- Mover -

I was looking at the tuning options of a M273 and realized I haven't seen anything with regards to altering/expanding the variable valve timing range.
From what I understand, the range is approx 40 degrees crank for both intake and exhaust valves for the M273.

Looking at some other high performance engines (that have an even higher compression ratio 12:1) I've come across an adjustment range of 65 deg intake, 40 deg exhaust.

I know there are quiet a few tuners out there (Brabus, Renntech, Kleemann, etc); has anyone come across a tuner that has researched and altered the variable valve timing range as well ?

pezzy669

The phasing limitations are physical relating to the internal vanes of the CAM gears (see pic below of a Toyota VVT gear), I don't think its even something that can be changed via software alone. VVT really doesn't add significant amounts of power on its own so I doubt the cost benefit of finding someone to engineer some new gears for you would even be worth the few HP you may gain. Your probably better off finding gains elsewhere.

- Mover -

Yes, I forgot to consider this. I was only thinking from the changes via software.

Although this engine has a 2 stage intake manifold, tumble flaps, etc, I was looking at the possibilities of getting more top end (non boosted) from this large engine.

Oda112

I don't think there's much to gain from the M273 unless you're willing to open it up and upgrade some internal parts. Unfortunately, it wasn't a very popular engine with the tuners and there aren't a lot of aftermarket upgrade parts for it, not that I know of at least. It has the same displacement as the M157, I always wondered if they have a similar block. There were some ECU tunes some companies sold online a few years ago but the gains were minimal, 7 to10% increased power output. Here's a remnant of that. https://catalog.kleemann.dk/catalog/...00550-v8-m273/
The K3 package could be interesting

- Mover -

Yes, for sure !