GT28r Internal Wastegate dumped to atm? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 10-06-2008, 01:27 PM   #1
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Oct 2007
Location: Fremont, CA
Posts: 173
Total Cats: 0
Default GT28r Internal Wastegate dumped to atm?

I'm getting ready to fab up a downpipe with divorced wastegate flow. What do you guys think about dumping the wastegate flow to the atmosphere? Any major issues that you guys can forsee?

I'm going to try and seperate the main flow from the wastegate the best I can with a baffle like begi, but it probably won't seal completely. Any issues that can arise from that small leak?

Thanks for the input.
rippledabs is offline   Reply With Quote
Old 10-06-2008, 01:40 PM   #2
Elite Member
iTrader: (5)
 
Join Date: Mar 2007
Location: NYC
Posts: 1,997
Total Cats: 1
Default

exhaust leak before the o2 sensor? it will probably sound like a bag of *** too for what that's worth.
johndoe is offline   Reply With Quote
Old 10-06-2008, 01:42 PM   #3
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,899
Total Cats: 1,792
Default

Quote:
Originally Posted by johndoe View Post
exhaust leak before the o2 sensor?
all relative.

Quote:
it will probably sound like a bag of *** too for what that's worth.
bag of ***, as in loud and ******* killer?
Braineack is offline   Reply With Quote
Old 10-06-2008, 02:40 PM   #4
I'm Miserable!
iTrader: (5)
 
Join Date: Sep 2005
Location: SLC, Utah
Posts: 1,591
Total Cats: 0
Default

why not just do it right??
zoom2zoom is offline   Reply With Quote
Old 10-06-2008, 02:48 PM   #5
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Oct 2007
Location: Fremont, CA
Posts: 173
Total Cats: 0
Default

Quote:
Originally Posted by zoom2zoom View Post
why not just do it right??
Merging the wastegate back into the main flow is an option too. Just want to see all the side effects of dumping it to atm.

My thinking was that dumping it would yield some quicker spoolup and maybe a bit more power since it doesn't introduce high pressure exhaust back into the lower pressure main flow. (maybe my thinking was overly exagerated?)
rippledabs is offline   Reply With Quote
Old 10-06-2008, 02:55 PM   #6
Elite Member
iTrader: (15)
 
Join Date: Dec 2007
Location: San Antonio, Texas
Posts: 4,889
Total Cats: 28
Default

I drove someones Miata that has a VTA wastegate and it works fine, though it is external. When the wastegate opens up the car produces a BRAAAAAAP that is not unbearably loud but is still quite noticeable. It resembles the sound of a Jake Brake on a semi IMO.

I am speculating here, but when the wastegate is closed, you could have a possible venturi situation where the flow across your baffle separator (turbine exhaust) will draw air in through the VTA tube for the WG. That would be a problem if you are making O2 measurements.

The vent tube could end up sounding like an exhaust leak too, all the time, which would annoy me to death.
ZX-Tex is offline   Reply With Quote
Old 10-06-2008, 03:42 PM   #7
Elite Member
iTrader: (10)
 
leatherface24's Avatar
 
Join Date: Dec 2006
Location: Pembroke Pines
Posts: 4,033
Total Cats: 2
Default

I love the sound. On my FD it was badass imo

You cant really hear it all that well here but oh well
http://videos.streetfire.net/video/M...t-to_33214.htm

Last edited by leatherface24; 10-06-2008 at 03:57 PM.
leatherface24 is offline   Reply With Quote
Old 10-06-2008, 04:17 PM   #8
Senior Member
 
Join Date: Mar 2007
Location: Denver, CO
Posts: 564
Total Cats: 0
Default

You'll only hear it at WOT under full boost.

I had all my Talons dumping and it's a very manly sound.

It's also sometimes helpful to be able to hear your wastegate opening to solve issues.

The O2 sensor is measuring a ratio so it doesn't matter if it sees full exhaust volume, I think this is what Brain was saying.
jwarriner is offline   Reply With Quote
Old 10-06-2008, 04:52 PM   #9
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,899
Total Cats: 1,792
Default

Quote:
Originally Posted by jwarriner View Post

The O2 sensor is measuring a ratio so it doesn't matter if it sees full exhaust volume, I think this is what Brain was saying.

something to that matter...shouldn't pose a problem if the dump tube is long enough....plus a divider so be in place, shouldn't be anyway atmospheric gasses could mix back down into the DP and throw the reading off.
Braineack is offline   Reply With Quote
Old 10-06-2008, 04:52 PM   #10
Senior Member
iTrader: (8)
 
Join Date: Mar 2006
Location: Indianapolis, IN
Posts: 758
Total Cats: 5
Default

Quote:
Originally Posted by rippledabs View Post
I'm getting ready to fab up a downpipe with divorced wastegate flow. What do you guys think about dumping the wastegate flow to the atmosphere? Any major issues that you guys can forsee?

I'm going to try and seperate the main flow from the wastegate the best I can with a baffle like begi, but it probably won't seal completely. Any issues that can arise from that small leak?

