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Re: Carb convert.
Posted: Thu Oct 28, 2010 3:09 pm
by angelix
907pasonut wrote:angelix wrote:
Actually it could be beneficial UPgrading to a P8...
how different is a p7 to a p8?...or what are the advantages

not a 100% sure about the technical differences, I guess the P8 has few features that the P7 does not have.
I see the swap more from and AGE point of view, the P7s were used on Ducatis around 1988-1992. the P8 came later therefore it will be less dated from the electronic components point of view.
As fare as the chip programming (Dyno) is concerned I remember asking around and I was told a couple of "I am not sure, will need to check" when i mentioned P7, whilst for the P8 it was always "no problem".
Last but not least, when I was after a P7 it took to me a long time before finding a good one; P8s were all over the place and they were also cheaper.
Tamburinifan wrote:the EFI on the 907ie might not be perfect but it is much better than any carburator setup.
I disagree.
My M900 f FCR & Ignitech works far better than a original 907 w P7.
I would not change to carbs either, get a good chip.
I am happy you disagree, but the point is that ANY EFI is 100 times more reliable and practical than ANY carb setup.
with few changes on a PC you can adjust your settings to whatever setup you have on your bike and can revert those settings in less than 10 minutes.
You cannot do that with the carbs... although I AGREE with the fact that carburators could give a smoother ride when picking up the revs our of tight corners; this effect is very tipical of the old EFIS, now adays the riding experience is much smoother.
Re: Carb convert.
Posted: Thu Oct 28, 2010 5:36 pm
by Tamburinifan
Differences P7/P8 I mentioned earlier in this thread.
although I AGREE with the fact that carburators could give a smoother ride when picking up the revs our of tight corners; this effect is very tipical of the old EFIS
Which is really my only point here,
my Monster has better driveability than original 907.
P7 is ancient in the injection world, not many shops and even fewer people could understand hex and make a new chip. It works OK but is quite primitive.
W my MyECU I can
with few changes on a PC you can adjust your settings to whatever setup you have on your bike and can revert those settings in less than 10 minutes.
but not w P7.
Need to understand hex or get Tunerpro or similar, be able to make chips etc.
You said above few shops made chips.
Re: Carb convert.
Posted: Fri Oct 29, 2010 12:41 am
by higgy
Lets make one thing perfectly clear here. There is no EFi system yet developed that can compare to a carb in terms of horsepower, torque, driveability, tractability or reliability for any gasoline engine manufactured to this day. The only reason the carb was abandoned in favor of any FI system was to keep those catalytic converters from burning. It is strictly an issue of emissions not usable power.
Even your most basic FI systems is far more complex than any carb. It is an extreme over simplification( bounding on criminal) to suggest that all you need is a PC and software to mod any Fi system to suit your needs in ten minutes. It takes hundreds even thousands of hours of very expensive development time to arrive at a mapping of fuel/timing that works without shortening the useful life of any SI engine.
Re: Carb convert.
Posted: Fri Oct 29, 2010 1:23 am
by Tamburinifan
Re: Carb convert.
Posted: Fri Oct 29, 2010 1:27 am
by angelix
higgy wrote:....
Even your most basic FI systems is far more complex than any carb. It is an extreme over simplification( bounding on criminal) to suggest that all you need is a PC and software to mod any Fi system to suit your needs in ten minutes. It takes hundreds even thousands of hours of very expensive development time to arrive at a mapping of fuel/timing that works without shortening the useful life of any SI engine.
I guess i did not explain myself enough, I apologize.
when i said it takes 10 minutes to change your settings it is because that is what it takes, provided you know what you are doing.
I never suggested you can do it in your garage!!
of course to cook a as many eproms as you like for different setups (racing / road cans , 2in1, open airbox etc etc) you need to have the maps worked out and that takes a lot of time and effort, a Dyno and all the necessary equipment. As for the burning process, once you have the map sorted out it litteraly takes minutes to load it on a PC, you could make a small change (ie rev limiter) and burn it on an Eprom but you need to know what you are doing.
I did not go into the details because I thought it was common knowledge you need dyno hours + a professional to cook a good map to start with.
P7 - P8
as mentioned before the P7 has NO offset map, basically one map does BOTH cylinders.
the P8 has two indipendent maps one for each cylinder therefore compensates or adjusts the fuel/ignition to suit the different temperatures in each cylinder; the P8 has also the possibility of running a second injector per cylinder.
Brad @ bikeboy.org playis a lot with maps and fuelling and wrote this which i find quite interesting :
[ulr]
http://www.bikeboy.org/fuelinjection.html[/url]
it is a little bit long but worth reading.
Re: Carb convert.
Posted: Fri Oct 29, 2010 11:14 am
by 907pasonut
this is very interesting stuff...first of all Im happy with my 907, but at low revs say 2 to 2500 revs it shakes (nothing a gearchange cant fix) then starts to smooth out at 3000, and you are wright re bit about pulling out of coners, but can this (torque at low revs) be improved...or can a 907 be more like a later model ducati by changing the FI system say a P8, and does it plug straight in or is it a re-wire and what about the rest...pick ups and sensors are they compatable?

