We ran across yet another Evo with crank wheel problems - its facinating if you comapare this guys lightweight crank pulley dyno sheet to the other guy we posted up the max power WITH the crank pulley is just about the same - 305 whp

The mods were 3" exhuast, HKS 264 cams and intake with MBC set to 20 psi

With the crank pulley he was having issues with a rough power band and not too much power

When he was in for his initial Dyno Flash back in October, he wasn;t doing that well on power - we thought he must have had a bad load of gas as we saw lots of engine noise and the knock sensor was pulling timing on the stock ecu if we tried to go over 310 whp

At that time - we were unaware of the Crank Pulley issue and we also were unaware that he had crank pulleys installed

Here is the AFTER dyno sheet - I know this is a bizzare order but I messed up somehow - anyway - this is a real smooth and nice dyno sheet - very rich and conservative in a/f and the car runs like a BMW M5 - lots of low end power and pulls smooth to red line

 

Here is the before with the lightwieght crank pulley and original Dyno Flash settings with the ecu having taken out lots of timing and created this super rough power band VS. the After dyno sheet - you can see the gains we could tuen back in without that crank pulley adding all that harmoinic engine noise

Again, this virtually duplicates the other guy's results both in pre and in post dyno numbers

 

With and without the pulley - never removed car from dyno - note pulley was on first and did make a 6 ft lbs trq increase down low - OR shall I say putting the stock pulley back on cost us 6 ft lbs

Its nice to see some gains on the dyno from the pulley

The PROBLEM is that with the STOCK knock function and sesnor intact - the extra harmonics from the pulley are causing false knock readings which makes the ecu pull timing and lower the power while making the power band rougher

IF you used a ecu with knock correction - desenitization - like a stand alone - then the harmonics would not effect the tuning and you would not suffer these probloems

I am posting this information becuase the DYNO FLASH is a stock ECU based tuning option which uses the factory knock sensor and when you are using the Dyno Flash it is NOT a good idea to add a crank pulley

I am NOT a mechyanical engineer so i am NOT commenting about bearing issues or other mechanical issues that others have discussed

Its clear that the pulley itself made power - the ONLY issue I am warning about is the stock ECU knock sesnor seeing more harmonics and noise and the stock ecu pulling timing

 

...Then, how come both curves (with stock pulley and with "crank" pulley, only) look so jagged and inconsistent? Wouldn't one ("stock" pulley") should have provided smoother output, on your baseline measures? What happened (or should have happened), here?

Honestly, I *do not* think that the 50+ HP difference between your crank-pulley baseline, and your retuned stock-pulley flash is attributable to "crank's" pulley "harmonics" pollution of the knock sensor. It looks like more of a flashing issue, though...

I simply do not have that kind of issues with my Unorth. pulleys (crank, Alternator, water), and my power curve is smooth as it can get (even without custom tuning at the dyno).

Even at idle, the car is smoother than what I remember with the stock pulley.

Happy racing!

 

The reason why the roughness remains in the dyno curve even right after we take off the pulley is becuase the ecu does not immediately restore the original timing

Runs 1 & 2 were with the aftermarket pulley - - - RUN 3 was made eaxctly an hour later after the pulley was removed and backl to stock - the car was not run in between - that hour was the pulley removal

We did not reset the ecu - the pulley was just removed and another run was done


The next time this comes up - just for kicks - I am going to do the A-B pulley test - THEN reset the ecu and redyno

As far as your pulley - I am glad you have good results.

I have seen this same low whp situation on many cars with pulleys and I am only posting this info b/c I do not want ANY of our Dyno Flash customers to go through this

My original findings and dyno sheets were questioned so when the chance came to do this again I jumped at the opportunity

People reading this stuff can reach their own conlcusions - however - the numbers are comming up exactly the same on numerous cars - even after tuning by other tuners on other dynos

BTW - we have not commented on any particular brand pulley that was used and in fact I do not know which pulley brand it was - I dont think it matters - IMHO a solid disk crank pulley is a bad idea on an evo

Trust me when i tell you if we were getting more power with these units we would be selling them to our customers so they could make more whp - AND - i would have one of them on my Evo as well

 

This is my car... I just wanted to thank you Al again for tuning my car.....

My car is crazy fast now....Oh ****.... This car pulls all the way to redline... My A/F is at 11.1....

Again Thanks Big AL.

 

Thanks man ! I tell you the dyno numbers were a bit lower than some other cars with sam mods, but the smoothness and "feel" was really, really good. Your car felt as smooth and linear as a n/a M5 - nice low end trq, smooth power band and pulls out all the way.

We'll see you again I hope with the Buschur fmic and pipe - that should see you in the 340 range

 

Yo Lou, didn't I tell you, BIG AL was Da' Man?!! I told u he'd figure it out and make u more power. I know ur happy with the way it feels, I'm still smiling Big Al knows his **** man Good luck Dude.........