cwis9992

hey everyone,
This is just a random idea that popped into my head and stuck since im on a budget. Anyway my idea was to take out the cats and where they are install glass-packs and attach the pipes on both sides and just cut out the rear mufflers and make it all straight pipes to the quad tips with the exception of the 'packs. my question is are there any after cat o2 sensors or anything that will give me any troubles, or any other ideas or tips??
-thanks

wshsbears

yes, there are pre cat and post cat o2 sensors and you will throw a code concerning the condition of the cat if there isn't one there. you can get drain pan bolts from a SBC to plug the holes in the exhaust where the rear o2's go and remove them and tune out the code and be good to go, but you're on a budget. Tuning it out normally costs $100 just for the credits on HP tuners. I would find a corvette body shop near you and see if they have any axle-back systems that are bent a litle or messed up due to scrapes or something and see if they'll give you an awesome deal on that. a tuned exhaust always sounds better than straight pipes on C5's

cv67

Pop that random idea back outof your head.

jrose7004

Yeah I'll bet those would be nice!

dougbfresh

Sounds like Dukes of Hazzard engineering

lucky131969

Sounds like a great idea

Papas02C5

Golly Gee Wizz Bubba. I had no idea these things could sound like your old pick-up. I wonder if we could git it ta run on moonshine.....
Really though it is a very bad idea to do this to your car. as stated above it would throw all kinds of codes and cause your car to run like crap.....

WhiteFRC99

Good idea. I used to make o2 sensor simulators. I stopped about a year ago, but it is a simple install and they should have some on ebay.
I had a pair on my car for years. You will need 2 of them:

http://cgi.ebay.com/ebaymotors/o2-ox...item43a957cfb9

Be sure to clear your codes
Good Luck

cwis9992

I do miss the sound of my old '85 chevy truck, but thats not my reasoning behind this idea. the reasoning is i figure it would free up a lil air flow as well as give it a very unique sound plus it wouldnt cost me anything at all hardly.

And yea i'd love it if she'd run good on a lil 'shine

AngryTurtle

why is it going to run like crap?

cwis9992

yea really, why would it run crappy if you deleted the BACKUP/SECONDARY o2 sensor that is there strictly to make sure the 'cats are working and they aren't even gonna be on the car.
small block chevy's ran for 50+ years without ANY o2 sensors (granted with carbs and not efi) and for what 15 years with only 1 o2 sensor and that was on one cylinder's tube. its only been in the last 10 or so years that they have found the need to have 2 o2 sensors, and nobody is going to dispute that they ran perfectly fine for all that time.

so other than making some hybrid drivers/ eco-bug types rather mad i dont see how any of this would have detrimental affects. if you can give me a reasonable reason not to i would greatly appreciate it, but don't just say its gonna be trash and then not tell anyone your reasoning.

Papas02C5

Well if I'm not mistaken, unless you spend quite a few dollars reprograming the ECM to operate properly without the 02 sensors it will run like crap. Therefore making the reason for doing this mod pointless... The original post said he is on a budget....Any exhaust mod this extreme on a Vette is going to cost good money to make it worthwhile.....
Just my .02 cents

cwis9992

i am on a budget yes. 90% of my goal is (at least for the short term) is to just make the thing sound better. i love my 'vette but i live in a truck world. i love to hear a big v-8 through flowmasters, and while i dont want that exactly i still want to be able to be heard. corvette's are the top dogs in this country, and i'll just start driving a foreign car again before i see a stock FORD out-do my chevrolet powered corvette in any way shape or form.

i do agree later it will take some doing, but again if i got one of those trick o2 sensors like they have for off-roading wouldnt that solve my problem? the ecm can still regulate the air/fuel ratio and such with the primary sensors because unless i'm very seriously mistaken, the second o2 sensors are mostly to make sure the cat's are doing their job (at least in my mind that makes sense, think about it if there where no cats nothing in the air that the sensor reads would change in a whole what? 18", 2'. just saying it doesn't make sense to have them there for any other reason. they omitted a spare tire, why would they install a redundant sensor that close together?) again if i'm wrong point me in the right direction but i would really appreciate more reasoning than that's just how it is.

Papas02C5

Like I said earlier this is just my .02 cents. I am not a mechanical engineer but have been an aircraft mechanic for over 27 years. I do not know about any trick off-road 02 sensor or how it operates but I do know if you start fooling around with the sensors it could cause a serious lean condition in your engine causing alot of damage if left uncorrected. The AF ratio in these cars is nothing to fool with just for exhaust note purposes. I still have stock exhaust on mine and am saving my pennies to buy the system I want for exhaust note and peformance reasons and will get a tune when installed to maximize the mods done.
Good Luck in your endeavor

cwis9992

thank's for the thoughts

the off road o2 thing i was talking about was from the post by whitefrc99 earlier, they're 10 bucks a pop and i need 2 so i figure i might try them out before any changes to the exhaust and see if they actually work or what if they dont then i'll just have to figure something else out
here's that link ->
http://cgi.ebay.com/ebaymotors/o2-ox...item43a957cfb9

dougbfresh

The front O2 are for fuel adjustment, the rears are for monitoring catalyst efficency. If I recall right, the firing order of the LSX is different from the SBC of old. Many have reported the LSx engine sounds pretty awful with little or no mufflers. And how many high end cars do you see "REDNECKED" like this? Seems pretty silly to me.

cwis9992

so.... what your saying is if i dont have any muffler at all then its gonna sound bad according to many?

http://marylandspeed.com/slp-loudmou...049-p-265.html

just saying man these things sound pretty good to me but i'm 18 so yea.. and yes it is silly but it's a car you dont like the results... ...you get you wrench out and fix it.

if you dint mind me asking what kind of exhaust do you have?

Bill Curlee

Put some spacer/s between the midpipe/over the axel pipe joint and use some longer bolts.

It will leave a gap between the pipes and allow you to see what a MUFFLER LESS C5 sounds like without spending a LOT of cash. I used some longer bolts and some large nuts as spacers. It is LOUD but the sound to me was a bit crude and gutteral.

The interior cabin DRONE will just about make your ears bleed when you are cruising at normal speeds! I had mine spaced out like that for about 6 months and got tired of the drone and put it back stock.

If you have an early C5 97-98-99,,, be careful as the fuel tank doesnt have metal shielding on it and the exhaust exits right there when the pipes are spaced out.

If you put glass packs in place of the CATs for a convienent location,, being that close to the manifolds will most likely destroy the glass mat packing inside the muffler in short order. A better idea would be to use a resonator and then your straight pipes if thats the way you want to go.

Bill

cwis9992

it's a 2003

so the only difference basically is that glasspacks have fiberglass in the middle and after so many miles they basically are resonators with fins or air restriction of some sort? or am i completely off on this one?

this would be a good result for me

http://youtu.be/RqCyB3jipRg

larryu

O.K. here we go. First I would have to agree that the putting glass packs on a vette would not be for me, but the straight pipe IS done all the time with Borla. I had the Borla straight pipes on my vette before I did long tubes and modded TI's. I personally loved the way it sounded from OUTSIDE the car but there was a lot of drone inside I did not like. If you can find a set of used Borla straight pipes they bolt right up to your stock H-pipe and they can be found at a reasonable price. If you delete the cats you will throw codes. If you do JUST the straight pipes you will NOT need to re-tune.(cheaper) The straight pipes are loud as hell and the only thing I did not like about them is the drone.