M112 - N/A Modifications

[SloppyClock]

Hello all,

I own a N/A 2006 Crossfire; powered by the M112 merc engine.

And after a year of ownership and lots of thinking, I want to go to town on really modifying the engine and drivetrain (in conjunction with suspension + brakes; these I have figured out already).

A couple of things before I start....

- Please dont tell me my car looks like a dog taking a dump; I know this fact well enough
- Please dont tell me my car will never be as fast as the AMG M112 powered SRT6, as I know it never will be
- Please dont tell me my car will be nearly unsellable once I'm done, I have no doubt that's the case

The reason I want to go down this route is to learn. I've been tinkering with cars ever since getting my provisional, but have always been fearful of working on anything beyond valve cover gaskets/plugs/wires and standard service items (oil changes/filters/coolant/belts etc).

Hope that doesnt come across as rude, just wanted to get that out of the way before cracking on

So, what I'm really looking to do identify the performance modifications I can make to my engine and drivetrain without going forced induction. The reason for this is the m112 is notoriously hard to force induct (heat issues/space issues/requirements for fabrication of mounts etc) and to be honest, I would like to go down this route - after taking care of other aspects first.

My car currently has:

- Cat back exhaust (rear cats removed, primaries in place)
- 3'' dcai running into the C320 airbox, K&N air filters to a 3'' MAF and 74mm TB
- E55 engine mounts (to reduce engine flexing as I read the M112 uses the mounts to reduce rotational inertia introduced by the balance shaft)

And a few minor things that arn't worth mentioning (sprint booster for example).

These are all pretty cheap bolt-ons. A few things spring to mind on how to get further gains:

1) port/polish the head
2) Fit 3-2-1 exhaust headers
3) High-flow cats (still trying to asses if these are even worth while to be honest, I'm curious if they will help more so because the cats are 10 years old vs being actually 'high flow)
4) Larger injectors (need to investigate cycle performance of the current ones, reading that at this point they are at max)
5) Further cool air intake (no idea how, need to figure out)
6) E55 fuel pump
7) ECU tune!
8) Karmaan camshafts

The thing is, this is all simple bolt on stuff. Does anyone know of any other mods that can be applied to the M112? Apparently the internal are forged already, and researching online brings up jack all!

[Krikkit]

Hate to say it, but how much is that lot gonna cost? Why not just buy an SRT6 instead?

Gains from N/A tuning will be minimal all-told, even with camshafts you're probably only looking at 10-20% power max.

[PaulKemp]

The basics are to de-restrict flow in and out
On a Duratec engine simply removing the restrictions in the inlet releases a big gain
Free flowing cats are a benefit, I would think a good exhaust manifold and free flow cat plus detest iced inlet is a good start
HOWEVER, tuning is not realy a bit by bit process, you should decide what you want and what modifications will achieve this

[CarsOrBikes]

Is there anyone that can tailor map it? If so head work and cams with better exhaust manifolds/cats would possibly make it nice without spoiling it, I'd like to do similar on my SL and CL because it can be discreet tuning which I like, and actually use less fuel ha.