Thanks for the input.
I can't see any good pics of BEGi's baffle on their site, but if you build one like Greg Dupree at Specialty Z does for the 300ZX, I don't think you'll have any leaking issues: http://specialtyz.com/downpipes.htm





I personally wouldn't want to run an open WG dump due to the unnecessary attraction from ricers and law enforcement, YMMV.
boileralum is offline   Reply With Quote
Old 10-06-2008, 05:00 PM   #11
Former Vendor
 
Join Date: Jun 2006
Location: Bell Tuning & Performance
Posts: 1,338
Total Cats: -78
Default

Quote:
Originally Posted by rippledabs View Post
Just want to see all the side effects of dumping it to atm.
Hmmm.... Rods thru the oil pan?
Stephanie
Stephanie Turner is offline   Reply With Quote
Old 10-06-2008, 06:13 PM   #12
Elite Member
iTrader: (12)
 
Join Date: Jan 2007
Location: Hermosa Beach, CA
Posts: 2,575
Total Cats: 11
Default

Quote:
Originally Posted by rippledabs View Post
I'm getting ready to fab up a downpipe with divorced wastegate flow. What do you guys think about dumping the wastegate flow to the atmosphere? Any major issues that you guys can forsee?

I'm going to try and seperate the main flow from the wastegate the best I can with a baffle like begi, but it probably won't seal completely. Any issues that can arise from that small leak?

Thanks for the input.
There are no side effects other than a badass sound. If I had a external wastegate I would defentally dump it to atmosphere.

Plus you can only hear it under WOT
cardriverx is offline   Reply With Quote
Old 10-06-2008, 06:24 PM   #13
Senior Member
 
Join Date: Mar 2007
Location: Denver, CO
Posts: 564
Total Cats: 0
Default

Quote:
Originally Posted by Stephanie Turner View Post
Hmmm.... Rods thru the oil pan?
Why would dumping the wastegate cause that?
jwarriner is offline   Reply With Quote
Old 10-07-2008, 01:10 AM   #14
Junior Member
 
Join Date: Sep 2008
Location: Head Wound City, CT
Posts: 215
Total Cats: 0
Default

Quote:
Originally Posted by Stephanie Turner View Post
Hmmm.... Rods thru the oil pan?
Stephanie
Say what?
MattEGTR is offline   Reply With Quote
Old 10-07-2008, 01:13 AM   #15
Junior Member
 
Join Date: Sep 2008
Posts: 218
Total Cats: 0
Default

Quote:
Originally Posted by Stephanie Turner View Post
Hmmm.... Rods thru the oil pan?
Stephanie
JimAtFSU is offline   Reply With Quote
Old 10-07-2008, 04:00 AM   #16
Senior Member
 
Join Date: Jun 2006
Location: Orlando FL - UCF
Posts: 688
Total Cats: 1
Default

Quote:
Originally Posted by Stephanie Turner View Post
Hmmm.... Rods thru the oil pan?
Stephanie
Sorry Steph, I don't get it...
coastertrav is offline   Reply With Quote
Old 10-07-2008, 09:21 AM   #17
Guest
iTrader: (6)
 
Join Date: Sep 2007
Location: Vaughan, On, Canada
Posts: 1,092
Total Cats: 0
Default

Neither do I? My old car ran VTA on my Wastegate for many years and at 498hp.
M-Tuned is offline   Reply With Quote
Old 10-07-2008, 09:23 AM   #18
Junior Member
Thread Starter
iTrader: (3)
 
Join Date: Oct 2007
Location: Fremont, CA
Posts: 173
Total Cats: 0
Default

Now that I think about it, I rather not attract more attn than I already do. Heading to the merged route.

On the another note. I was having a hell of a time trying to get the turbine housing clocked. It's pretty arkward to hold and bash at the same time, but I found a method without the need of any bashing or heat, although heat may help, and lots of PB Blaster.

Bolt Jack method. I backed out the turbine housing bolt against a steel plate and a wood block. This popped the turbine housing off with the quickness. The heads of the bolt got a little scruffed, but when that housing popped off, felt like I got high.
Attached Thumbnails
GT28r Internal Wastegate dumped to atm?-boltjack.jpg  
rippledabs is offline   Reply With Quote
Old 10-07-2008, 09:58 AM   #19
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,899
Total Cats: 1,792
Default

Quote:
Originally Posted by [email protected] View Post
Neither do I? My old car ran VTA on my Wastegate for many years and at 498hp.

I think she was referring to more powah!!! Unless it was something haverty said....
Braineack is offline   Reply With Quote
Old 10-07-2008, 10:36 AM   #20
Elite Member
iTrader: (15)
 
Join Date: Dec 2007
Location: San Antonio, Texas
Posts: 4,889
Total Cats: 28
Default

Quote:
Originally Posted by boileralum View Post
I can't see any good pics of BEGi's baffle on their site, but if you build one like Greg Dupree at Specialty Z does for the 300ZX, I don't think you'll have any leaking issues: http://specialtyz.com/downpipes.htm


Snap... if you use something like that, forget what I said about leaks. That is a nice way to do it.
ZX-Tex is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Another Cast Manifold Corky Bell Prefabbed Turbo Kits 18 11-22-2016 10:01 PM
LucaCarMods's Boosted Dutch Miata Build! LucaCarMods Build Threads 11 02-14-2016 07:13 AM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM
1996 Turbo Build Goldwar DIY Turbo Discussion 2 09-29-2015 10:20 AM


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 02:35 AM.