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
Registered User
 
Join Date: May 2014
Location: Fort Thomas, KY
Posts: 242
Garage
First 930 - What do you expect from your Turbo?

Hey guys,

I recently acquired an '87 911 Turbo. Absolutely astonished by the performance and drive of the car. I have one issue though, that I have spent a lot of time researching here and other places - engine cut off under boost. The car is very well maintained with 116k on the clock.

Getting a ton of answers and different suggestions, I've decided to take a larger scope on the issue.

This is the first air cooled turbo charged 911 I have driven. As I have read in multiple places my issue is not entirely uncommon - around 4,000 RPM or a little above .8 bar the engine cuts out. The ol' kiss the dash is the proper description for how it feels.

Now I've read and heard boost pressure switch, 02 sensors, wiring and fuse issues and a bad waste gate could be the issue.

So my bigger question is, being this is my first 930 ownership experience - how should this car perform? How should I be driving it? I also drive an '86 3.2 so I know you need to place yourself in the time period when you drive these classics. I know these engines are durable but also the turbo is extremely powerful so I understand the grenading danger.

Say we are in 1987 and rolling along in a brand new 930. Cruising on the highway taking it down to third gear and building boost...up to .8 or a touch more ...would a brand new 930 cut out like this if too much boost is built up? I understand this technology is older but I didn't expect to have that concern in the back of my mind at all times.

Honestly, I have given the 930 a good thromp or two but have never put it to full throttle.

So experienced 930 owners... Do I have to keep this in the back of my mind at all times? I have been told its just the nature of the beast, but to this extreme?

What are the sings of a waste gate not opening? Could this be the issue?

The more I think about it the more prepared I am to do a checklist hunt and start working down the above mentioned issues.

So in closing, how do you guys drive your 930's and what do you expect? This is an amazing car and I want to ensure it is on the road as long as possible.

(Had to post this from my phone so apologies for the wandering nature of my text!)

__________________
Collection Manager for HH Motorcars, LLC
hhmotorcars.com
Old 10-06-2014, 02:24 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
Drive it like you stole it.

It should take full throttle willingly and once on boost rush to red-line like the Millennium Falcon making the jump to hyperspace. Cut out is not something you should need to worry about. It is a problem that should be fixed. It certainly sounds like the overboost relay kicking in. Non-functional wastegate could lead to overboost situation.
__________________
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 10-06-2014, 02:30 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Banned
 
Join Date: Nov 2007
Location: Rockwall, Texas
Posts: 8,760
No to keeping the over boost possibility in the back on one's mind.

If the wastegate and overboost circuit is working as it should, the over boost protection does not trigger until about 1.2 bar or so (well beyond .8, in other words), and you can full throttle it as you see fit.

Some possibilities that you should look into - 1) is the wastgate actually opening as it should, 2) is the overboost switch and/or the overboost relay working. BTW - the over boost protection circuit disables the fuel pumps and that's what causes the "dash in the face" effect.

Last edited by Ronnie's.930; 10-06-2014 at 02:32 PM..
Old 10-06-2014, 02:30 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered User
 
mark houghton's Avatar
 
Join Date: Jul 2008
Location: Central Washington State
Posts: 3,874
You should feel confident with stuffing your right foot to the floor and just holding it there until she tachs to red line.....then repeat 3 more times. These cars are made to be driven that way, period. Make sure you have clean line of site for at least 3 miles, and a really fine radar detector on board before you attempt to stretch her legs.

If she's shutting down aka face in dash'ish, well it's usually a faulty over boost pressure switch. Simple....unplug the single wire and ground it. Now, if you truly overboost due to something like a faulty wastegate, you'll first experience more performance than you ever realized possible as your cheeks morph back toward your ears...only to end in the rattle of death as you blow holes in your pistons.

Seriously, those overboost switches become problematic over time. Feel free to disconnect and ground, but keep an eye on your boost gauge and get your foot out of it if you start seeing over 1.0 bar (indicative of a WG problem). If this is happening a "little bit above .8 bar" as you stated, that's not a big concern but what's your definition of a little bit? Make sure your boost signal hose to the WG is connected at both ends.
__________________
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 10-06-2014, 05:03 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: May 2014
Location: Fort Thomas, KY
Posts: 242
Garage
Hey guys,

It is great to hear that I can pin the 930 to warp drive. Now, the adventure begins to find the problem. There are plenty of resources here to aid in this process - so much so I have been overwhelmed where to start!

I initially thought overboost switch but I do not feel comfortable grounding the switch and boosting it. I would rather spend the cash to get a new switch - cheaper than 'kaboom!'

The wastegate not working properly is then the next step. I'm playing with rebuild or buying new...rebuilding seems to be a pain in the rear.

Now one thing to check that mark houghton mentioned is the boost signal hose. Fuel cut off or not, I want to ensure I have a proper boost pressure reading.

So I will tell you, the amount of acceleration at the moment is monumental for what I have experienced so far. I am excited to feel the full force of the 930's power.

OK so next question, say the overboost switch is OK and the waste gate is not opening properly... Any ideas to fix this issue without replacing the waste gate or rebuilding it? I ran BG44k, as advised by a very reputable tech. I thought it initially did the trick, but inevitably it cut.

What I have decided is replacing the overboost switch may be good anyhow.

I appreciate the input. I know there is a lot on here about 930 cut off... really my main concern is damaging the 3.3 ... and unleashing the powah.
__________________
Collection Manager for HH Motorcars, LLC
hhmotorcars.com

Last edited by thenewgarage; 10-06-2014 at 05:40 PM..
Old 10-06-2014, 05:38 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Large Member
 
krasuskyp's Avatar
 
Join Date: Nov 2001
Location: top of 3rd
Posts: 4,279
Garage
coupla points

when I first bought my 39k stocker, mine was doing the very same - wastegate stem was seized and the 'kiss the dash' is the overboost relay @ 1.2bar

it may or may not be able to be repaired - test it w/ air, if not opening pull it out and apart and see what the bits look like

I ended up swapping on a low mileage stock WG, or you could go TiAL.

the comment about your not going full throttle with it is the key

previous owner prob guilty as well

that is why the WG's seize - lack of use (seriously, RTFM it's in there 8-))

now

how to drive

yes, like you stole it - fersure

caveats:

- once fully up to operating temps
- except 1st gear yer really just making noise on a stocker past 5400, better off upshifting (again, RTFM the curves are published fer yer driving bemusement)
- defffffffffinitely ensure 2 things before WOT stuffage: good line of sight / space, and nose pointed & settled where you are ohsoquickly about to be
- don't outrun yer brakes (or the peasely 205s up front sans ABS... lockup city, veryunfun)
- always ensure long enough ride to get up to temp, and at least one WOT, and some cool down if really been whomping on it

That about sums it up. You'd be well served to have a local enthusinut 930 owner take you for a burn in theirs if you need further elaboration. Coming from a 3.2 tho you should be all set - the biggest tip would be make sure the rears are settled / planted before WOTage, otherwise it gets loose quick whenst the Boosthammer unleashes - esp on diminutive / dry 245's .

Beyond that, WOT often and in good health.

Oh, almost forgot... Vote to Ban unless pics are up - stat...
__________________
Paul... CT | '87 930 | '08 M3 6gang vert |
past:

| '07 S6 | '98 M3 vert | '01 M5 | '96 993 C2 cab | '05 S600 Sport - biturbo V12@Just Not Right 495rwhp / 612rwtq |
| '58 TR3A | '01 S8 | '95 S6 6gang | '88 M5 | '87 190E 2.3-16 |

Last edited by krasuskyp; 10-06-2014 at 05:42 PM..
Old 10-06-2014, 05:39 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
Join Date: May 2014
Location: Fort Thomas, KY
Posts: 242
Garage
I got you.

Pointers like that are exactly what I want to know with driving a 930. Much thanks!

I need to take some better pictures. I usually find myself staring at it and forget about pictures. It really is lovely. To look at and drive. Knowing there is more potential is awesome.



__________________
Collection Manager for HH Motorcars, LLC
hhmotorcars.com

Last edited by thenewgarage; 10-06-2014 at 05:56 PM..
Old 10-06-2014, 05:53 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Non User
 
infraredcalvin's Avatar
 
Join Date: Sep 2007
Location: Ladera Ranch, CA
Posts: 1,354
Garage
Quote:
Originally Posted by krasuskyp View Post

it may or may not be able to be repaired - test it w/ air, if not opening pull it out and apart and see what the bits look like

Oh, almost forgot... Vote to Ban unless pics are up - stat...
2 things:

1). If you decide to open up he WG clamp the cover before undoing the nuts, the spring is under pressure and will launch the cover into your face if you're not careful.

