I am looking for a turbo back to eliminate cat. I dont want it to be real loud, still be able to talk normal inside,just sound better reduce EGT's and backpressure.

A lot of guys really like the MBRP stuff, but I used one of the $300 "turbo back" kits off Ebay from a company called "Warp Speed Performance" and it works perfectly. Easy DIY install, dropped EGTs and I gained about 1 MPG consistantly.


http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33630&item=7947019475&rd=1&ssPageName=WDVW

I tried a 4" system and saw no gain and got codes. I went back to my stock exhaust and replaced the cat pipe with a stock LB7 pipe. Only a little louder than stock, but no codes.

I had a Banks put on and it is running cooler. HP gain, I can’t tell. No codes.
Feels like it runs better, less back pressure. I got it because I have a heavy camper on the back and climb long mountain roads, and all is fine.

i put a banks 4" catback on and didn't really notice any improvement but I'm sure it helped. I think it's just an incremental improvement so it's not that noticeable.

It may also be because I still have a cat and factory downpipe. easy install though. Only complaint is that Banks doesn't ship the kit with the strap-type clamps and paying a premium for a Banks kit vs. a local shop chopping up 4", I'd expect them to ship the strap clamps instead of the cheapo's.

hardest part of the install is getting the old pipe out. if you're not on a lift, plan on chopping it up a bit.

btw: this is where I got my strap clamps -
http://shop.ivalueinternet.com/bigexhaust/index.cfm/action/productdetail/product_id/862.htm

We recommend the MBRP systems as we believe them to be the best. They are available in Alumized, T409 SS, and T304 SS. The systems are "cat back" bolting right up to the 4 bolt flange. With this sytem you will NOT set any codes as the Cat is not touched.

Finger Stick will eliminate the codes from exhaust changes.

I think the consences was that if you keep your muffler and eliminate the cat you won't get codes..or at least get a muffler that will still give you some back pressure.

Like RickDLance said..I also installed a 4" exhaust however I did see quicker spool up and lower EGT's, but I got codes and truck started to blow white smoke not to mention smell of diesel fuel through exhaust. It messed with the EGR.

anyways.. installed stock pipes with cat and have had no problems. Already sold the exhaust to a buddy with an LB7.

I purchase the SS kit from RPM Outlet, but I would check out the MBRP system from the vendors on here first.

good luck.

I have the MBRP and am very happy with it. The sound inside the cab isn't loud at all. The truck just sounds a little meaner. You can still talk with normal voices in the cab with no problems.

The Kennedy 4/5 rocks and sounds sweet. Makes the truck a rolling jet.....

I got a 4" dual exhaust kit from rpm outlet and Im over all happy with it. Throttle response is a lot quicker. Not real impressed by the jet sound Im learning that thats the only sound you can get from a LLY. Still a better sound over stock. I got the check engine light soon after putting it on but it went off and I havent seen it since.

will it hurt anything if i cut my cat out and put a straight pipe in, already cut muffler off. does cutting cat off affect warranty or anything?

thanks

will it hurt anything if i cut my cat out and put a straight pipe in, already cut muffler off. does cutting cat off affect warranty or anything?

thanks
I am debating on leaving the cat in place and drilling a three or four inch hole through the honeycomb inside the cat. This would give the appearance of a working cat because your dealer is going to pitch a hussy-fit if you remove it.

Melvin Hatcher,

We have had a lot of customers do that, in fcat most of them just knock all the stuffing out of it. Some even have taken our pipe and welded the cat over our 4 inch pipe.

Mark @ DPPI

JB weld it on. I know someone who did that. Maybe I can talk him into posting pics...:))

Melvin Hatcher,

We have had a lot of customers do that, in fcat most of them just knock all the stuffing out of it. Some even have taken our pipe and welded the cat over our 4 inch pipe.

Mark @ DPPIHi Mark,

Exactly what I was thinking at first, "knock it all out.!" Then I thought it would be better to take a out little at a time to find the sweet spot that I am looking for. I have the cool duals but, not the sweet sound as I heard on the online sound clip of your system. My duals are not much louder than stock. My old lady is the family's hot rodder and she wants a little more throaty authority from the pipes. :)

JB weld it on. I know someone who did that. Maybe I can talk him into posting pics...:))
Get some pics of that, we have to see it....

