Dear Barth Friends,
It has been suggested to me that replacing the standard air filter with a K&N permanent filter, and adding dual exhaust pipes after the catalytic converter could improve mileage and/or performance. Is this true? What is your experience? My Barth is a 1996 22' short Regency with the Chev. 454 gas engine. Perhaps the very last short Regency style built. This forum has helped greatly, last year, by showing me how to change the alignment from "potato chip truck" alignment to proper motor home alignment. The difference was amazing! Now, any suggestions on air filters or dual exhausts would be appreciated. And, would either of these changes create too much noise in the cab while driving?
best regards from
Allan Pacela of Solvang

Hi Allan,

This could be opening a can of worms but when I took my Buick into the dealership for service last year, I had just put in a K&N filter and was thinking about converting to a complete K&N system. My mechanic advised me to pitch it and put an AC filter or similar type filter back in the car. The reason: the K&N filter cause the sensors down stream from the filter to fail and voided warranties. some of these types of filters have a film of oil on them that coat the sensors downstream. I knew him before having my car serviced there and have no reason to doubt him. He didn't care where the replacement filter came from as long as I got rid of the K&N. Note, K&N competitors are reportedly not any better.

On the flip side, when I had my Ford Powerstroke in for service at the Ford truck service center, they had K&N filters and complete systems for sale.

I'd recommend speaking with a mechanic either here in the forum or locally for advice about these types of filters. In some older applications like a 69 Mach 1 or my 66 Buick Riviera GS, they might work great but I'd be concerned with newer vehicles.

quote:

Originally posted by Allan:
Dear Barth Friends,
It has been suggested to me that replacing the standard air filter with a K&N permanent filter.

Nope.

All a K&N filter does is let more silica into your engine. Even if a K&N did have less restriction, engines are fine with up to 20 inches H2O restriction, and even that is not a consideration until the throttle is WFO. The rest of the time, the throttle, by definition, is restricting the flow of air far more than an air cleaner ever could. An AC or Baldwin element is about as good as you can get.

That said, if you have TBI, I will send you a K&N if you donate half of its retail price to the site.

Same deal for a Tornado air straightener-outer/turbulator.

quote:

and adding dual exhaust pipes after the catalytic converter could improve mileage and/or performance. Is this true?

Would you describe or photograph your exhaust system?

My gut feeling is that you might get a little more power with a set of Thorleys and a free flowing muffler with your single exhaust system. The cat is your holdup, and may not be legally replaced with a freer flowing one unless there is a "good" reason. I am speaking from memory here, and you should check with your smog guy on the legal stuff. With a freer flowing cat or dual cats, things would get better.

People who know do not agree on single vs dual exhausts on motor homes. Both can work well. My gut feeling is that Thorleys, an X pipe, dual free flowing cats and free flowing mufflers would be the best for mid range power, but I don't have the figures to back it up. I would not expect much economy improvement, though. Have you looked at a performance chip?

Is your engine a TBI or Vortec? Do you already have cold air induction?

Your shorty is already pretty light, and should have decent performance already. What do you tow?

quote:

Originally posted by towerguy:
Hi Allan,

I had just put in a K&N filter and was thinking about converting to a complete K&N system. My mechanic advised me to pitch it and put an AC filter or similar type filter back in the car. The reason: the K&N filter cause the sensors down stream from the filter to fail and voided warranties.

Your mechanic is right in principle, but that does not happen often. regardless, there is no need for a K&N. As far as cost goes, most air filter elements are replaced way too soon. A Filter Minder will tell you when to change the element.

I had a 65 Riviera GS, with dual AFBs, and it had an air cleaner the size of a garbage can lid.

I'm with the majority here: K&N filters, as claimed, let air in more freely. Sadly, they also let crud in more freely.

I use Wix (or the NAPA Wix-made equivalent) oil, fuel, and air filters exclusively on the Barth and my diesel Ford E350 1-ton van.

If I can figure out where to put it, the stock GM filter canister will be replaced by a Donaldson...

I am a real believer in using AC air filters whenever they fit. One of the Duramax forums had a test that showed the AC to be clearly superior. Even better than Baldwin or Wix.

To All: Many thanks for the comments!
OK, so the consensus is to forget the K&N Filters and use AC Filters. I will do that.
To Bill h:
Before we discuss improving the exhaust system, let me comment that in this short 1996 Barth, I don't tow and already get 9 to 10 mpg on average, depending on the amount of mountain driving, so I suspect that a "performance chip" would not be necessary. Do you agree?
Next, I purchased the Barth as a "Chev. 454." How would I check to see if the engine is Vortec or TBI? Finally, regarding "cold air induction" what I have is stock: just the straight flexible air pipe going from the air filter straight to some kind of a baffle plate directly forward of the air filter near the front of the coach. What would "cold air induction" entail and what does it accomplish? Obviously, I don't know much about engines, so all comments will be appreciated.
best regards,
Allan of Solvang

quote:

Originally posted by Allan:

To Bill h:
Before we discuss improving the exhaust system, let me comment that in this short 1996 Barth, I don't tow and already get 9 to 10 mpg on average, depending on the amount of mountain driving, so I suspect that a "performance chip" would not be necessary. Do you agree?

A chip is never necessary. It is a choice. It depends on how much power you want. Notice, I said "want", not "need".

Same with headers. The shorter the coach, the lighter it is, and the better will it climb hills. It is all a matter of choice. Thorleys and a free flow exhaust system will improve your climbing, but will not help much on the mileage. A speed shop had a sign that said, "Speed costs money. How fast do you want to go?"

quote:

Next, I purchased the Barth as a "Chev. 454." How would I check to see if the engine is Vortec or TBI?

