Yes, I used the search feature and everyone know forums search features are horrible so I'm starting a thread and asking my questions.
currently I have and MK113 with the following mods:
83mm pulley
race IQ tune
Long tube headers
High flow cats
rear Resonator delete
PLM XL heat exchanger
Upgraded 001 heat exchanger pump

Everything else is stock. I'm getting a new tune cause the current one feels too rich and lacks power down low, really not happy with it. So im considering a smaller pulley for more boost, and was wondering should I go with a 76/77 MM pulley and if it's safe for our motors, and what type of gains could I expect.
Car is used as a highway rocket not drag raced with back to back pulls.

So...77mm pulley or should I invest in the crank pulley and get the extra boost from there? If so what size crank pulley and belt combo?
picture for attention...

 

clean up the tune you have, keep going smaller on the pulley more chance for belt slip. when i tested my 83mm pulley i make same if not more than average 77mm pulleys and as soon as i creep into the gas pedal im gone. but i did a few different things.

 

what's your take in the larger crank pulleys?

 

great but if you have to be set up for it. i have driven a few pulley and crank pulley cars that felt lousy compared to my stock pulley set up at the time. You do not need a big amount a boost to make these cars feel good.

 

that's good to hear. I feel as if my off boost performance could be better, I don't like the Power Band between 1000 amd 3000 rpms when the clutched pulley engages. Also the engagement is more harsh and noticeable than I would like. l also notice a small hiccup at 2800 rpms right before it transitions over. IMO it's a ****ty tune I was sent.

 

mine is really smooth drives like stock pulley part throttle rips no need to floor it. nice part about the 83mm intercooler temps are not sky high

 

I agree. Thanks for your input! Made my decision easier. Im just gonna clean up my tune and do some new wires and plugs. Maybe down the road ill invest in buying someones project car to mess with making a beast. Right now i like the way my car is a daily driver wearing dominatrix lingerie underneath. 😬

 

Data log or don't bother doing any tuning......you will never know where you are with AFR and Timing without it as it is an absolute mandatory thing to do to keep these motors alive for a long time.

 

Crossing 200k miles with a 72mm.

A 77mm is safe.

 

do you get tons of belt slippage?

 

none, I have ultimate PD belt wrap kit.

 

nice, what kind of power you make?

Also what other supporting mods and did you do a crank pulley?

Thanks in advance

 

Tune is most critical piece of a smaller pulley, go with a nice, conservative tune; unless you're tracking and trying to break records. You don't have to worry about heatsoak as much as some people make it out to be- your basic larger IC pump and larger HE will be sufficient. You have long tubes that will also help a good bit keeping IATs down. Always gotta keep your eyes on temps especially if you're new to this platform/motor, so I'd also recommend a logger - I had an LM-2 when I cared about that stuff... now I just know the car, when I romp it and how many times, and don't bother logging anything.
Best of luck

EDIT:
PS Personally, I'd never touch the crank pulley, but that's just me. I know plenty of folks have run bigger cranks (a lot of those same folks are stacked, too) with thousands of headache-free miles. No matter what you do, I'd recommend the UDP pulley kit and belt wrap kit - helps with slippage and holds full boost all the way with aftermarket pulleys (even stock pulleys).

 

I agree with others that I would never touch the crank pulley in a hand-made 20 year old high power supercharged engine. I'm just paranoid.

All the mods on mine:
72mm clutched pulley
Belt wrap kit
010 pump
split cooling system with larger front mounted intercooler
kleemann mid length headers, all cats removed
"custom dyno" ECU tune after all mods were installed

as for measured power figures my car is an anomaly. The shop did it for the previous owner. The shop is "Solo Motorsports" in Atlanta. They measured only a minimal increase in HP and torque at the rear wheels. When all was said and done, if you assume 20% drivetrain loss my car was making stock power with all the mods. It was on a Mustang dyno, which is known for breaking hearts.

But the butt-dyno in the real world says it's making far more.

 

https://calculatorshub.net/mechanica...on-calculator/

 

No data log.......no information to help you. Get one, you won't regret it !!