I have a 84 GS pretty much fully stock. I have been advised several times to remove my fully functional emissions systems. They kill performance, make working on my car a chore and are ugly. I could probably maybe get stickers on my car without them so why do I keep them around?

 

Because it increases gas mileage, throttle response and overall performance.

Only advantage is it makes your carb easier to take off and it looks cooler, which are amateur cop outs.

Upgrade the exhaust, go RB, lose the air pump and that useless power steering.

100 lbs. gone, no more leaky pump repairs and way uglier than the rats; also makes the plugs harder to change.

Also dis the AC if you haven't already.

Then enjoy.

 

Ray just about nailed it. I'd say don't remove it until you've 1. upgraded the exhaust and 2. Got another carb rebuilt and stripped with accel pump modification. Then remove everything carefully so as to preserve it for future generations.

Oh, and keep the AC if it works. Makes the drive to DGRR much more pleasant.

 

Are you saying the stock rats nest and associated junk offers greater performance over a stripped down carb and manifold??

 

Just about, yeah.

 

Based on my recent experience it's everyday 'driveablity' that suffers with the fuel economy. The performance is essentially the same.

My recently installed Sterling has restored the driveability. To better than new, I'd say.

 

OMG. It never ends.

 

@stevan ...i know right? ...lol

 

Watching trees wilt when you drive by is fun.

 

You probably already gave up on the notion of amazing gas mileage (good enough will do for most of us) when you bought the rotary, so that is not a good reason to keep the nest. I'd remove it for the following reasons:

1. Like stated by everyone else the first thing you are going to improve on any RX-7 is the exhaust which once you yank and go with something more free flowing you will need to remove a lot of the ridiculous vacuum and air valves. The car doesn't way enough to need power steering so get rid of that and the cruise control if you had it too.

2. You have a better chance of passing emissions (the test, not the "why doesn't it look like the picture" inspection) with no rats nest compared to one that has become faulty with age.

3. You free up overall ambient vaccuum in your car since you have less clutter sitting above and to the side of your engine. More vacuum means more space for hot air to spread = overall less nasty hot zones in your car.

4. You get to play with some basic electronics when you de-pin and strip your harness of all the extra dead connectors and wiring. Your main XO-1 connector ends up going from 18 or 19 down to 9 pins once stripped.

5. If you end up going with a non stock carb you can't use it anyway.

Also unless you live in the desert isn't doesn't get hot enough anywhere in the continental U.S. that you need A/C (even the drive across TN to Deal's Gap). There is a reason your grandfather wore an undershirt, its so your sweat from your back and pits doesn't stain your nice shirt that says "no pistons." Ditch that heavy compressor and put something cool in that big new gap you just made in your engine bay.

 

I hope you where just kidding with these suggestions. Passing emissions without the rats nest and air pump would be very hard. Plus, the air pump is needed for the cat.

I also hear so many people that say they removed the AC because it's need needed in most areas. I can tell you that here in Missouri, you sweat your *** off in the summer without out it.

OP: If you plan on using the car for anything other then a track car, keep the rats nest and AC. the engine bay can still look clean and it's not hard to work on.

We hear so many people that say that they removed the rats nest and now it runs like crap. Throw on a good exhaust and a FMOC if you don't already have one. A factory 12A only makes about 105 HP. Have fun with it. If you want more power, drop in a 13B NA or turbo.

 

Nicely stated KC.

That stuff mentioned above about "improving the exhaust by removing the nest" is the most ridiculous claim I've heard yet. In fact, none of that guy's 5 arguments make any sense.

I always hate to see a new SA/FB owner rip out the rats nest under the misguided impression that it's a good idea, only to discover later why it was a mistake.

Taking out the nest DOES NOT IMPROVE PERFORMANCE! Instead, it does the opposite, by significantly reducing gas mileage, increasing emissions and messing up your throttled response, all of which begin the decline of one of the few remaining unmolested examples and decrease resale value.

 

What milage do you get with the rats nest?

 

I'd like to thank everyone for giving the clear pros and cons. At least for me, it's now very clear that my rat's nest will be staying!

