I like the ati over the fluidampr but its pretty well known they are both great products. btw, both are slightly od (not ud) and weigh approx. .5 lbs over stock.

 

wouldn't the stock elastometer rubber deteriorate over time as it is exposed to the elements and slowly dcrease its effectiveness for whatever purpose it is meant serve?

 

From my discussions with a couple master techs I know and other people familiar with the process, the stock rubber ring's predominant function is NVH.

 

my question was will a OD wether fluid or ati have negative gains compared to a stock pulley in a NA z. My understanding was that gains where only shown when a Z was UD. Im intrested in the fluidampr but dont really know the effects of OD the engine vrs UD in a NA Z form.


I understand there designed to supress vibrations etc, but since UD claim modest gains does the slight OD and heavier fluidampr and ati benefit the Z in its NA form gain wise. Im already aware of the vibration prevention at high rpms.

 

you are in complete denial. I ran a UR pulley and had significant crank damage as a result. I broke a ringland in a piston and tore the motor down. I had the crank mag'd during the rebuild process and had stress cracks in the front cylinders resulting from the crank pulley. you could see the cracks walking rearward from the front of the motor. I was lucky I caught this before the crank completely let go and caused any damage.

I spoke with two separate machine shops that have seen crank pulleys damage motors all the time. On a motor like ours, there is concern about the lack of damping transfering vibrations not only into the crank, but also into the oil pump. my machine shop said they have seen it multiple times where guys running crank pulleys have premature oil pump failures.

It is a person's choice if they want to run one on their car. I have seen the damage first hand and will not run one ever again on any of my cars

 

Good info. Thanks for sharing~

 

Read this and if you still don't believe it, check these pics out from our website:

http://us.st11.yimg.com/us.st.yimg.c...1990_163910938

We keep these in stock if anyone has a built motor or big boost, you need one as the stock crank pulley is not "tuned" to the different resonances that double or triple the power output creates.

 

That picture is worth a thousand words!!! And will maybe save a few thousand dollars
down the road.

Thanks SGP....

 

Ouch, that pic underscores the neccessity of proper dampening...

 

That picture does not show what happened to the crankshaft when the pulley broke!

 

And were you F/I or N/A when you experienced crank damage with the UR pulley?

I've never heard/seen a N/A bolt on Z/G experience crank failure from a properlly installed lightweight pulley with pressed in steel collar.

It's foolish to run a lightweight undampened pulley on boosted applications imho; I'm not denying that. Sounds like you learned your lesson.

 

my car was boosted.... street use, no track time, about 10K miles on it.
edit:
The pulley was on from my N/A days. I didn't even really think about it when I had my motor done. It just transfered right over on the build.

 

I was actually thinking about that when I looked at the "Cracked Crank" post from MRC and laughed about it...

You guys wanna see the crank???

 

Could anyone explain what are the effects of OD the vq opposed to UD. Im contemplating the fluid ampr.

 

You know, it's funny. I'm in my garage right now, removing a UR UD pulley, and installing a Fluidampr. I liked the effect the UD pulley had when I was N/A, and while I normally can't feel any small HP/torue differences, the UD pulley did make a difference. However, now that I am F/I, I feel that the small (5-10) HP difference a UD pulley makes is just not worth the possible risk that an undampened UD pulley carries with it.

So, I am installing the nicely dampened Fluidampr, and will make up the 5-10 HP difference by turning up the boost half a PSI!

Dave

 

OD only benefits those with superchargers as far as power increase from what I know.

I don't know why you would want a slightly heavier and OD fluidampr/ati pulley on a N/A unless you have a built engine and are revving really high for extended periods of time.

For F/I, I think it is almost a must for safety and reliability.

 

So your saying the OD properities pose negative effects for NA use.

 

Not necessarily. Depends what "effects" you are talking about. For canceling out harmful NVH and safety, it would have positive effects.

I don't think you would notice much power diference in N/A form between the stock pulley and the ATI/Fuildampr units. Technically, since it is .5 lbs heavier and slightly od, It would result in a small power loss, but I dunno for sure. Maybe someone else could chime in.

To answer your question, imo, the positive effects would outweigh any negative effects, but I don't see the need for one, unless you are F/I or built high-revving N/A.

 

Well, got it installed, and I can say that the engine just feels smoother,a nd quiter. Can't tell a hp difference, but then my butt dyno has never been able to tell 5-10 hp difference.

Anyone want to buy a used Unorthodox Racing UD pulley set in black?

 

I feel the same way, maby it's in my head, but I felt it was smoother at idle!!?? I think you made a good choice Dave.
Kevin