BRABUS786

HI

Guys


Just been doing some work on my c63 car and decided to increase the boost of the SC


Low boost 67mm pulley

622.27 WHP (734bhp )
536 WTQ ( 632.48 TQ )


60mm pulley

673.69 WHP (794.95 bhp )
603.92 WTQ ( 712.62 TQ )


Video will be up later

Merc63

I have this pulley sitting in the garage, too scared to try it.

Did you Ice it durning these runs? IATs didn't rise too much.

Looks like it leaned up a whole tick. Did you give it time to adapt? What fuel did you use with the smaller pulley?


My car is running so good right now, 20,000km on it under stage 3... This is tempting, but I need to grow some more *****.

Merc63

You should do some pulls and ice it, id love to see the difference.

Oh ya forgot to ask, what boost are you making with each pulley? I'm hitting 10psi with the 67mm.

mthis

Congrats on your numbers. Your car must haul a$$

average joe

I know the car
It's running a ice tank and a killer chiller so IATs will be staying nice and low.

It certainly will be an animal on the road

Ezec63

Nice numbers glad to see some stage 3 numbers being tested. I have mine coming in around next week super excited to get it on but haven't seen many dyno results so this is good info.

Now when you say "low boost" pulley is that what comes on the standard stage 3? Do you have a facelift with MCT or Pre facelift with 7G? I have to talk to weistec about the pulley sizes you know I want that 60mm :-)

Merc63

The 60mm doesn't come with it. You need to ask for it. You need to know what you are doing if you are going to try that pulley. IATs need to be monitored, new spark plugs, no low rpm full throttle, ice tank, is stay away from hot ambient temps.

The 67mm is plenty, way more than you will even be able to put down on the street..

I spin 2nd gear all the way to redline line like I'm in first. It's been cold here lately, 5-6c, I spun third gear at 100kmh on the freeway, scared the hell out of me. When it's cold out the car feels like it has 100hp more.

Ingenieur

That is a lot of torque

I would estimate the boost increase close to 3 psi (2 / 0.7)
2 to make the torque and 1 consumed by the blower and increased charge temp
Torque increase 12.5%

1 psi ~ 6-7 % torque increase
Assumed net at the manifold with an eff of 70%

Ezec63

Merc thanks for the info there really isn't much if any info on these cars with the blower it's crazy. My car is a '12 coupe with MCT + valve body/TCU so I think it's strong enough to hold. I also have the black series coolers + speed driven trans pan. Traction will deff be a big issue and eventually a wide body will be done to fit some big tires.

As far as the pulley IAT's I have one step colder plugs on the car and have the trunk tank on order. One thing I've been thinking about for the future is a meth kit based off MAF voltage pre manifold since this works great cooling iat's and the twin screws as done on many domestics. Wouldn't be anything for octane just strictly iat reduction. Maybe I should start off with the 67mm and work my way up? Is it just a pulley swap and diff ECU tune?

Ezec63

Also adding on to my last post .. Why no wot at low Rpms? Thanks for the info !

Merc63

Low rpm full throttle puts a lot of pressure on the pistons, rods and crank. Imagine clicking your 10spd into a high gear going slowly and trying to pedal as fast as u can, it's very hard, stuff can break.

You don't get a retune with the 60mm. The ecu is left to adapt on it's own, so afr must be monitored and race gas used to protect from detonation.

average joe

One of the uk guys is running water meth on his stage 2 E63 (devils own kit).
It reduced IAT by 10 degrees which we were all impressed with.....he then added a 150 shot NOS kit for good measure lol which pushed it to 820bhp and also helped reduce IAT further at WOT

jrcart

NICE! You can go even smaller....trust me. I think my low boost pulley is smaller than that lol. These motors are stout, you can push a ton more boost through a stock P31 motor, the trans will go before the motor. Let's just put it this way, Weistec machined me a special pulley for the Michigan Mile event which made 790whp on my C BS

Enjoy it man! Get ready to buy some tires

AMG6.3

Hey those of you running a blower on your m156 motors, specifically with high boost (north of 10 PSI) did you reduce your stock compression ratios? The reason I am asking is I though these cars stock have a 11.5 to 1 compression ratio which is not really ideal for boost. Yes it can be done but it is not ideal for pistons or connecting rods.

My past experience with built motors you typically don't want to exceed 9.5 compression.

Merc63

The stock comp ratio of 11.3:1 is left alone.

The dynamic compression ratio changes with the variation in cam timing to bleed off some of the compression I assume.

roadtalontsi

correct- with the cam adjustment they can bleed off the extra. Compression ratio is always a balance between boost, compression and octane requirements. Keeping the high comp ratio allows the motor to retain the n/a v8 spunk we all love about the m156. Most all out performance cars now that are running race gas or e85 are running 11:1 with 30+psi. thats why 1000whp is so ubiquitous today.

gzim335

Sorry to revive this old thread but did you run that custom pulley on a complete stock motor?im assuming u ran it with ms109?i have a p31 and run meth too and I'm thinking about running the 60mm