evoIII and 3" exhaust...

[mstrpimp02]

i know i'll prpbably get alot of ish for this but i think i've finally searched myself retarded trying to find this since machv went down last week, so anyways... with an evoIII 16g do i need a full 3" exhaust and dp or would 2.5 be ok?

 

[DSMSpyder99]

To me a 16G is a 16G it doesnt matter if its small, big, or EVO they all flow similar (within 100cfm of each other). It has been proven that a 2.5" turbo-back is more than enough for a 16G. I have called vendors a while back ago and they say a solid performer is a 2.5" DP and a 3" cat-back. It offers better low-mid torque and good peak HP

 

[mstrpimp02]

so then i should be fine with, let's say an A'pexi WS2 which is 2.5 and necks into 3"?

 

[blcknspo0ln]

in all honesty most DSMers will never tune to see the full benefits of getting a 3" over a 2.5". either size will do, whether it necks down or not.

oh, and PLEASE port the crap out of your o2 when you get your dp/cb, because if you dont, she's gonna boost creep like no tomorrow

 

[ItsStockOfficer]

3 inch makes more power on any 16g setup on any tune.

 

[clownface]

The bigger the better, you might have to do some stuff to get rid of boost creep though.

 

[DSMSpyder99]

Why start out at 2 1/2" on a small turbo like a 16G? If you are running on the stock O2 sensor housing, even ported it is 2 1/2" inside diameter. When the exhaust gasses are hot, they flow better, 2 1/2" is plenty for the first 12"-24". As the gasses cool , bigger helps. By going to 3" after the flex section, we allow this expansion and also allow for better clearance at the front where room is tight.

Dont you just love it when people argue simple logical explanation Oh yea wait bigger is always better :laugh:

 

[pianoman]

as far as boost creep, if you port out some of the center section of your o2 sensor housing, it should get rid of it, i did it on mine and its not creeping anymore.

 

[mstrpimp02]

so now i'm getting confused.. should i not go with 2½" then?

 

[rarson]

To me a 16G is a 16G it doesnt matter if its small, big, or EVO they all flow similar (within 100cfm of each other). It has been proven that a 2.5" turbo-back is more than enough for a 16G. I have called vendors a while back ago and they say a solid performer is a 2.5" DP and a 3" cat-back. It offers better low-mid torque and good peak HP

To me, the numbers speak for themselves. I am just about maxing my small 16g out at ~35 lbs/min. An EVO III, on the other hand, flows over 40 lbs/min. Not to mention the fact that I will never be able to turn the small 16g up to 26 psi and make MORE power. Yeah, you're right, they're all the same.

I noticed no loss in low-end torque stepping up to a 3" downpipe.

 

[1993eclipseGS]

I have a 2 1/2" downpipe and test pipe, I have a 16g. The catback is stock. I ordered an RnR 2 1/2" catback but it didnt get here yet, I dont feel stupid for not going 3". Isnt 2 1/2" good up to 400hp or something like that?

 

[DSMSpyder99]

To me, the numbers speak for themselves. I am just about maxing my small 16g out at ~35 lbs/min. An EVO III, on the other hand, flows over 40 lbs/min. Not to mention the fact that I will never be able to turn the small 16g up to 26 psi and make MORE power. Yeah, you're right, they're all the same.

I noticed no loss in low-end torque stepping up to a 3" downpipe.

Your whole statement is off-topic this thread is does he need a 3" DP for a 16G turbo, so stay on topic. Which is no you dont need a 3" DP for a 16G; the only reason i can think of getting a 3" DP is just to say "hey im cool i have a full 3" turbo-back exhaust." You can call any competent DSM shop and they will say a 3" DP for a 16G is overkill. I dare one of you to call RRE and argue with them that 3" DP are better than 2.5" DP for a common turbo like a 16G. Why do you think there DP are 2.5" until the flex section and 3" after that. I rather trust a company that has been around DSM since the beginning with logical explaination why 2.5" DP is better than a 3" DP that some peers pounding their chest like an angry ape saying bigger is better

 

[bigjangin]

a 3" exhaust setup will make more power than an identical 2.5" setup, even on a 16g. Do you absolutely have to have a 3" over a 2.5"? Of course not. In my opinion should you just pay up the couple extra bucks to get a 3", yes.

