Thanks Ray! Great post!!
Stu Aull
80GS
(with 83-ish Sterling awaiting install)

 

Hey Stu, is the snow gone up there yet? Or is Al Gore having his way?

Here's the Denso's:






Here's the videos's:


http://youtube.com/watch?v=sa9uyh_P-EE

http://www.youtube.com/watch?v=o-kKEB4NvJI


Here's tonight's pics:











Could someone tell me how to hook that PCV valve up?

 

Ignorant question time, are rat's nests only for 1st gen's?

 

Yeah the PCV setup cleans up stuff quite a bit IMHO. I think the labeled pic of my setup in the second thread you posted (https://www.rx7club.com/1st-generation-specific-1979-1985-18/ive-got-lung-mustard-491461/) is pretty straightforward. I used an appropriate size of fuel hose to make all the connections. Appropriate = whatever the smallest size I could screw the PCV valve's threaded end into. I find it to be a much simpler setup, and if you can find large vacuum hose to use instead of fuel hose it won't be as big and bulky as mine is.

Jon

 

Hey Ray-
watched the 2 vids! not bad shooting! (I'm a TV cameraman)! but you can't beat your photos. Looking at them I see my Sterling is identical model to your carb - 85 right?
Its still sitting on my work bench (very attractive paper weight - thanks Carl!!
but when I get around to installing it I would love to pick your brain about your cable and hose runs - really fine work!
(And its 22 hours of sun and 70 degrees thankyouverymuch Al Gore!)
Stu Aull
80GS
Alaska

 

Looks like Ray is on the Slippery Slope.

 

not done on a nikki but htis is how i had it done on a Holley

https://www.rx7club.com/showthread.p...highlight=lung

 

"Looks like Ray is on the Slippery Slope"

Yeh Matt, the slippery slope to putting my rat's nest back in.

That nice clean engine bay looks pretty but doesn't perform nearly as good as the nest. Yeh, it really takes off when you put your foot to the floor, but it also has herky jerky throttle response, the gas mileage has gone down and I'm getting cramps in my right leg.

That's a pretty carb you got Stu, I'd like one of those. And yeh, sorry about those videos, I don't know what youTube did to them, the one's I've got on my computer are smooth as silk.

So with 22 hours of sun, do you stay up at night just to see what it's like?

DJ, you were one of the one's who talked me into stipping my Nikki, which now has reached paper weight status like Stu's. And taking out the rat's nest, which I'm thinking about putting back in next weekend (totally redone, of course).

So you ain't talkin' me into buyin' no damn Holley.

But I'll take a look at the pics anyway.

Ray

OK I looked at the pictures and you are right DJ, that's pretty. But how does it run, what's your gas mileage and if you weigh 160 like me, how's your right leg doing?

 

lol, I don't even remember talking you into stripping your carb, I'm not one about gas milleage, as you can tell from the holley, but then again, I'm also switching to a whole new game level, Individual Throttle bodies (ITB's) with a Megasquirt. So what is the difference between with and without rats nest?

 

You teach by example DJ, there must be something about all this megasquirting you guys do, it got me curious. But I need a smooth ride to work, the 7 is the ride and I'm thinking the rat's nest is what was making it smooth. Anybody know where I can get those little colored dots that go on top of the vacuum solenoids?

 

lol ... alright, well Fuel injection, should yield you in better results with tuning to achieve better mpg but obviously comes at a price. This is rought break down on things:

Megasquirt: 300$
Cabling: 100$
Wideband: 300$
EGT: 250$
IDA style manifold: 150$
ITB: 1000-2000$
Injectors: 400$
2nd gen CAS and igniters: 100$
K&N filter: 150$
_________________________

Total: ~ 3500$

Definatly not the kind of money anyone would just throw away, but would one yield in awesome performance and not to mention throttle response. But you could also lean things out under normal load to save on gas.

 

Let's see the pics!

 

don't have it yet ... I would like to have it done by the end of this summer, but by the way things are going, looks like not till next summer. we can blame trochoid for luring me into buying more of his parts :P

 

hmm... I don't get jerky throttle response or a sore leg on my stripped stock nikki (that I'm running while my Sterling is being tuned) or on my Sterling either.

Gas mileage isn't bad, about 400km/tank. Not as good as my winter beater sunfire, but good enough for me. The Sterling takes more gas than my stripped stock nikki, down to about 300km/tank if I'm into the secondaries all the time, and who wouldn't be with power and control like that at your foot.

Nope, the only time my right leg hurts is on long trips, and that's because of the transmission tunnel twisting my knee, not because of anything else.

Describe a bit more about the problems you've been having lately... maybe we can help you fix it up and get it running the way you want without the nest.

And if you can hold out a few days, I'm making a little write up on the stuff you can strip from the stock nikki... you can check your work against mine.

But if you want to put the nest back in, go ahead... I've got it out because
a) It gives easier access to the idle speed and mixture screws for easier tuning
b) it really simplifies the process of removing and reinstalling the carb when you have to
c) I'm running RB Street Port exhaust, so emissions are null anyway, might as well remove what's not being used and
d) more vacuum tubes and more solonoids = more points of failure, and I *HATE* tracking down vacuum leaks

and after taking out the nest I had the same, if not better, driveability than with the nest in place. However, your car looks to be in much better shape under the hood than mine is, so I might have had a bum solonoid or vacuum leaks buggering up the mix.

