Increase In Noise with a Banks Exhaust System

blocksofwood · 10-01-2004, 10:04 AM

I'm considering putting a Banks exhaust system on my 95 Airstream Motorhome to increase the towing power for climbing hills, etc. Its a Chevy 454 throttle body injected engine on a P-30 frame. I've put performance exhaust on some cars/trucks and there was always a noticable increase in the noise levels. I called and emailed Banks Power Systems and asked for definitive answers on how much I should expect the noise level to increase but have not been able to get an answer from them. If anyone has noise level increase numbers I would love to know what they are. I would like it in db (decible) levels if known. If you don't know the db increase then any subjective information would be helpful.

andoboba · 10-01-2004, 11:23 AM

Quote:

Originally Posted by blocksofwood

I'm considering putting a Banks exhaust system on my 95 Airstream Motorhome to increase the towing power for climbing hills, etc. Its a Chevy 454 throttle body injected engine on a P-30 frame. I've put performance exhaust on some cars/trucks and there was always a noticable increase in the noise levels. I called and emailed Banks Power Systems and asked for definitive answers on how much I should expect the noise level to increase but have not been able to get an answer from them. If anyone has noise level increase numbers I would love to know what they are. I would like it in db (decible) levels if known. If you don't know the db increase then any subjective information would be helpful.

I too am interested in putting the Banks system on my '94 Suburban with the 7.4l. I have put fancy headers on lots of stuff and it has always increased interior noise. The claims banks makes are impressive! Have you also looked at the Gibson stainless system? I will start e-mailing them with the same question so we can get an answer.
This is an expensive setup so it would be a drag to install and then regret!!

JeepinAudiophile · 10-01-2004, 11:58 AM

My parents ran the banks setup on our 95' Land Yacht... I just called him to ask what his thoughts on it were... we told me that the 0-55 time was cut in half, and he also believed that the in-cab noise was actually quieted!!! (Part of the reason I went with Banks Header on my Jeep) Please shoot me a message if you want any more information.. I do destinctly remember that the hill climbing became much less of an issue, as they were a major struggle before-hand... Our next power upgrade was a diesel-pusher however...lol --Chad Bleakney--

blocksofwood · 10-01-2004, 12:28 PM

Quote:

Originally Posted by andoboba

I too am interested in putting the Banks system on my '94 Suburban with the 7.4l. I have put fancy headers on lots of stuff and it has always increased interior noise. The claims banks makes are impressive! Have you also looked at the Gibson stainless system? I will start e-mailing them with the same question so we can get an answer.
This is an expensive setup so it would be a drag to install and then regret!!

Thanks for the info. I looked at Gibson (used their SST mufflers in the past) but found opinions that they require an exhaust gasket while the Banks does not. The gasket is an indication of poorer quality machine work. The banks has the matting surfaces machined after fabrication to be flat so no gasket is required (so I've been told). The Gibson was not machined after fabrication so the gasket is needed.
Jerry

swebster · 10-01-2004, 12:29 PM

I only have subjective information and unfortunately it's not specific to either the Banks or the Gibson exhaust. But if it helps you then here it is:

I installed a new exhaust made up of a set of Headmans, free flow mufflers and a pipe kit on our Airstream (A carbureted 454 on a P30). I tried to match the basic concept of the Banks/Gibson exhaust when I did it along with lot of advice from other forum members. While I was looking into the Gibson at the time I elected go with this solution as a cost control since at the time money was pouring into the 345.

Here is a quick overview of the basic system: Primaries merge into 3" collectors and then step down into 2.5" pipes. There is an "H" cross member installed just behind the transmission. Each pipe enters a free flow muffler then rearward and exiting just before the drive wheels on each side of the motorhome.

Again, I haven't measured noise levels but I can say that there was no noticeable noise increase inside the coach once this system was installed. There was, however, a pitch change (lower) inside of the coach. I should point out that my doghouse has sound/heat insulation in it (installed by the PO) which I suspect, based on noise reports from others, really helps control the cockpit noise in our unit.

