Which is better for power..

-3" open dp
-3" dp straight piped catback
-3" dp 3" inlet/outlet high flow cat and catback

Ive seen dyno sheets that claim to produce more power with a random tech. high flow cat vs. straight piped.

Or is a open downpipe ultimatly the best, providing the most unrestricted exhuast?

 

In theory open dp would be the best, but depending on how much power you are making you may not be able to tell the difference.

On a lower hp set up 250-300ish there may not be a large difference between the 3" straight back or with a 3" cat. I made 272whp with 3" a hiflow cat and straight back exhaust. Then I replaced the cat with a testpipe and I have not noticed any changes in power. I think that if i was making 400-500whp and removed it I would definatly see some change, but it all depends on the set up.

Hope this helps somewhat, maybe someone else will have a little more concrete info. Good luck!

 

Yeah, in theory a open dp would be best, producing the least amount of backpressure. But engines dont always listen to mathmatical equations.

My goal is 400whp. I currently have a 2.25" dp, god knows why the expletive turbonetics puts those in a kit designed to make 300+whp but that sure as hell did.

I guess i'll wait to hear some other peoples thoughts and experiences with this.

 

ttt

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ella94 &raquo;</TD></TR><TR><TD CLASS="quote">
Or is a open downpipe ultimatly the best, providing the most unrestricted exhuast?

</TD></TR></TABLE>

yeps, theorically...but it's noisy as hell. i would just run an ecutout to save the life of my ears. lol

 

Well what will this car be used for? Daily driving? Track car? Weekend fun?

If its a DD the amount of tickets will add up really quick to the cost of a full exhaust system.

If its a track car, don't worry about exhaust unless you are trying to get into a street muffled bracket.

Weekend fun car, you could run open dp but it is still risky on the street.

Good luck !

 

Yeah forgot to add, its a weekend beater. Never sees rain/cold weather.

So, 3"dp with 3" straightpiped catback?

 

4 inch Downpipe

 

A good free flowing 3" catback wouldnt create enough backpressure to really bog down the motor vs. a open dp, would it? Been reqading some on this, and a good mandrel bent exhaust only produces a good 3-6 psi of backpressure, right?

Im thinking straight piped now.. dont feel like getting tickets for a open dp