Pod vs stock intake filter on 80's 1000cc motor

[brider]

I would have bet $$ that "pod vs stock filter" would've been the start of many previous threads, but all I found was a smattering of peripheral discussions. Someone please direct me to a previous thread on this subject to save us all time.

But anyway: Never ran pod filters on my Cal 2, but I'm sure I did back on my Convert, and fer-sher on my Eldos. Didn't set them up that way, they all came like that. Thinking of maybe switching to pods now, just to eliminate the major hassle of dealing with the stock intake after I remove it to work on my stock dizzy very soon.

Is the intake noise likely to become a LOT louder if I do? Will I need to re-jet (stock exhaust)? Is there likely to be ANY performance improvement? Mine is an Auto, remember, no such thing as neck-snapping acceleration.

[Chuck in Indiana]

Is the intake noise likely to become a LOT louder if I do?

Yes

Will I need to re-jet (stock exhaust)?

Maybe

Is there likely to be ANY performance improvement? Mine is an Auto, remember,

[Antietam Classic Cycle]

IMO, the intake noise isn't that much louder, it's just more noticeable because it's right below the rider now instead of more forward. I don't really mind it 90% of the time. I haven't found it necessary to rejet, only raised the needles one notch. No performance increase, though it might sound faster. 

[brider]

Wow, that's a really nice-looking Convert, my 2nd one was black, too. I still say that seat is the most comfortable I ever sat on, just LOOK at how much room there is to move around, with just the right foam density (matter of preference, I know).

[guzzisteve]

I would make sure it at least had the euro jetting set-up on the PHF carbs.

[Toecutter]

In my experience... pods suck. They're great for WoT riding... but tough to tune for low and mid range.

[Tusayan]

I ran both my CX100 and 1000SP with individual K&N filters, like almost all of those bikes the air boxes had been removed to make service much easier.   Tuning was no problem with either 30-mm square slides, 30-mm round slides or 36-mm round slides (I ran all three over time) and the intake noise was pleasant.

[Kiwi_Roy]

I put pods on my VII Sport, it gave it a flat spot mid range until I took the intake rubbers off the original air box and used them between the pod and throttle body, I guess they act as a Velocity Stack
The pods looked nice when they were new but they got grimy looking with age, I would stick with something like the original filter, but that's just me.
The way the carbs face the pods would be buried wouldn't they?

Lovely old girl there Charley 

[Tusayan]

I put pods on my VII Sport, it gave it a flat spot mid range until I took the intake rubbers off the original air box and used them between the pod and throttle body, I guess they act as a Velocity Stack

They act to increase the tuned length of the intake tract, which may have benefits - witness the extremely long stacks used on the Daytona race kits.  On an engine like the small valve 949, using a standard 70s/80s cam, I'm not sure changing intake tract length would make much difference, although dyno results would be interesting to see.  A '76-78 850 Le Mans uses the same cam with no air box, only short Dellorto stacks - maybe that is optimum. 

In my experience the small valve 949 engine does need the the exhaust crossover for mid range power, better when close to the heads as on the 850 Le Mans or Bub headers.

In any case, the gentle chuffing noise through the intakes is pleasant on these engines.

[sidecarnutz]

On the older Cali's you had an air box  that was a complete PITA to get into to service the filter. And the vinyl hoses would harden with age making it even more difficult to change. At that point, I would put some K&Ns on it to simplify it. I have a 1990 Cali III that I changed the filter on last year. I promised myself that when it comes due again, I'll switch to the pods.

I liked the air filter on my 1997 Cali better. It was an honest improvement on the older ones. You could prop the tank up on a wood block, slip your hand in there with a 1/4" drive ratchet/socket and raise the rear of the lid open enough to slip the old filter out and the new one in without too much trouble.

IMO I don't think the small valve motor from that era CAN make more power. They are pretty well strangled by the small valves and 30mm carbs. But they are great steady state cruising motors that get great gas mileage! Torque is their forte vice HP.

