wondering how to get the vacuum secondaries to open at a lower rpm... ive searched and didnt find anything so opening up a thread

 

remove the spring

 

wouldnt it engage them on start up tho? and when you are idling ?

 

check out mechanical secondary mod

 

for sure

 

Or just use a lighter spring...

 

There are several mechanisms that you need to alter to get vacuum secondaries to open earlier. One is the spring (e.g. cutting it shorter or removing it), but personally I think this has the least effect.

You also need to block the vacuum feed that runs from the secondary main venturi. The best way to do this IMO is by removing the venturi, rotating it so the opening in the venturi doesn't match up to the hole in the carby body, then re-inserting it. The reason for this, as stated in the carby manual, is that vacuum that feeds the secondary diaphragm is sourced from both primary and secondary venturis. Until the secondaries open, there is no vacuum at the secondary venturis, so basically this hole is leaking vacuum out from the primary venturis and weakening the vacuum signal to the diaphragm.

Finally there is a lock-out on the secondary throttle linkage that prevents vacuum secondaries opening too early. You need to investigate how this works and modify it to allow the secondaries to open when you want them. This is the main thing that stops them opening early.

 

1. It's a good idea to start up a word document with links that will help you in your rotary future. I did it and it has helped me a ton, I have many threads that I categorized so that I can retrieve information on amazing threads detailing the rat's nest removal, mechanical secondaries, carb rebuilds, things like that.

2. Searching is your best bet. With many hours of searching you will find what you need, and it has helped me out tremendously.

sterlingmetalworks.com
https://www.rx7club.com/showthread.p...al+secondaries
https://www.rx7club.com/showthread.php?t=969355&highlight=mechanical+secon daries

....are just a few I found after a 5min search. Good luck, and I'm considering the same thing this winter when my 7 is in hibernation!

 

thanks bro i still am lost when it come to this i wish there was a pic tut i cant go off of reading im a visual learner not a psychic you know? haha

 

Just go with mechanical secondaries, the mod is a lot easier. Check the 1st gen FAQ for a really easy way to do it.

 

+1 on mechanical secondaries. This modification only took me about an hour to do. Very simple.