I bought a 4" dual exit exhaust from rpmoutlet.com. Im pretty happy with it. Throttle reponse difference is awesome. Cant see any difference with the mpg. Sound is pretty good, not too loud. Looks cool too with the 5" tips out behind the rear wheels. And the best part... it was only $400. I thought that was pretty good for duals compared to the rest. Also an easy installation. I would strongly recommend.

If i Modify the cat by piping through it, am I going to have the same benefits as a cat eliminator pipe? Is it better just to save it incase there is ever emission testing? Where are you guys getting your straight down pipes? Summit?

I just got a Summit 5" exhaust, we'll see what hapens next week when I get it and my finger stick installed.

Ordered the Summit 5" too. I'll post when I get er in.

I bought an El Cheapo brand off of Ebay.

Don't do that. You will be sorry. :D

I think it was used corral pipe that was bent just right to hit everything under the truck.

It takes "talent" to install the uninstallable.:)

JB weld it on. I know someone who did that. Maybe I can talk him into posting pics...:)) Oh man, it was -5* here this morning and now I have to go roll around under there tonight with a camera?:eek: Maybe my wife will let me use her side of the garage for a bit since my side has been overrun with my growing collection of green machines.

I'll try to get something posted by Sat. afternoon.:ro)

The Kennedy 4/5 rocks and sounds sweet. Makes the truck a rolling jet.....
Dyno proven performance:

http://www.kennedydiesel.com/photogal/pages/dyno.htm

Kennedy!
Looks very good. Is there a chance to get a plot for the normal stainless 4 inch system you sell? I don't want the extra noise generated by the 5 inch system. I am looking for a very quiet exhaust and still deciding between yours and MRBP exhaust

Kennedy!
Looks very good. Is there a chance to get a plot for the normal stainless 4 inch system you sell? I don't want the extra noise generated by the 5 inch system. I am looking for a very quiet exhaust and still deciding between yours and MRBP exhaust

The plots are likely to be pretty close for both KD exhausts. The 4 inch system or the 4/5 system both get rid of the big bottlenecks, the cat and stock muffler. The 5 inch section starts at the exit of the muffler and is mainly for a little extra sound and looks.

Thanks BMDMAX that helps!

Get some pics of that, we have to see it.... Okay, you've got to understand, Fingers is poking fun of me 'cause I believe JB Weld is one of the fundemental building blocks of the universe like duct tape and bailing wire...

Second, I bought my JK exhaust about 9 months after I got my truck when I had my first "e-check" and I noticed that my tailpipe was swinging to and fro when they hooked up the cone to it - idiots didn't notice that the tailpipe had completely separated from the muffler - no surprise I scored a "0" for opacity!

Anyway, put the JK exhaust in, didn't fuss with the cat, after all, I had 2 yrs to deal with it, right? Flash forward 2 years and oh, cr*p, I have to get e-checked tomorrow or I'm running with an expired sticker. Now I'm not a bad MIG welder, problem is I only have a stick machine and after I thought about it, I didn't want to put a grinder or the welding heat on my nice aluminized piping. I had taken a lot of care to cut out the cat to very close tolerances to the 3.5" tubing, so I just put a hole in the top of it to take a self-tapping bolt that provided clamping force down on the pipe - I dimpled the pipe with a ball peen hammer to create a "socket" for the bolt.

At this point, all I needed to do was obscure the fact that there was no mechanical connection between the cat and exhaust pipe - enter JB Weld.

As you can see from the pics, it hasn't lasted all that well in the 3.5 + years its been there, but next time I need an e-check I'll just run thru a mud puddle on my way in. So far 3 e-checks and they've only rolled the mirror under ther once. At this point I'm just trying to keep this thing together long enough for Fingers to get his truck totally built, get bored with it and sell it to me!:muahaha:

Looks better than I remember it looking! Have to admit, JB weld rules.

And as far as my truck is concerned, You may be waiting a while. I'm having too much fun playing with this puppy.

BTW, installed the 5" Summit over the weekend. Oval muffler is a little quieter than the bullet muffler and for me, just right. Nice throaty growl. Slight resonance at about 1600 RPM, but only at certin engine loads. Not an issue at highway speeds. It is fun to hear the VVT adjust at idle.

