Have an Aster Bracket on the way so need to order an longer belt (7.65 crank pulley and a 4.0 head unit pulley). Looks like I will need PN K080525.

It appears that Gates has at least three product lines so just because one orders a Gates K080525 for example that doesn't necessarily mean that you will get a RPM belt from the RPM product line. You would have to order a K080525RPM instead. The RPM product line is mfg specifically by Gates for FI cars, but I rarely see that product line mentioned in this forum.

Yes I have done a search. Most recommend the green stripe or even the Century series or just supply a part number but not the product line.

Bobs (Brute Speed) sticky doesn't mention that product line either. Does anyone know if ProCharger rebrands the Gates RPM line as their own or will I have to find a jobber that handles that product line?

"Gates RPM belts are specifically engineered for forced induction and high-output engines. Featuring a high-modulus, low stretch Aramid or Polyester tensile cord, nylon-fiber reinforced undercord, and dual adhesion gum layers,these belts can handle more power and withstand more punishment than any other belt on the market."

Perhaps Bob will chime in.

Thanks in advance.

 

The green "fleet" belts are what you want...

 

After more internet research (however reliable that is ) the review from CTS forum say they don't stretch at all and pretty sticky due the construction compared to the green Fleet product line.

Think I'll try one. Found that Jegs sells them unless Bob at Brute can get them.

https://www.ctsvowners.com/forum/4-e...ies-belts.html

BTW - not saying that green Fleet is bad, just might be that since the RPM line is a newer product no one has heard of it. Link above has a source at Gates too - good to know.

 

If they work better, even better.

 

 

Good to hear.

 

I haven't got a chance to use the new RPM belts yet. Not a lot of places seem to stock them or can get them(it's been a while since I checked though) We use the green belts on pretty much anything making more than 10psi.

 

 

This is the one I ran with my SDCE and a 3.7

 

Very interesting. I'm happy to hear that there is a better option.

 

O'Reilly's has a k080424 that is slightly smaller than the 424 and I found it gives me better belt tension than the 5.

 

Is this your source at Gates?

Chad.Cossette@gates.com

I am going to send an email and ask about best source for these belts - specific for Fbody and Procharger lengths. Jegs has the K080525RPM but not in stock with a projected ship date so looks like they are drop shipping perhaps.

BTW - the link I posted from the CTS forum is about a year old - so hopefully by now the supply chain is filling up - or NOT - since still appears few are aware of this new product line.

For those who didn't click on link in an earlier post of mine (this is product description).

"RPM (Racing, Performance, Muscle) is a new, no compromise belt built specifically for supercharged applications.

Whereas 99% of all belts on the market today use a polyester tensile cord, the RPM series uses an aramid tensile cord. This is the same fiber found in bulletproof vests and is 10x stronger than steel and 5x less elastic than polyester. When polyester heats up (which it does even from normal use) it will stretch out. As you can imagine, when that belt stretches out you experience belt slip and boost loss. Eventually the elastic properties of the polyester will fail and the belt that was once 100” will stretch to 100.25”, at which point the tensioner can no longer compensate for the stretch and generally results in belt failure.

Due to the strength and minimal elasticity of aramid fiber, the RPM series of belts will not stretch which allows the belt to maintain its true length throughout its service life. This results in more consistent boost and in some instances, users have reported a 1-2psi increase merely from switching from HD belts to RPM belts. We actually have some user submitted under hood video on our Instagram page (GatesRPM) that clearly demonstrates the difference between polyester and aramid corded belts.

Another main benefit of the RPM line is the use of two layers of adhesion gum. These layers create a sandwich around the tensile cords which transfers the load to the strongest part of the belt; the jacket (or smooth backside of the belt). FleetRunner HD belts got a reputation for strength because they use one layer of adhesion gum, standard micro-v belts forgo any adhesion gum.

RPM belts also utilize a patented rubber compound with the highest coefficient of friction available and are built in common OE supercharger sizes as well as many sizes used with aftermarket setups. The RPM line has expanded to 299 part numbers with new numbers being added every quarter. "

Link below - is an interesting read on how to tension the RPM belt compared to a Green. Completely opposite to promote long belt life.

https://www.svtperformance.com/forum...lower.1140578/

 

RPM Belt Size Chart

https://assets.gates.com/content/dam...t-newbrand.pdf

 

When I was running the green belt , I would run the smallest belt that would fit because it would stretch so much. I would get a month out of one. Same with the gator back ( continental elite) . With the rpm , even though they don't make my size (K060923HD ) or (k060919) I can run a slightly larger K060926RPM because it don't stretch .the Whipple Camaro kit has a really strong tensioner . It's been a month, and it hasn't moved at all.

 

Dont know if you reviewed this link - but when sizing a belt if we use the RPM belt the belt doesn't have to be as tight (about 20 percent of what is required for a Green belt).

Just a hunch, but suspect your RPM belt is actually working better with the tensioner because it isn't set as tight because of the longer belt and/or has more travel to reach it's maximum travel and still with no slip. If there is less slippage also less wear so the inside dimensions of the belt stay static and doesn't grow in length.

"The correct way to tension a RPM belt is almost the exact opposite of a standard stretchy "poly belt" - only apply 20-30% of the tensioner travel to the belt... because it won't "stretch - that's fine when the belt is under load - but then when you jump off the gas and the belt unloads - there is a long way for the tensioner to move before hitting the full open stop."

Will be interesting to see is how the Aster J - Bracket (fbody Procharger tensioner bracket) reacts with the RPM belt when I get it and get it installed. Might be able to loose the lower pulley and/or set the tensioner at the loosest setting vs the tighest.

 

So is the K060915RPM too short? Looks like difference in OD is 7 mm or 9/32 of an inch compared to the OD of a KO60919 (2340mm vs 2347mm).

K060915RPM K06 13/16” x 92 1/8” - Black 6 91.56 2326 92.125 2340

 

 

 

DuWayne, with your combination using the Aster bracket, a green belt will work just fine if you can't find an RPM belt in the size you need. If you go with the green belt, don't go wot for an hour to break in the belt, then readjust the tension and you should be good to go. I have no data on the newer RPM line. Thanks. Bob

 

I've said for years, that if they could make a belt that stretched less, it would help tremendously. This makes me want to swap the factory 6 rib belt to this as well.