Early 916 Strada / 916 SP Injection System(s)

[Gobert23]

Hi folks,

I'm looking for a lil' advice and to hopefully draw on some of the expertise and experience of the forum members...

I've recently picked up a set of 916'SP' throttle bodies, with injectors, 'plumbing' and the wiring.

These should offer four injectors (two per cylinder), as compared to my 916 Strada's two injectors (one per cylinder).

Now, that's about the sum total of my research so far, beyond a basic understanding that the Strada and the 'SP' models and knowning that both used the Magnetti Marelli P8 ECU.

I've also got a spare (working) P8, so that I don't have to take mess with my (setup) P8, as currently fitted to the bike.

So, before I take apart a (perfectly functional) machine and get myself in a bit of a twist, has anyone on here done a swap like this before?

I know that the 'SP' had strong rods, pistons and larger valves (not to mention slightly different heads), but I'm hoping (perhaps rather foolishly?) that this set-up will be 'better' that the stock 'Strada' set-up.

G

[Bat Fastard]

Thing is fella, what are you trying to gain with the extra injectors? Ive had 748, ( 853) 916 and still own a 996sps. Worked on em, tweaked em etc.

Now if my memory serves me correctly, The 916 ran 50mm throttle bodies. Same as the 996 bip. The 996 often had a fuel glitch with owners changing fuel chips and disconnecting one of the injectors on each T/B. Thus running one injector per cylinder. The 996 bips ran with the 1.6 ECU which would fire all injectors at the same time, resulting in the glitch. It didnt have the memory to run additional mapping. The 996sps ran the P8 ECU which fired one injector per cylinder and later fired the 2nd injector when the engine needed it. Thus no fuel glitch.

So to run the P8 you need the power amplifiers and the additional sensor found on the alternator side engine casing.( Basic models had the one sensor, sp and sps had two) So you may well end up needing a bit more of the loom from a 996sps.

I never had the 916 strada. That may well have the two sensors needed and it ran the P8???? If thats what you are saying??

Basically, Changing from single injector to double injector per cyclinder wont really gain you anything. There may be people out that have done it but I think its just a lot of hassle for nowt.

[Gobert23]

Cheers for getting back to me

I'm not really in any sort of rush to start 'tinkering' with my Strada. Certainly no more than I've done already. I just happened to clock a set of 'SP' injectors and thought them a bit of a 'bargain'... Curiosity and all that.

See, I've picked up a 'spare' Magnetti Marelli P8 ECU (since they're getting thin on the ground anyways), so I'm treating this as a bit of an 'experiment' and give myself a puzzle to try and work through.

At the moment, all my understanding is being drawn out of Ian Falloon's books, a Ducati Workshop Manual and a few scattered images from the 'Race' Manual.

It's tricky, without speaking to someone that actually knows the 'Strada' and 'SP' models inside out; what the definative and exhaustive list of differences are...

What I do know is:

The 'Strada' and the 'SP' (1/2/3) models (I'll stick with UK only models for the moment) shared the same 'architecture', with the (Magnetti Marelli P8) ECU mounted in the tail, with the spark amplifiers mounted either side and (what looks like) 'similar' loom layout*, etc , etc

Both bikes 'appear' to use a single connection to the injection system (at the 'fuelling' end of business) with a 'MIL' socket, where the wiring is then different and branches out to the extra injectors (they're just 'switches' after all, yes?)

From what I understand of the P8 units, they're all pretty much the same, with the exception of the 'chip' that's fitted and the functions/capacity that's actually used on specific models (in other words, not all of the processing/functionality was used on 'lower' models).

*I've got a bit of homework, comparing wiring diagrams and layouts to do, between the 'Strada' and 'SP' models.

What I do need to find out is, what differences there are in 'sensors' and other sundry components on the bike(s). As there may not be enough inputs on a Strada to meet the requirements, when adding the extra complexity of the 'SP' setup (if you follow me...)

Anyways, all hypothetical for the moment... Gives me something to try and work out.

G

NB. There's no worries for me, in regards to the known issues with the other fueling/ECU systems. Since both the Strada and the SP use the larger 'big brain' P8 units.

[DesmoEddy]

I know that the 'SP' had strong rods, pistons and larger valves (not to mention slightly different heads), but I'm hoping (perhaps rather foolishly?) that this set-up will be 'better' that the stock 'Strada' set-up.

Thing is, the single injectors will flow enough fuel for the 100hp or so of a Strada / Biposto and in fact are capable of flowing enough for 120hp. The 916SP doesn't need the two injectors to make its power; they were only there to homologate the bike for WSB racing. Grafting these throttle bodies onto your bike might be an interesting exercise, but ultimately pointless.

The current incarnation of my 1996 Biposto includes single-injectors, SP heads & cams, 12:1 pistons and an Ultimap chip. Trouble with this set-up is that it moves the power up the rev range but I don't have the Ti (or steel Carillo rods) to take advantage of a potential 11k redline.

Cheers,

Eddy

[Gobert23]

I can see the setup sitting on the shelf and waiting until I dig up a set of heads, cams, barrels, pistons and any other sundries from a 'SP'...

Ah well, at least I've got a spare ECU now