Tuning 2009 GP 1.2 8V Camshaft Question

[chricol]

Hi All,

I hope this question has not been asked yet but I did a quick question in the forum and did not find any info.

My question is what camshaft is fitted in the 1242cc 8V engine as standard? Is it the 866 cam from a punto 75 or more similar to the one in the mk2 or 60s?

My car has various mods including
-LPG Conversion
-GSR Intake
-MK1 75 Manifold
-Mk1 75 Exhaust System up till flexible union (This translates to a custom De-Cat using just fiat OEM Parts)
-Iridium/Platinum Plugs (Due to LPG Conversion)

I have kept the factory backbox to keep exhaust noise down and ended up with a slight raspy note with a deeper tone which I really like when combined with the sound of the GSR.

So the next mod that I would like to do is fitting a Mk1 75 camshaft which I happen to have, unless it is exactly the same as the one already fitted in my engine as standard. Can anyone shed some light on this?

Thanks

(first post )

 

[fingers99]

If you already have an 866 cam (which I doubt -- even the Mk2 never got it due, I think, to emissions issues), I'd expect 866 to be stamped on it.

C & B have some lumpier 8v cams than the P75, might be able to suggest something.

At some point a proper remap on a RR is going to be essential.

 

[chricol]

The spare cam i have is from a punto 75 head.. i actually saw it getting disassembled. However it does not have 866 stamped on it. rather it has "4x4" and "3C20A" which is rather confusing to be honest.

It's good if the 866 never made it into the GP as that means I can get some gains from replacing whatever's in there. I don't care about emissions as it will pass due to running on LPG.

Is it essential that the remap is done on a RR? I was planning to remap only the LPG ecu and the installer usually hooks up his laptop and takes it for a spin on the road while doing the mapping.

P.S. Yes, I know it's a 1242 and I cannot expect any supercar performance from it, but for me, tweaking and achieving something (however little) is the fun part.

 

[fingers99]

I'd check with your LPG man, but my guess is he'll just be tweaking signals from the original ECU -- there may come a point where more is required/desired.

The cam thing is puzzling. AFAIK, the 4x4 cam is different from (and later than) the P75, but.......

You never know with car manufacturers. Often they'll fit parts intended for another model simply to keep the line going. Only a back to back, head off test for lift and duration would give us any real data (ot FIAT's figures).

 

[chricol]

So if it's later, it will have less aggressive timings due to emissions control right? Maybe it's not even worth installing then. Do you know what models came out with this cam?

As regards the LPG tuning, the system has a separate ecu which maps fuel according to load and rpm. It is very tweakable and interfaces with the engine ecu via obd. I would say that it is enough but we'll cross that bridge when we get to it. Not sure I can get a proper remap here as I am from Malta and to my knowledge, no one tunes petrol ecu's on RR's.

 

[fingers99]

I'd think it will be less bumpy. My guess, Pandas, but I'm only guessing.

Trick with the ECU would be to tweak the ignition advance: LPG is high octane (110 or so) so it loves ignition advance (and turbos).

My guess is that someone in Italy will have all the details you need: there was/is an active forum there.

 

[chricol]

The GP ecu has already taken care of advancing ignition timing. In fact when I once ran out of LPG and switched to petrol for a day, I immediately noticed pre-ignition pinging from the engine.

I'll try to swap the cam I have for a true 866 camshaft and book a remap of my LPG Ecu then.. hopefully i can find a decent RR to check the results.