Install was fairly easy, but the clearances are tight. I had to assemble the whole thing and shake it around several times to get it to route right and miss everything. The big pipes are a little more difficult to get started together. I didn't go with the band clamps. No good reason other than the local parts store didn't have 5" and I was too lazy to look any further.

No Performance info yet.

There isn't anything wrong with using JB weld for stuff if you can't get a welder in there. On my 2000 I hit the crossover pipe on a rock crossing the river. It hit everything on the bottom of my truck. Put a dent in the transmission pan, skidplates, and knocked my exhaust loose on the drivers side. It bent the flange so I couldn't get it to seal. I had it up on the hoist and took it on and off about 4 times trying to bend the flange back and make it seal with the proper gasket. Finally I got tired of it and ended up putting jb weld in and putting it back together. Sealed it great, hadn't leaked again in the 10000 more miles I put on it before I traded it. I'd hate to try to take it loose now though..:clap:

i have the mbrp complete system and i am quite happy with it

How much louder is the MBRP Cool Duals flange - back (on a scale of 1-10, 10 being the loudest) while driving (compared to stock)?

If it comes down to 409 or aluminized:

http://dieselplace.com/forum/attachment.php?attachmentid=1605&stc=1

I just installed a Summit 4” system this weekend (I know, but it was given to me off the demo table for $150) system fit is pretty decent but it’s loud! Almost as loud as a straight pipe! This system is for the 01-03 however it does (with minor trimming) fit my 05, oh yea and my kitty ran away when it saw this system :D

Which muffler?

How much louder is the MBRP Cool Duals flange - back (on a scale of 1-10, 10 being the loudest) while driving (compared to stock)?On my 04.5LLY I would rate it 1.5. I would like it a little louder to :grd: .

Melvin

Which muffler?
The bullet style muffler, might as well be a straight pipe :D

Thought so, the oval is a much tamer muffler without being wimpy.

Hopefully I can get my 5" summit on soon too.
Your stick came the other day too, thanks.

Which is better Aluminized or Stainless? I am considering the MBRP system.

Thought so, the oval is a much tamer muffler without being wimpy.
Hmmmm... I might have to cut that bullet outta there and give the oval a shot. I'm not lookin for sleeper quiet as I do want the vehicle next to me to know I'm on it, I just don't like the entire town knowing I'm bout to blow another rice rocket away ):h

Which is better Aluminized or Stainless? I am considering the MBRP system.One is just as good as the other as far as performance is concerned although, the stainless will last a lot longer. If you are "not" going to keep the truck over four of five years, then go for the Aluminized. If you are going to keep the truck longer than that, then go for the Stainless.
Since I am going to keep my truck, until at least six days after the devil's great grandson dies. I chose That shinny Stainless MBRP cool dual system.:cool2:


Melvin:exactly:

this is what i am thinking of doing i want to gain a little more performane with out getting an codes. leaving stock system on but gutting the cat? will this be any good at all? thanks:confused:

bundysgn-I replaced the stock front pipe with the cat in it with the catless front pipe from an 03 and it has more turbo whistle, a little quicker spoolup and seems a litle snappier. More hiss at idle though.

Hiss is from the VVT clamping down.

Yeah I knew that.. It's a shame though.. Wish it had more of a rumble at idle instead. Oh well.. Thinking about removing the muffler too and see how that sounds. I realize it won't change the hiss but I just want to see how it sounds when I get on it. Not really much louder than stock right now.

How does the t304 stainless stand up to winter vs t409. I live in Canada and winter is HELL on just about everything. Road salt and sand seems to be able to corrode anything. I will use a clamp on tip so it is removable, but was wondering if the t304 will eventually turn brown like the t409 does of if it is really worth the extra expense.

dslpwr,

The 304 is a non magnetic stainless with a high content of chromium and nickel, hence the higher price! But it will pretty much stand up to anything out there the road crews can throw at you. In the spring if you want to spend the time to wash it down and rub it out a little it'll look nearly like the day it came out of the box.

The 409 stainless is a little better than the stock material and does real well, but it is a magnetic stainless and will especially in climates like yours get gray/brown and show some spots on it here and there.

Really depends on how long you want to keep the truck and how shiney you want it to be. Call us if you have any questions and we will be glad to help you.

