www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You

Order your TDIClub merchandise and help support TDIClub


Go Back   TDIClub Forums > VW TDI Discussion Areas > TDI 101

TDI 101 Got a simple/basic TDI question? Are you a newbie (new to the forums). Feel free to post your question here.

Reply
 
Thread Tools
Old August 1st, 2020, 17:49   #1
Andyinchville1
Veteran Member
 
Join Date: Apr 2016
Location: Virginia
Default //// Help me choose a downpipe ////

HI all,

Looking to get some PM work done to my car and I figure while stuff is being worked on / apart might as well upgrade a little too.

I know many people say the stock intake and exhaust are sufficient for a relatively stock situation like mine but I did have a relatively stock 1993 Dodge with the Cummins and a 4" straight pipe from turbo and it sounded sweet , had lower EGTs (not that I had EGT issues tho) and helped with fuel economy (granted some of that may have been the result of me babying it more after the exhaust upgrade since it was pretty loud and I didn't want to get grief from the man so I figured I'd do the same to the Jetta.

Anyways, I would like some input to help me make a choice ...

I am currently debating between ID parts 2.5 inch down pipe and Kerma's 3" downpipe.

1) I have a question regarding flow .... According to ID Parts, their 2.5 inch downpipe features a custom cast piece to gradually "flair up" to the 2.5" diameter downpipe pipe (I'm guessing this is similar to what my Dodge system had as far as a transitional "cone" to smooth / help prevent turbulence as the exhaust gas flows out of the turbo

I am not sure if Kerma's down pipe has the same feature ... i.e. a smooth transition from the turbo exhaust outlet to the 3" pipe..

Given the above, which downpipe flows better the 2.5" with smooth transition or the 3" non transition downpipe ?

2) Does the optional resonator make a real difference in drone reduction ?

Thanks in advance for all input / help

Andrew

FWIW - At the same time I'm upgrading the exhaust I am also going to install (or have installed) a BRM intake manifold with adapter (it's only been sitting in my shed for what seems like a year by now!) to help the intake side as well ...
__________________
2003 Jetta tdi wagon , 5 sp, 316k miles, 11 mm pump, DLC 520, Malone stage 1, P205 70 R 15 Ecopias on Avus rims, hammer mod

Last edited by Andyinchville1; August 1st, 2020 at 17:52.
Andyinchville1 is offline   Reply With Quote
Old August 1st, 2020, 20:21   #2
ghohouston
Veteran Member
 
ghohouston's Avatar
 
Join Date: Apr 2013
Location: Lewisville, Texas
Fuel Economy: 40 Mpg
Default

If you're installing exhaust, just go with 3" turbo back. No where close to as loud as a 12 valve, but sounds great through the rpm range. Almost like a mini cummins
__________________
2001 Silver Jetta Sedan TDI 5 Speed,3" Kerma turbo back straight pipe
Allard EGR Delete
Bosio DLC 764's. 1997 Ford F350 CCLB 7.3 Powerstroke Diesel ZF5, straight piped
ghohouston is offline   Reply With Quote
Old August 1st, 2020, 20:36   #3
Andyinchville1
Veteran Member
 
Join Date: Apr 2016
Location: Virginia
Default

Quote:
Originally Posted by ghohouston View Post
If you're installing exhaust, just go with 3" turbo back. No where close to as loud as a 12 valve, but sounds great through the rpm range. Almost like a mini cummins
HI

I see you have the same system on your car ... did you get the resonator option?

How is the drone or is there much of it ?... did you get any gains in mileage ?

I think it may be worth it just for the sound and possible weight savings tho...! (it's good if its not as loud as the cummims because that did pound on my head for long drives (of course the sheet metal interior with no floor mats or carpets probably didn't help!).

Thanks
__________________
2003 Jetta tdi wagon , 5 sp, 316k miles, 11 mm pump, DLC 520, Malone stage 1, P205 70 R 15 Ecopias on Avus rims, hammer mod

Last edited by Andyinchville1; August 1st, 2020 at 20:39.
Andyinchville1 is offline   Reply With Quote
Old August 3rd, 2020, 11:55   #4
ghohouston
Veteran Member
 
ghohouston's Avatar
 
Join Date: Apr 2013
Location: Lewisville, Texas
Fuel Economy: 40 Mpg
Default

Mine is straight piped. There really isn't any drone. Mine exits a little beyond the rear tire, at probably a 60 degree angle, I attribute this as the reason I don't have much drone. No mileage difference. Spool up is definitely improved with the larger exhaust/ straight pipe.
__________________
2001 Silver Jetta Sedan TDI 5 Speed,3" Kerma turbo back straight pipe
Allard EGR Delete
Bosio DLC 764's. 1997 Ford F350 CCLB 7.3 Powerstroke Diesel ZF5, straight piped
ghohouston is offline   Reply With Quote
Old August 3rd, 2020, 15:40   #5
Mongler98
Veteran Member
 
Join Date: Mar 2011
Location: Northern MD
Fuel Economy: Race: 12mpg, Gandma:65mpg
Default

unless your going nuts with your build, or you just simply want a full 3"
don't
go 2.5. much easier to work with and get things around. sound will be as nice.
Mongler98 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
The Ugly Downpipe , the low cost downpipe is in stock at kermaTDI VailPowder Vendor & GroupBuy items for sale 19 July 19th, 2010 13:18
which would you choose? canadatoon TDI 101 9 February 23rd, 2007 13:08
of these tires which would you choose Glennbo VW MKIII-A3/B4 TDIs 8 October 31st, 2006 07:26
WTB: stock PD downpipe for production of performance downpipe joevat Private TDI Items for Sale/Wanted 0 August 16th, 2006 07:08
Help me choose please!! snubasu TDI 101 10 April 21st, 2003 11:52


All times are GMT -7. The time now is 07:47.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
1996 - 2020, All Rights Reserved
Page generated in 0.12513 seconds with 13 queries
[Output: 72.15 Kb. compressed to 63.74 Kb. by saving 8.41 Kb. (11.65%)]