rats nest...what to get and what to lose
03-19-12, 10:37 PM
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rats nest...what to get and what to lose
hello everyone, im still new and this might not be the right place for this post, but maybe i could have a bit of help.
As everyone who knows and digs deep into our cars knows, the rats nest isnt something that many(if any) find nice to look at. Being one of these i my self thought when i first lifted the hood though,"ya....thats going to go soon." But my question is, what am i really going to gain from taking it off? What will i lose? i have time, to much time -_- so i could do it all myself. im just concerned about what the end diffrence will be, other then a pretty engine bay. THANKS to everyone who has helped!
Mr Twitches
As everyone who knows and digs deep into our cars knows, the rats nest isnt something that many(if any) find nice to look at. Being one of these i my self thought when i first lifted the hood though,"ya....thats going to go soon." But my question is, what am i really going to gain from taking it off? What will i lose? i have time, to much time -_- so i could do it all myself. im just concerned about what the end diffrence will be, other then a pretty engine bay. THANKS to everyone who has helped!
Mr Twitches
03-19-12, 10:59 PM
#2
Don't Cross The Streams..
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hello everyone, im still new and this might not be the right place for this post, but maybe i could have a bit of help.
As everyone who knows and digs deep into our cars knows, the rats nest isnt something that many(if any) find nice to look at. Being one of these i my self thought when i first lifted the hood though,"ya....thats going to go soon." But my question is, what am i really going to gain from taking it off? What will i lose? i have time, to much time -_- so i could do it all myself. im just concerned about what the end diffrence will be, other then a pretty engine bay. THANKS to everyone who has helped!
Mr Twitches
As everyone who knows and digs deep into our cars knows, the rats nest isnt something that many(if any) find nice to look at. Being one of these i my self thought when i first lifted the hood though,"ya....thats going to go soon." But my question is, what am i really going to gain from taking it off? What will i lose? i have time, to much time -_- so i could do it all myself. im just concerned about what the end diffrence will be, other then a pretty engine bay. THANKS to everyone who has helped!
Mr Twitches
03-20-12, 11:42 AM
#6
I just removed mine last weekend. Car starts better for me, and has a noticeable throttle response gain. Mileage may go down, but it's worth it for a more responsive throttle for me 
Along with the simplicity aspect, I love that. It only took an hour or 2 (with hardware store runs for bolts and such) and around $75 for me. Go for it!
Along with the simplicity aspect, I love that. It only took an hour or 2 (with hardware store runs for bolts and such) and around $75 for me. Go for it!
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kenneth_ugalde (06-08-21)
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03-20-12, 01:45 PM
#8
I agree with DD, done right rats nests are a thing of beauty, whether customized like DD's (above) or just plain stock like mine (below).
A properly functioning rats nest gives a smoother, more progressive throttle response, a big boost in gas mileage, lower emissions and bragging rights for knowing how they work and how to keep them that way. Yes a well maintained rats nest truly is a thing of great beauty.
A properly functioning rats nest gives a smoother, more progressive throttle response, a big boost in gas mileage, lower emissions and bragging rights for knowing how they work and how to keep them that way. Yes a well maintained rats nest truly is a thing of great beauty.
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kenneth_ugalde (06-08-21)
03-20-12, 10:02 PM
#10
Wow...wow DD, that's amazing. I just took mine out and I'm almost tempted to put it back in due to this picture! And since I noticed she's not idling how I'd like, need to check for the 5th time to make sure its done right. Tempted to throw it back on but not quite to that point yet.
03-21-12, 12:33 AM
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"Daaang!" was all i really had to say Ray and DD. those look great! =D i guess ill end up keeping mine on for the time being, i drive a lot as it is. i average about 80 something miles a day or more depending on if i have to go get food for the family. I guess from those who i have learned from(and thats not many. this does not include what you guys have helped me with off of here) that the word performance and rats-nest could never belong. Is this mainly, or if any, true?
03-21-12, 03:44 AM
#12
Yep DDs rig is all about the eye-candy!
