 New guy carb question- how to select the right jets? |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
| Chily89 |
 Oct 13 2014, 07:28 PM
Post
#1
|
|
Newbie  Group: Members Posts: 2 Joined: 13-October 14 From: Ohio Member No.: 18,013 Region Association: Upper MidWest  |
I'm helping my friend get his car working correctly. We are having some carb issues. What is the process for getting the correct idle jets? I have read instructions on the redline website but I'm still having issues. The 914 is a 4cyl 2270 with dual weber 44 Idf's.
I read something about removing the main stacks then driving around. Can somebody please explain this method further. |
   |
 
|
  |
Replies
| ThePaintedMan |
Oct 14 2014, 05:56 AM
Post
#2
|
|
Advanced Member Group: Members Posts: 3,887 Joined: 6-September 11 From: St. Petersburg, FL Member No.: 13,527 Region Association: South East States 
|
When you say it's "always too rich", what specific a/f ratio are you seeing? If it drives well, it may not be as far off as you think (in which case: keep (IMG:style_emoticons/default/driving.gif) it!)
If it's always too rich and too hard to tune, then I would suspect that you have venturis(chokes) too small for that engine. Especially if you're running 45 idles and it's still rich/hard to tune. Look down in the top of one of the throttle butterflies with the engine off. Toward the side of the throttle body, but way down inside it will be a ring with numbers stamped on it. What is that number? This is the main venturi which has a huge impact on the rest of the carb's performance. |
|
|
|
| tornik550 |
Oct 14 2014, 06:15 AM
Post
#3
|
|
Senior Member Group: Members Posts: 1,248 Joined: 29-January 07 From: Ohio Member No.: 7,486 Region Association: None |
QUOTE(ThePaintedMan @ Oct 14 2014, 07:56 AM)  When you say it's "always too rich", what specific a/f ratio are you seeing? If it drives well, it may not be as far off as you think (in which case: keep (IMG:style_emoticons/default/driving.gif) it!) If it's always too rich and too hard to tune, then I would suspect that you have venturis(chokes) too small for that engine. Especially if you're running 45 idles and it's still rich/hard to tune. Look down in the top of one of the throttle butterflies with the engine off. Toward the side of the throttle body, but way down inside it will be a ring with numbers stamped on it. What is that number? This is the main venturi which has a huge impact on the rest of the carb's performance. A/F ratios are about 12.2 idle and 10.5 wot. Vents are 36. The car really does drive quite well- lots of power. |
|
|
|
| tornik550 |
Oct 14 2014, 06:40 AM
Post
#4
|
|
Senior Member Group: Members Posts: 1,248 Joined: 29-January 07 From: Ohio Member No.: 7,486 Region Association: None |
QUOTE(tornik550 @ Oct 14 2014, 08:15 AM) QUOTE(ThePaintedMan @ Oct 14 2014, 07:56 AM) When you say it's "always too rich", what specific a/f ratio are you seeing? If it drives well, it may not be as far off as you think (in which case: keep (IMG:style_emoticons/default/driving.gif) it!) If it's always too rich and too hard to tune, then I would suspect that you have venturis(chokes) too small for that engine. Especially if you're running 45 idles and it's still rich/hard to tune. Look down in the top of one of the throttle butterflies with the engine off. Toward the side of the throttle body, but way down inside it will be a ring with numbers stamped on it. What is that number? This is the main venturi which has a huge impact on the rest of the carb's performance. A/F ratios are about 12.2 idle and 10.5 wot. Vents are 36. The car really does drive quite well- lots of power. (FYI- it is my car the original post was talking about) |
|
|
|
Posts in this topic
Chily89 New guy carb question- how to select the right jets? Oct 13 2014, 07:28 PM
ThePaintedMan
I read something about removing the main stacks t... Oct 13 2014, 09:04 PM
McMark
I read something about removing the main stacks ... Oct 13 2014, 10:52 PM Chily89 There currently is an AEM wideband installed. The... Oct 14 2014, 04:58 AM ThePaintedMan Okay Tornik, that makes sense.
36s should be in t... Oct 14 2014, 07:36 AM tornik550
Okay Tornik, that makes sense.
36s should be in ... Oct 14 2014, 07:46 AM stugray AFR gauges are nearly useless except at WOT with a... Oct 14 2014, 09:38 AM McMark What you're describing about the AFR sounds li... Oct 14 2014, 09:29 PM stugray
stugray - Narrowband AFR gauges are nearly useles... Oct 14 2014, 10:00 PM tornik550 Thank you for every ones help. I found a very in... Oct 15 2014, 05:45 AM ThePaintedMan Yes. Which is why I suggested to start there first... Oct 15 2014, 06:04 AM stugray
Stu - think of it this way, widebands operate usi... Oct 15 2014, 07:14 AM ThePaintedMan Hope this doesn't get too hijacked...
But St... Oct 15 2014, 07:51 AM |
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 9th July 2025 - 04:23 PM |
Invision Power Board
v9.1.4 © 2025 IPS, Inc.