Send me a picture of the engine with the air cleaner off. Or wait and I will post a picture of a TBI with the air cleaner off when my wife brings the truck back. In a nutshell, a TBI engine has an air cleaner that looks like a carb air cleaner with two nuts instead of one. I mention this because trucks changed from TBI to Vortec in 96, but some motor homes didn't change until 96. And we all know that some 96 MHs had 95 chassis.

quote:

Finally, regarding "cold air induction" what I have is stock: just the straight flexible air pipe going from the air filter straight to some kind of a baffle plate directly forward of the air filter near the front of the coach. What would "cold air induction" entail and what does it accomplish? Obviously, I don't know much about engines, so all comments will be appreciated.
best regards,
Allan of Solvang

Without a picture, I could only guess, but right now, I would guess that you have cold air induction. Basically, it is ducting that allows the engine to get cold air instead of doghouse air. It has been on cars since forever, but many motor homes did not use it or left it off. It gives you about 1 percent more power and mileage for every 10 degrees of temp reduction. I have read this from respected tuners, but my limited dyno budget did not allow testing. They charge by the minute. I will say that it was effective on my boat on the 110-plus Colorado river, as verified by a digital tach and GPS speedometer. A jet boat is almost a water dyno, so the premise is valid.

Bill h:
I have been trying to attach photos of my engine and exhaust system to this response ... with no luck. I reduced the photos down to about 79KB from a couple of hundred KB but the server won't accept even one. Is there a trick to attaching a photo in this Forum? Or, may I send them directly to you via an email (I don't know your email)?
best regards,
Allan of Solvang

It will be a little more interesting to others if you post here. Dave has some good instructions on how to do that HERE.

Thanks, Bill h!
Here is a link to a photo of my engine:

Next, here are three photos of the exhaust system:

Second exhaust photo:

Third photo of exhaust system showing the Y:

Your comments will be appreciated. The subject is how to improve mileage or performance, without increasing noise for the passengers.
best regards,
Allan of Solvang

That is TBI or Throttle Body Injection.

It looks like you already have cold air induction, which is good. Can you tell by looking around if the air duct into the air cleaner housing sucks cold air?

As for your exhaust, it looks a little kinky. Those wavy kinks on the inside of the bends hurt flow at higher rpm. Thorley or Banks would definitely help power and maybe mileage. The problem with mileage is that header users use that extra power, which takes more fuel.

I would not buy a muffler without hearing it first. Walker makes a nice one for RVs, and so does Dynomax and Edelbrock. With a straight-through muffler, longer is better. I would avoid Flowmaster. The ones that are quiet hurt power.

Thread drift follows:

Hey, what's that Italian restaurant in Solvang right next to that nifty antique store? Is it still good? Near the park, I think.

Thanks Bill h:
I will look into Thorley or Banks next, and if I go that way, will fix the "kinky pipes" as well. (I didn't know that I have a "kinky Barth," but who knew?) Meanwhile, can you tell if this is a Vortec or a TBI engine from the photo?
Next, now that I am into this photo thing, here is a photo of the air intake. It is a flexible pipe from the air cleaner housing to a baffle plate just above the radiator. I would assume that this is not cold air at that location? See Photo here:

Finally, ... Thread drift:
That would be the Cafe Angelica. The original owner was a great Chef. He sold out many years ago, and the current menu has subsequently not changed in ten years, but like thread drift, has drifted so that the dinner delivered is no longer exactly what is described on the menu. A few locals still like it, but we don't. We do highly recommend Matti's Restaurant in Los Olivos, or the Red Barn in Santa Ynez. Or for simple, low cost, old fashioned, good coffee shop food with great breakfasts, go to Ellen's Danish Pancake House in Buellton. Or, for a great location and good standard food, the River Grill at the Alisal golf course on Alisal Road (looks like a private club but is actually public).
best regards,
Allan of Solvang

quote:

Originally posted by Allan:
Can you tell if this is a Vortec or a TBI engine from the photo?

The top photo in your last post shows it to be a TBI. Carry a spare fuel pump.

quote:

Next, now that I am into this photo thing, here is a photo of the air intake. It is a flexible pipe from the air cleaner housing to a baffle plate just above the radiator. I would assume that this is not cold air at that location?

That's cold air. Banks takes their cold air from underneath, but ram air into the grille is cold air, too. I doubt that one cold air is better than another. I would not spend any extra money on a different intake system. Your intake manifold is the late one, so it is the good one.

quote:

Finally, ... Thread drift:
That would be the Cafe Angelica. The original owner was a great Chef. He sold out many years ago, and the current menu has subsequently not changed in ten years, but like thread drift, has drifted so that the dinner delivered is no longer exactly what is described on the menu. A few locals still like it, but we don't.

Sorry to hear that. So many restaurants slip after new owners.

quote:

We do highly recommend Matti's Restaurant in Los Olivos, or the Red Barn in Santa Ynez. Or for simple, low cost, old fashioned, good coffee shop food with great breakfasts, go to Ellen's Danish Pancake House in Buellton. Or, for a great location and good standard food, the River Grill at the Alisal golf course on Alisal Road (looks like a private club but is actually public).
best regards,
Allan of Solvang

Thank you so much for the recommendations. We'll check them out next time we are Cachuma or Jalama. One can eat only so many Jalama burgers, ya know.

Bill h:
Are you serious about carrying a spare fuel pump? Has there been a fuel pump issue with the TBI engines? Is my fuel pump electric or mechanical? I am not sure where to look for it.
best,
Allan of Solvang