So A Q here, to the rats-removed crowd - if/when I get around to installing my RB exhaust/header, since the air pump goes (or can go) - what is the point of KEEPING the rats in place? Presume with the header, etc in place it sort of puts the carb/intake side in a bit of a kilter that requires some mix tweaks, etc so would HELP to be rat-less...no? And then there is that damn Sterling sitting here...
Stu Aull
80GS
Alaska
So A Q here, to the rats-removed crowd - if/when I get around to installing my RB exhaust/header, since the air pump goes (or can go) - what is the point of KEEPING the rats in place? Presume with the header, etc in place it sort of puts the carb/intake side in a bit of a kilter that requires some mix tweaks, etc so would HELP to be rat-less...no? And then there is that damn Sterling sitting here...
Stu Aull
80GS
Alaska
03-21-12, 07:04 AM
#13
the rats nest is actually pretty simple and if there's a vacuum leak, it will be easy to find. replace all of the vacuum hoses with black silicone 4mm semi hard line from mcmastercarr.com and they will last the life of the vehicle. as Ray said, the rats nest is a beautiful thing that provides a more progressive throttle feel, much better mileage, and smoother running conditions. people remove them because they are afraid to learn to work on them.
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kenneth_ugalde (06-08-21)
03-21-12, 08:41 AM
#14
To be sure, removing the rats nest does make things look a lot simpler and cleaner under the hood and it makes removing the carb and other work much much easier.
When I first installed an RB header I was thinking much like Stu is, without the air pump, who needs the rats?
So two summers ago I removed the air control valve and the rats nest, using the well documented procedures you can find on this forum. I have to admit, it looked pretty good and created a whole bunch of space under the hood.
But it certainly didn't add any power and I didn't like the throttle progression, not smooth and linear like it was with the nest in. The worst part was the big drop in gas mileage on my 110 mile a day daily commute - it went from 22-23 mpg down to 18 mpg or less - not acceptable.
I worked and tweaked that set up all summer long trying to get it to behave better, but finally after two months I gave up and put the nest back in.
Nest reinstallation took about 2 hours and I immediately got better throttle response and gas mileage went back to 22-23 mpg. That's when I learned to love the rats nest.
Having said this, I have plenty of RX-7 friends who have removed their rats nest, some installing aftermarket carbs and all swear they get just as good gas mileage as long as they drive it right.
To each his own, but if you take it out put it in a box somewhere, you may have second thoughts.
When I first installed an RB header I was thinking much like Stu is, without the air pump, who needs the rats?
So two summers ago I removed the air control valve and the rats nest, using the well documented procedures you can find on this forum. I have to admit, it looked pretty good and created a whole bunch of space under the hood.
But it certainly didn't add any power and I didn't like the throttle progression, not smooth and linear like it was with the nest in. The worst part was the big drop in gas mileage on my 110 mile a day daily commute - it went from 22-23 mpg down to 18 mpg or less - not acceptable.
I worked and tweaked that set up all summer long trying to get it to behave better, but finally after two months I gave up and put the nest back in.
Nest reinstallation took about 2 hours and I immediately got better throttle response and gas mileage went back to 22-23 mpg. That's when I learned to love the rats nest.
Having said this, I have plenty of RX-7 friends who have removed their rats nest, some installing aftermarket carbs and all swear they get just as good gas mileage as long as they drive it right.
To each his own, but if you take it out put it in a box somewhere, you may have second thoughts.
03-21-12, 09:21 AM
#15
Ray. Your advice is always pretty good..........BUT, I will argue this one.
Pull the rats nest. Yank out that old tired 12A. Go 13B turbo fuel injected. Get 330rwhp and 26.5mpg on a trip. Who says that you can't have power and fuel economy?
BTW. Most people buy these cars because they are a SPORTS CAR. If you want fuel mileage, get you a Mazda Protege for a DD. I did. On a bad day the Protege gets 35mpg
Just messing with you. The rats nest is a debated topic that I no longer have to worry about.
Pull the rats nest. Yank out that old tired 12A. Go 13B turbo fuel injected. Get 330rwhp and 26.5mpg on a trip. Who says that you can't have power and fuel economy?
