belts...

[lefty o]

maybe a dumb question, but curiosity got to me. has anyone ever dyno'd the difference between a v belt and say a 6 rib belt in the same configuration? is there a power difference between the two types of belts?

[mag2555]

If there's any to talk about then it must be minisule and if your fighting for every darn last scrap of power, then surly there still must be better places to scratch at on your motor!

[lefty o]

just plain curiosity.

[cgarb]

I would say look at what's on a cup car...if anyone would invest large amounts of capitol for a small gain is in that series of racing.

[RCJ]

I heard That the serpentine belt takes less power than a v belt.I've switch over to a Jones serpentine, it was about a pound lighter and a lot more trouble free.

[mag2555]

I would think that rotating mass in regards to lighter weight pulleys is where any true power gain comes from.

[roc]

The engine with V-belt makes more power... because of belt jumps!
Whenever applicable, I wouldn't think twice to adopt serpentine belt.

[carmakerevive]

I would think that rotating mass in regards to lighter weight pulleys is where any true power gain comes from.

Basically this.

And there is a lot to think about, the tension of the belt required to get minimal slip while not placing the pump/alt bearings under too much side load, what loss there is from inevitable belt slip, and belt stretch.

Serpentine belts seem to stretch less than v-belt counterparts in my experience. Belt slip is essentially drag on a particular component, so its not good...

[promod754]

if any belt is going to gain horse power i would think a synchronous belt will yield the most.

[lefty o]

if any belt is going to gain horse power i would think a synchronous belt will yield the most.

i dont think any belt is going to gain horsepower.

[stealth]

OEM's went serpentine for a reason....

[CharlieB53]

My two cents, the contact area of the V belt is causing a lot of friction sliping in/out of the deep grooves of the pulleys. Multiply this by the number of pulleys and multiple belts this may add up.

The serpentine belt has a much reduced contact area DEPTH but greatly increased WIDTH, making for an over-all reduction in frictional loses.

Every little bit adds up.

[BOOT]

One of the benefits of a serpentine belt is it bends/wraps easier and so do notched back V belts. Surface contact on either type belt can be reduced with a cogged type version that would also reduce bend/wrap effort/losses. I read something long ago about a small engine that gained a ok amount of efficiently from switching to a notched & cogged V-belt. Serpentine may be more surface contact area because they usually are routed to wrap more or I would think because of the design. It's not just the tip of the ribs that touch the pulley but the sides(one more than the other prob) and valleys or the entire backside on some pulleys if so routed.

Far as oems are concerned the serpentine last longer and is more reliable from a warranty perspective. With a basic three or two non-tensioner pulley setup, I'd think either would be about the same used with a good belt.