Re: Carb convert.
Posted: Fri Oct 29, 2010 1:23 pm
by Tamburinifan
the P8 has also the possibility of running a second injector per cylinder.
Not w independant firing. At least on SBK Ducs the dual injectors were simply Y-wired.
pasonut,
my findings is that a offset map possibility is really a benefit
but a good aftermarket chip would get you close enough.
But if you
really want it
very good....
can a 907 be more like a later model ducati by changing the FI system say a P8, and does it plug straight in or is it a re-wire and what about the rest...pick ups and sensors are they compatable?
My software/ECU wizard friend want to test his latest creation, P8 on mine w adapted 907 P7 EU 023 map.
I`m sure it will work, hardwarewise no problemos, will get back on this.
Hasn`t anybody in f e US tried a 907 chip from Doug?
Bet he`ll make a good one, done it before:
http://www.visi.com/~moperfserv/907comp.htm
Re: Carb convert.
Posted: Fri Oct 29, 2010 6:05 pm
by Finnpaso
Intresting topic, but very funny to read ALL opinions, as seems, that everybody have own attitude .... Thank's for all
ANYWAY i am in quite same line, as Angelix with things...
Have to add little: P7 is better with FIM chip, IF AMB circuit board is fitted to P7 and FIM chip is finetuned with FIM software. No any doubt; all carbs are crap compared to finetuned and well maintained injection no matter is it P7 or P8...
IF someone here have changed from P7 to P8 computer (in 907IE!!!), let us know results!!! (and then needs also some dyno run papers with P7 and then with P8...) I dont trust before i see such papers what confirm that changing ECU makes much improvments. Ok, this is little "side" from what Angelix say, but he is in right way and he have played with things to know...
Anyway; I love 907IE injection compared to any carb systems. (I keep my bike's fuel systems in clean condition allways)
907 Pasonut: "but at low revs say 2 to 2500 revs it shakes" ??? What? Such engine is designed to work FROM 4500 RPM upwards !!!! All such Ducati engines SUFFER ALOT, if drive them with too low RPM and if such happen, then u can find hard engine failure quite fastly... Simply, Ducati engine DONT work and it suffer if driver drive it with too low RPM....

Re: Carb convert.
Posted: Fri Oct 29, 2010 10:09 pm
by 907pasonut
Finnpaso wrote:
907 Pasonut: "but at low revs say 2 to 2500 revs it shakes" ??? What? Such engine is designed to work FROM 4500 RPM upwards !!!! All such Ducati engines SUFFER ALOT, if drive them with too low RPM and if such happen, then u can find hard engine failure quite fastly... Simply, Ducati engine DONT work and it suffer if driver drive it with too low RPM....

I fully agree with you Finnpaso, normally there in no need to go too low on the rev range, but sometimes..say..city riding in traffic..low speed, it can be a bit annoying

Re: Carb convert.
Posted: Sat Oct 30, 2010 12:09 am
by angelix
907pasonut wrote:Finnpaso wrote:
907 Pasonut: "but at low revs say 2 to 2500 revs it shakes" ??? What? Such engine is designed to work FROM 4500 RPM upwards !!!! All such Ducati engines SUFFER ALOT, if drive them with too low RPM and if such happen, then u can find hard engine failure quite fastly... Simply, Ducati engine DONT work and it suffer if driver drive it with too low RPM....