Outside of the coach is a different story. With the driver’s window open I can certainly hear a louder and lower exhaust note from the tailpipe on the driver’s side. This is especially noticeable if I'm at highway speeds and next to a truck or "Jersey Barrier". Most of the time I don't really notice it but it now sounds closer to a truck than a Cadillac (btw - it never sounded like a Cadillac

)

The performance gains are certainly noticeable but I can't isolate them to this exhaust switch as I rebuilt the carburetor and replaced the distributor/coil/wires all around the same time.

I would suspect that the Banks setup on an FI engine would really improve things for you.

No matter what you decide (Banks/Gibson) please report back on your findings. It is a lot of money to spend for performance but if the gains are there then it would be well worth the upgrade.

Pahaska · 10-01-2004, 03:00 PM

You are so far from the exhaust tip that noise emitted there should not be an issue. When I put the Banks system on my 5.3L Chevy pickup, the only real noise increase I noticed was at the exhaust outlet, Under-hood noise didn't seem to change. I found the overall noise level quite acceptable.

The performance increase was very noticeable. Mileage went up a smidgeon.

andoboba · 10-01-2004, 03:37 PM

Quote:

Originally Posted by blocksofwood

Thanks for the info. I looked at Gibson (used their SST mufflers in the past) but found opinions that they require an exhaust gasket while the Banks does not. The gasket is an indication of poorer quality machine work. The banks has the matting surfaces machined after fabrication to be flat so no gasket is required (so I've been told). The Gibson was not machined after fabrication so the gasket is needed.
Jerry

I just talked with Banks as I am very interested in this product. They confirm that the flanges are machined 5/8" superthick SS. The noise underhood and incab should not increase and maybe even decrease. I am going to use a stainless 3.5 inch cat converter to finish the system off. This is the coolest system I have ever seen! It even comes with a neat air cleaner upgrade. Call them they are very helpful and want to sell direct to customers. John called me right back and was very knowledgeable. Their # is 1-800-438-7693 and John's ext is 4111. Good Luck!!

JeepinAudiophile · 10-02-2004, 01:43 AM

Some additional information... We did the Banks Power Pack system... My father tells me that it brought the 0-55 time from 24 seconds down to 12 seconds... he is pretty good about recording the information and doing thorough testing. Hope this was of help!!!

Tarheel · 10-02-2004, 09:32 PM

I running the exhaust as well as the turbo and intercooler system provided by banks along with a pac exhaust brake. The system is no louder than it was before and performance is greatly increased. Fuel mileage has remaind pretty much the same.

ALANSD · 10-03-2004, 08:08 AM

I read the post with the 24 second 0-55 time, pre Banks. I know my 82 without anything hight tech in the exhaust dept, just a free flow single muffler each side off the shelf at our local muffler shop- will get up to 55 quite quickly. I don't know how much the Tornado air thing, a real clean carb and fuel system plus a good state of tune would contribute versus the $2500 in exhaust upgrades, but it trucks on very well.
The Banks is terrific from all accounts, just not justified to my bank account.

wa3vez · 10-09-2004, 03:42 PM

Quote:

Originally Posted by blocksofwood

I'm considering putting a Banks exhaust system on my 95 Airstream Motorhome to increase the towing power for climbing hills, etc. Its a Chevy 454 throttle body injected engine on a P-30 frame. I've put performance exhaust on some cars/trucks and there was always a noticable increase in the noise levels. I called and emailed Banks Power Systems and asked for definitive answers on how much I should expect the noise level to increase but have not been able to get an answer from them. If anyone has noise level increase numbers I would love to know what they are. I would like it in db (decible) levels if known. If you don't know the db increase then any subjective information would be helpful.

I have been running a Banks for over 7 years. It is everything they claim, particularly on my 1990 345. I did not notice any significant change in the noise levels and in fact, it may be slightly quieter. Adding this and a Gear Vendors has saved me vast amounts of dollars. I have had no desire to buy a new Motor Home for the past 7 or 8 years since I am so happy with my Classic.