The air has more velocity the hotter it is, thats why closer to the turbo smaller diamter piping is ok. 2.5" should be ok to the flex section.

 

[rarson]

Your whole statement is off-topic this thread is does he need a 3" DP for a 16G turbo, so stay on topic. Which is no you dont need a 3" DP for a 16G; the only reason i can think of getting a 3" DP is just to say "hey im cool i have a full 3" turbo-back exhaust." You can call any competent DSM shop and they will say a 3" DP for a 16G is overkill. I dare one of you to call RRE and argue with them that 3" DP are better than 2.5" DP for a common turbo like a 16G. Why do you think there DP are 2.5" until the flex section and 3" after that. I rather trust a company that has been around DSM since the beginning with logical explaination why 2.5" DP is better than a 3" DP that some peers pounding their chest like an angry ape saying bigger is better

My statement was not off-topic. I was merely correcting misinformation and then adding a data point from actual experience on the subject, instead of presenting some bench racer theories. Thanks for the $0.02, I don't think he'll be able to buy anything with that though.

 

[mstrpimp02]

hahaha i love how quickly arguments get started on here... anways, i couldn't pass this deal up. it's an A'pexi WSII for $415 shipped so i had to get it.

 

[ItsStockOfficer]

You could also say, hey, I have a 3 inch exhaust, my cars faster then yours. 3 inch exhaust is faster on 16g powered cars....it's also faster on 14B powered cars. DSMspyder, YOU call RRE, when Robert, who you will talk to when you call 80% of the time, answers....ask him about the difference between a 2.5 and 3 inch o2 housing on his Galant with a 16G. It made a substantial difference.

Adequate is not the same as best. If you have a 2.5 inch exhaust and you remove it all from the o2 housing, your ET's will drop substantially, if you put on 3 inch, they will be somehwere in the middle. There is no torque difference.

The fact of the matter is that standard exhuast theory simply doesn not apply to a turbo car. To reduce this to extreme web forum simplicity.....Turbo cars make power and spool based on the pressure differential on eitheir side of the turbine. Bigger allows a more favorable pressure ratio.

 

[mstrpimp02]

hahahaha i love you guys... you're all so entertaining

 

[NDgsx]

Why do you think there DP are 2.5" until the flex section and 3" after that.

....because the bolt spacing a 1g or 2g o2 housing is not wide enough to allow access to the studs if you weld a 3" flange to it. Running a 2.5" pipe to the flex is easier to make, cheaper, and easier to service than flaring out to 3" right after ther flange.
On EVO 3 o2 housings we run a 3" pipe to the flange. On 1G/2G we run a 2.5" pipe to the flex just like RRE.
ItsStockOfficer is right you're worried about the pressure differential across the turbine wheel here. While a 3" exhaust may loose off boost torque by some finite amount it really doesn't matter, just put your foot down farther .
I've gone from a 2.5" to 3" tubular o2 housing on my car with the 20G and noticed significantly quicker spoolup. We also did on Andre's galant going from a ported evo III to a full 3" o2.

 

[ItsStockOfficer]

....because the bolt spacing a 1g or 2g o2 housing is not wide enough to allow access to the studs if you weld a 3" flange to it. Running a 2.5" pipe to the flex is easier to make, cheaper, and easier to service than flaring out to 3" right after ther flange.
On EVO 3 o2 housings we run a 3" pipe to the flange. On 1G/2G we run a 2.5" pipe to the flex just like RRE.
ItsStockOfficer is right you're worried about the pressure differential across the turbine wheel here. While a 3" exhaust may loose off boost torque by some finite amount it really doesn't matter, just put your foot down farther .
I've gone from a 2.5" to 3" tubular o2 housing on my car with the 20G and noticed significantly quicker spoolup. We also did on Andre's galant going from a ported evo III to a full 3" o2.

So when the hell do I get a wiseman tag?

 

[NDgsx]

When you master quantum physics :laugh: