Ducati.ms - The Ultimate Ducati Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
First off, I've searched through the site and found a few answers on the filters, Stock vs others manufacturers.

My 748 has carbon fiber air runners, and the stock filters do not fit well inside of them. There is visible evidence of them not seating against the sides of the runners and that is concerning. I still have the mesh grills on the front fairing so at least no big debris is getting by them.

I do not take this bike to the track. So crashing and sliding into gravel is not going to happen, well, not on a track anyway. ;0)

It has a full Fast By Ferracci exhaust system and matching chip on it.

Does anyone have a recommendation on what to use? I hear you have to do some drilling to install the BMC filters.

I do not want to use one of those foam filters that cover the bells in the airbox because the airbox is a Helmholtz resonator or whatever.

Any help would be awesome! Thanks.
 

·
Registered
Joined
·
616 Posts
First off, I've searched through the site and found a few answers on the filters, Stock vs others manufacturers.

My 748 has carbon fiber air runners, and the stock filters do not fit well inside of them. There is visible evidence of them not seating against the sides of the runners and that is concerning. I still have the mesh grills on the front fairing so at least no big debris is getting by them.

I do not take this bike to the track. So crashing and sliding into gravel is not going to happen, well, not on a track anyway. ;0)

It has a full Fast By Ferracci exhaust system and matching chip on it.

Does anyone have a recommendation on what to use? I hear you have to do some drilling to install the BMC filters.

I do not want to use one of those foam filters that cover the bells in the airbox because the airbox is a Helmholtz resonator or whatever.

Any help would be awesome! Thanks.
The BMC-style filters do require some drilling to attach their holder to the inside of the airbox.

Other 748 owners with Ducati Performance carbon fiber air runners have found success using the Pipercross filters that are shaped like the stock filers – but are thicker and seal better around the edges.
Thicker means they seal to the air runners better and hold more dirt. They also filter better since they use a coarse layer (similar to the stock unit in cell size) bonded to a smaller cell foam layer so they capture smaller dirt particles. They can be washed and reused. (Just make sure that the filter's coarse foam layer points toward the air tube inlet, the fine foam layer towards the airbox.)
K&N, UNI and Febur.it make similar products but I don't know if they seal better than the stock units.

I don't know who sells Pipercrross in the US. Ebay UK sells them. I suggest that you source some filter foam (try HKS) and cut to the same shape as stock but about 1/2 to 3/4 inch wider and then fit that to the stock plastic filter frame.
 

·
Registered
Joined
·
258 Posts
I run the MWR foam filter that covers the stacks on my 996. No downwards change in performance (street riding only).
 

·
Registered
Joined
·
616 Posts
I run the MWR foam filter that covers the stacks on my 996. No downwards change in performance (street riding only).
I won't dispute that for normal street riding you don't notice a big difference, but dyno testing gives a different answer. Here's two earlier posts:

"My JHP filter causes a loss of almost 6 hp and 3 ft-lbs. of torque. This was confirmed by back-to-back dyno runs and this is using the large-capacity EVR airbox. I wonder what it does using the small strada airbox?" — duc572

"The filters that fit over both stacks together and fill a large amount of the airbox lost 15 hp from the top end on my SPS. Back to back runs on the same dyno, about 5 minutes apart. Filter went in the bin. — ducv2

One reason for using an air box and intake runners is to direct cool air to the engine. This design also results in an small pressurization of intake air that increases with speed. It also reduces the volume of the intake flow noise.

But there's also a performance benefit because the airbox is a Helmholtz resonator. That is, a resonance effect occurs when you connect a suitable enclosed volume to an engine’s intake stacks causing the air inside to resonate at a frequency that results in pressure peaks coincident with the cylinders’ intake strokes. This can increase power by 10–15% within a particular rev range. Airboxes need to be well sealed and stiff in construction to maintain these resonance characteristics.

However, when you fill up a large portion of the airbox volume with an aftermarket foam filter you change the resonance characteristics of the airbox.

Further, if you use the auto industry's standard calculation of air required for "nil" vacuum restriction within the air filter system, you should have at least 130% of engine capacity in available air volume between the butterflies and the air filter element. Over-the-bellmouth filters don't meet that 1300 cc. volume need so throttle response will be degraded. This is because when you crack the throttle open it'll run rich until the air downstream of the filter get's moving. The stock system has several times that amount of air downstream of the filter in the air box ready to enter the velocity stacks unimpeded.

Regarding the large foam in-airbox filters, the people at Sigma Performance (www.sigmaperformance.com) distributers of arguably the best aftermarket chips for earlier superbikes recommended using the stock filters. They state that all FIM chips are made and tuned with the stock filters, and they highly recommend staying with the stock units.

This is because they have found that a new CLEAN stock air filter gives 2–5% better performance than any of the aftermarket filters and they have only seen reductions in performance when using over-the-bellmouth filters. As a type, they change the airbox resonance and require about a 3% leaner mixture to get back some of the power. In particular, these filters have flow characteristics that aren't well matched to the fixed metering of the stock fuel injection system.
 

·
Premium Member
Joined
·
4,917 Posts
I run a BMC setup on my '02 R. I can't tell you whether or not they affect performance, I've not noticed any difference. I can however state that in the R, with the larger CF airbox, they do maintain the 130% rule, and best of all, filter maintenance requires only the removal of the tank.