Mark @ DPPI

bundysgn-I replaced the stock front pipe with the cat in it with the catless front pipe from an 03 and it has more turbo whistle, a little quicker spoolup and seems a litle snappier. More hiss at idle though.Other than the turbo whistle, a little quicker spoolup and more hiss at idle. How about the exhaust note, is it that much louder than with the cat installed?:grd:

Melvin

It is louder than with the cat, but not much. Not as loud as an MBRP, and I thought that was pretty quiet. I ran it with the cat and no muffler, and it's louder with the muffler and no cat. Sounds better than stock but not very loud.

It is louder than with the cat, but not much. Not as loud as an MBRP, and I thought that was pretty quiet. I ran it with the cat and no muffler, and it's louder with the muffler and no cat. Sounds better than stock but not very loud.
Thank nar,

My plan is to cut a hole through the honeycomb in the cat the same size as the down pipe leaving the remainder of the catalyzing honeycomb in the outer cavity of the converter, hoping to leave some catalyzing effect and enough back pressure to satisfy the computer.

:grd:

whats a finger stick?

Look here (http://dieselplace.com/forum/showthread.php?t=21428)for finger stick info.

Has anybody tried the Hog Performance 4"? I have been looking at that one.
I havent done any mods to my 04.5 DA LLY yet. Looking at this site

http://everythingoffroad.com/index.htm?catalog8_0.html

for the combo kit. Any body gone this route?

Great looking forum. I just found it by accident yesterday, joined and am trying to read all the threads.
Scott
________
'04.5 Chevy 2500HD 4X4 crew, LLY

ssduramax states "Great looking forum. I just found it by accident yesterday, joined and am trying to read all the threads."

ssduramax, too bad you found this site! It's going to cost you... ):h

The other addicts know what I'm talking about Best to be prepared and get yourself a new credit card, start with about $5k credit limit, kiss your wife and kids goodbye cause your either going to be at the computer or in/under your truck from now on! Welcome! JJ :)

i have the 5" heartthrob exhaust. i like it because isn't to load but it does make some noise. and it is different then all from everyone else that has the 4"

Well, unless I am mistaken, I blew the stuffing out of the oval muffler today. Pulled the heavy trailer today and as I crested a hill, all of a sudden, the exhaust note changed.:wtf: Tone is not as deep and a fair bit harsher. I am a little disappointed. I now have a definite drone in the 1600-1800 RPM range.

Hi to everyone! New to the forum.

does anybody have any opinions on the Magnaflow exhaust fot the LLY's?

Thanks

Well, unless I am mistaken, I blew the stuffing out of the oval muffler today. Pulled the heavy trailer today and as I crested a hill, all of a sudden, the exhaust note changed.:wtf: Tone is not as deep and a fair bit harsher. I am a little disappointed. I now have a definite drone in the 1600-1800 RPM range.
Take muffler off and turn it around.

The inside is a mirror image front to back.

Take muffler off and turn it around.

The inside is a mirror image front to back.
. . . And what does this accomplish, other than just to be doing something?:confused:


:cool:

Take muffler off and turn it around.

The inside is a mirror image front to back.
I think, and I am only guessing, I either compacted of blew out the packing. Whichever, I am looking for 5" straight through mufflers now. When I pull the old one I will see what happened. I guess the soot could also change the tone, but I havn't heard much about that.

Any ideas how Bassani or Borla will sound? Want to get rid of the drone between 1500...2000 RPM
Thanks!

:grd:

PS: Like the new smilies!

I think, and I am only guessing, I either compacted of blew out the packing. Whichever, I am looking for 5" straight through mufflers now. When I pull the old one I will see what happened. I guess the soot could also change the tone, but I havn't heard much about that.What size is the turbo pipe (exhaust) and the tailpipe? I don't think a five inch muffler will help you that much if it is reduced down to a three and a half or four inch tailpipe.
I think it will serve you better if it was fed from a five inch exhaust pipe from the turbo and exit into a five inch tailpipe.

:grd:

IT is a summit 5" which starts at the front as 4" then steps up to 5" at the cross member and is 5", including the muffler, from there on.

IT is a summit 5" which starts at the front as 4" then steps up to 5" at the cross member and is 5", including the muffler, from there on.:cool2: Very good! I suppose now that the current muffler is to noisy, you would not consider a straight pipe?

