Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 / 930 Turbo & Super Charging Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Have to drive a 917
 
MonroeBoater's Avatar
 
Join Date: May 2011
Location: Indianapolis IN
Posts: 12
Garage
One single "pop" sound between shifts - lean?

I tried searching the forum for a similar issue, but couldn't find exactly what I am looking for. Here's the situation:
I just had the original turbo replaced with a K27. At the same time, I had a wastegate dump tube installed. Prior to this, the car (an 87 930), had a fabspeed IC, 1 bar spring, borla exhaust, and cat delete installed. Prior to the install of the dump tube and the new turbo, the car always made the typical popping/gurgling sound on deceleration. No big deal. But now, if I am well into the boost, and shift from second to third, while lessing accelleration once in third (because by then, I am way over the speed limit anyway), I occasionally hear what I would describe as a single muffled POP. It definitely sounds like it is coming from the drivers side exhaust or waste gate dump tube. Not as loud as a backfire, but definitely different from the deceleration gurgle/popping.

I guess I have read to many horror stories about what can happen when a car is running too lean. Does this sound like my situation, or is it just my new turbo/dump tube sound? If it sounds like it is running lean, how serious of a situation is this and what is the most common fix?

The boost guage doesnt seem to go past .8 and is running great!

Sorry for the long post/question. Any advice is greatly appreciated.

Old 09-30-2014, 07:11 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
beancounter
 
jwasbury's Avatar
 
Join Date: Jan 2008
Location: Weehawken, NJ
Posts: 3,627
Most likely it's the opposite. When you're WOT in 2nd, your car is probably rich (and you want it to be). Next you close the throttle to make the shift, the fuel system takes a microsecond to adjust and in that time dumps a bunch of fuel that doesn't fully burn in the cylinder because you've shut off the air supply (throttle). When that raw unburnt fuel hits the hot turbo and muffler, and is in the presence of some oxygen, it ignites - you hear a nice 'boom'

At night you'd probably see the flash of some flames shooting out the exhaust pipe.
__________________
Jacob
Current: 1983 911 GT4 Race Car / 1999 Spec Miata / 2000 MB SL500 / 1998 MB E300TD / 1998 BMW R1100RT / 2016 KTM Duke 690
Past: 2009 997 Turbo Cab / 1979 930
Old 09-30-2014, 08:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Have to drive a 917
 
MonroeBoater's Avatar
 
Join Date: May 2011
Location: Indianapolis IN
Posts: 12
Garage
Thanks for the information Jwasbury! Makes me not worry as much!
Old 10-01-2014, 02:33 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
beancounter
 
jwasbury's Avatar
 
Join Date: Jan 2008
Location: Weehawken, NJ
Posts: 3,627
Quote:
Originally Posted by MonroeBoater View Post
Thanks for the information Jwasbury! Makes me not worry as much!
No sweat. Welcome to the forum. I recommend you post a new thread introducing yourself and showing off pics of your 930. Your info says you're in Indiana, but the screen name MonroeBoater has me wondering if you hail from Bayou DeSiard.

You are wise to be concerned about your air-fuel ratio...an overly lean condition can cause serious engine damage. Many of us have installed wide-band AFR gauges as a way to monitor this.
__________________
Jacob
Current: 1983 911 GT4 Race Car / 1999 Spec Miata / 2000 MB SL500 / 1998 MB E300TD / 1998 BMW R1100RT / 2016 KTM Duke 690
Past: 2009 997 Turbo Cab / 1979 930
Old 10-01-2014, 02:54 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Have to drive a 917
 
MonroeBoater's Avatar
 
Join Date: May 2011
Location: Indianapolis IN
Posts: 12
Garage
Will do. Been posting on renn for a while. Kinda new to pelican though. Monroe boater comes from Lake Monroe in Bloomington IN. I dont do my own wrenching and have no mechanical background, so forums like this seem to be the only good way for me to get reliable opinions that I can discuss with mechanics. I've taken my car to a number of porsche specialized mechanics and almost always seem to get conflicting opinions from each. Sometimes it seems like getting a sip of water from a fire hydrant. I appreciate your insight though and will discuss the afr gauge with them. Thanks!
Old 10-01-2014, 06:38 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Mar 2000
Location: Auburn,In. U.S.A.
Posts: 2,449
Monroe:

Welcome and you are in the right place for good opinions and information.
This is the perfect place to run such issues past those in the know, they are
a great bunch and always willing to help.

Anymore the forum seems more about present 930 values and cars for
sale. Today I wasn't totally awake when I loged on and I thought I was
in the classifieds or on Rennlist. SUCKS !!!!

Cole
__________________
Cole - 80 930 "The Old Sled"
Mods: TurboKraft Custom IC, 934 Headers, GSX 61, Zork, Port Work, SC Cams, Air Mod Fuel Dist Relocated, Water Meth Injection, BL WUR, MSD 6530, Greddy EBC, Synapse Bov, Short 2nd & 3rd with 8:37 R&P, Wevo Shifter, Coupling, and Mounts, MTX-L SSI-4, Big Brakes, Rebel Coilovers, Bilstein Sports.