2). Need pics!

Welcome to the madness...
__________________
Infraredcalvin - AKA Pat
'76 Turbo Carrera #311 - Factory LSD, Sport Seats
'75 914 GT clone project
'71 914 track car
Old 10-06-2014, 05:53 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
Join Date: May 2014
Location: Fort Thomas, KY
Posts: 242
Garage
One more with a ton of glare
__________________
Collection Manager for HH Motorcars, LLC
hhmotorcars.com
Old 10-06-2014, 06:00 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Large Member
 
krasuskyp's Avatar
 
Join Date: Nov 2001
Location: top of 3rd
Posts: 4,279
Garage
ah, the most bestest and fastestest color of course - perfection!

Quote:
Originally Posted by infraredcalvin View Post
clamp the cover before undoing the nuts, the spring is under pressure and will launch the cover into your face if you're not careful...
sounds like advice you should give mywife?



(pun intended on the smiley choice? hmmm)

yervelcome, newgarage - mebbe add a name to a sig or something so we don't have to call you Mr. Newgarage... we're gentlike round these here parts, except fer Ronnie butfocourse

only other advice I'd suggest about WOTage is: make yourself faster before making the car faster... once you get the technique and the know how "seat-of-the-pants'ed", add throttle / speed

then



MUWHAHahahahaaaaaaa... it's Just Not Right.

think that's fun?

power / traction mods reaaaaaaaaaaaaaalllllllly suit these things ohso well

__________________
Paul... CT | '87 930 | '08 M3 6gang vert |
past:

| '07 S6 | '98 M3 vert | '01 M5 | '96 993 C2 cab | '05 S600 Sport - biturbo V12@Just Not Right 495rwhp / 612rwtq |
| '58 TR3A | '01 S8 | '95 S6 6gang | '88 M5 | '87 190E 2.3-16 |
Old 10-06-2014, 06:16 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Banned
 
Join Date: Nov 2007
Location: Rockwall, Texas
Posts: 8,760
Quote:
Originally Posted by thenewgarage View Post

OK so next question, say the overboost switch is OK and the waste gate is not opening properly... Any ideas to fix this issue without replacing the waste gate or rebuilding it? I ran BG44k, as advised by a very reputable tech. I thought it initially did the trick, but inevitably it cut.
Good looking car!

Nope, if the wastegate is not working properly (after you have confirmed that the hoses are hooked up correctly and do not have holes/cracks in them etc.), you'll have to remove and dismantle it to see what the problem is. Once dismantled, you might find that it is non-rebuildable like I did (the top "bell" on mine was corroded about 1/2 way around on the ridge/lip that the large diaphragm seats in) - I then had to fork out the big bucks for a Tail.

BG4KK, might help clean-up some deposits in the fuel system, but will have no effect on the wastegate.
Old 10-06-2014, 06:20 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Banned
 
Join Date: Nov 2007
Location: Rockwall, Texas
Posts: 8,760
Quote:
Originally Posted by krasuskyp View Post
. . . we're gentlike round these here parts, except fer Ronnie butfocourse
Paula, the only reason I'm not gentle with you, bub, is because you told me explicitly that you like if rough, ya' bisch!!!
Old 10-06-2014, 06:22 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
Registered User
 
Join Date: Jul 2006
Location: Honolulu, HI
Posts: 6,445
Enjoy the new ride, but be careful of these guys and their advice. Think of it as black ice. It gets very slippery and once you're in it, you're in it. Pretty soon you'll do an exhaust, turbo, twin plug... LOL
__________________
Bryan O.
77 930
88 Carrera cab
14 535i M Sport
Old 10-06-2014, 07:09 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered User
 
Join Date: May 2014
Location: Fort Thomas, KY
Posts: 242
Garage
Yes my whole life I have heard about the beast within the 930 and its a car you have to respect. Don't feel like abusing that until my skills are better and I am more familiar with the car.

