Does it mater? What will be different egt’s, hp, tq, sound?
Will I lose power with a 5in pipe? If I don’t have lots of power/ cfm?
Please help 4in. or 5in. turbo back?
Thanks

 

I've always been told that if you plan to exceed 450hp-500hp 5in would be adequate, but otherwise a good 4in mandrel bent exhaust will be plenty. I've seen ppl run 5in and lost a little low end and slightly slower spoolup w/o big mods. The main thing I guess would be the sound difference. Hope this helps, because i know about "bigger being better"(supposedly).

 

I have a 5" turbo back system on my truck. it is a straight pipe system and it is loud. it is loud inside. you wont see huge differences in egts (X 100 degrees) but whats the point of buying a whole 4" system when you can get 5" for a little more. with bigger pipe I think you loose some bottom end power. Im a fan of 5" for the deeper tone and looks of the big pipe on the truck. I would put it on a stock truck, but thats me. some guys say you dont need it. its your choice. it takes away some of the raspy tone and gives it something deep and noisy.

 

I agree 100%. The stock 4" system when straight piped is raspy. The 5" system is much deeper and sounds much better. I didnt notice a loss of low end either.

 

On a turbo motor you can run as big an exhaust as you want. The turbo spool-up speed is a funcion of Delta P (inlet vs. outlet pressure), so the less restriction the better on the turbo outlet. The turbo itself keeps the big pipe from over scavenging the exhaust.

I have had several turbo race cars (drag and road race), and a dump pipe is the best for power, including bottom end power.

On the other hand, a 4" single should flow more than enough for a stock to mederate CTD. The 4" will start to become a restriction after about 400hp.

The sound frequency is determined by pipe diameter (think trumpet vs. tuba), a larger pipe produces a longer wave at a lower frequency.

 

if you run a muffler i bet you didnt loose power. when I put a 5" kit with a muffler on my 05 it seemed to run fine. my truck now is a dog in the bottom end.
maybe cause its an auto with a big turbo and a triple lock conv. I am thinking about getting all new exhaust. Im thinking of getting the new 5" from silverline. the drone is getting old again. I want something stainless and 5" thruout. I wish mbrp made stainless 5" I would get it. well you saw the truck. I think I met you in bowling green to buy those tires/wheels from you. I have a red truck like yours now

 

Yeah i run the mbrp "muffler" in mine. It doesnt do much for muffling. The thing is still pretty loud.

Yeah that was me you met in bowling green.

 

is the droneing real bad. i am going to do the smarty, cr49 and mp8 soon hopefuly, so i think i will be in the 400-500 range

 

Well if you already have a 4in (not sure when it started) but i know the 06's have 4in SS from the factory. that being said, why would you purchase another 4in exhaust if you already have one. So get the 5in....

I like others above, have heard if you go too big with not enough mods you will lose bottom end power, it sounds awesome and loud but useless otherwise.

good luck

 

I agree with JWB and BOZ, but if you are doin a smarty, tst, and mp8 please, please, please have an aftermarket turbo ready to install when or before you add all the fuel. Not to mention the trans needs some attention too.

 

I have 5 inch from the turbo back and the drone is not too bad unless you are going up a pretty steep grade and lay into the throttle. Or if you are pulling a heavy load and lay into the throttle also. I am happy with mine. I had a muffler in mine when I got it but ended up taking it back out because I didn't like the way it sounded.

 

Thanks for all the info guys. ill prob go with the 5in.
wap. you said make sure i have bigger turbo..which one of those 3 programmers do you reccommend that i get first and second, without turbo and trans upgrade.
Thanks

 

any of them to start out is good. a tst is adjustable so you can turn it down on the fly and run it on lower levels until you get your trans built. the smarty you can run on lower levels also and it is gonna make a difference. I can spool a nice size turbo with just the smarty on the street. I agree with wap also. if you are gonna stack modules have a bigger charger, it is much easier on everything and less heat on the engine components

 

thanks for all the help guys

 

Yep like the fellas above stated.. 4" straight is way too raspy and louder than the 5" to me.. My 5" straight was hugely tooo loud for me but that's towing every day so I needed to quiet it down some.. and a charger is a must!!!