Last edited by cole930; 10-01-2014 at 08:27 PM..
Old 10-01-2014, 08:15 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
Registered User
 
Join Date: Dec 2012
Location: Indianapolis
Posts: 160
Garage
Monroe:

I'm also in Indy. So, let me know if you need help with anything.

Todd
__________________
-Todd
1987 911 Turbo, Marine Blue, GT35R, BB Headers, Tial, Andial IC
Old 10-01-2014, 08:27 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Have to drive a 917
 
MonroeBoater's Avatar
 
Join Date: May 2011
Location: Indianapolis IN
Posts: 12
Garage
A930Pilot, we may have met at cars and coffee a few months ago. 96th and meridian? Will be there saturday.
Old 10-01-2014, 09:19 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Banned
 
Join Date: Nov 2007
Location: Rockwall, Texas
Posts: 8,760
Quote:
Originally Posted by cole930 View Post

Anymore the forum seems more about present 930 values and cars for
sale. Today I wasn't totally awake when I loged on and I thought I was
in the classifieds or on Rennlist. SUCKS !!!!

Cole
Cole, I hope you are doing well, and I couldn't agree with you more on this subject. I've participated in those threads, but in the role of the "foil", of course! All of the jibber jabber about valuation, keep it stock, return it to stock, and so forth, really leaves an enthusiast of these cars with a bad taste in the mouth (not from "that" Paul ).
Old 10-01-2014, 09:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Banned
 
Join Date: Nov 2007
Location: Rockwall, Texas
Posts: 8,760
Monroe, Jacob gave excellent advice about getting an onboard AFR meter for your car. It really is a must have tool for fuel related tuning and troubleshooting, and eliminates much of the guess work and "shot in the dark" business. It's one of those tools that will have you wondering how you did without it.
Old 10-01-2014, 09:37 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Have to drive a 917
 
MonroeBoater's Avatar
 
Join Date: May 2011
Location: Indianapolis IN
Posts: 12
Garage
This may be a dumb question, but since I dont understand afr, I'm going to ask anyway. would it not be easier and safer to just have a TiAl wastegate with a .8 spring installed, in replace of my stock wastegate with a 1 bar spring? Wouldn't this keep the turbo/engine from spooling up so fast, thus not requiring the extra fuel? I would be ok with a little less power in exchange for engine longevity. This new k27 has made the car crazy quick compared to the stock turbo, so a little reduction wont bother me (for the time being anyway).
Old 10-01-2014, 10:18 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Registered User
 
Join Date: Mar 2000
Location: Auburn,In. U.S.A.
Posts: 2,449
Monroe:

What you have done to the car with the K27, Borla, Cat delete, and
having a larger IC are things that should be done to insure the engine
is going to stay together. The factory wastegate is as good a
wastegate that was ever made so save your money and just change
to a .8 bar spring. With the way your car is set up now it would run at
1 bar all day long.

I have a .8 spring you can have if you want to swap your 1 bar for it.
Before you go changing things it's a lot cheaper to lighten up on your
right foot until you get to know the car. A year from now you would be
looking for all the goodies your talking about taking off so you could
make the car faster.

The AFR gage is an excellent idea for any high performance car. It will
display real time air/fuel ratios that tell you if your running too rich or to
lean. This is a real time indicator of how the fuel system is working.
Innovate makes an excellent AFR set up , the MTX-L, thats relatively
inexpensive and easy to install.

For now just step back and enjoy the car, winter is coming and we
will make a Porsche mechanic out of you before spring.

If you have any questions or need anything just give me a call.

260-925-0219


Cole
__________________
Cole - 80 930 "The Old Sled"
Mods: TurboKraft Custom IC, 934 Headers, GSX 61, Zork, Port Work, SC Cams, Air Mod Fuel Dist Relocated, Water Meth Injection, BL WUR, MSD 6530, Greddy EBC, Synapse Bov, Short 2nd & 3rd with 8:37 R&P, Wevo Shifter, Coupling, and Mounts, MTX-L SSI-4, Big Brakes, Rebel Coilovers, Bilstein Sports.
Old 10-01-2014, 11:11 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
 
Registered User
 
Join Date: Mar 2000
Location: Auburn,In. U.S.A.
Posts: 2,449
Ronnie:

The Old Coot is doing well. This Cancer is still trying to kill me but I'm
outlasting it.

The Sled is up and running and it is seriously quick, much more fun
than a 71 year old fart should be having. Last weekend I had one of my
son in laws screaming like a little girl. I'm lovin it.

I still have some pics and video to post but I need my tech savvy
grandson to pull the video together for me.

Hope you and your's are well and wish you the best !!!!!!!

