8.1 exhaust question, need help

[randym]

-I tried this post on the 6.0 / 8.1 forum section with no results; there doesn't seem to be as much readership there as here so I have reposted hopeing to get some needed results. If you know what you have please respond.-------------------------------------------------------------------------
Per my conversations with the R&D department at Gale Banks Engineering in regards to the production of an exhaust system/performance kit for the 8.1 GM engine it seems that they are unsure of the configuration of the exhaust system as manufactured for the domestic market. My contention is that only the vehicles manufactured for sale in California have the four cat system (two pre-cats along with the air injection system and two cats nearer the muffler) and that all the other vehicles manufactured for the domestic market have only the two cat system. Banks thinks that the four cat systems are sold everywhere and therfore are hesitant to develope a system for them because of the limited potential that the four cat system lends itself to, ie short tube/non torque enhancing headers like some of the other manufacturers are now marketing.
My request is that the participants on this forum post a reply to this post stating the number of converters that your 8.1 exhaust system has and the state or country in which you purchased your truck. By providing evidence that the vast majority of the trucks have the two cat system maybe we can turn on the light bulb in what is normally a progressive company but has fallen asleep on this one. Your response would be greatly apprieciated.
Thanks in advance,
Randy Moss

[mackin]

Randy Moss,


Hey is this the NFL R. Moss? Do you catch the pig skin for the Vikings? LOL :D Just had to ask .........


Anyway there are Dual exhaust out for the 8.1 although not Banks I guess ........ Petition Brandy to find out some info ..... She'll probably assist you if you ask nicely ......... Follow this thread, or shout out to her ....... ======>http://forum.62-65-dieselpage.com/ubb/ultimatebb.php?ubb=get_topic&f=7&t=003344 The info you want is on her last post ....... If your heart is set on a Banks, I guess you have to wait ..... There is a couple posters here with your configuration ....... How is your gas mileage? Friend of mine in NY is Bit*** N about his, big time ............
Good Luck on your quest,
MAC :D

[ 05-18-2002: Message edited by: mackin ]</p>

[randym]

I'm not interested in duals per-se just looking for something to give the thing a little more pull in the 2,000 to 2,600 rpm range. Nobodys making a true long tube design that I am aware of; just the typical - - make something that will fit, looks like a set of headers, strap a loud muffler on it, and the normal dim wit who thinks noise has some direct relation to power will buy it.
As for the gas mileage thing if we drive at 70 (seldom) we get about 15.5 mpg, above 75 and it becomes 14.5 or less, pulling 8,500lb TT 70 or above it can be 8 to 10 depending on terrain and especially wind speed and direction.

[big dipper]

I had a 2001 ec/lb with the 8.1 and it had only 2 converters. Never got anywhere close to 14-15mpg though. You must have gotten the "economy" version! ;) I must admit it was probably the fastest production truck that I ever owned.

[Piney]

Randy,
15.5 mpg? That is some great mileage! Do you have a 6 speed? I've talked to some local guys about exhaust upgrades and all of them have told me the same thing. The stock exhaust is going to be pretty hard to beat, with the exception of replacing the muffler with a less restrictive unit. Adding headers should help some too. I haven't found a muffler (except for the magnaflow) that offers the same inlet/outlet dimensions as the factory muffler. I am going to give the aftermarket guys some more time to come up with some other alternatives before I take the plunge. And I don't plan on spending $800-$1000 for a replacement system that only offers a minimal benefit (at best). B&B performance exhaust offers a complete system for the 8.1 but it costs $891.00. Too rich for my blood.....

[randym]

Piney,
You failed to answer the question, does your truck have 2 or 4 cats? I need this info so that I may have a little leverage in getting to the root of the problem that Gale Banks is having with the 8.1, their R&D seems to be responsive but on the same hand appear to be a little inept at accessing the market.
As for the gas mileage I don't see it as being anything special as it is comparible with some of the 454's that I have had experiance with. GM claimed an aproximate 10% increase in effency with the release of the 8.1 so a would have to say that that claim has fallen just a bit short. One differance in you truck and mine that would account for some variance in mileage (if you are not getting as good as what we are) is the fact that you have the Allison which seems to rob a bit more power than the 4L80E that we have, but one would also think that the extra heft of our Suburban would nullify the advantage.
Again- - - please post the configuration of your exhaust system and the state in which you purchased your truck.

[ 05-21-2002: Message edited by: randym ]</p>

[8.1PWR]

Randym I have the 8.1L with the Allison trans. My truck has 2 cats. I also get 15.5mpg empty at 65mph and 12.1mpg with my Lance camper at 65mph. I actually get 1 mpg better loaded with the 8.1L that I did with my 99 powerstroke. I have also been waiting for Banks to come out with a kit intake and exhaust.

[randym]

8.1PWR,
We'll be towing our 27'Carrilite to NM this weekend even though the prospects for fishing appear dreadful. Heading for Tres Ritos a traditional spot for us knowing that La Junta is closed so we have reserved a spot (yuck) at Sipapu so that we will at least be guaranteed a parking spot.
I can just picture myself standing in a bone dry Rio Pueblo trying to determine, to the best of my limited abilities, the proper dry to tie on in order to bring them to the top. Seriously though it is an extremely disheartening situation that is being faced by not only NM, but also Colo.,Mont., and Wyo; and one of such a magnitude that I do not recall ever happening in my lifetime. I fear for all of you wildlife, fish, mammal and fowl and can't imagine what the lasting effects will be if the situation lasts much longer.
We have scheduled tee times at nearby Panderee?? sp in case the fishing is in fact a total bust.
Folks a bit of a prayer for the relief of this vast and beautiful area of our great country would be in order if you are so inclined.

[ 05-22-2002: Message edited by: randym ]</p>

[Mike O.]

randym,
Your coming to my neck-of-the-woods. Not a fisherman, but certainly agree with you regarding the draught conditions. Golf at Panderie should be great--weather is forecast to be high 70's to low 80's for the weekend. Good luck.

[Piney]

randym,

Guess you didn't read my reply on this topic in the other forum....so... I have two cats and purchased the truck in Texas. You fellas getting 15+ mpg are doing very well....whatever you're driving. I'm lucky to see 10.

[IndigoDually]

The 8.1 in my motorhome on a Workhorse Chassis has 2 cat's. I think that mufflers and tailpipes are the only thing to change. The rest of the system looke mandrel bent and very straight.

John