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I was wondering if this would be an easy way to shift the redline to 6300 from 5800?

The ECU doesnt control ignition timing or advance, correct?

Hi Grant,
I would be worried about wide open throttle situations.
When you go WOT the ECU switches to open feedback and doesn't look at the O2 sensor. This means that it would look at the rpm and just dump in the amount of fuel it was programmed for a 2.5L. This might be an acceptable level because normally they are designed to squirt in more fuel then needed but i would doubt it would be adequate for a 3.0L. Since your goal is to increase the redline, i don't think there is a time you'd be going to hit that except at WOT. To answer your question thought the ECU doesn't control ignition, and the only ignition retard or advance is done by vacuum from the intake manifold.
Bob

Hi Bob. I see what you are saying, but in practice I found that it runs just as rich at WOT as before, if not richer! I think this is because the ECU still computes fuel supply based on AFM position when in WOT.

After driving with it for a few days I noticed hesitations when the engine was cold (JUST LIKE EVERY 2.5 LITER MILANO I'VE DRIVEN!). I love the sound of the 3.0 at higher RPM, it's starting to sound sweet finally, but the stock engine really dies off at higher RPM. Pretty dissapointing. I'm goign to switch back to the old 3.0 ECU after this excersise.

Grant; How are determining a/f ratio at WOT or high rpms..? wideband?

Yeah, a la Innovate LM-1.

Not sure why, but there does seem to be hesitation here and there. I think I've conluded that it would be better to stick with a 3.0 ECU that has the rev limiter moved.

But honestly, the 3.0 tapers off so badly in stock form, the stock redline is actually fine. Might as well go to 3rd party engine management if you bother doing the internals...

I was chatting with APE a while back when I was sourcing a 3.0 motor. They said they liked the 2.5 ECU better. You might want to give them a call about this as I'd be interested when I finally get my 3.0 rebuilt and installed.

Well, like I said, so far it hasn't been that great. I don't see any advantage to the higher redline on the stock 3.0 actually, power seems to fall off.

It was an interesting exsercise, I've been drivin gon it for about 4 days now. Definitely more stumbling than before, especially when cold, but I can' wait to build my engine up for higher RPM and power, it sounds awesome!

Hi,

I develop an eprom to modify the BOSCH 3.0 ignition ECU: set the rev limiter at 6100 or 6300 or 6500 and to adapt the ignition advance .

the differet test i do on a stock 3.0 give a good result until 6000rpm
a 6100 rev limiter is suffisant.
going to 6300 is not necessary.
on track I use 5900 max, 6100 to stay on the same gear.

no problem with Jetronic ECU, enough fuel.

If you need some more info. no problem.

nimbus: more info please.....

Hi,
some more info...

I work on the optimisation of the advance curv from the Bosh ECU 0 227 921 035 to improve usage of the V6 3.0, on track and to permit to use the Bosh ECU on a 2.5.

Starting from the fist brand of ECU, 0 227 921 035, rev limiter at 5900
I modify the rev limiter value and advance WOT table.

the advance curve in normal drive is not modify to stay compliant with emission.

when changing the rev limiter, the advance curve must be modify because it not well initialise on the stock ECU for rev upper 5900.

About the advance otimisation, a friend use the standard ignition from a 2.5 and it works well then we can put more advance between 3500 and 5500.
The only condition is to use 98 Ron fuel ( not the 95).
More power between 3700 and 5500, same mower at 6000 ( max power).
then we need some extra rev on track to go to 6200 between curves. normaly with the stock I change gear at 5800.

To change the EPROM you have to remove the orginal one, sold a socket and to plug the new one, 2732 with the right program.

If you need a copy i can provide the modify file or the eprom.

About the Bosch ECU, 0 227 921 035 and 0 227 921 036 there is different brand:

0 227 921 035 - serie 1 rev limiter 5900 the best power with alot of advance.
0 227 921 035 - serie 2, rev limiter 6300, less power
0 227 921 036 for catalyser, limiter 6500, no power, rev to high.

The modify program can be install on any ECU, 0 227 921 035 or 0 227 921 036 ( same electronic). It will boost the car.

the advance curve and rev limiter are in two different boxes...

did you modify both?

Pictures of soldered socket in ecu if you have any?

HI
On the 75V6 3.0, there is two boxes:
one ECU bosch, small black box on the right of the passenger side, to control the ignition, with the rev limiter.
one ECU Bosh L-Jetronic ( passenger side, front screen, to control the fuel injection, no rev limiter ( 3.0 any ljet model or 2.5 V6 calatys.).

the idea is to optimise the ignition on a stock motor (camshaft and fule injection as stock). About the fuel injection, the only possibility is to optimise the setup: not too rich, not too lean ( be carefull to use good injector, clean injector filter, etc...). I use a standard Ljet and set up the AFM to optimise the mixture at hight RPM (working on the spring, one notch less on mine to lean the mixture), and working on the battery compensation to align the mixture at idle ( to allow the fine tunnig using the screw of the AFM.

The next step will be to use the stock block with a MAF instead of the AFM.
it is necessary before working on the head and camshaft.

Best regards.

About the picture, i will take tomorrow,