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 Technical BBS > 1- Porsche Technical Forums > 911 / 930 Turbo & Super Charging Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Sep 2016
Location: Asheville, NC
Posts: 21
930 correct boost gauge source point

What is the best place to tap for source boost for my boost pressure gauge?

I have an 86 930 running a 3.4L EFI with Garrett G35 & Tial waste gauge. I have a Andial tattle-tale 2 bar boost gauge in lieu of the clock and am running a 0.8bar Tial wastegate spring.

When I tap the boost source at the Tial the gauge works & tracks boost well BUT bounces the tattle-tale to 1.8bar on shifts. I then moved the tap point to the throttle body and solved the bounce problem but the gauge only shows boost under a hard pull and then only momentarily BUT does stop at the correct 0.8 bar.

Recommendations?
__________________
1986 Ruf 930
2015 991 GTS-MT
2006 993 S-MT (Gone)
1969 911 T (Gone)
Old 08-04-2017, 03:41 PM
  Pelican Parts Technical Article Directory    Reply With Quote #1 (permalink)
Registered User
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 2,809
Up front - off your brake boost line.
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 08-04-2017, 05:48 PM
  Pelican Parts Technical Article Directory    Reply With Quote #2 (permalink)
Registered User
 
Mike80911's Avatar
 
Join Date: Oct 2010
Location: New York Where only a criminal can have a gun
Posts: 1,418
Garage
As stated above get an adapter to tap off the vacuum line for the brake booster
__________________
86 930 Grand Prix White
04 Cayenne
1970 Chevy Nova SS
Old 08-04-2017, 05:55 PM
  Pelican Parts Technical Article Directory    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Sep 2016
Location: Asheville, NC
Posts: 21
Manual non-boosted breaks on this one.
__________________
1986 Ruf 930
2015 991 GTS-MT
2006 993 S-MT (Gone)
1969 911 T (Gone)
Old 08-04-2017, 07:46 PM
  Pelican Parts Technical Article Directory    Reply With Quote #4 (permalink)
Registered User
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 2,809
You are kidding, right? No vacuum assist brakes?
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 08-04-2017, 07:54 PM
  Pelican Parts Technical Article Directory    Reply With Quote #5 (permalink)
Turbofrog
 
smurfbus's Avatar
 
Join Date: Aug 2009
Location: Europe
Posts: 1,358
Where can one find a wonky adapter for that booster line? I havent seen one in regular autostores.
__________________
************************************************** *******************************
79 930: HX40S#16, MS3pro+ID1000+044+E85, Ignition: 123/TUNE/MSD6A, True split BB, 2*turbosmart38,
99 Audi S4: RS4 engine/E85/K24brids, KW3, Movit+RS6 discs
Old 08-04-2017, 10:29 PM
  Pelican Parts Technical Article Directory    Reply With Quote #6 (permalink)
Crotchety Old Bastard
 
RarlyL8's Avatar
 
Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,255
Garage
You've already got a line to the engine - where the boost line belongs. Pipe it below the throttle plate so the gage only sees the boost that the engine sees. Above the throttle plate you will see chop throttle spikes. Cutting into brake vac lines is nuts, those are your BRAKES.
__________________
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 08-05-2017, 06:05 AM
  Pelican Parts Technical Article Directory    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Jan 2015
Posts: 1,263
Tapping into the brake booster line for a boost gauge has no effect on brake booster action, it's still a closed system. For my AEM boost gauge and data logger I tee'd into the rubber booster line on the inside right behind the go pedal. It connects to the steel line in the tunnel that runs back to the engine bay and then goes to the manifold with a rubber line.
Old 08-05-2017, 06:24 AM
  Pelican Parts Technical Article Directory    Reply With Quote #8 (permalink)
Registered User
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 2,809
Brian - makes no difference to the brakes. At all. Think about all the manifold leaks and hose leaks in the engine when you have tuning issues. They also feed into the brake vacuum system. No effect. Your engine is a 3.3 l vacuum pump. It overwhelms any leaks - even assuming you have a leak at the boost gauge line. Think about all the cracked and missing hoses - makes no difference to the brakes.
Regards
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 08-05-2017, 01:26 PM
  Pelican Parts Technical Article Directory    Reply With Quote #9 (permalink)
Registered User
 
VZ935's Avatar
 
Join Date: Apr 2005
Location: Burlingame , CA
Posts: 2,291
Garage
Send a message via AIM to VZ935
I didn't have a booster on my 930 either


