Is it possible to run no tensioner on the alternator belt to cut down on drag and potentially gain a couple of hp without slinging the belt off ?

 

Of course using a smaller belt.

 

You could even go with a fixed-tension setup that would enable you to set a custom tension based off of the parasitic drag on the accessories by listening for belt slippage (squealing) while all systems are SIMULTANEOUSLY at their heaviest load.

Here's an example on how this is done:

-AC compressor- AC is turned on (this also assists in maximizing electrical loads due to activating cooling fans)

-Alternator- Turn headlights on high beams

-Power steering pump- Turning steering wheel to wheel stop and holding it

-Crankshaft pulley- Revving the engine up (roughly 4k-5k rpms)

While holding the conditions shown above, slowly loosen the tensioning bolt until you begin to hear belt slippage. Once the slippage disappears, tighten the bolt another 1/4 to a 1/2 turn for the additional tension that will be needed during moments of when the engine speed rises quickly. Once finished, tighten the tensioner pulleys lock bolt to prevent any loosening/tightening then recheck belt slippage again by blipping the throttle to high speeds.

Combine this with an underdrive pulley setup and maximize your gains. One should run an underdrive system with caution given to the electrical system and its ability to sustain adequate amperage with engine idling under high electrical load. This is because the underdrive pulleys spin the accessory pulleys slower and the alternators output is (in a sense) proportionate to its rotor speed. In my line of profession as an automotive electrical tech, I refer to this as simply a "charging threshold" or in other words the minimal speed at which the alternator begins to charge.

Also, you could look into retrofitting the j35z's low drag automatic tensioner setup which is part of Hondas new move on ultra efficiency by reducing parasitic drag and internal engine friction.

 

Thanks for your input.
I just pulled the tensioner off,gonna try some belts tomorrow.

Right now I have no ac compressor.
I have a underdrive pulley set but Im not drawing much electrical at the moment besides ignition,power windows,fuel pump,gauges etc.
The car is gutted.
Im also running a lithium battery so I dont need a big charging system.
looking for a tiny 40-50amp alt with a 5 rib pulley I can make work.

 

Np man.

I would seriously reconsider running an alternator that produces less than 50 amps on an EFI system vehicle. Especially if you ever drive the car at night and still have the dual cooling fan setup. Even the lithium battery can work against you more than you think as its rebound rate is much higher than that of a typical water/lead battery. In other words once it discharges energy from the engine startup and the alternator is spinning, it will try and rebound back to its sitting voltage very quickly and could pull large amounts of the already limited 50 amps to do so. While this is happening, all other components/devices may not receive adequate voltage during this phase.

Consider these factors:
Cooling fan 8-14 amps each
Headlights 4-6 amps
EFI system 3-7 amps (non-DBW 2-5 amps)
Other misc. exterior lighting 3-6 amps
Other misc. functions (cluster, nitrous solenoids, etc) 4-10 amps
Battery rebound after startup 10-15amps (short duration of maybe 3-5 minutes)

Then, the fact that most standard alternator regulators are designed to run 50%-70% max of their rated ability. Get my drift?

Keep the rating where it's at or knock off 20-40 amps at most and you should be fine. I think the 01-03 CL's have a 120 amp peak alternator capacity so maybe down to 80-100 amps. You may even be able to retrofit from another Honda model such as a Civic or Fit and free up some parasitic power while keeping oem reliability from a factory alternator unit.

 

Well, That worked out good.
Saved 2-3lbs and reduced some drag for sure.
I just had to unbolt alt upper bolt and loosen alt upper bracket bolt,and using a 2" shorter belt it had the perfect tension when bolting the alt back up.
No other mod needed till maybe the belt stretches.

3g tl guys don't use my 2" shorter belt (370) as a guide because I'm sure we don't have the same size belt to begin with.

Just posted over here to get better opinions,not many hi performance guys over in the cl section.

Now I need to find a light weight alternator to shed more weight.