Rats Nest and AC Delete
 

Hey so I am new to the rotary community and was doing a lot of research on deleting the rats nest and what not. I am curious as to what the "throttle opener" is? I want to take out my AC which means taking out the solenoid which I believe plugs in to the "throttle opener", can I just plug it? Any info would be awesome thanks.

First thing, does your car currently run? If not, I wouldn't suggest any mods yet. What would be your purpose for removing the rats nest?

might i suggest

Foxed.ca - Mazda RX-7 Manuals

Yes it runs, I am not doing this right now, just curious for the future. I want to delete the rats nest cause hp and weight and simplicity. But I also want to delete the AC cause I don't mind sweating. I was looking thru the rats nest removal tutorial but in it they keep AC meaning they use the "throttle opener" with the solenoid etc. So I am just wondering if I just plug that throttle opener nipple or I have to use a hose?

Also it's a 1983 RX-7 with a 12a manual.

Plugging it with a nipple is fine. My only suggestion would be don't make any changes you can't put back to stock. Keep all the old parts. Unless you're good with carbs, this can be a challenge because of the tuning. I'm not saying don't make the mods you want, just be careful. You would be surprised at how many newer members take on removing that rats nest only to run into issues and give up. Removing the rats nest won't magically give you more horsepower. The throttle response can be improved, but it all depends on how well you can tune a carb.

Let's be clear, there is no secret HP to unlock by removing the vacuum lines. You'll gain some power by installing a header and deleting the air pump and air control valve, but everything else on the carb and specifically the rats nest can and should be retained on a street driven car.

I meant by the AC chuyler1, I thought you were smart enough to assume that. Yes it just a few hp and a few pounds but in a light car things count.

Ok thanks for the help, I will just plug it. Don't worry I have worked on carbs before so no need to worry.

To be fair you clearly stated:


"Originally Posted by Yoshioka58
I want to delete the rats nest cause hp and weight and simplicity"


So let's reel it back in and start again. No horsepower will be gained by removing the rats nest. Nothing other than ease of working in the engine is gained. With the stock vacuum and solenoid setup in place the engine will run and perform well. Removing that setup can cause running issues and loss of fuel mileage. With an aftermarket carb and intake setup you can gain some power and driveability will remain excellent. Removing the a.c. will also not gain any additional power. It will save weight and not a ton where you will notice a big difference. You are starting with a 101hp engine. It's not an overly fast car by any means but with some bolt on modifications you can make the car accelerate very well.

Let's review what you will be removing and what it does.

From left to right by solenoid...

1/2) leading/trailing vacuum advance. To get full advance, these pull air from below the throttle plates and the ECU will turn them off for the motor to idle at 0 degrees. Without them you can hook the advance up to a "port" vacuum signal just above the throttle plates but that doesn't give you the right advance off throttle. Commence back firing and rough deceleration.

3) switching valve - you can remove this if you have removed the air pump. It only provides control to pumping the right amount of air into the catalysts.

4) shutter valve solenoid. This will close off the rear rotor under decel. Helps with deceleration, assuming it works and improves gas mileage. The shutter valve getting stuck is an easy fix but many don't know that and they rebuild the whole carb chasing an issue where the motor is idling on one rotor.

5) relief valve solenoid, works in conjunction with shutter valve to improve deceleration.

6) a/c solenoid, boosts idle when the compressor is engaged, if you don't have a/c you can remove it, but it's not hurting anything.

7) purge valve, pulls air through the charcoal canister and crank case under cruising conditions, with the complete evap system in place you won't lose gas to thin air, bonus points for your garage not smelling like gas all the time. Without purge system you need a catch can or at least a way to vent the crank case or you'll end up with schmutz in the oil filler neck and it will quickly rust from the excess moisture.

Also in there is a cold air idle compensator, cruise control lines, carb heater, hot start assist, and a few things I'm not thinking of that make the 12a with everything functioning properly a pull choke turn key start in any weather conditions.

But hey, it's your car, if you want it to look cool the few times you open the hood at a car meet then by all means ditch that stuff and strip the carb.

Ok seems everyone is against removing it. Why is it a thing then?. Btw only driving the car during summer times and not too too often, just my fun car.

No one is against you removing the stuff you want to remove, we are just trying to inform you of the consequences of removing those items. Being well educated on how the solenoids and the vacuum lines on the rats nest work is very important. We just want to make sure you know there are side effects. People remove the nest under the pretense that power will be gained and the engine will magically be easier to work on. Ray Green did a study and write up on rats nest removal years back and found that his mileage, idle, and performance suffered. He ultimately reinstalled the rats nest. I attempted to the same test on an 85 GS years back and the engine ran poorly. I also reinstalled the stock emissions rack.

Its a thing because as much as it may help the car run, when it has issues like vacuum leaks, bad solenoids, or electrical gremlins it soon becomes apparent that just yanking it out is the best option. Its kind of like tonsils.

It's also a "thing" because this forum is/was filled with guys that used their cars for spec racing where the Nikki has to be retained and only thing that mattered was full throttle between 5000-8000 RPM. When you're chasing someone with the exact same car, weight matters, but idle speed does not, cold starts aren't important, and ignition timing doesn't need to be variable, set it for wide open throttle and be done with it.

By the way, a cleaned up rats nest with new colored silicone hoses is quite a sight and far more impressive to see than an engine with nothing on it.

I think Ray is gonna like you for sure!

Some of us got rid of it when we went to aftermarket intakes (Webers, Dells, etc) and lost the pieces (DOH!). Either way its a personal choice for sure. One thing is with it removed, when folks look at the engine they are usually amazed at how really small it is.

its really hard to search for this, but for every 'im going to remove the rats nest" thread there is usually a follow up "my car doesn't run right" thread.

that being said, if you don't have A/C the throttle opener comes right off, and you plug the line, and call it done.

the other thing is that the whole rats nest weighs maybe 3lbs, so you have to think about the amount of work vs weight saved, and in this case it doesn't pencil.

Got it sounds good.