why not consider the ATI performance damper pulley, lightweight but still has a harmonic damper. Might not give the ultimate weightloss but should make up for it for those with concerns of dampning.

http://www.atiperformanceproducts.co.../damnissan.htm

 

me again... okay, okay still lovin' my pulleys just thought i'd send out the link so you all could read up on 'em, since i'm like the only on on here w/AMS pulleys.

 

buddy of mine at work runs the full UR-underdrive set on his 350Z with no complaints or issues, but he does baby his car and has a reflash with all of his mods and is also running a stock clutch/fw package.

 

Heres something to think about, granted the conditions these motors were put through dont make it any better, but heres 2 engines which may have been damaged by a pulley. granted one busted a oil pump as well, but this could explain why hiarline cracks wear on the crank.

http://www.my350z.com/forum/showthread.php?t=337947

Now i know a lot of you will probably try and say "well it was a 6k launch... " blah blah whatever. I dont buy performance parts so I can baby them. I buy track proven parts so I get gains and actually RACE them. If a undampened pully is going to make me lose a crank, then F that.

 

It was a 6.5k launch done via launch control from an ems!--That's nutz --I'm pretty sure the same thing would have happened if the stock pulley was on there. To say it was caused by the UR pulley is speculation at best.

Maybe the ATI/Fluidampr could have helped prevent that, but I doubt the stock crank pulley could helped with that either.

If you are REALLY a RACER and do not drive your car on the streets and you only buy "track proven" parts, then surely you would be considering a RACING dampened pulley like the ATI or Fluidampr and wouldn't be content with even the stock pulley.

If you drive on the streets and desire to do a 6.5k launch via launch control on the street, your a tard and you're gonna need a lot more than a dampened pulley.

 

I've had the UR pulleys on my G for over 75000 miles and all oil analysis has come back fine. If they are installed correctly, no issue with reliability. One thing for sure is DO NOT attempt to drive a blower with an aluminum crank pulley. The load from a blower at full boost can be as high as 40-50 HP and that means huge strain on the pulley keyway. Some guys have had their pulleys basically weld themselves to the crank after they stripped out. If you go FI, gotta go back to stock pulley.

 

on the MRC car it was a 6.5k launch with launch control, what about the other 2 people who posted crank problems in that thread, one who did not have high horse power. For N/A cars the stock pulley is just fine since it is dampened via the elastomeric ring. for F/I'ed cars, i wouldnt do without. Btw i do have an ATI pulley. As for driving on the streets, yes my car is still street legal and can be driven on the streets depending on which set of tires i use and what i have removed for race trim, but do not for a minute think that i race on the street, all of my racing is done at sanctioned SCCA or NASA events or on a closed course. I'm not saying the stock pulley would have saved MRC's crank, hell there is still no proof that the damage wasnt done by the previous wreck, but a lightened undampened pulley is opening up all kinds of doors.

 

I ran UR pulleys on my Acura CLS for 100 miles without any hint of problem.

I would do them again in second--and may do so after this thread has re-ignited my interest in them and I need new belts anyways.

 

You like buying mods that haven't been proven to work? No legit dynos or track data supports the UDP claims for the VQ series motor. While many will claim this is an apples to oranges comparison, I had a UR pulley on my decently modded 96 Maxima 5MT that saw about 250 1/4 mile passes. I had the UR UDP on that VQ30 for about 20K miles and ~50 1/4 mile passes. I also dynoed before and after. The stock pulley weighed ~6lbs and the UR UDP weighed 1.5lbs. The VQ30 pulley design is exactly the same as the VQ35s. These are my results:

1) On the dyno, no gains what so ever

2) On the strip, absolutely no improvement. If anything, the car was fractionally slower because it was more prone to bogging off the line. When I reverted back to the stock pulley, I posted my best ever ETs and MPHs. No other changes were made to the car. Very similiar DA conditions, 60 foots, and same track.


The only differences I noted with the UR UDP was a quicker revving engine in neutral, more prone to bogging, harder to land smooth shifts around town, and a harsher engine revving from 5500-7200rpms.

It's been my opinion that many people know that cars like the Ford 5.0 V8 makes decent gains (8 to 10whp) from UDPs (full set) so they automatically assume the VQ will make the same gains. Little do they know that most of the gains from the UDPs on the 5.0 are because the alternator and water pump are greatly underdriven which is why they make the gains they do. Since the VQ's water pump is driven off the timing chain and the alternator pulley is already very small, the VQ just won't see the gains.

 

^good point...no pulleys for me then, staying w stock on this one.

 

So, basically what all the threads on G35driver and my350z are concluding is that lightweight pulleys are way too much of a toss-up to be worth the some 11hp gain?

I just got mine from Top Speed (they probably just sell the UR or AMS set, I haven't asked them about this actually), but I'm considering returning them for some headers instead. Those are less delicate and will produce solid results without chances of my engine blowing up down the road.

Do I have the right idea?

 

sounds good. go for headers or modding the intake plenum if you havent done that yet. power yields are similar

 

headers are only worth it if you pair them with HFC's/TP's imo, the labor is high.

 

I plan on putting mine on. I liked what they did for my maxima.

 

I agree. They are right next to each other, so makes sense to throw the HFC's in there while the mech is under there. I would try headers myself but I just kept reading how much of a PITA the install is. Being a pretty noob mechanic myself won't help the install time of what it seems like 4-8 hours and 8 being normal.

I am just not too happy about the HFC prices. Fast Intentions 300 cell are like $700 or something. The Top Speed headers will run me about $150; for comparison.