:rolleyes:

No straight pipe!!

Have to look around for a diesel rated muffler.

I like the banks had it on my 02 moved it to my 03 and 04 lly no codes all ok

. . . And what does this accomplish, other than just to be doing something?:confused:


:cool:As I said it is a mirror image inside w/ 1/3 of the muffler has small scoops facing the end and center 1/3 is same size as outside.

SO if he turns it around it would be same as putting NEW muffler on it.

I don't think it has any stuffing in it, I'll try and look tonite since mine is still setting on the shelf.

We recommend the MBRP systems as we believe them to be the best. They are available in Alumized, T409 SS, and T304 SS. The systems are "cat back" bolting right up to the 4 bolt flange. With this sytem you will NOT set any codes as the Cat is not touched.
So for an '05, this must be a "cat back" system? Does the cat back have mileage and performance gains like the non-cat back system?

So for an '05, this must be a "cat back" system? Does the cat back have mileage and performance gains like the non-cat back system?A. where do u live, emission testing?
B. the older lb7 trucks have the same exhaust so u can loose the kitty.
C. many here report much improvement loosing the kitty over straight pipe for muffler.

I think, and I am only guessing, I either compacted of blew out the packing. Whichever, I am looking for 5" straight through mufflers now. When I pull the old one I will see what happened. I guess the soot could also change the tone, but I havn't heard much about that.
I looked at mine last night and it's ALL steel, so something else changed.

BTW check your airfilter, maybe it got sucked through the turbo and lodged in the muffler :banghead: ):h

Is yours Oval?

I got a HOG performance exhaust on ebay for $500. Made w/ T304, not loud inside the cab and has a nice exhaust turbo whistle from the back..I love it, hasn't even tarnished at all and its been a year so far. Fitment was great and it came w/ a 6"x22" polished tip...It eliminated the cat and so far no problems at all..I had to change my intake since my stock filter plunger always reads that the air filter is dirty..Put a TruFlow fitler and no problems w/ that. now...

Can anybody tell me how much difference there is in egt between stock,cat back,and full?Don't really care to make it louder but would like to try and keep the egt down.Thanks!

Is yours Oval?
Yes

If there isn't any stuffing, then switching to a straight through packed muffler will really make this system sound nice. Low grumble most of the time with a nice blast at WOT. :) I never looked inside other than to note that the muffler was unidirectional.

No straight pipe!!

Have to look around for a diesel rated muffler.
Back in my early CTD Bombing days, it seemed that alot of guys were using a muffler from Walker that was available from NAPA. Straight through design, diesel rated, decent sound and price. Now that was 7+ years ago, and I don't know if they have 5" but I'd bet they do...

I Have a 05 duramax with afe intake and mbrp duals and I changed the cat pipe I got codes anybody Have any ideas I really don't want to give in and put the cat back on. It is me emmisions.
thanks craig

Did you have any luck cutting up the catThank nar,

My plan is to cut a hole through the honeycomb in the cat the same size as the down pipe leaving the remainder of the catalyzing honeycomb in the outer cavity of the converter, hoping to leave some catalyzing effect and enough back pressure to satisfy the computer.

:grd:

I Have a 05 duramax with afe intake and mbrp duals and I changed the cat pipe I got codes anybody Have any ideas I really don't want to give in and put the cat back on. It is me emmisions.
thanks craig
Look here (http://dieselplace.com/forum/showthread.php?p=483172#post483172) for more info.

Did you have any luck cutting up the catbaumbanshee, the weather has been quite cool here in Maryland although, we had a few warm days last week, the cat was put on the back burner.
Actually, I have been busy working on the better half's car.
I will start hacking on the cat this weekend because, it's laying on the floor in the basement and the ayatollah is going to tan my hide if it don't move soon. I will update you on the ease of cutting the honeycomb.
OBTW, the performance increase and the sound from those duals must sound good, for you not wanting to go back to the cat.
:cool2:

I Have a 05 duramax with afe intake and mbrp duals and I changed the cat pipe I got codes anybody Have any ideas I really don't want to give in and put the cat back on. It is me emmisions.
thanks craig
get a fingerstick. Fingers will hook you up and say bye-bye to those codes and you don't need to put the cat back. :)