question about 3" turboback

[Mits3gts]

i am very much undecided if i should get a 2.5" turboback or a 3" turboback.i am not looking to make crazy HP,but would be happy with 230-240whp.i know there are a million threads about this,but everyones setup is different,and i'm at work so i cant use the comp. for a long time. i just want to take my stock rusted exhaust off and install the new system,without any hassles with boost creep or anything. i can get the 2.5" and 3" for about the same price.just dont know what to order
thanks for the help,much appreciated

 

[L2RTSiAWD]

Just get a 3inch.

 

[InjenTalon96]

well with a 3inch turbo back u will def boost creep, like i did, that was also with a test pipe, u wont creep with a 2.5 thou, ill tell u, its worth getting a 3inch just because there is so much more flow and that is prolly one of the best mods i have ever done. i also fixed the creep by installing a bigger wastegate flapper and a o2 dump, not as good as an external but it sounds nasty and does the job!!!

 

[Shadowfax]

Don't complain about boost creep.

Boost creep means you're making good power, and support more.

I'll give you an example- one of the fastest 3/S TT's runs a pair of 14B's to the tune of 11.1@127mph. Not bad true, but his best dyno was 488WHP... from a PAIR of 14B's while running stock DSM ic's and a BUNCH of things- but oh, his exhaust happens to be a 2.5" downpipe to a 3" catback...

You think he's EVER seen boost creep?!? 240WHP from each 14B while on racegas isn't anything amazing. Sure it's good for a 3/S - but I know there is more than one DSM'er running 106-110 traps on a 14B while making 270+WHP...

Yes, different car, different setup, blah blah - the point still comes down to the fact that if you aren't creeping, with a stock internal wastegate and ported turbine, then you've got need for more exhaust.

Take Spoold U - 98 GS-T 14B (unported) with 3" O2 back, MAFT in blowthru, 190lph pump, Starion IC, 106 traps on 93 octane no dyno tuning. I've seen DSM's trap as high or higher with 2.5 - but not without more mods.

3" exhaust for a TD05 should be a given. No matter what the engine it's on, the airflow from the turbo needs a certain amount of breathing room in the exhaust.

I hope that isn't too far off topic- but we see the "dreaded creep issue" all the time, and the idea that boost creep is bad enough to warrant the making of less power is dumb IMHO

 

[Mits3gts]

yeah this system comes with a test pipe also.would the boost creep still be there if i get an aftermarket o2 housing?or even a ported 2g housing? and one other question,what if i eventually get a b16g,will it still creep also..sorry for the questions,but i am new to turbo dsm's.

 

[InjenTalon96]

i duno what the last guy is talking about but yes is u bolt up a 3inch downpipe, a 3inch test pipe, and a 3inch catback u WILL creep, i can bet my whole car on that one, i creeped even with diff o2 housing, i had a 2g one that was ported then i made it dump, then a bigger flapper and it all went away. getting the flapper installed with parts wont cost u much, its just the fact that u have to take the turbo off. unless u just get a o2 dump tube and it will help out alot. and yes if u get a 16g you will creep too

 

[Shadowfax]

IMHO the best cure for the average street driving joe would be -

Bullseye Turbine housing with 38mm flapper
Tubular O2 with wastegate Dump


Granted the only 100% guarenteed solution is external - however a lot of us want to remain mostly stock looking, and to retain an internal wastegate- you need to make sure the O2 flows enough (dump works pretty dang well) and a turbine housing with a larger wastegate passage including wastegate inlet, would be needed too. Hence my recommendation.

 

[InjenTalon96]

yes a complete external dump would solve any type of boost creep problem, but if u dont wanna spend alot of money and want to have a stock look, get a dump tube and a flapper

 

[Mits3gts]

then i think the 2.5 turboback will be good for me.like i said,i'm not looking to make alot of hp,just something a little better than stock.i am on a budget,since this is just my play car. thanks for all the info,but i dont want to keep sinking money into the car just to elimate a problem.i only need to get rid of the stock rusted out exhaust.

 

[Shadowfax]

That's how we all get started

My 3" O2 back cost me $165 including an $80 magnaflow muffler.

Good luck with your exhaust!