Potential VQ35 failure due to UDP. Currently being reviewed:

https://g35driver.com/forums/engine-drivetrain-forced-induction/74386-300hp-engine-stronger-not-really.html

 

Jesus Dave, if you're going on a personal crusade to discredit the crank pulley at least be truthful in your statements. The guy's engine was 3 quarts low and he's running a twin turbo. Quite a few other variables as well since he's heavily modded.

 

Well I had no idea that he was running a twin turbo setup. There was absolutely no mention of it and I don't even know who "Paranormal" is. I would have to agree that the turbo setup probably did cause the bearing/rod failure especially since he mentioned this happened at ~3500rpms when boost starts to build. A lot of NA cars with aftermarket turbos typically have failures when they're coming under boost because this is the hardest portion to tune correctly. It's hard to tune that super lean low rpm A/F as it transitions under boost and a huge surge in power. Since the VQ35 already has weak rods to begin with, the failure isn't surprising.

 

as others have pointed out, this product isn't so much in the "gain" category as it is with the "insurance" category. as chicagox put it, it has to deal with longevity.

 

Better response and informative. Thanks. I agree the pulley is not for everybody. For 5-8hp you're rolling the dice but likely not until 100K+. By then we'll have lost interest in this debate.

 

Well, installed my UR UD pulley this morning. Didn't need a pulley puller, and I also used the "put the breaker bar on the floor and crank the engine" method, except I cranked the engine a little too much and it started....instantly I shut it off.

Only affect was that the pulley bolt just spun right off... heh

Anyways, I like it, I can feel maybe a little kick, maybe not. But, as I said in the MREV mod thread, my butt dyno is poorly calibrated. Still worth it, though, judging from results on other cars. (most notably, my 300ZXTT, in which the pulley made about 10 HP)

Also, the stock pulley is incredibly heavy compared to the UR UD pulley.

Dave

 

Dave - It'll take 3-5 days - or about 250 miles of driving before the computer properly registeres the lighter weight of the crank. Your only feeling the underdrive benefit now - and that's only about 15% of the benefit to begin with - the weight is where the real change/benefit is.

Also - if you reset your computer and Andretti your car for about 10 minutes - you'll get the full benefit in about 100 miles of driving instead.

Enjoy...

 

Hmm, ok, not really sure why the ECU would need to adjust to a lighter crank pulley. To me, its one of those things like lighter wheels, or lightweight flywheel, or just overall lightening your car, it should just instantly work.

But we'll see, if there is a bigger difference in a couple of days.

Dave

 

Hey Dave,

I was looking to do this mod.. Do you think it will work against me because of all the equipment I have to run?

 

Do you mean electrical equipment?

If so, no, since I am running a JL Audio 500/1 and a JL Audio 300/4 amp, and a hard drive mp3 player in the trunk. I know of others that are pushing even more in their sound systems, and have the underdrive pulley, and have no problems.

Honestly, it really doesn't underdrive much, I think the big thing is the weight difference.

Dave