Backfire on shift - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 04-11-2013, 01:09 AM   #1
Elite Member
Thread Starter
iTrader: (6)
 
blaen99's Avatar
 
Join Date: Sep 2010
Location: Seattle, WA
Posts: 4,112
Total Cats: 27
Default Backfire on shift

If I get on the Miata real, real hard, I've noticed I can trigger backfire if I shift fast after I switched to a MS3.

Is this something I need to worry about/potentially damaging, or can I leave it as is?
blaen99 is offline   Reply With Quote
Old 04-11-2013, 01:21 AM   #2
Elite Member
iTrader: (4)
 
Pen2_the_penguin's Avatar
 
Join Date: Dec 2009
Location: Reno, NV
Posts: 3,690
Total Cats: 97
Default

doesnt a backfire mean unburned fuel?
Pen2_the_penguin is offline   Reply With Quote
Old 04-11-2013, 01:21 AM   #3
Elite Member
Thread Starter
iTrader: (6)
 
blaen99's Avatar
 
Join Date: Sep 2010
Location: Seattle, WA
Posts: 4,112
Total Cats: 27
Default

Yep.
blaen99 is offline   Reply With Quote
Old 04-11-2013, 01:43 AM   #4
Elite Member
iTrader: (4)
 
Pen2_the_penguin's Avatar
 
Join Date: Dec 2009
Location: Reno, NV
Posts: 3,690
Total Cats: 97
Default

The only thing I can think of is the cat being damaged, but I think youre fine.
Pen2_the_penguin is offline   Reply With Quote
Old 04-11-2013, 01:48 AM   #5
Elite Member
Thread Starter
iTrader: (6)
 
blaen99's Avatar
 
Join Date: Sep 2010
Location: Seattle, WA
Posts: 4,112
Total Cats: 27
Default

...I got no cat dude.

This is something specific to the MS3, and a change that happened in my switch from my old MS2 to the new MS3. If it doesn't hurt anything, IDGAF though.
blaen99 is offline   Reply With Quote
Old 04-11-2013, 02:16 AM   #6
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,367
Total Cats: 1,331
Default

You can either tweak decel fuel and the high RPM/low load fueling cells to fix it, or DGAF/YOLO/etc.
Savington is offline   Reply With Quote
Old 04-11-2013, 04:07 AM   #7
Elite Member
iTrader: (4)
 
Pen2_the_penguin's Avatar
 
Join Date: Dec 2009
Location: Reno, NV
Posts: 3,690
Total Cats: 97
Default

I came up with one:

FIRI- **** It, Run It.
Pen2_the_penguin is offline   Reply With Quote
Old 04-11-2013, 04:58 AM   #8
Elite Member
iTrader: (5)
 
Erat's Avatar
 
Join Date: Oct 2011
Location: Detroit
Posts: 4,199
Total Cats: 260
Default

Do you maybe have a launch control setup on? Mine will pop if i don't clutch>release gas fast enough on some rare occasions. But it makes me sound cool when i'm yoloing so i keep it.

I don't think my turbo likes it though.
Erat is offline   Reply With Quote
Old 04-11-2013, 09:23 AM   #9
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,196
Total Cats: 2,583
Default

My ms2 did that, its not ms3 specific. Basically what sav said
18psi is offline   Reply With Quote
Old 04-11-2013, 09:33 AM   #10
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

I came up with one:

tune the car.
Braineack is offline   Reply With Quote
Old 04-11-2013, 09:35 AM   #11
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,196
Total Cats: 2,583
Default

NO WAY!!! Sounds like bs
18psi is offline   Reply With Quote
Old 04-11-2013, 09:47 AM   #12
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,093
Total Cats: 90
Default

Wait is it a back fire or popping from the exhaust. A backfire is baaaaaaddddd on a turbo car, that **** will eat the compressor wheel. Popping from the exhaust is no biggy, it means there's hot unburnt fuel in the exhaust and that you're introducing enough clean air for it to light off, probably from decel cut or from a pinhole in the downpipe area.
Leafy is offline   Reply With Quote
Old 04-11-2013, 09:51 AM   #13
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,196
Total Cats: 2,583
Default

Quote:
Originally Posted by Leafy View Post
Wait is it a back fire or popping from the exhaust. A backfire is baaaaaaddddd on a turbo car, that **** will eat the compressor wheel. Popping from the exhaust is no biggy, it means there's hot unburnt fuel in the exhaust and that you're introducing enough clean air for it to light off, probably from decel cut or from a pinhole in the downpipe area.
Us normal people on this almost normal forum, refer to backfire as the latter of your description, and nothing having to do with the intake side of the engine. At all.
18psi is offline   Reply With Quote
Old 04-11-2013, 09:55 AM   #14
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

when's the last time you heard someone describe an afterfire as such? Never.
Braineack is offline   Reply With Quote
Old 04-11-2013, 11:11 AM   #15
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 407
Default

I will vote for "exhaust leak in the downpipe region" give or take. backfires like a bauuuuuus
y8s is offline   Reply With Quote
Old 04-11-2013, 11:31 AM   #16
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

I vote for overrun not turned on from lack of tuning.
Braineack is offline   Reply With Quote
Old 04-11-2013, 11:32 AM   #17
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,196
Total Cats: 2,583
Default

Only solution is a v8 swap
18psi is offline   Reply With Quote
Old 04-11-2013, 11:38 AM   #18
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Quote:
Originally Posted by Braineack View Post
I vote for overrun not turned on from lack of tuning.
+1

My cars and the cars I've tuned almost never shoot fire on decel, even when downshifting. This differs from every turbo, AWD car I've ever seen.
hustler is offline   Reply With Quote
Old 04-11-2013, 11:39 AM   #19
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,196
Total Cats: 2,583
Default

Quote:
Originally Posted by hustler View Post
+1

My cars and the cars I've tuned almost never shoot fire on decel, even when downshifting. This differs from every turbo, AWD car I've ever seen.
All of which are obviously not tuned all the way either, or actually tuned to do that on purpose. None of my many turbo awd cars ever backfired **unless** I was in a ricey mood and intentionally made them do it
18psi is offline   Reply With Quote
Old 04-11-2013, 12:37 PM   #20
Elite Member
Thread Starter
iTrader: (6)
 
blaen99's Avatar
 
Join Date: Sep 2010
Location: Seattle, WA
Posts: 4,112
Total Cats: 27
Default



I love you guys, so much right now. Wake up, come back to this thread, get useful information AND laugh my *** off.
blaen99 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
1994 Spec Miata Race Car SM/SM2/SSM For Sale Quinn Cars for sale/trade 6 10-23-2016 08:58 AM
Transmission Heat Shield Thread patsmx5 General Miata Chat 46 06-06-2016 11:27 AM
FS/FT: 03.5 Mazdaspeed Protege leatherface24 Cars for sale/trade 15 10-16-2015 12:35 PM
Odd Steering issue interestedofold Suspension, Brakes, Drivetrain 5 09-29-2015 02:42 PM
Are my coils failing? viriiguy General Miata Chat 5 09-28-2015 08:39 PM


Tags
joe perez

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 07:35 AM.