83mm or 80mm Pulley Clutched.
 

It's a new pulley size that only VRP makes so not many would have tried it yet and the tuning may not be dialled in 100% for it either. Cooling for 77mm is pretty much just heat exchanger and pump so you don't have to rule it out for a street driven car at least. I find the 83 insane enough but 77 would definitely get your goal.

Why not upgrade your throttle body? Can make some nice HP increases with the headers instead of a smaller sc pulley?

A TB will not make more HP than a smaller pulley.

As for HP gains with an 82mm TB you would be looking at 20-30HP as seems to be the consensus on the forum.

As for power here is a nice little formula for hp gain per mm of pulley size lost. https://mbworld.org/forums/w211-amg/...ize-boost.html

I would recommend read all the posts about people having trouble with throttle body upgrades. You really spin the wheel of fortune on that one and some people can never get their car back to normal even going back to a stock 74mm TB. Some people it works perfectly but a back to back dyno with other mods showed only a 10whp difference 82mm vs stock TB, worth the risk?

By shorty headers, hopefully you mean mid length? Shorties (keep stock downpipes with huge restriction + cats) are a wasted modification on these engines.

Yep I would stay stock exhaust if I were you unless you later on consider mid or full length headers with cats. Shorties will not yield much at all except possibly unreliability and annoying temperature related sounds. The only major restriction in the whole exhaust is the stock manifold flange and opposing downpipe flange. This is the goal to eliminate. Just get an 83mm and see how you like it. I can't get traction until over 100km/hr in the dry. You can always change it to smaller later. Eurocharged have a very reasonable $35 retune fee and I am sure it is not hard to sell pulleys. Eurocharged or shardul often do a good deal for pulley/tune.

Stock heat range will be fine.

You can keep stock plugs with the 77 id say. You could go 77mm plus upgraded heat exchanger or water meth or killer chiller for strong power off the bat and less chance on doubling pullies if your hungry for power. If the car is already a handful to you, 80 or 83 would be good. While its true 80mm is new. I think tuning shouldnt be too hard, different pullies pull different boost at different altitiudes and tthey can predict the amount on the size so not too risky in my opinion but im no expert.

I think shorties can yield 12 wheel but give you header tick which personally i dont like the sound of but woth mid or long its worth the tick for the power gainz. Ill let you know if lsd is worth it shortly. Just gotta get back from holiday to install..

Can I go one step colder while stock? planning install 83mm soon. I already have the plugs.

Yeah definitely (i did no problems).

an 80mm supercharger pulley will be similar to around a 172mm crank pulley and there are plenty of threads on those if you want to see reviews on that size. there are lots of guys that had 180mm cranks (same as 77mm supercharger) that ran slower times due to timing being cut from heat even if they had longtubes and tons of cooling as an FYI. more pulley isn't always better. if you are just doing short bursts on the street the 180 or 77 will make a ton more torque, but that comes with a cost. Most guys go back to a less aggressive pulley that track as they get more consistent times

I did initially order a 77mm pulley but changed it to a 80mm pulley instead. So its purchased and its on the way, just went with the 80mm and called it a day. With the cooling I have I should be ok for a once in a while run here and there. Im gonna mostly focus on how to get around this header's issue I really want Long Tubes but California sucks bad. Id like to run it with 4 high flow cats but then im looking at it being really expensive.

If you take off your plastic intake when looking sth the engine fro the front on the right side youll see a metal braided line going inti the furl rail, make sure thats tight with a spanner. Mine was loose once and leaked petrol onto the engine cover, it was so strange id never heard petrol crackle before as it evaporated on hot engine...it didnt ignite thank the lordie...