__________________
A bunch of old race cars
Old 08-05-2017, 04:49 PM
  Pelican Parts Technical Article Directory    Reply With Quote #10 (permalink)
Registered User
 
Join Date: Sep 2016
Location: Asheville, NC
Posts: 21
Thanks Guys... I'm tapped into the intake below the throttle plate. Works without spike but is not very sensitive to partial boost. And yes, no power brakes or steering on this one... pure.
__________________
1986 Ruf 930
2015 991 GTS-MT
2006 993 S-MT (Gone)
1969 911 T (Gone)
Old 08-05-2017, 05:39 PM
  Pelican Parts Technical Article Directory    Reply With Quote #11 (permalink)
Registered User
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 2,809
Quote:
Originally Posted by VZ935 View Post
I didn't have a booster on my 930 either


So, forgive me, but why wouldn't you run a brake booster on that beast? Was it the physical limitation of fitting it in? You must have developed some strong thigh muscles. Maybe that was the reason :-)
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 08-05-2017, 07:31 PM
  Pelican Parts Technical Article Directory    Reply With Quote #12 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Knee Pads are Overrated!
 
Rawknees'Turbo's Avatar
 
Join Date: Apr 2016
Location: Norf TexASS
Posts: 6,824
Quote:
Originally Posted by Alan L View Post
You must have developed some strong thigh muscles. Maybe that was the reason :-)
Alan
Based on all his awesome cars, past and present, I'm pretty sure that Big V used (uses) his d**k to actuate the brake pedal!!!

Old 08-05-2017, 07:42 PM
  Pelican Parts Technical Article Directory    Reply With Quote #13 (permalink)
Registered User
 
VZ935's Avatar
 
Join Date: Apr 2005
Location: Burlingame , CA
Posts: 2,291
Garage
Send a message via AIM to VZ935
Nice even peddle. Easy to modulate and no real strength needed. Won every Frozen Rotor "Best Braking" award in every race I ran that included cup cars with ABS. Stacked up those free Cryogenic treatments.
I swear if I dialed all the brake to the front I could stand that car on its nose if I wanted to.



Quote:
Originally Posted by Alan L View Post
So, forgive me, but why wouldn't you run a brake booster on that beast? Was it the physical limitation of fitting it in? You must have developed some strong thigh muscles. Maybe that was the reason :-)
Alan


__________________
A bunch of old race cars
Old 08-05-2017, 07:44 PM
  Pelican Parts Technical Article Directory    Reply With Quote #14 (permalink)
Registered User
 
VZ935's Avatar
 
Join Date: Apr 2005
Location: Burlingame , CA
Posts: 2,291
Garage
Send a message via AIM to VZ935
Quote:
Originally Posted by Rawknees'Turbo View Post
Based on all his awesome cars, past and present, I'm pretty sure that Big V used (uses) his d**k to actuate the brake pedal!!!

Glad its not that long and strong or my only option would be to mate with animals on the Serengeti
__________________
A bunch of old race cars
Old 08-05-2017, 07:49 PM
  Pelican Parts Technical Article Directory    Reply With Quote #15 (permalink)
Knee Pads are Overrated!
 
Rawknees'Turbo's Avatar
 
Join Date: Apr 2016
Location: Norf TexASS
Posts: 6,824
Quote:
Originally Posted by VZ935 View Post
Glad its not that long and strong or my only option would be to mate with animals on the Serengeti
Hmmmm, some of those are pretty hot!!!
Old 08-05-2017, 07:51 PM
  Pelican Parts Technical Article Directory    Reply With Quote #16 (permalink)
Registered User
 
Join Date: Apr 2007
Location: wisconsin
Posts: 2,213
Quote:
Originally Posted by VZ935 View Post
Nice even peddle. Easy to modulate and no real strength needed. Won every Frozen Rotor "Best Braking" award in every race I ran that included cup cars with ABS. Stacked up those free Cryogenic treatments.
I swear if I dialed all the brake to the front I could stand that car on its nose if I wanted to.







How?

My 930 got towed at the track, motor off. I didn't have enough power to slow down and not hit the tow truck if it stopped suddenly. It required a 500% increase in force...

With the motor running, can stop from 120 pushing down with my pinkie toe...
Old 08-05-2017, 08:58 PM
  Pelican Parts Technical Article Directory    Reply With Quote #17 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 12:24 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2016 Pelican Parts - 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.