[rodekyll]

On my short wheelbase Convert the decision to go to pods was a matter of convenience accessing things and a search for space to install a bigger battery.  With the pods attached directly to the velocity stacks I noticed no performance change at all, one way or the other.  I'd think any small performance increase would be lost in the slip and stall speed of the torque converter.  Remember -- it's not a locking t/c.  It always slips.   And it always slips and stalls the same, regardless of the input power.  So the acceleration and gear reduction are the same regardless.  I went from the 1100 hydro to a 1200 in the torque-converter equipped trike and noticed a disappointing lack of increased acceleration (although it holds the hills better).  That's a lot of added horsepower.  But without also modifying the initial T/C slip rate and stall speed it will always want to "wind up" to a certain point before delivering power to the wheel.  To really take advantage of more engine power you need to change the t/c properties.

Since you can't conveniently open up the t/c and change out the innards, the way to Convert performance is to convince it to wind up faster.  The easy way to do that is to lighten the flywheel.  You can remove at least 50% of the weight without compromising the flywheel structure and still have plenty of weight left (remember that T/C full of fluid) to idle well.  It gives the added advantage of removing parasitic weight.  The engine can apply the energy savings to the road.  I've lightened three 'Verts now (all different approaches and different weights) with exciting results.  Not only does acceleration improve dramatically, the bike has an actual engine brake effect instead of the 'coast' effect you get when you roll off the throttle of a heavy flywheel bike.

If you want a performance transformation, find a Jackal or hydro engine and EFI and give the bike some of that.  With a light flywheel it's what the Convert should have been.  You'll wonder what's up with that useless gearbox business . .  .

[John A]

a little bit of a thread drift but can a transmission shop that builds hot rod automatics massage the torque converter for more spirited use? I remember back in the mists of time watching a shop do that to converters

[Rough Edge racing]

a little bit of a thread drift but can a transmission shop that builds hot rod automatics massage the torque converter for more spirited use? I remember back in the mists of time watching a shop do that to converters

 Primarily, torque convertors are modified for more durability and a higher stall speed.. The higher stall should give better standing start acceleration...Goog le "high stall convertor" and read the theories and opinions......There are many....

  I've run pods on quite a few carburetor bikes...Some required a bit of tuning ,some not...Back around 1971? I read a road test of the new Moto Guzzi Sport in Cycle magazine....One thing they mentioned was the loud intake "honk" from the lack of air filters?

[Antietam Classic Cycle]

Back around 1971? I read a road test of the new Moto Guzzi Sport in Cycle magazine....One thing they mentioned was the loud intake "honk" from the lack of air filters?

The 850-T and V7 Sport had no air filter - just a rubber plenum with a piece of perforated metal covering the opening.




The Benelli 650S Tornado didn't either.

[antmanbee]

I have been using this setup on all my tonti's since the late 70s. Keep the velocity stacks that came with the bike and toss the airbox. There is a spring inside the foam sock that just slides over the stacks. You have to cut out the end of the foam so both ends are open. Only about $12 and reusable.










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[Guzzistajohn]

Both of my old bikes were already fitted with k&n’s when I got them, always ran fine never really had to do any excessive tweaking. It’s been trouble free. An old dude up in greenwood mo tuned my LeMans III, I’ll trust his experience. 30 plus years?...

[brider]

On the older Cali's you had an air box  that was a complete PITA to get into to service the filter. And the vinyl hoses would harden with age making it even more difficult to change. At that point, I would put some K&Ns on it to simplify it. I have a 1990 Cali III that I changed the filter on last year. I promised myself that when it comes due again, I'll switch to the pods.

This is exactly where I am now. I swapped out the filter a couple of years ago and spent HOURS re-plumbing the engine breather system and trying to fit the original intake box extension "horn" that runs forward to past the dizzy. Prior to that I did not have forward part of the airbox installed, so the entire front of the filter was open, and the intake noise was LOUD. I breathed a sigh of relief after the intake was back to stock because of the quietness, but I shudder to think of doing all that again after I get the dizzy back in.

[brider]

I have been using this setup on all my tonti's since the late 70s. Keep the velocity stacks that came with the bike and toss the airbox. There is a spring inside the foam sock that just slides over the stacks. You have to cut out the end of the foam so both ends are open. Only about $12 and reusable.

Now THAT'S interesting. Is that a generic filter sock, reduced to a cylinder? Do you periodically oil it, like a dirt-bike filter? My first thought was filter area, but if some 850s ran with no filter at all, I guess that's a moot point.

