Dodge SRT Forum banner
1 - 18 of 18 Posts

·
Registered
Joined
·
38 Posts
Discussion Starter · #1 ·
ok what im looking at is the borla exhaust which is 2.5 in but theres a lot of systems that are 3 in. Borla is known for making a good product and what im trying to get to is that if 3 in. pipes are better wouldnt borla go with that? what do you think i should go for borla?
 

·
Registered
Joined
·
6,282 Posts
If your going past 300 whp, you must go 3 inch to take full advantage of a exhaust modification.
 

·
Registered
Joined
·
626 Posts
2.5" exhaust is good enough for up to like 300whp...so as long as you stick to the stock turbo w/ no nitrous, the borla is all you'll need. i guess it's done to keep the price down and they assume that if you stick to just mopar upgrades, you won't need anything more than a 2.5".
 

·
Registered
Joined
·
119 Posts
2.5 or 3

borla was designed in conjunction with mopar to be a bolt-on, yes there is a performance gain, but it wasn't designed with 500hp monsters in mind.
the choice to go 3in. over 2.5 really depends on what kinda total hp you're trying to acheive. if you're looking for 350 or under and like the mopar style then go with that. if you're looking to "build a beast" you might wanna go 3in.
also remember the downpipe and o2 housing can be upgraded to suit your hp levels...
hope this helps i'm just babbling while dinner is cooking.
 

·
Administrator
Joined
·
39,599 Posts
do you plan on over 300hp? if not, then the borla is fine. If yes, then is it worth the ~$700-800 for a few hp? I would go and get the maxxfab borla combo that has shown the exact same hp as a full 3" system. I was able to get the borla for under $300 and I don't plan on doing any major power upgrades for at least a few years.
 

·
Registered
Joined
·
5,370 Posts
Tought to say, but I'd guess 5-10 hp.

As far as exhaust diameter, a basic rule of thumb is 2 inch for the first 100 hp, then add .5 inch diameter for every 100 hp after that. So it goes like this:

100 hp 2 inch
200 hp 2.5 inch
300 hp 3 inch
400 hp 3.5 inch

This is a very basic rule...obviously there's a lot more to exhaust system design than diameter, but just thought I'd throw that out there.

You can see most S1, S2 cars are putting out less than 300 hp, so they are fine with 2.5 inch (Borla exhaust).

At 350 hp, I'd definitly go 3 inch.

ALso keep in mind, if your making 310-320 hp with a 2.5 inch exhaust, the gains by going over to a 3 inch exhaust may not be that much. Gains are small at first, then go up the more hp you make.
 

·
Registered
Joined
·
3,169 Posts
^
|
|
|
yep, what they all said ;) on a side note, i had just installed the mopar catback... my car used to just chirp 2nd gear (even w/ the iceman intake mods) now it absolutely shreds both tires all through 2nd gear with mad torque steer and chirps 3rd :eek: after just installing the mopar :thumbsup:
 

·
Registered
Joined
·
1,038 Posts
noTe said:
1,000 HP = 10 Inch Exhaust

So if you got 10" exhaust the you will have 1,000hp :rofl:
 

·
Administrator
Joined
·
39,599 Posts
well it isn't as simple as that, because the area of a circle is pi*r^2. A 2.25" exhuast has an area of 15.9, while a 2.5" exhaust is 19.6 and a 3" has 28.25. One would think that you could do it as proportions. If a 2.5" exhaust has enough flow for 300hp then a 3" will be good until 432hp.


this is all theoretical and it is impossible to fully test all this without an engine capable of putting out these kind of power levels (or more) along with the test equipment.




or I might be talking out my ass because I took too many math classes.
 

·
Registered
Joined
·
5,370 Posts
stowaway said:
well it isn't as simple as that, because the area of a circle is pi*r^2. A 2.25" exhuast has an area of 15.9, while a 2.5" exhaust is 19.6 and a 3" has 28.25. One would think that you could do it as proportions. If a 2.5" exhaust has enough flow for 300hp then a 3" will be good until 432hp.


this is all theoretical and it is impossible to fully test all this without an engine capable of putting out these kind of power levels (or more) along with the test equipment.




or I might be talking out my ass because I took too many math classes.
That's why I said this is a very basic rule guys......it's just a guide and in no way is an absolute. Please don't take it for more than is intended.

Bottom line is how the exhaust performs. Theories are great, but ultimatly parts should be designed to perform in their intended environment.....even if it goes against the popular theiories.
 
1 - 18 of 18 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top