Accelerator Cable for Dual Carbs ? Options

[cary]

In putting Mark's engine back in and replacing the broken accelerator cable. It seems the cable isn't quite long enough to work/fit correctly. In the FI arrangement the cable crosses the engine at 45 degrees. In dual carbs it needs to come at the bar at 90 degrees. Which pulls the bowden out of the firewall. Which will allow water down the cable tube.

What have others done to work around this ?

[jd74914]

​Apologies for sticking my nose in here since I have no real stake in the game but I really felt compelled to comment since Darren is taking so much fire. I'm not going to comment on any of the linkages; they all have positives and negatives ranging from price-point to complexity to robustness. I also know Racer Chris well and consider him a friend. (IMG:style_emoticons/default/smile.gif)

What I really wanted to say is that I can see where Darren is coming from and it seems that most people are getting caught up in the criticism rather than the intent. Maybe his writing is a little harsh, but it's quite difficult to actually read intended tone from forum text. When you spend a lot of time looking at failures you end up being hypercritical which isn't necessarily bad thing. Almost all car parts can use improvement in some manor, though in general older Porsche design is quite good (look at the stress relieved heads of the lower shock bolts, etc.).

It seems that not many people here have sat in a lot of detailed FMEAs. They tend to change your perspective on things a little bit, especially when people who have extensive experience with reliability and failure analysis are in the room. The discussion is really focused around improvements with participants who have less bias due to decreased stake in the game than the designer. Essentially you are 'arm-chair quarterbacking" to increase safety and reliability. In an FMEA you are assessing the design for an impact factor which is based on severity of the failure's effects and frequency of failure.

The problem with aftermarket car parts is that the severity rating can be quite high (death in the extreme), but in general the occurrence rating is unknown. In engineering failure analysis, low occurrences are often measured in mean-time between failures of 10,000 to one million hours, etc. That sample just isn't possible with specialty parts for niche cars.

As far as the throttle actuator discussion here I play (work is only work when it's not fun) a fluidic/thermal controls engineer and am personally a huge fan losing the throttle cable altogether and going DBW since you can tweek the actuation curve, but that's not really in the scope for most induction packages here. (IMG:style_emoticons/default/laugh.gif)