BTW. Most people buy these cars because they are a SPORTS CAR. If you want fuel mileage, get you a Mazda Protege for a DD. I did. On a bad day the Protege gets 35mpg
Just messing with you. The rats nest is a debated topic that I no longer have to worry about.
03-21-12, 09:29 AM
#16
It's important to remember that first gens, especially the carb'ed ones and particularly SA's, don't benefit from decades of computer-aided design optimization or the precise mixture control that can be had by a modern, computer-and-sensor controlled fuel injection.
A carburetor is essentially a mechanical computer which tries to calculate a proper air-fuel ratio, but which has very little input to work from, and very few ways it can adjust to conditions.
A goodly part of what much of the rat's nest does is to help compensate for the linear nature of the carb's function under certain conditions. It's a compensation system.
Some of it is emissions-related, some of it is drivability-related, and some of it (like the air-con solenoid) only relates to accessories.
A carburetor is essentially a mechanical computer which tries to calculate a proper air-fuel ratio, but which has very little input to work from, and very few ways it can adjust to conditions.
A goodly part of what much of the rat's nest does is to help compensate for the linear nature of the carb's function under certain conditions. It's a compensation system.
Some of it is emissions-related, some of it is drivability-related, and some of it (like the air-con solenoid) only relates to accessories.
03-21-12, 12:20 PM
#17
Both Ray and DD have amazing rats nests, that has definitely been established.
So with this comment, it makes me think about redoing my hoses.
I've always loved the look of colored vacuum hoses and have seen your engine bay before on the forum here DD, so I was wanting to do the colored hoses.
mazdaverx713b, you say to use 4mm tubing. In a calculation, 4mm metric vacuum line tubing internal diameter is about .15748in. 5/32" vacuum line from O'Reilly Auto, or Advance Auto internal diameter is about .15625in. So only a difference of .0123in. Almost no difference. The reason I brought math into it, is if I wanted to redo all the vacuum line on the rats nest I could just use some 5/32'' vacuum line from a local auto parts store. Here's the best deal on colored silicon tubing 4mm Blue Silicon vacuum hose.
DD, I'm not asking for any trade secrets, but what size tube and how many feet did you use to redo yours? Seeing the drop in mileage and different issues that arise from removing these necessary parts I think I may just redo my tubing and throw her back in.
Not trying to steal a thread. But for the masses I think the information would be awesome when trying to redo the lines, get the right side vacuum tubing, and all that comes with it. So what size lines necessary? How many feet of what? If doing the carb lines as well is it the same size?
With this info I think this thread should be archived, that's just me though. It would have definitely persuaded me not to remove mine and just redo the tubing. Live n learn huh?
I've always loved the look of colored vacuum hoses and have seen your engine bay before on the forum here DD, so I was wanting to do the colored hoses.
mazdaverx713b, you say to use 4mm tubing. In a calculation, 4mm metric vacuum line tubing internal diameter is about .15748in. 5/32" vacuum line from O'Reilly Auto, or Advance Auto internal diameter is about .15625in. So only a difference of .0123in. Almost no difference. The reason I brought math into it, is if I wanted to redo all the vacuum line on the rats nest I could just use some 5/32'' vacuum line from a local auto parts store. Here's the best deal on colored silicon tubing 4mm Blue Silicon vacuum hose.
DD, I'm not asking for any trade secrets, but what size tube and how many feet did you use to redo yours? Seeing the drop in mileage and different issues that arise from removing these necessary parts I think I may just redo my tubing and throw her back in.
Not trying to steal a thread. But for the masses I think the information would be awesome when trying to redo the lines, get the right side vacuum tubing, and all that comes with it. So what size lines necessary? How many feet of what? If doing the carb lines as well is it the same size?
With this info I think this thread should be archived, that's just me though. It would have definitely persuaded me not to remove mine and just redo the tubing. Live n learn huh?
03-21-12, 02:13 PM
#18
I bought my tubing from MazdaTrix (they had several colors available at the time) & IIRC they have a recommended quantity list on their site.
