Exhaust cut out.

[Bouncer88]

Would it be beneficial at all for when I bring the car to the track? Would it increase spool up speed? More power?

[boostedbruiser]

Would it be beneficial at all for when I bring the car to the track? Would it increase spool up speed? More power?

a cutt out would hepl IF your current exhaust is restrictive. after doing a little test with my setup i found my exhaust isn't very restrictive and i run full exhaust. its loud, but not obnoxious.

[vrinner]

I had a straight through 3" over the rear axel. The sound wasn't too bad...for a track car, but way to loud for a street car.

Spool up quicker? I honestly dont remember it's been so long ago, but I do know that you shouldn't have too much of a problem with sound as long as you at least dump it out the side of the car.

[turbosvo]

i have a 3" cut out on my car and it spools quick! boostedbruiser has heard it before, i drive it without the cap on everyday. Unless i have my daughter in the car then ill cap it. I love the sound of the turbo just sitting there;-)

[svono50]

Back when I was drag racing my car I did a set of runs through the full exhaust and another straight out the 3" DP. Results were my ET & MPH were the same across the board, no difference. This proved to me that my cat-back exhaust wasn't holding anything back...except noise.

[giamanut]

Ted just out of curiosity did you launch at the same rpm.
what did you run before the turbo an E6 or header?
did you run a 3" DP ? All these will effect the result of a cutout.
A turbine is a turbine is a turbine meaning it is all about the pressure drop across the T wheel.
IF you have a 3" dp and 2.5 cat and flow through muffs then a cut out will probably be worthless but stock to 3" cutout oh yeah there will be seat of the pants difference.
DISCLAIMER: Although I do talk to rocket scientist once in awhile I am not one of them! So all statements are just opinions.

[caroth]

Back when I was drag racing my car I did a set of runs through the full exhaust and another straight out the 3" DP. Results were my ET & MPH were the same across the board, no difference. This proved to me that my cat-back exhaust wasn't holding anything back...except noise.

I would agree with this. I went to the track with only a downpipe and then went with an ATR cat back system and the averaged et and trap speeds were identical. When I added a high flow 3" cat, I lost 4mph in the quarter.

[giamanut]

yeah it all kind of starts at the intake/boost
low boost and lots of air would most likely be best because
less pressure means less heat and on the intake side thats good but now comes the exhaust some say small exhaust valves and runner for higher pressure and quicker spool.
although I believe that concept It still comes down to the
p drop across the T wheel the only real limit is massof the wheel. Say you have large valves and large runners
say a t3 t4 hybrid ar63 with a 57 trim the answer to the p drop would in my mind be a 4" DP t just before the cat 3"
to the muff and 2.5 out the back. This would allow a huge drop and vast amounts of air through the head without reverse flow IE exhaust remaining in the cylinders or flow back into the cylinder. You can cram air into anything but getting it out through a turbine is where all the power is.
SORT of.

[Rob.]

answer

So the answer is YES.......and no. Its all rather subjective and a matter of personal preference. Kind of like "What's the best color, black or white?" If you want to be loud and you feel it makes you faster then you are. If you don't feel like that then why bother?

[giamanut]

no the answer is you don't need the cut out the exhaust is large enough for a long enough distance. 3"DP cut out =3" dp, cat, flow through muff, or muffs, 2.5 single out the back, or dual 2.25 s .The gas cools as it goes down the pipe reducing pressure 750 to a 1000 hp it might make a difference but probably not for the typical or hot svo

[Rob.]

Kind of my point. The payoff is so miniscule for the amount of time and money invested, that unless you really like the added attention of being really loud, why would you not focus your energy elswhere?

[giamanut]

what Rob said plus1
Hey check out my header

http://www.svoca.com/forum/showthread.php?p=170439#post170439

[svono50]

Ted just out of curiosity did you launch at the same rpm.
what did you run before the turbo an E6 or header?
did you run a 3" DP ? All these will effect the result of a cutout.
A turbine is a turbine is a turbine meaning it is all about the pressure drop across the T wheel.
IF you have a 3" dp and 2.5 cat and flow through muffs then a cut out will probably be worthless but stock to 3" cutout oh yeah there will be seat of the pants difference.
DISCLAIMER: Although I do talk to rocket scientist once in awhile I am not one of them! So all statements are just opinions.

Sorry, been on a forum hiatus I guess. Actually working on my vacation plans and new exhaust system...pics later.

I run an E6 and had a 3" DP on at the time. The turbo outlet elbow was opened up to 2.25" or so with a 4" stub of 2.5" pipe then the main portion of the DP was 3" with a 3-2.5" reducer/ball end on it. The mufflers that were on my car were some generic turbo mufflers that had lost all their packing material once the baffles had rusted and fallen loose.