I fully agree with you Finnpaso, normally there in no need to go too low on the rev range, but sometimes..say..city riding in traffic..low speed, it can be a bit annoying

some time ago I discovered that i had a seized chain ling so I took it as an chance to replace the whole transmission upgrading the chain and sligtly modifying the gear ratio.
I went for a DID 520ERV racing chain which a very light low friction x-ring chain.
For the gearing, I opted for a change of rear sprocket (+2, 15/42) and that made quite a big difference and i still manage to get to the max speed.
The advantage of the +2 rear sprocket is that where before you used 2-3 gear all the time, now you keep the just 3rd always in and really enjoy the ride.
You could eventually change the Front sprocket (-1, 14/40) but that would shorten the final gear even more.
Re: Carb convert.
Posted: Sat Oct 30, 2010 9:11 am
by Finnpaso
It is difficult to find 14 to front in 907, but easy to find bigger to rear and that is huge imporvment to behaving of bike. I use 15 in front and 46 (!!!) in rear and never back to original gearing. Rear is same as in many Monsters, SS, etc... I really dont need 210km/h top speed but now i can use also bigger gears more often to reach allways good and suitable RPM in engine (as gears are now more closer to each others)

Re: Carb convert.
Posted: Sat Oct 30, 2010 2:01 pm
by higgy
A little more on the p7/p8
ECU Notes
The P7 has identical fuel/ignition maps for front and rear cylinders, and in fact it only has one map which is applied to both front and rear. So, P7s have no rear cylinder offset map.
The P8, with its larger memory has two maps, one for the for the front cylinder and one for the rear. The basic reason that the P8 has better performance is that the two cylinders can be fueled independently and differently to compensate for combustion chamber temperature differences caused by a reduced airflow pattern across the vertical cylinder. Ducati did not take advantage this facility on the 888, and made the front map the same as the rear.
Both the P7 and P8, with the appropriate chip, can run dual injectors as in the SPs. In these cases the second injector joins in at higher revs and throttle openings to get the required amount of fuel into the engine.
The P7 and P8 have a mechanical CO adjustment like the later 1.6M. More recent 1.5M and 5.9M ECUs need to have their diagnostic port connected to a Mathesis in order to adjust the CO.
The 851, 907 and early 888's up to serial number 000508 (including SP5, LTD and Corsa,) and ‘93 Supermono used the Weber-Marelli IAW P7 ECU. Later 888's from serial number 000509, 916 Strada, 916SP, 916SPS, 996SPS 955 SPA, 916 Racing, and some 996RS use the Weber-Marelli IAW P8 ECU.
The P8 also came in earlier Moto Guzzi Daytona and California and Laverda 668 (I think.) If you need a replacement, they're all the same.
The problem with the Weber-Marelli engine management system is that the system was never designed for use by those outside the factory, so the knowledge of the structure and content of the data files is limited to those with the time and expertise to crack the code.
Another limitation for the tuner is the fact that the fuel and ignition data is held on an Erasable, Programmable, Read-Only Memory (EPROM) chip. As the name implies, this is a read-only memory store which cannot be written to while in service. This means new data must be programmed or 'burned' into a new ROM in a separate ROM programmer and the new chip then installed in the Weber.
The tuning option for most people has been to seek out reprogrammed ROM chips from aftermarket suppliers who have spent time cracking the factory software. A variety of modified chips is available. The FIM chip is highly regarded.
Re: Carb convert.
Posted: Sat Oct 30, 2010 7:56 pm
by Finnpaso
Just that way !!!!

Re: Carb convert.
Posted: Sun Oct 31, 2010 2:39 am
by samandkimberly
higgy wrote:Lets make one thing perfectly clear here. There is no EFi system yet developed that can compare to a carb in terms of horsepower, torque, driveability, tractability or reliability for any gasoline engine manufactured to this day. The only reason the carb was abandoned in favor of any FI system was to keep those catalytic converters from burning. It is strictly an issue of emissions not usable power.
OK, I'll take the bait...you're saying that F1, modern off road M/Cs, virtually 100% of auto and motorcycle racing where FI isn't explicitly prohibited are all wrong?
I'd agree that carbs are easier to rough tune, and that in many cases (including a 907IE) carbs may be the easiest way to improve fuel delivery. But the idea that the only reason carbs are being replaced with FI is for emissions is rather simplistic at best. EFI, and it's control of engine fuel mixture via any input change, not just engine vacuum, can allow far more extreme cam timing and overlap in a race engine and still keep acceptable low end tractability. It's independence of vacuum permits huge, low restriction intakes, while modern showerhead nozzles can increase intake velocity rather than use intake energy to draw fuel into the system.
I would completely agree with the statement that setting up a good EFI system requires resources well beyond most individuals. But seriously, do you think even the best tuner on earth could get better power, torque, driveability or reliability out of a stock 1098 using carbs?
Sam
Re: Carb convert.
Posted: Sun Oct 31, 2010 6:02 am
by 907pasonut