Yep; they recommend 10 ft of 3.5mm and 6 ft of 6mm. I believe I had to buy some extra, but I did some non-standard things too.
http://www.mazdatrix.com/c-silhos.htm
One downside of silicone hoses; dirt sticks to them. And silicone is fuel-permeable (gasoline will slowly migrate through it) so don't use it for fuel-carrying lines.
03-21-12, 11:56 PM
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lindahlish i think that is a great idea, and the fact that a rx7 owner could then see the pros and cons i think would help with there final choice. i personnaly think that i am going to try and keep them on as long i can. (till my racing beat intake and carter carb are ready to be set on a ported engine.)
03-24-12, 02:36 AM
#22
I guess the added "WTF?" with my Sterling is it is an 82 or 83 (?) carb - for an _automatic_ no less. None of which, according to Carl, was an issue in the Sterling-i-za-tion of it (he stopped Sterling-ing SA carbs early on he said). But does beg the Q as to what good 80 Nikki emissions bits will be with the later Carb?
Apologies, a bit off topic....
Stu Aull
80GS
Alaska
Apologies, a bit off topic....
Stu Aull
80GS
Alaska
03-25-12, 10:30 AM
#24
There is nothing in the nest that adds 5 mpg. Fuel mileage and throttle progression are affected by the mechanical secondary mod, Not the the rats nest removal. There seems to be some confusion that the mech secondary mod is included in the rats nest removal. It is not.
03-27-13, 02:17 PM
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Both Ray and DD have amazing rats nests, that has definitely been established.
So with this comment, it makes me think about redoing my hoses.
I've always loved the look of colored vacuum hoses and have seen your engine bay before on the forum here DD, so I was wanting to do the colored hoses.
mazdaverx713b, you say to use 4mm tubing. In a calculation, 4mm metric vacuum line tubing internal diameter is about .15748in. 5/32" vacuum line from O'Reilly Auto, or Advance Auto internal diameter is about .15625in. So only a difference of .0123in. Almost no difference. The reason I brought math into it, is if I wanted to redo all the vacuum line on the rats nest I could just use some 5/32'' vacuum line from a local auto parts store. Here's the best deal on colored silicon tubing 4mm Blue Silicon vacuum hose.
DD, I'm not asking for any trade secrets, but what size tube and how many feet did you use to redo yours? Seeing the drop in mileage and different issues that arise from removing these necessary parts I think I may just redo my tubing and throw her back in.
Not trying to steal a thread. But for the masses I think the information would be awesome when trying to redo the lines, get the right side vacuum tubing, and all that comes with it. So what size lines necessary? How many feet of what? If doing the carb lines as well is it the same size?
With this info I think this thread should be archived, that's just me though. It would have definitely persuaded me not to remove mine and just redo the tubing. Live n learn huh?
So with this comment, it makes me think about redoing my hoses.
I've always loved the look of colored vacuum hoses and have seen your engine bay before on the forum here DD, so I was wanting to do the colored hoses.
mazdaverx713b, you say to use 4mm tubing. In a calculation, 4mm metric vacuum line tubing internal diameter is about .15748in. 5/32" vacuum line from O'Reilly Auto, or Advance Auto internal diameter is about .15625in. So only a difference of .0123in. Almost no difference. The reason I brought math into it, is if I wanted to redo all the vacuum line on the rats nest I could just use some 5/32'' vacuum line from a local auto parts store. Here's the best deal on colored silicon tubing 4mm Blue Silicon vacuum hose.
DD, I'm not asking for any trade secrets, but what size tube and how many feet did you use to redo yours? Seeing the drop in mileage and different issues that arise from removing these necessary parts I think I may just redo my tubing and throw her back in.
Not trying to steal a thread. But for the masses I think the information would be awesome when trying to redo the lines, get the right side vacuum tubing, and all that comes with it. So what size lines necessary? How many feet of what? If doing the carb lines as well is it the same size?
With this info I think this thread should be archived, that's just me though. It would have definitely persuaded me not to remove mine and just redo the tubing. Live n learn huh?
would using the 4mm be ok over the 3.5mm? would that slight increase hurt anything or change any thing vaccuum wise?
