|
|
|
|
| Author |
|
|
Crew Chief
Join Date: Nov 2001
Location: Wilkesboro, NC
Posts: 1,678
|
Problem after Intercooler install
I installed a Garettson Longneck Intercooler on my '83 930 with the C2 turbo bypass assembly.
The car runs great until the 2-3 shift , that is when it hesitates for a about a second( like you forgot to press the Gaspedal ) then it pulls fine. I changed the Bypass valve and it did not fix it . then i reinstalled all the stock intercooler components including the Bypass manifold assembly and the problem was gone. Any ideas ? 
__________________
Herbert B. GruppeB #093 Carolinas Region PCA Member National PCA Driving Instructor _______________ '71 911 RSR look '74 914 2.0 '76 911S Targa '83 930S Slantnose (13000 miles) '86 951 Prototype Testcar built in '84 (56000 miles) Serial #00014 '86 951 '87 944 "Life is short , drive Fast" |
||
11-06-2006, 04:16 AM
|
|
|
Me like track days
Join Date: Sep 2003
Location: Kirkland, WA
Posts: 10,209
|
Boost leak. BTDT, 'rubberband delay effect' was my description when it happened here -
Just a guess
__________________
- Craig 3.4L, SC heads, 964 cams, B&B headers, K27 HF ZC turbo, Ruf IC. WUR & RPM switch, IA fuel head, Zork, G50/50 5 speed. 438 RWHP / 413 RWTQ - "930 is the wild slut you sleep with who tries to kill you every time you "get it on" - Quote by Gabe Movie: 930 on the dyno Last edited by Craig 930 RS; 11-06-2006 at 10:02 AM.. |
||
|
11-06-2006, 08:42 AM
|
|
|
Crew Chief
Join Date: Nov 2001
Location: Wilkesboro, NC
Posts: 1,678
|
Craig,
i was unable to find a leak , where could a leak be large enough to cause this deadspot ?
__________________
Herbert B. GruppeB #093 Carolinas Region PCA Member National PCA Driving Instructor _______________ '71 911 RSR look '74 914 2.0 '76 911S Targa '83 930S Slantnose (13000 miles) '86 951 Prototype Testcar built in '84 (56000 miles) Serial #00014 '86 951 '87 944 "Life is short , drive Fast" |
||
|
11-06-2006, 11:17 AM
|
|
|
Me like track days
Join Date: Sep 2003
Location: Kirkland, WA
Posts: 10,209
|
My IC partially popped off the inlet tube - causing a situation that I can describe as:
"boost had to build to a point to adequately pressurize the intake system - caused a hugely noticeable delay in boost buildup"  Where the IC inlet joins the IC -
__________________
- Craig 3.4L, SC heads, 964 cams, B&B headers, K27 HF ZC turbo, Ruf IC. WUR & RPM switch, IA fuel head, Zork, G50/50 5 speed. 438 RWHP / 413 RWTQ - "930 is the wild slut you sleep with who tries to kill you every time you "get it on" - Quote by Gabe Movie: 930 on the dyno |
||
|
11-06-2006, 11:36 AM
|
|
|
Me like track days
Join Date: Sep 2003
Location: Kirkland, WA
Posts: 10,209
|
Also check the join to the manifold -
__________________
- Craig 3.4L, SC heads, 964 cams, B&B headers, K27 HF ZC turbo, Ruf IC. WUR & RPM switch, IA fuel head, Zork, G50/50 5 speed. 438 RWHP / 413 RWTQ - "930 is the wild slut you sleep with who tries to kill you every time you "get it on" - Quote by Gabe Movie: 930 on the dyno |
||
|
11-06-2006, 11:37 AM
|
|
|
7.0:1 > 11.3:1 > 7.0:1
|
Did it have this 2-3 delay since since you originally installed the I/C or did the delay start sometime afterwrds?
Try lifting hard on the ends of the intercooler to see if it moves up off the O-ring seats. The O-ring seats are almost 3" dia. At one bar of boost this equates to 105 Lbs of force pushing up on each end of the I/C. Jim |
||
|
11-06-2006, 06:11 PM
|
|
|
|
Me like track days
Join Date: Sep 2003
Location: Kirkland, WA
Posts: 10,209
|
Popped mine right off......because I was a moron and didn't tighten the strap bolts from IC pipe to IC.
