Gauging Interest. 2.5s Underdrive Crank Pulley

[ReviT]

http://www.wrptechnology.com/p...4.htm

This has been confirmed to work with our coupe or sedan 2008 QR25 Motors. need to get peoples interest in this because i am talking to the guy about a group buy!

[D-Roll]

Im all about it! Been waiting

[ReviT]

Im all about it! Been waiting

I know you been waitin just got to build so more interest.

[D-Roll]

Here's another link..

http://sportcompactonly.com/Ni...6.htm

[spockrock]

Umm..... I recall reading a thread a while back on a G35 forum on light weight pulleys and one of the members on the forum was an engineer provided all the mathematical calculations to prove it but the gains from these are 3-4HP *in first gear* out side of first gear the increases become null. The reduced weight in the pulleys also reduce your engine life. The conclusion was that these pulleys are not worth it.

[theoctopussi]

aren't unorthodox pulleys better? is this the best pulley out for our engines?

[theoctopussi]

does the rest of the stuff on that site work too?

[D-Roll]

does the rest of the stuff on that site work too?

Just the pulley

[theoctopussi]

Aye D-Roll, you think Unorthodox pulleys are better?

[LongBeachCoupe]

the gains from these are 3-4HP *in first gear* out side of first gear the increases become null. The reduced weight in the pulleys also reduce your engine life. The conclusion was that these pulleys are not worth it.

did you guys miss that? maybe for a track car... but Daily Driver approved?

[spockrock]

did you guys miss that? maybe for a track car... but Daily Driver approved?

The problem is the stock pulleys have harmonic dampeners after markets usually do not. There is increased vibration which is the reason for premature engine failure. Other times the added mass put there for a reason, and the reduced mass can also cause failure. Its a toss up some people say these have caused damage to their car others say their butt dynos give them better response. From what I can tell they add minimal increases on and off the track, and potentially cause more harm.

[D-Roll]

Aye D-Roll, you think Unorthodox pulleys are better?

Both are the same imo. I had the Southwest Autoworks pulley on my 02 Nissan SpecV for 2+yrs and had no issues prior to selling the car at 99000 miles on it.

[ReviT]

Here's another link..

http://sportcompactonly.com/Ni...6.htm

I dont believe that one will work. this pulley was tested on an 07 QR25HR Sentra then fitted to our cars. Only place i found with these available after talking to the guy.

[D-Roll]

I dont believe that one will work. this pulley was tested on an 07 QR25HR Sentra then fitted to our cars. Only place i found with these available after talking to the guy.

It was a long shot lol...let us know how it goes for ya

[cuzzbubba420]

I replaced all pulley's in my 97 integra and agree that you gain most performance in 1st gear. The draw back from pulley's was it affected my alternator and my lights were constantly dimming if I wasn't in gear. I would much rather go for a header or intake manifold!!! vroom..

[TheBourneAltimatum]

do not buy from WRP!he's a scamming possearch myspecv and other b15 sites and you'll know what i'm saying

[Hussain]

i saw on the stillen site that they had light weight pulleys for G35 and 350Z so i was thinking about putting them on my 3.5se in the future........ all these issues people had (not enough power for alternator or air conditioning or engine life), was this from having a small crank pulley and large pulls for the other stuff (forgot if that's exactly what UNDERDRIVE pulleys are). there are light weight pulleys that are the same size as stock and don't mess with the alternator or air conditioning, it's just a lighter pulley.

[spockrock]

i saw on the stillen site that they had light weight pulleys for G35 and 350Z so i was thinking about putting them on my 3.5se in the future........ all these issues people had (not enough power for alternator or air conditioning or engine life), was this from having a small crank pulley and large pulls for the other stuff (forgot if that's exactly what UNDERDRIVE pulleys are). there are light weight pulleys that are the same size as stock and don't mess with the alternator or air conditioning, it's just a lighter pulley.

Well from all the reading on other forums is that, on the VQ's these pulleys no one can conclusively say that on the dyno or on the track these have added benefits.

Quote »You make the decision.

The Facts

1) The stock crank pulley is two piece unit with a sandwiched elastomer ring.

2) The elastomer ring serves as a damper for certain order crank vibrations that occur during various rpms under load.

3) The clutch assembly or torque converter serves as the damper on the other end of the crank.

4) The VQ series is very beefy with 4 bolt mains and a crank girdle which makes the entire motor, including the crank, very strong.

5) Removing the dampening capability pulley can cause vibrations across the crank. These vibrations can then impact the valve timing and ultimately power.

6) No one has yet so show proof on the strip that the VQ35 pulley works.

7) Do not trust engineering speak from the billet pulley manufacturers because they claim the OEM is not a damper. This is completely wrong.

8) No VQs have been destroyed by a UDP/lightened pulley assuming the pulley was manufactured correctly with a steel key.

9) The VQ is internally balanced just like any motor built after the 1980s. The concern is what the engine, specifically the crank, does when explosions hit the pistons. These explosions place tremendous forces on the pistons, rods, and then the crank. As the explosions increase, rpms increase. As the rpms increase, certain order vibrations occur across the crank. To quell these vibrations, engineers use dampened crank pulleys as well as the cluth/TC on the other end. The term "internally balanced" is a moot point. Be VERY cautious when a manufacturer or vendor tells you "oh, the engine is internally balanced, it doesn't need dampers on the crank". This is not true and completely questions their true automotive knowledge.

10) Underdriving a crank pulley will result is very minimal gains, if any. The biggest accessory drain on the engine is the water pump and that is driven by the timing chain. The AC is the second biggest source of drain and that pulley is free wheeling when the compressor isn't engaged. The alternator can cause significant drain, but the pulley is already very small.[/quote]

Quote »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.[/quote]Here are some opinions on UD Pulleys on the VQ, granted its your money and your car you are free to do what ever, it it seems these bolt ons won't do much for our coupes.

[Hussain]

ya i see what you mean, thanks for the info. i might have to look into something else that will make me faster lol

[spockrock]

ya i see what you mean, thanks for the info. i might have to look into something else that will make me faster lol

Well I maybe able to help you out with that hopefully soon

Or you can go with a turbo, or super charger.

[Hussain]

lol what did you have in mind? cuz i want to do a lot of stuff to my car but kinda a bad time at the moment lol business is going slow, gotta paint my stillen front fascia, just got a ticket for not making a complete stop before turning right at a camera intersection lol

[spockrock]

lol what did you have in mind? cuz i want to do a lot of stuff to my car but kinda a bad time at the moment lol business is going slow, gotta paint my stillen front fascia, just got a ticket for not making a complete stop before turning right at a camera intersection lol

Well if I said it would not be a surprise, LOL. It it might be a while before I can officially make my contribution to the Altima Community.

[nogears909]

I replaced all pulley's in my 97 integra and agree that you gain most performance in 1st gear. The draw back from pulley's was it affected my alternator and my lights were constantly dimming if I wasn't in gear. I would much rather go for a turbo or supercharger!!! vroom..

fixed