sport, and he said the compression was a bit higher, AND his pre-ignition or pinging went away as well. I'm not sure if those pistons are domed differently or more efficiently , or what exactly caused the pinging to stop. For some reason, I thought one of the V11 variants had dual pugged heads. If they do, you could probably utilize that ignition map to some extent. Ken 1
sp838 Posted January 8, 2015 Author Posted January 8, 2015 moto fugazzi, that's a very interesting idea, I'll look into it. The Breva 1100 has twin plugs, for instance... From what I've read so far, an across the board 8º retard on the spark would work just fine, and will be a good starting point. Fine tuning the actual ignition map is something that I think would be best done on a dyno. Mike Rich's piston are far far superior to stock, and cost as much, or less, than it would cost me to machine the gasket surfaces on the heads and on the cylinder jugs. Not gonna do that, it's a poor solution really.
motoguzznix Posted January 13, 2015 Posted January 13, 2015 @ Ken: The Breva 1100 iginition map is no good idea for the V11. It has a lot more pre iginition than even the V11 stock map. It will cause pinging and bad running behavior. It only works with a moderate compression ratio and low volumetric efficiency of the engine. The same goes for the standard ignition coils of the Breva. @ sp838 8 deg less overall will not work fine as the engine needs the 8 deg around idle. Reducing to near zero in that area will decrease from idle Quality. In case of real interest I can email a tunerpro file with a good working ignition map for a V11. Let me know your email address.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now