Cole
__________________
Cole - 80 930 "The Old Sled"
Mods: TurboKraft Custom IC, 934 Headers, GSX 61, Zork, Port Work, SC Cams, Air Mod Fuel Dist Relocated, Water Meth Injection, BL WUR, MSD 6530, Greddy EBC, Synapse Bov, Short 2nd & 3rd with 8:37 R&P, Wevo Shifter, Coupling, and Mounts, MTX-L SSI-4, Big Brakes, Rebel Coilovers, Bilstein Sports.
Old 10-01-2014, 11:25 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered
 
Join Date: Jul 2003
Location: Back in B'ham, AL
Posts: 3,451
^^^Hang in there Cole... we're with you and conquer!!!
Old 10-02-2014, 05:41 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered
 
xbmwguy's Avatar
 
Join Date: Apr 2008
Location: west palm beach fla
Posts: 1,716
Garage
glad to hear youre doing well Cole!!!
Old 10-02-2014, 07:54 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
beancounter
 
jwasbury's Avatar
 
Join Date: Jan 2008
Location: Weehawken, NJ
Posts: 3,627
Quote:
Originally Posted by cole930 View Post
Last weekend I had one of my
son in laws screaming like a little girl. I'm lovin it.
^ priceless

Thanks for sharing Cole, and glad to hear that you're properly enjoying the Old Sled.
__________________
Jacob
Current: 1983 911 GT4 Race Car / 1999 Spec Miata / 2000 MB SL500 / 1998 MB E300TD / 1998 BMW R1100RT / 2016 KTM Duke 690
Past: 2009 997 Turbo Cab / 1979 930
Old 10-02-2014, 08:03 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Registered User
 
Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
Can't wait to see your video(s) and hear the turbo whistle from your zork Cole!
I'm glad you got a TurbosDirect.Com Web Site - Home ball bearing billet wheel Garrett GSX 61 too. I love mine!
I didn't know you had a Greddy EBC until I read your car description in your post above.
With your factory 934 headers, open zork, shorter gearing, and what you've done to free up the air flow through the CIS that turbo must really spool up fast and your car should fly! Enjoy it!

If it doesn't rain today ...for a change, and when my car cover dries off from last nights rain I'll go for a drive. It's sunny at the moment and we're supposed to get a mini cool front this weekend!

Enjoy your car!
Old 10-02-2014, 08:45 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
Registered
 
T77911S's Avatar
 
Join Date: Oct 2006
Location: MYR S.C.
Posts: 13,771
if you want to get the miles out of the engine, go back to the .8 spring. if you dont know where the AFR's are at, that is the safest thing.

dont worry about the pop. may be wastgate, may be a little flame.

i like to drive at night and when there are cement barries on the side of the road, i can see the reflection of the flames real good. good way to check to see if yours is doing that.
__________________
86 930 42kmiles [__] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD
88 BMW 325is 200K+ SOLD
05 BMW 330CI 130K:: [__] RUNNING: [__] NOT RUNNING:
08 VOLVO V70 190K:: [__] RUNNING: [__] NOT RUNNING:
90 B2200[__] RUNNING:[] NOT RUNNING:__2000 MER E320 WAGON [] WRECKED:[]RUNNING:
Old 10-02-2014, 09:06 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
 
Registered User
 
Join Date: Mar 2000
Location: Auburn,In. U.S.A.
Posts: 2,449
How nice to hear from all you bums, I love every one of ya !!!!!!

My good buddy Fairman and I talk several times a week, he keeps me straight.
I can't remember s--- and Fairman is like a walking encyclopedia so he keeps me
from steping on my dick.

First time out in the sled the junk Ultimate Motorwerks K27S took a dump and I
limped home smoking like the old Cheech and Chong f--- bus. New turbo time and
Fairman turned me on to the Garrett GSX 61 and my good friend and hero "Chris
the Turbo God Carroll" sent one off to me.

This Turbo rocks !!! With my gear set there is no lag this thing is a serious rush,
I actually had the car sideways in 2nd. Hell it just cost 45 Grand to replace my
pacemaker just a couple months ago, if I had had this turbo on sooner I could
have saved the pacemaker money and just used the rush from the Sled to restart
me.

Cole
__________________
Cole - 80 930 "The Old Sled"
Mods: TurboKraft Custom IC, 934 Headers, GSX 61, Zork, Port Work, SC Cams, Air Mod Fuel Dist Relocated, Water Meth Injection, BL WUR, MSD 6530, Greddy EBC, Synapse Bov, Short 2nd & 3rd with 8:37 R&P, Wevo Shifter, Coupling, and Mounts, MTX-L SSI-4, Big Brakes, Rebel Coilovers, Bilstein Sports.

Last edited by cole930; 10-02-2014 at 01:57 PM..
Old 10-02-2014, 10:18 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #19 (permalink)
Registered
 
mark houghton's Avatar
 
Join Date: Jul 2008
Location: Central Washington State
Posts: 3,887
Quote:
Originally Posted by cole930 View Post
limped home smoking like the old Cheech and Chong f--- bus. Cole
Old One, you're showing your age again! Not many people remember Big Bamboo, or even what to do with it.

I'm excited to hear you got your ol' sled on the road finally! How cool is that, going sideways in second! So now we've got two very reputable people atttesting to the virtues of the GSX 61 turbo.

Tell your grandson to get off the stick and do a video for us. Gotta see your ride in action, man.

__________________
Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, stock everything else. The result of a massive Pelicanite good will fire recovery effort. Truely an open book, ready for the slippery slopes to modification.
Old 10-02-2014, 11:54 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #20 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 12:32 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.