While at JDMs on Sunday I was looking at the Metco Cageless interchangeable lower pulley set-up(Very Sweet). BTW- I know what you guys are going to say(caged against cageless) but if you do a search on when the Metco came out I was very Impressed with the set-up.

Anyway I decded to put a Metco 6 lb. lower ring against a JDM 6lb. lower ring. What a difference.

Both have a lip and I did not measure, but you no me. I took a pic.

I do not know if there is any boost lost, but the Metco 6# is definately smaller then the JDM.

Pic. Although you can not see the table , both rings are sitting level.

 

It does look shorter, but it also looks wider?

I'm sure it puts out about the same boost....

 

All of the Metco/LFP pullies are about 1/4" in diameter smaller when compared to other pullies. This is being addressed as we speak, starting with the 6# ring i was told, with 4 weeks in between the 4# being next, then the 2#. Mark has addressed this with the new run of rings.

I will say, it is one of the nicest pulley setups out there though.

However, i did get a look at the new West Coast pulley with built in harmonic balancer and i must say, its one of THEEE nicest pulley's ive seen. Someone, i wont mention names, said it couldnt be done. Ill post pics the next time i get a look at it

 

Have been saying this for a while. The JDM pulleys are a little bigger than the rest.

 

Measure the circumference, not the dia. They could have two different lips. Use a seamstress type measuring tape and check the circumference of both.

 

So the 4# is smaller too?

 

If it is round AND the lips are approx the same then a taller pulley wil put out more boost.

Basic geometry ...

BUT it should really make any difference the lb #'s advertised are estimates anyway ....

Doug

 

So what your saying is,
People are sometimes getting more Boost than they pay for,
"OR"
Less than they're paying for

Oh thats just great
makes tuning even funner doesn't it

 

The problem is labeling the pulleys in lbs and not inches. Not every truck has the same boost increase as another with the same pulley. It depends on other mods too.

 

Even stock trucks generate diff amounts of boost, so to say some one is getting more or less is misleadiing. The pulleys lb ratings are estimates.

Weather, mods, and slippage will all effect the net boost

Doug

 

It would be nice to get the pulley sizes in inches.
Today for instance since I'm running 22 psi worth of pullies I can say I have a 2.5" upper and 7.9" lower. The average guy can look at the pulley size and figure out it is a 3.16:1 ratio which means I'm spinning my KB 17380rpm at 5500 engine rpm.

 

I understand that Doug,
but everyone's (all mfg) should measure the same,
if it's CLAIMED to be the same

 

that Metco was aware of this sizing problem and was going to fix it on next run? Can anybody confirm, plus are "revised ones" available yet? Need to get a 4 lb, but was hoping to find an interchangeable one used? What diameter or circumfrence for tru 4 lb? Any idea on best one, source, and price? thanks

 

I've already addressed this issue with Metco. When we first were made aware of the size difference, I called Ron at Metco to discuss it with him. He had no idea of the size difference. He was told the sizes by someone else, which turned out to not be correct. I gave him the correct pulley sizes from our PSP designed ASP pulleys, and he has started to make the Metco rings in the larger sizes. I just got a bunch of Metco 4s and 6s in, and they both match our PSP 4s and 6s.

 

So what are the correct sizes?