 

They should have put them nests on the IMSA GTU 7's in the 80's, they would have won even more races with increased performance and mpg. LOL.

 

X # of people remove their rats nest and have bad results.
Their conclusion is: Removing the rats nest is bad for performance.

X # of people remove rats nest and have good results.
Their conclusion is: The group that had bad results did something wrong.

 

I agree with X # of people.

 

Someone gets the proof of concept.

 

"X # of people remove their rats nest and have bad results.
Their conclusion is: Removing the rats nest is bad for performance.

X # of people remove rats nest and have good results.
Their conclusion is: The group that had bad results did something wrong. "

Well said Stevan.

The point of a discussion like this is not to make decisions for people, they'll do that themselves and live with the consequences.

Rather the point is to inform, hopefully by folks who have some experience with this mod, so that people who are considering a rat's nest deletion can make a more informed decision.

Personally, I tried the nest deletion several summers ago on my 84 GSL because it sounded like a good idea, less clutter, less to fix, looks cool and who knows, maybe even more power!

What I got was less clutter and that was nice.

But I also went from 22-23 mpg to at best 16 mpg, a rough idle on a cold engine and throttle response I never could get used to. Also, absolutely no increased power, that stayed the same, at least once the engine warmed up and got past the stumbles.

Not to mention what must have been a huge increase in emissions. But who cares about emissions, right? Most likely we'll all be dead before the oceans reach our front door, at least those of us here in northeast Georgia.

So, after spending the summer tweaking the carb, double checking the connections and consulting with friends, I came to the conclusion that all I was going to get was less clutter, at the price of decreased performance in terms of gas mileage, driveability and emissions.

So, at the end of the summer I put the rats back in, which took about an hour. Gas mileage immediately went back to 22-23 mpg, driveability went back to the way I remembered it and I must say, after a good cleaning, those rats looked pretty good.

That's when I learned to appreciate both the performance and aesthetics of the rats nest. Along the way, I also learned what the rats do and how to keep them in proper functioning order. Turns out they aren't as complicated as they seemed at first.

Just my two cents (well actually at today's pump prices it's about $20 per fill up).

A final note, several of my RX-7 friends, who I highly respect for their intelligence and mechanical ability, have ditched the rats in favor of aftermarket carbs, with excellent results. I might try this myself someday. But as long as my beloved Nikki lives under the hood, she'll have the rats to keep her company and make her happy.

So when it's all said and done, I agree with Jeff20B.

 

Rb header half *** stripped nikki and no ratsnest no cats and I get 24 mpg fairly consistant. Mech secondarys throttle actuation feels good. I don't have a larger ap so its a bit of a lag between calm and go fast. That 24 is also a mix of stupid 20 year old in a sports car/ old man driving.

 

lol, they were not driving those things around on the street @2000rpm and part throttle...

 

I like a good strappy T-shirt as much as the next old guy, but I also like my AC. Call me a wuss, but in Michigan the humidity during the summer is like a jungle and with all that glass from the rear hatch it gets pretty unpleasant. Plus, if you keep it you won't have to listen to your passengers gripe about how hot it is.

 

Who drives like that? Not me 3k rpm minimum.

On the AC subject. Everyone has a comfort temp range, 79°(at low humidity) is when I like to have at least air moving around me if not AC. I have worked with guys that would be sweating bullets at 70° and hardly moving.

 

Thanks for all of the input! I will keep the nest unless i decide to go with a different carb. My last 7 didn't have the rats nest when i bought it so im not new to FBs, just emissions legal ones. My shutter valve is not functioning correctly atm but im going to sort that out soon(got it plugged for the moment). Otherwise the emissions systems are working well.

 

Well thankfully the OP has come to his conclusion so I can derail this thread onto this A/C addiction.

A/C is great, but I'm going to stand by my statement that except for in the arid extremes in the U.S. it is not really needed. I spent the majority of the last decade in a place that spends most of the year at 90%+ humidity and never ran my A/C unless I was driving a big sedan full of family.

Wear an undershirt like your grand dad did. That way when you sweat it doesn't show up on the heavier overshirt you are wearing, and you stay cool with your bodies own A/C, powered by all the water you drink during the day.