so whats the truth about vortec's????

[flyinbryan06]

this kid i know swears up and down that hi flow exaust is bad for vortec engines, he says they need all the backpressure they have to ahve optimal hp. to me this deosnt seem right,


on another note,
ive got a gibson cat back with a punched cat and im getting popping from not enough back pressure, would stock exhaust get me better hp then what i have with headers too??? i was thinking headers but if the above is true then thats a huge wast of money for me.. :confused:


idk anyone know FOR SURE??

[s10mafia50]

I am not sure if it is bad for them, but i was also told that headers were a waste. I also get a pop everytime i run a gear to redline before i shift, but i also have a flowmaster and a pipe instead of a cat. If you have a 96 newer you must get a o2 sensor simulator to keep your ses light from coming on. hope this helps,
Andrew

[flyinbryan06]

sorry i worded that wrong, i didnt mean literally harmful, buit bad in terms of horsepower :-D

[s10mafia50]

I was told headers were a waste of time so i am still running stock manifolds with a few mods and dont have any problems. The biggest exhaust problem i had was my 2>1 pipe under the trans got flattened when i bottomed out real good.
Andrew

[flyinbryan06]

hahaha ouch that can ruin ur day

[s10mafia50]

Tell me about it, had to tow it to the muffler shop. $350 worth of custom work gave me a 2>1 tucked by the crossmember and no cat(I swear cali, it wouldnt fit!!!!LOL)
Andrew

[adam]

I'm considering purchasing some headers possibly in the near future, what is the best brand for the price?

[bill 4.3L 5spd]

ok few things here

#1 headers DO make a noticable difference

#2 put your cat back on. the gains from removing a cat today arent nearly as much as removing one from 15 years ago. they dont kill performance like the old styles.

#3 free flowing exhaust good as long as you keep some backpressure.

[daryl]

Headers, stock Y pipe, with bigger piping from the cat back and a high flow cat and muffler do make a difference just make sure you keep back pressure and don't get too big. I noticed it revs a more quickly since I got a high flow cat and muffler and I still have stock manifolds and Y-pipe.

[s10mafia50]

:) ok few things here

#1 headers DO make a noticable difference

#2 put your cat back on. the gains from removing a cat today arent nearly as much as removing one from 15 years ago. they dont kill performance like the old styles.

#3 free flowing exhaust good as long as you keep some backpressure.


Ok, #1, i may have to get some headers when i can afford them, btw what year do you have bill? And what brand should i get?
#2 My cat had 130k on it and the way my exhaust runs now the cat would hafta be about 3" long. LOL
#3 i just like the sound of the unrestricted v6 with a flowmaster. Just make sure to get the caspers o2 elim. Other than that i may have to get some headers now and trust you on that one!
Andrew

[Old Man]

Anyone that says headers are a waste on anything, had to have been looking in the mirror when they said the word WASTE!

The factory manifolds are the ##########111111111111 restriction within the exhaust system, PERIOD. Cat backs, high flow cats and the likes fit the mold of a waste 10 times more than a set of headers.
Ever try to leave a parking lot after a ball game, movie etc and so on. You have multiple isles exiting onto a single lane hunk of pavement leading to the exit. What happens??? Traffic backs up and if you get treated nice enough someone will let you out of the isle section lane onto the other single lane heading for the exit. Slow as f**k aint it, and if someone dont let you out its a long wait , isnt it? Same idlea applies to a factory exhaust mani. You have 3 ports (isle) sharing a one lane to and exit point. Now headers make 3 single lanes directly to the exit and are ramped in for the highest speed allowable for the merge. Just think of it along those lines, your better off and the ideal is simple!

[flyinbryan06]

noone said headers were a waste of time..i was talking about high flow exhaust in general, in terms of not geting enough backpressure and loosing hp as apposed to gaining it.

[Old Man]

Its mentioned all the time and in this series of posts also that headers gain nothing, need to be on SC motor for the best and only gains etc.
Yes Vortecs do like having backpressure, but not to little, nor to high due to the factory camming etc. Like 1/2-1 lbs of pressure!!

[flyinbryan06]

i appreciate the help with everything guys..


by the way is there a way to test for backpressure, like measure the acual amount?

[Old Man]

If you really wanted to you would need to add a small nipple bung before the cat and after the muffler and use a vacuum gauge to read it. Any stock system will or should be under 1.5 if its US made. When your too free or running too large a tailpipe you'll get that annoying pop under de acceleration! Thats a sign of 1/2 or so and possibly under!

[s10mafia50]

crap, whoops....A pop eh? LOL..... O well, thanks guys for the help!!!!!
Andrew