XDI with hi comp pistons

Are the high compression Pistons part of a fresh engine build? Or were they in use with the old ignition? I assume you have validated the timing with a light and you are using premium fuel.

 

I don't know anything about the Forza ignition but ignitions are ignitions...

Have you checked to be sure each plug wire is connected to the proper distributer terminal?

Have you verified that all cylinders are firing?

As noted, have you verified the ignition timing in accordance with whatever the Forza instructions call for?

FWIW, with a conventional ignition system, it works well to set the timing for the best power at WOT and let the idle advance fall wherever it ends up. Every engine is different and using the "stock" timing setting is often not the best setting for a particular engine. Of course, a Dyno makes that a lot easier than driving the car/making successive changes.

One other thought - Was there any change made to the valve timing when the new pistons were installed? This could change optimum ignition timing.

 

The flywheel goes on only one way and are adequate accurate. The pick up for the XDi is what I would be questioning.

 

First thing to do is verify timing with timing light. Once that is done, remove the crank sensor wheel set screws one at a time and reinsert with Loctite.

Next is to make sure the ground from engine to frame is 100% solid. Preferably, move the ground strap to the other side of the engine (away from the Crank Sensor).

 

I have run a lot of Ferrari V8's at 10-11:1 compression range and never had a detonation issue. Italian cars in general have slower longer advance curves than we like to set them up here. Not sure what RPM it is happening but if it is right off idle and you have zero or -6 at idle I'd be exploring some of the other suggestions.

 

I have seen determined people put them on wrong. Worth a check.

 

Nicks forza's kit comes with a phone number for free help/support direct from their techs. Maybe give them a call. I had a marathon thread going over the summer about a power loss, and we looked every which way at my new Xdi ignition. I'll say one thing: not sure what you mean when you say you moved the sensor wheel, but I believe that thing is ALWAYS supposed to have the trailing edge of the 11th tooth centered with the laser pickup at TDC. I would NOT mess with that unless Nick's guys say to.

Also, I've called electromotive and asked for their lead tech, and found them to be VERY helpful; they have knowledge of the 308 setup.

 

What do you think about these XDI systems in general assuming, of course, that they are installed correctly?

 

I have never installed one so I really do not have an educated opinion. In general ignition systems have improved a lot and if I was going to significantly modify one of these I would consider it but that is not really what I do. In California it was illegal anyway so there was no advantage to me doing any of that commercially.

The injected cars already have a good system for normal use. If I had a carbureted car with an ignition system stolen from the Smithsonian Institution I would be installing something else.

 

I am bouncing back and forth over doing it to my QV. I put several hundred miles on a 2Vi that had one and I liked it, specifically because the car seemed to have more pull right off the clutch in first. I assumed it was because the timing can stay advanced over the entire throttle movement rather than just on, off, full throttle. The car just felt better off the line.

It didn't feel like it had more power, it just felt like the torque curve started earlier on the rpm band.

Was I imagining this or is that the type of thing that can be achieved with XDI?

 

There are a lot of marks on the flywheel and are hard to read. Use a dial indicator to find TDC and see what is there then put a paint mark on it.

 

Tommy,

coming from the opposite end of the spectrum compared to Rifledriver's level of expertise, I installed XDI on mine (by myself) and am very happy. It may give better (or more consistent) spark at start up (less fouled plugs?), but I doubt much increase in performance compared to a WELL SET UP AND SERVICED OEM set up (twin dizzies in my Gt4).

And there lies the rub, you need to have your OEM set up in fine fettle and be able to work out where and why it isnt, whereas the XDI system is pretty stable/reliable with no parts to wear out (although the trigger wheel or sensor could loosen up).

I drilled only two holes in a cambelt cover for the sensor mount and can return everything to OEM.

For me it was the set and forget, no ongoing maintainence that has allowed me to concentrate on other areas when problem solving.

 

I really liked Electromotive's HPV1 over their XDi which was the replacement. The earlier version was an all inclusive unit which had the tuning dials and coil packs all on the one single board that was about 12" long, so a person only had to mount the single unit. I luckily found one and installed it on my old car which made for a nice tidy drama free installation.

 

If you think your advance was 6 degrees off, I'd keep the trigger wheel where the manual says it should go, and just dial in 6 more degrees of advance on the rpm dials.

OOOH, did you check for proper dip switch positions? Unscrew the dial settings face plate and check to see if they're properly configured for your engine. THAT could cause some interesting problems.

 

That could well be. Ferrari has always been very conservative about both compression and timing, especially on US models. It wouldn't surprise me if some gains were to be made especially in the low and mid range with just timing. Now that I am back in the USA I will probably do some of that type of work. I know in all the 308/328 motors there is a lot that can be done even without putting blowers on them. With good rods they are really strong so the limits really come down to how much you want to spend.

 

No worries. Happens all the time. Not like they are easy to read after all.


Not surprised it was detonating. That was enough advance for a nitro motor.

 

Wow! Glad to say that I haven't done anything like that...










this week...

 

This is true. Who has the quote Never idiot proof anything?