HI all with UD pullies.

 

Just had one fitted and I just wanted to get an Idea of what I can expect.

 

All the devices off the pully are running ok but when I get over 5000 rpm I get a bit of vibration and noise from the engine which gets dramatically worse by the time I hit 6000 rpm. Car used to be happy revving to 7000 so it's sounds like the pully needs further balancing or is this a trait with all pullies.

 

Ta

 

Eddie ;-)

[This message has been edited by crazy_eddie (edited 27-05-2001).]

 

[This message has been edited by crazy_eddie (edited 27-05-2001).]

im not to sure that is right? better have it looked at, cause if anything the car should want to rev more freely now!!!!

Doesn't sound right..

The engine sounds different with the UD pulley..more raw, but it nothing dramatic.

 

Maybe they damaged something when removing the stock pulley or they screwed up the timing after fitting the pulley.

I'd check the timing first and see if the pulley is not wiggling or something

 

-Eric

 

------------------

http://300zx-twinturbo.com

 

[This message has been edited by lymon (edited 27-05-2001).]

With the pulley being smaller than the original crank pulley, it is difficult to accurately set the timing with the markings.

 

As Eric has said, the engine note changes at the higher rpm but you shouldn't feel any vibration.

 

Which pully have you fitted? I have the ASP one fitted without any problems.

 

Steve

Not noticed any vibration from my ASP pulley, just a nice, aggressive engine note from 3.5k rpm plus. 8)

I'd get it checked out if I was you.

Dave

Thanks guys I will get it checked out Tuesday.

 

BTW I found this on TT net if you pully guys are interested

 

http://www.dinanbmw.com/html/danger_of_power_pulleys.htm

 

Ta

 

Hi All,

 

Pete has put my Z back together after the demo at the open day and sorted my pully problems, no vibes or odd noises and car revs quite happily to 7k again (loose my bottle after that).

 

I am a happy Eddie.

 

Thanks for all your Input guys.

 

Ta

 

cool, is there a consernable difference with the pully? or cant you notice it.. i am really interested in that product, it looked very well made

So Far,

 

I found light throttle driving to have the best improvement, driving around making 4psi, the car felt much lighter, crisper on throttle. Hard accel very little difference.

 

I will offer a proper evaluation at the end of the week when I have done some miles.

 

Ta

 

Yup...you'll notice the pulley, no doubt !

Especially in the first 3 gears.

Engine revs quicker, and as said before it sounds a bit different also

 

-Eric

 

Hmm, curious about this me is...I was reading about installing UP on twinturbo.net...or was it TT's of Dallas???

 

Anyway, I was considering this seeing as my engine is out of the car at SE, but the guy who wrote up on this was saying that the crank has to be tightly balanced e.g. as good as when it left the factory otherwise with the pulley being lighter it can cause a "wobble" of the crank which is bad news apparently!!!

 

Does anyone have more to add on this, it's a relatively cheap upgrade and does provide noticeable HP increase but is this dodgey over a period of time?

 

Tim

;-)

 

Bottom Line.

 

Is the Lightened UN Pulley worth while HP whys ?

 

Yes - very good hp per pound!

 

Will the Pulley damage my engine ?

Yes with time it can and probably will damage something - how long will it take on the Z bottom end ? at least 3 -4 as the american guys have been running them for at least that long - And had no problems at all. No one can say for sure as a close examination of resulting Crank wear has never been undertaken on the VG30DETT engine to my knowledge.

 

Then why should i get one ?

All aftermarket mods will damage your car in some way - that is why Nissan didn't include them in the package most of the time. Race cars have used the same technology for years but then again there engines are rebuilt often. If you want power gains you have to live with the risk - as simple as that !

 

Im Confused ... Should i but one ?

If you want a more driveable - more powerfull car and are willing to live with the fact that in the time you own the car you may well need to rebuild the engine - then YES get one. If you want a car that will be reliable day to day and run as cheaply as possible but would still like more performance then NO.

 

The final factor to consider is the state of your car. If you have a intergallactic miler from japan with a bottom end that has more knockers than a Red top press inside front then i would not mod the car at ALL. increasing the horsepower of a imperfect car is dangerous to the life of the car and the owner.

 

This is a fine answer altho this is basically what i would tell anyone that is thinking of going above stage 2 (intake and exhuast)

 

Hope that helps ya'll

 

Z ya

Nico 91TT

 

 

Thanks Nico, you're right I suppose, now I'm pondering having Pete put one on mine before engine goes back in! Bloody 'ell, at this rate I'll be running in this years NASCAR season! It all adds up, metal head gasketts, ported & polished heads etc. etc.

 

Best get some serious work done in the next few weeks to pay for all this stuff!

 

Tim

;-)

 

hmmm we spoke about this and based on the fact that the crank on this car is so strong it should not be a problem, i mean i have read that they used what is effectivly a stock crank for the gtp race car that did lemans (i stand to be coreected)

...starting to get the urge for an ASP Underdrive Pulley! Does SE sell these? Phuong does, may get one included with my Techtom order as he mentioned ordering something else to reduce the burden of the shipping cost.

 

Interesting!

 

Thanks chapZ

 

Tim

;-)

 

Might be able to get you a Techtom as I'm in Phildelphia next week .... Can't be arsed to carry a pulley as well though !

Warren,

 

The IMSA GTS car that Steve Millen ran a stock Nissan crank that was race prepped ( blueprinted balance and polished - basically)

 

I dont think NISMO have ever made a Race Crank as all Nissan cars that are used in motorsport have a strong enuff crank for about 800hp. it just needs a bit of care.

 

Z ya

 

Nico 91TT