PDA

View Full Version : will downpipe create creep?



talonted
06-14-2004, 04:03 PM
I've been reading around about all kinds of mods to do to my talon, and from what i've read if i put a 3" downpipe and catback on my otherwise stock car (except intake) it will create boost creep. Is this true, and if so what do i have to do to keep the boost from happening?

EK 2.0
06-14-2004, 04:08 PM
if you have left your boost stock, and have only done the BCS mod...you SHOULD be ok...and within totally safe limits...the way to eliminate the potential problem is to port the O2 housing and surrounding area...as well and increase the flapper for your wastegate and port that area as well...check the FAQ's for more answers to most of your DSM related queries...I have included a link...


DSM FAQ (http://www.vfaq.com/FAQlocator-index.html)

5.9 R/T
06-14-2004, 04:12 PM
Go with a 2.5", 3" is overkill.

heavyD
06-14-2004, 04:23 PM
Honestly I think it varies from car to car. I have seen threads where two guys will have the same mods and one guy will have creep problems and the other guy won't. The only way to find out is to get the downpipe. If you get boost creep try porting the O2 housing and turbo exhaust housing, etc. until you get rid of it.

Also like 5.9RT said, 2.5" will suffice for the downpipe feeding a 3" catback exhaust. There are varying opinions on this though.

WGR4Pussies
06-15-2004, 01:32 PM
turbo car=you want no back preasure= you get the biggest you want.:nut:

5.9 R/T
06-15-2004, 02:06 PM
Originally posted by WGR4Pussies
turbo car=you want no back preasure= you get the biggest you want.:nut:

DSM=not a turbo honda=you don't know what you're talking about!

If Buschar racing can run a 2.5" downpipe and still run 10's then why would a stock DSM need 3"? You're just asking for boost creep that way.

legendboy
06-15-2004, 02:14 PM
Why not just convert to external wastegate?? I welded a turbosmart flange on redec's talon manifold and it turned out fine. Looks good too.

redline
06-15-2004, 03:32 PM
plus that o2 housing is only, maybe 2" even with a 4" downpipe you still have the 2" restriction

tsi_neal
06-15-2004, 11:05 PM
im running a mandrel bend 3" turbo back with no boost creep issues. My setup isnt stock tho. evo3 16g & O2 housing with ported everything.

the bottom line is if your wastegate is working/flowing properly you wont have boost creep issues. You will likely have to port it for it not to creep tho.
As for the O2 housing only having a 2" outlet, well a stock 1G is. An evo3 is 2.5" from the factory, ported its possible to get it around 2.75" (mine measured at 2.65") I also wouldnt call this a restriction in the exhaust as right out of the turbo is a 2" hole (less at the wheel, it makes a cone shape) and the gas is flowing fastest, and can carry its velocity through the O2 housing. If the 2" section was after a 3" section then id call it a restriction.

StupidWade
06-16-2004, 06:31 PM
Tsi_Neal is correct. 99% of boost creep is caused by a faulty wastegate actuator or a too-small wastegate opening on the turbine housing.

I'd say put the 3" downpipe and exhaust on the car, but be prepared to have the wastegate opening ported if needed or even to upgrade the flapper to a larger size if the creep is too serious (shouldn't be, lots of people run 3" DPs with the 14B.)

talonted
06-17-2004, 12:44 AM
k awsome thanks