977300
 

·
Registered
Joined
·
3,528 Posts
The air filter doesn't matter. BMC, over the velocity stacks, attached to the velocity stacks, panty hose, whatever. You aren't going to notice a difference in performance, but I don't think that is the object of your post.

You an old robust 748. The worst filters I've run were the Madduc velocity stack filters. I had about 2,000 miles on them before I replaced them. They made the engine felt slightly rough, but not really, but that is the only word I can used to describe their effect. But I didn't notice until I did a back to back run with the ITG filter. The ITG felt much better.
 

·
Registered
Joined
·
616 Posts
The worst filters I've run were the Madduc velocity stack filters. I had about 2,000 miles on them before I replaced them. They made the engine felt slightly rough, but not really, but that is the only word I can used to describe their effect. But I didn't notice until I did a back to back run with the ITG filter. The ITG felt much better.
There's lots of posts that repeat your experience with Madduc filters. Here's a couple:
977311

"Last year I came across my first set on a customers 748 also from ebay it was making 80 bhp and we could not understand why. We removed those lovely simple-looking filters and 88 bhp was the result which I think ended up at 92 with the fuel trimmed.

The second time I saw these was on a modified desmodue racer in the UK, also bought from the bay. I suggested that he removed them for a few laps and his times proved he was going faster.

Air flows around the circumference of the bell mouth and into the throttle body. The sharp edges on those filters disrupts the flow and kills your power a bit like the sharp step restrictor in a 748r." — Chris Steedman

==============
"Those filters suck! I have no idea why, but I have witnessed, with my own eyes three different dyno runs on the same bike (Race only 996) and the difference between those mushroom filters and a FBF filter was about 10 hp.

The bike belongs to Ben Fox at http://www.foxperformanceengines.com/. He also could not figure out why those little filters would rob so much power but the bottom line is that they do. We tested a Pipercross filter on my friends 998 and the difference with the filter and without a filter was less than one hp." — mr.duc
==============

Also, keep in mind that air filters are protective devices not performance devices. They need to capture dirt efficiently and hold a sufficient quantity over time, without degrading engine performance. The MadDuc’s don’t.

PS. Next time you're doing some dyno work, place your finger near the top edge of one of the velocity stacks and watch the power output drop-off big time. This is absolutely the worst place to place a filter because it turns laminar (smooth) airflow into turbulent flow.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
The BMC-style filters do require some drilling to attach their holder to the inside of the airbox.

Other 748 owners with Ducati Performance carbon fiber air runners have found success using the Pipercross filters that are shaped like the stock filers – but are thicker and seal better around the edges.
Thicker means they seal to the air runners better and hold more dirt. They also filter better since they use a coarse layer (similar to the stock unit in cell size) bonded to a smaller cell foam layer so they capture smaller dirt particles. They can be washed and reused. (Just make sure that the filter's coarse foam layer points toward the air tube inlet, the fine foam layer towards the airbox.)
K&N, UNI and Febur.it make similar products but I don't know if they seal better than the stock units.

I don't know who sells Pipercrross in the US. Ebay UK sells them. I suggest that you source some filter foam (try HKS) and cut to the same shape as stock but about 1/2 to 3/4 inch wider and then fit that to the stock plastic filter frame.
I'm not real sure if the carbon fiber, runners and air box, is Ducati Performance carbon fiber, as I bought the bike that way. I know the guy I bought it from and I'm guessing he would have used them instead of some knockoff brand, he did put the FBF exhaust system and chip on it, so money was not an issue for him. So I'll go with them being the Ducati Performance carbon fiber.

Thanks for your reply Strega!
 

·
Registered
Joined
·
5 Posts
Discussion Starter #9
The air filter doesn't matter. BMC, over the velocity stacks, attached to the velocity stacks, panty hose, whatever. You aren't going to notice a difference in performance, but I don't think that is the object of your post.

You an old robust 748. The worst filters I've run were the Madduc velocity stack filters. I had about 2,000 miles on them before I replaced them. They made the engine felt slightly rough, but not really, but that is the only word I can used to describe their effect. But I didn't notice until I did a back to back run with the ITG filter. The ITG felt much better.
Namor, do you have a model number for the ITG filters? Or know the best place to get them?
 

·
Registered
Joined
·
86 Posts
Get the Pipercross from ebay. $25 delivered from England.

While you're at it, check your spark plugs. I had an FBF chip and it made the fuelling so rich my plugs were just black and oily. Switch to an FIM Ultimap. Much better mapping. They're still available on ebay.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #12
Get the Pipercross from ebay. $25 delivered from England.

While you're at it, check your spark plugs. I had an FBF chip and it made the fuelling so rich my plugs were just black and oily. Switch to an FIM Ultimap. Much better mapping. They're still available on ebay.
TNR,
Thanks for the info.

I'm not really up to speed on the differences in chips. I've read a few articles but that just confused me even more LOL.
Do I need any special software to program that chip?
I was reading this thread here: https://www.ducati.ms/threads/how-the-fim-programable-eprom-works.32324/
and it says the software to program them is no longer manufactured.

I am trying to buy from Ferracci, the diagnostic software for my chip (stage1) F00170 11/99. But it's slow going and I can't get a price as of yet.

I will check my plugs as you suggested. Why I didn't think of that, I'm not sure.

When I took the bike in for its 12,000 mile service, the tech's tuned it as best they could, but the sputtering I was experiencing at low rev's was better, but not gone. Which is why I'm trying to go through Ferracci.
 
1 - 12 of 12 Posts
Top