Forged Pistons - mapping?

[Greedo]

If I were to run forged pistons in place of a de-comp plate, would I need to have the omex map tweeked? Or would it not be needed?

[dannygti]

Yes you would need it tweaked. There's no guarantee the compression would be the same.

[jones91]

As above, yes the mapping will need to be tweaked because forged pistons will probably be a different compression to a de-comp plate

I'm pretty amazed your running 14psi on standard internals too

[Greedo]

Trust me, not every day I'm not :y:

Cheers for comments guys, didn't consider the compression differences... although it should of been obvious.

[yr51ocw]

compression will be different (no doubt), but also the change in the shape of the combustion chamber will effect the knock limit of the engine, so yes a quick overcheck/tweak of the map would be advised.

[Greedo]

Looks like I need to find someone to tweak my omex map in the midlands then.

Would driving the car on low boost (approx 3psi) to the tuner's location cause any damage?

[jones91]

It might be best just to go back to where you first had it mapped, I think some places might knock a bit off the cost if you used them beforehand

[Greedo]

Sounds like a plan, providing it'll not be destroying the engine driving it lightly :y:

[yr51ocw]

I would is there anyway you can access the software and change some settings yourself? If so, I would retard the ignition by 3deg in the section of the map you plan on using when driving to get the car mapped.

That said, its only a safety measure. Unless it was mapped right on the knock limit and the new pistons make things alot worse there shouldnt be too much in it. Does the omex have the function to change the igntion when detecting knock?

[Greedo]

" Knock sensing capability" is part of the Omex 600's features.

I'll see what I can do with the map myself, Omex's are notoriously hard to connect to laptops due to old rs232 connections

[jones91]

Personally mate I would just completely leave the map alone until you get to the mappers, with changing just the pistons I would of thought as long as you keep the revs below 3 - 3.5k the engine should cope ok until you get to the mappers

[ThrushMotorsport]

Keep it out of boost as much as you can, and you should be fine.

[Greedo]

I'll be able to travel at around 2.75 - 3k easily. Good peace of mind then. Cheers guys.

On a similar note, I'll be upgrading my VTS coilpack to a ford pack and HT leads - will this change the ignition output - thus meaning tweaking of the map for this too?

Just wondering if I can get away with fitting HT leads now, or if I should wait until I upgrade the pistons too.

Cheers :y:

[welshpug]

got a wideband gauge?

[Greedo]

Got one I'll be fitting next week

[Greedo]

I'll be upgrading my VTS coilpack to a ford pack and HT leads - will this change the ignition output - thus meaning tweaking of the map for this too?

Just wondering if I can get away with fitting HT leads now, or if I should wait until I upgrade the pistons too.

Cheers :y:

Can anyone shed some light on this?

[tweeqd]

swapping the leads will have no affect on the map

[Greedo]

But a car that never ran leads....?

[tichy]

But a car that never ran leads....?

No mate changing to ht lead set up won't affect the map

[Greedo]

Awesome, cheers chaps. Appreciate it