 Made all kinds of weird sensations - this was all post-rebuild-first-time-on-track so I was wondering WTH was going on. BIG lag in the truest sense of the word!
__________________
- Craig 3.4L, SC heads, 964 cams, B&B headers, K27 HF ZC turbo, Ruf IC. WUR & RPM switch, IA fuel head, Zork, G50/50 5 speed. 438 RWHP / 413 RWTQ - "930 is the wild slut you sleep with who tries to kill you every time you "get it on" - Quote by Gabe Movie: 930 on the dyno |
||
|
11-06-2006, 08:58 PM
|
|
|
Crew Chief
Join Date: Nov 2001
Location: Wilkesboro, NC
Posts: 1,678
|
All the joints look fine ,
it builds Boost quick thru 2nd gear and sometimes into 3rd but then the boostgauge bounces and it acts like you took the foot completely off the throttle ( boost drops to 0 ) for a second or so and then it is back at full boost and runs fine from then on until you go thru the gears again
__________________
Herbert B. GruppeB #093 Carolinas Region PCA Member National PCA Driving Instructor _______________ '71 911 RSR look '74 914 2.0 '76 911S Targa '83 930S Slantnose (13000 miles) '86 951 Prototype Testcar built in '84 (56000 miles) Serial #00014 '86 951 '87 944 "Life is short , drive Fast" |
||
|
11-07-2006, 02:51 AM
|
|
|
Registered
Join Date: Jun 2001
Location: Sweden
Posts: 5,911
|
You are sure you aren't hitting the overboost switch?
Boost builds higher in higher gears, It might be so that you are just tripping the switch in 3-rd.
__________________
Thank you for your time, |
||
|
11-07-2006, 05:20 AM
|
|
|
Crew Chief
Join Date: Nov 2001
Location: Wilkesboro, NC
Posts: 1,678
|
I do not use the Overboost switch ( dont have one ) and the curcuit is bypassed
__________________
Herbert B. GruppeB #093 Carolinas Region PCA Member National PCA Driving Instructor _______________ '71 911 RSR look '74 914 2.0 '76 911S Targa '83 930S Slantnose (13000 miles) '86 951 Prototype Testcar built in '84 (56000 miles) Serial #00014 '86 951 '87 944 "Life is short , drive Fast" |
||
|
11-07-2006, 06:35 AM
|
|
|
Me like track days
Join Date: Sep 2003
Location: Kirkland, WA
Posts: 10,209
|
Can you post some pictures?
This way we might get a better idea of the layout so a leak or ? can be located easier -
__________________
- Craig 3.4L, SC heads, 964 cams, B&B headers, K27 HF ZC turbo, Ruf IC. WUR & RPM switch, IA fuel head, Zork, G50/50 5 speed. 438 RWHP / 413 RWTQ - "930 is the wild slut you sleep with who tries to kill you every time you "get it on" - Quote by Gabe Movie: 930 on the dyno |
||
|
11-07-2006, 08:04 AM
|
|
|
Crew Chief
Join Date: Nov 2001
Location: Wilkesboro, NC
Posts: 1,678
|
At this time i have the stock intercooler back on the car with the stock bypass manifold
__________________
Herbert B. GruppeB #093 Carolinas Region PCA Member National PCA Driving Instructor _______________ '71 911 RSR look '74 914 2.0 '76 911S Targa '83 930S Slantnose (13000 miles) '86 951 Prototype Testcar built in '84 (56000 miles) Serial #00014 '86 951 '87 944 "Life is short , drive Fast" |
||
|
11-07-2006, 08:15 AM
|
|
|
|
7.0:1 > 11.3:1 > 7.0:1
|
Hmmm, if the boost drops to zero rather suddenly it makes me wonder if the BOV is opening up for some reason.
Where did you connect the actuator hose? Anything T'd into the actuator hose? |
||
|
11-07-2006, 05:39 PM
|
|
1970 
1972 6 conversion 
1972 Datsun 510 
1986 