[Gliderjohn]

Always ran K&Ns on my T-3 with no problems or regrets. My hearing is such I could not hear any intake noise difference when I switched from the stock set up.
GliderJohn

[antmanbee]

Now THAT'S interesting. Is that a generic filter sock, reduced to a cylinder? Do you periodically oil it, like a dirt-bike filter? My first thought was filter area, but if some 850s ran with no filter at all, I guess that's a moot point.

Plenty of filter area. I oil it with the tacky foam filer oil. I think I used Belray. I oil it and run it for a year or two and then clean it and oil it again. I did this with mt T3 and Convert and now my Jackal and Calvin.
It is a UNI U-802. It was a sock and now just a cylinder. I needed to buy an extra hose clamp.

[lazlokovacs]

Plenty of filter area. I oil it with the tacky foam filer oil. I think I used Belray. I oil it and run it for a year or two and then clean it and oil it again. I did this with mt T3 and Convert and now my Jackal and Calvin.
It is a UNI U-802. It was a sock and now just a cylinder. I needed to buy an extra hose clamp.

that looks like a really good idea!

nice one

[brider]

Plenty of filter area. I oil it with the tacky foam filer oil. I think I used Belray. I oil it and run it for a year or two and then clean it and oil it again. I did this with mt T3 and Convert and now my Jackal and Calvin.
It is a UNI U-802. It was a sock and now just a cylinder. I needed to buy an extra hose clamp.

That's it, I'm going for it. For $12 it's worth the $$ just to see how well I can integrate it. I even have a bottle of foam filter oil.

Does the internal support spring come with it? Do you modify jetting after the conversion (I need to research how to diagnose and accomplish jetting mods)?

[Rough Edge racing]

 Not a Guzzi , but I think it's relevant....While tuning my speed record Triumph 650 on the dyno I tried different intakes and air filters....3 x 6 Uni foam filters correctly oiled, were restrictive and cut top end power about 5 percent compared to no filter..K&N 3 x 5 filters were about the same.....This was on a vintage 650 Triumph making  55 rear wheel HP @ 7000 rpm... Side note, velocity stacks and long intakes also cut the top end power despite jetting changes...This may not be the situation on other engines but I believe it says there is no consistent results ....
 Some riders make the mistake of thinking the bike is faster but actually what happen is the midrange went soft and then the engine pulls harder once past this and give of impression of more speed, but it's actually slower overall....

[chuck peterson]

If using k&n pods be sure to keep the velocity stacks...they smooth the air flow and increase .....you guessed it, ...velocity. Without will mess with low mid range...I had a machinist turn down the outsides to fit the pods...only change was raising the meddle one notch....Guzziology has a lot of this

[brider]

If using k&n pods be sure to keep the velocity stacks...

Aaaaaand, here we have a problem on my Cal 2. There are no "velocity stacks" beyond the machined flare on the intake side of the carbs themselves, and these only extend ~ 3/8" or so, just long enough to clamp the rubber boot to the airbox. There are no extensions like shown in blu guzz's post. Are  my rubber boots performing the same function as a velocity stack?

[Antietam Classic Cycle]

On VHBs I consider it necessary to use velocity stacks, but PHFs - not so much.

[chuck peterson]

These used to be made from unobtainium.....

http://www.mgcycle.com/index.php?main_page=product_info&cPath=279&products_id=3201

[antmanbee]

They come with springs.
U-801 = 1 3/4" ID
U-802 = 2" ID

I am not sure what the OD of the aluminum velocity stacks is.
On the injected later models the OD of the plastic stacks is 2".

Would be a good idea to check first.

[lazlokovacs]

On VHBs I consider it necessary to use velocity stacks, but PHFs - not so much.

yeah, my lemans 1000 doesnt seem to suffer without the stacks

Just 2 whopping great K&N pod filters

really like the unifoam idea for its tidiness though... pods always llok like they're about to fall off

(and sometimes do)

[Rough Edge racing]

On VHBs I consider it necessary to use velocity stacks, but PHFs - not so much.

  Yes, depends on many factors...A few years back my 84 Cali "boober" was run at the land speed racing track in Ohio. One mile standing start, the engine is stock with cheap small cone shaped pods , no stacks....I fitted one size larger mains and moved up the metering rods slightly..The bike made four runs, two with pods on, two with them off on 93 octane E10 pump full...all four runs were  timed between 117 -118 MPH...