AMGandS1K

Has anyone replaced their Under Drive Crank Pulley with either the VRP or UPD option?

I'm coming up on a big service I'm going to do and am considering some "while you're in there" upgrades if possible.

If anyone has, what benefits have you seen? Have you seen the benefits that they claim?

Also, does anyone have a video or instructions on doing this? Is this something I can do myself with basic tools or will the engine need to be out to do it?

Thanks in advance!

JettaRed

iTrader: (1)

I'm not sure what that is. Is it a lightweight crank pulley claiming to reduce inertia of the factory pulley so you will rev faster? If so, don't do it. I put one of those on a VW GTI back in the day and the car shook like a Diesel sounds. The crank pulley is often called a harmonic balancer, because that's what it does. If I'm totally wrong, oh well.

JettaRed

iTrader: (1)

"VRP 63 AMG Under Drive Crank Pulley (M156, M157) · Improved Throttle Response · Improved Horsepower and Torque · Approximate Gains: 10-20hp & 10-15ft/lbs "

Oh, my! 10-20 hp for $550?

AMGandS1K

Yep, advertising is always tempting haha! And apparently about a 1-3 hr job if you can get your hand in there form below yourself.

But, based on your comment, I don't know whether to pull the trigger or not. There is also a thread about the UPD offering having the OP have some sort of issue that puts him into weird shifting at 5th gear. BUT, other posters in that thread said that it worked awesome for them when installed.
So, I had hoped that given it's been some years since that thread there might be more users or at least some long term users of them who could chime in.
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JettaRed

iTrader: (1)

Sure. I bought into the hype for my GTI. The logic makes sense. But, what they don't tell you is that your car will now sound and vibrate like a diesel truck, or what harm it may be doing to the engine's internals. Of course, my GTI had a manual tranny on a 1.8T 4-cylinder. No telling what it would be like with an automatic.

People who usually spend a lot of money on something that doesn't work are reluctant to admit it.

Baltistyle

Hmm, a VRP product with bad reviews that nobody talks about…..with included false advertising, lol

stay away from VRP at all costs. Trash company, Trash people.

sickSVT

I'm running one on my 3L Whipple supercharger setup. Never had an issue with it, they'll save your idler pulleys and accessories from overspinning at high RPM's.

They're worth about 5-10rwhp but it's pretty hard to notice on a high HP engine.

Cifdig

im surprised you run that given it robs boost from you and changes your pulley ratio. But yea those crank pulleys come with a damper plus the m157 are internally balanced not external where crank pulley weight and size are vital

sickSVT

Yeah, I can just swap to a smaller upper pulley if I want more boost. I'm more scared of overspinning the idler pulleys and accessories revving to 7K @ 650-700rwhp. lol

Cifdig

Makes total sense. We find after a certain power level we are puking coolant from the bottle from the fast pressure build up . Problem is the thermostat is restricting the flow at WOT pulls creating a **** Ton of pressure . Most think it's the expansion tank failing but I think it's not. It's that pressure build up from the over spinning. I no longer have a thermostat. But that crank pulley was my option for that same reason, to help keep accessories and water pump from over spinning . I have it in the box I'm yet to install it. I've been wanting to do a back to back comparison at some point.

sickSVT

Yeah same here, running the blackboost race thermostat. Definitely performs very well, dropped my coolant/oil temps from 20-40*F.

AMGandS1K

The perfect person to stumble upon my thread 🙏🏼.

So would you recommend trying one? I'm at ~715-725WHP (depending on Dyno) right now and want to go higher once you get your intake system to market. I'm looking to do mods that maintain the health and longevity of the engine, especially when I'm driving her hard or racing.

If you have any other recommendations that'd also be awesome, as I have a big service to do the rear main seal and turbo coolant lines + a bunch of other "while your in there's" coming up in the next 6-12 months.

AMGandS1K

You know I thought I had replied to your thread on your build with the questions I wanted to ask you and was wondering why I never had a response... Turns out my dumb*ss never sent the reply in the thread 🤦🏼.

Cifdig

honestly I haven't installed mine yet, my drivetrain and trans are shifting so insanely fast I figured the best way for me to see if the crank pulley has any gains/benefits in the rev/ or even just some improvements, I wanted to wait until I'm fully dialed in with a new tune that I rarely have time to work on. I haven't even done one pass in my car yet I've been so swamped at the shop. Sicksvt would have a better take on it . But my opinion is there's no reason not to try it . I'd definitely suggest doing some data and logs and perhaps post it on the thread. That way perhaps anyone on the fence can make an informed decision based off what you find.

sickSVT

Biggest benefit is extending the life of your idler pulleys, alternator, ac compressor, water pump, and power steering pump.

Second benefit is weight and looks, the billet pulley is lighter and looks prettier than the stock heavy cast pulley.

For only $400, I think it's worth it for a potential 5-10rwhp. Every little bit counts when you're trying to squeeze more horsepower.

AMGandS1K

Noted! Would it affect those accessories power delivery, i.e. a weaker AC etc? I genuinely don't know about this mod's consequences other than the advertised benefits, hence the thread 😅
BY the way, where do you see it for $400 at? Lowest I found was $425 I think.

sickSVT

I've noticed no effects on AC or Alternator charging issues, and I'm running a Antigravity lithium-ion race battery.

Cifdig

Its not even hard to test voltage output after it's installed . Just put a scanner on, and if you are seeing 13.5-14.5 coming from the alt during idle, then you know 100% the size is not small enough to effect charging . My reason for getting one is the same as SICKsvt. To remove stress from accessory and if any extra benefits come about then even better . At these power levels it's gonna be hard to see these gains. But when your after efficiency and every little extra hp sometimes the small things are not seen until later when they add up.

AMGandS1K

Thabks, yeah I'd just put a multimeter on it to check throughout the system.

that's also the way I look at it, Id like to keep the car as health as she can be.
So I looked at it as:
1. Remove stress from accessories.
2. Weight savings (best and easiest way to go faster lol)
3. The claim of increased throttle response.
4. The claim of increased power.

Sounds like I should put in an order. Do you know if I can get this done myself without removing the engine? Someone in an old post said they got to it from below without a lift but it took awhile.

sickSVT

I installed mine using a flywheel locking tool for Mercedes. Very easy removing through the bottom of the engine bay, the stock balancer slid right off without any pulley puller tools.