I'll get the car in the air tomorrow and double check the hoses, including the boost signal hose.

Thanks for the info and welcome. I've been bitten by this car for sure.

I'll be reporting back!
__________________
Collection Manager for HH Motorcars, LLC
hhmotorcars.com
Old 10-06-2014, 07:39 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Registered User
 
T77911S's Avatar
 
Join Date: Oct 2006
Location: MYR S.C.
Posts: 13,586
the rubber boot on the left side of the engine that goes fromthe AFM to the turbo, or the pipe to the turbo should be very hard. what can happen is the engine is taking in so much that boot can collapse and shut down the motor under boost.
they use to be about $45.
__________________
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 10-07-2014, 08:46 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
Registered User
 
Join Date: Dec 2002
Location: Long Beach, CA
Posts: 1,128
In my car, the cut out was a defective overboost switch. The switch threads into my American radiator pressure tester, which enabled me to measure that it was cutting off fuel at a little under 0.8 bar. A new switch ($70) solved the problem. The specs for the switch are in the manual.
Old 10-07-2014, 09:28 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Registered User
 
Join Date: May 2014
Location: Fort Thomas, KY
Posts: 242
Garage
So I went ahead and bought a new overboost switch. I received it tonight, from our friendly host.

Todd, known here as OSI930, told me to give him a call and he taught me some good stuff. Helped me locate the overboost switch, gave me details about the intercooler piping and testing the wastegate, to name a few.
Thank you everyone for the help and input so far. I'll be asking more questions for sure.

These 930's are crazy machines and the car has captivated my curiosity.

We are supposed to get like a week of rain so hopefully it'll dry up enough to where I can comfortably wind it out.
__________________
Collection Manager for HH Motorcars, LLC
hhmotorcars.com
Old 10-09-2014, 05:38 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
Registered User
 
PrimeMvr's Avatar
 
Join Date: Dec 2010
Location: Iowa
Posts: 370
Garage
My vote is the overboost switch that you just bought will fix it, but if not, one thing to try before messing with the WG is make sure your intercooler is well-grounded. I had this issue and solved it by securing a wire to one if the IC mounting bolts to the coil ground bolt.
__________________
87 930 - Black - 3.4L/964 cams/K29/Powerhaus IC/6AL-2/B&B dual exhaust/MTX-L/235-315 Toyo R888/18" Kinesis wheels/Big Red brakes/LSD
10 997.2 Cab - Speed Yellow
83 SC Cab - Guards Red [SOLD]
17 NSX - Nouvelle Blue
Old 10-09-2014, 06:56 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
 
Registered User
 
Join Date: May 2014
Location: Fort Thomas, KY
Posts: 242
Garage
Alrighty so, replaced the Over Boost Switch. Pedaled it out to a nice stretch of road ... hoping to be able to floor it soon, wapack! Cut out, right at a touch over .8

So, next thing is checking the waste gate. I undid the line from the intercooler to the wastegate at the intercooler ... shot some air through a regulator and honestly it sounded like it was blowing out somewhere else - definitely not the wastegate. What is the proper name for this line? Wastegate hose?

After a little hunting and cramming myself under the decklid I found that the line is loose at the wastegate. I mean, like loose enough that I can twist the accessible end and the line will twist on the wastegate mount. This could be where air is escaping.

I do not know if this could be causing the cutoff issue but I would like to tighten the clamp on the hose no matter (there is a joke in there someplace). So assuming you followed my terrible description of the loose clamp, any bright ideas on how to get something in there to tighten it without removing the intercooler, etc.?

While we are on the topic, I found myself asking how this system works. How does the intercooler correlate to the pressure of the wastegate and when it opens?
__________________
Collection Manager for HH Motorcars, LLC
hhmotorcars.com
Old 10-13-2014, 08:46 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #19 (permalink)
Chain fence eating turbo
 
Join Date: Dec 2008
Location: Austin, TX
Posts: 8,844
Quote:
Enjoy the new ride, but be careful of these guys and their advice. Think of it as black ice. It gets very slippery and once you're in it, you're in it. Pretty soon you'll do an exhaust, turbo, twin plug... LOL
There's no possible way in the English language to portray a more truthful statement than this......

Old 10-14-2014, 05:58 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 12:28 AM.


 
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.