Jon

 

I thought I'd add that the Australian cars never came with rat's nests, and the older rx's didn't have them either, so I don't think they contribute much to driveability, just emissions control. Though if you have A/C, one of the solonoids is needed for that, and if you've got cruise control, I think one is needed for that as well. I'd rig something up somehow.

Jon

 

That *so* doesn't look like a Sterling. It looks like one of the cleanest stock or near-stock Nikkis I've seen, but it can't be a *normal* Sterling because the choke stuff gets in the way of taking the top off.. and one of the big things Sterling is huge on is making the carbs easy to get into for jet and air bleed changes. Hell, he kept trying to convince me not to have my fast idle rod hooked up because the one extra cotter pin adds precious seconds to the amount of time it takes to get the top off!

Jon

Jon

 

You know Jon, you might be right, it's all in my head. On the ride in today the White One was wonderful, behaved itself perfectly. Even all the stop lights turned green for me.

I think maybe I'm expecting too much after working on the car for two weeks. And I'm still getting 350 miles+ on a tank, so that's not bad (although I was hoping for 400).

After all, maybe I still don't have everything tuned just right, I'm a biochemist, not a mechanic.

But you are definitely right about one thing, working on the car is 100% easier. Changing plugs is a snap, now the the PS and AC are gone and adjusting the idle is no longer a major challenge better executed by blind people. And taking off the carb is about as easy as removing the plugs, I do it sometimes just for the fun of it.

I'll be looking for your right up on what can be removed, some improvement would be in order over the scattered reports on the forum. I already know I don't need that throttle damper for the AC.

Here's a question, I kind of think that shutter valve might be a good idea, it cuts gas off on deceleration and stops backfires (which mine still does sometimes out on the highway) and some folks say it might help gas mileage a bit, which means a lot to me.

Doc says (and I believe him) that the shutter valve is operated by the computer and therefore needs the rat's nest. Would it be possible to hook up just the solenoid for the shutter valve and get this to work?

And I agree DJ, everything is definitely Trochoid's fault.

Ray

Ray

 

Jon good to hear you got my old carb up and running, what did you have to do since we last talked? And I too am waiting for you to make my old carb famous

 

Ray:
The shutter valve has a bad habit of getting stuck or seized. Most of the FBs I've worked on have had this problem. Some were lucky and siezed in "Full open" position, while others weren't so lucky and siezed in almost fully closed position.

With my modified stock nikki the only time I get backfires is a single small one when I shut the car off, at the very end of the engine spinning down. Backfires when driving, in my experience, come most often from running too lean. Usually from vacuum leaks (which should be nice and easy to track with the nest out).

You can leave it on there if yours isn't siezed, but I don't actually know offhand if it's driven by the "computer" (I use the term lightly because it barely applies), or by vacuum pressure.

Biochemist eh? That's awesome. Well, working with gas is *technically* organic chemistry isn't it

Sam: I replaced the accelerator pump gasket, adjusted the nut on the adjuster rod, and ran a few tanks of gas with a bottle of carb/fuel injector cleaner through it. It's running fine but I don't think my secondaries are opening fully... I had my friend's FB (running a modded stock nikki like mine) take me, but he only started gaining me in 3rd, around the time when my secs should kick in.

It's nice to see better gas mileage again though, compared to my Sterling... but I miss the power.

Jon

 

Jon I wired the shutter valve open back when I was playing with my stripped Nikki and just left it that way when I reinstalled the stock Nikki. Here's the stripped Nikki thread, in case you missed it, lot's more nice photos of a carb I couldn't get to work right:

https://www.rx7club.com/showthread.p...stripped+nikki

The White One had another wonderful ride in this morning, running better than ever and acceleration from 80 mph to pass some of those left lane blockers is a blast. I think I just might be happy.

I also think I might have found another gas saving device, pumping up the tires. This morning after tanking up I increased the tire pressure from the specified 28 to 32 lbs and the ride was noticeably smoother. I'm going to run a tank at 32 and see how it does, if it's better then I'll move up to 36 lbs and maybe even to 40. I've heard some gas saving fanatics go even higher than that, above 50 lbs. If it works I'll post a thread.

I'm still getting that little backfire though when I let off the gas at highway speed, I wish it were a vacuum leak but there's not much chance of that since there's not much left to leak. What else could cause it too run lean and cause this highspeed backfiring? (I already put in a new fuel filter and even swapped fuel pumps, but it seems to be delivering gas to the carb just fine).

My understanding of how the shutter valve works, which is pretty meager, is that on decelleration the computer sends an electrical signal to the shutter valve solenoid, causing the solenoid to open. This sends vacuum to the shutter valve, causing the valve to close. If the computer still knows when you are letting up on the gas after the rat's nest has been removed, it might still be smart enough to tell the shutter valve to close, saving a bit of gas and reducing the backfires. If so, maybe I could just hook up that one solenoid?

Biochemistry is how I pay the bills, not a bad living if you like working in a lab and writing grants. Working with gas is indeed organic chemistry, which is the chemistry of carbon (including things like gas, alcohol and plastics). But biochemistry isn't organic chemistry, its the chemistry of living organisms - proteins, carbohydrates, fats, DNA and that kind of stuff. Much more interesting.

Somebody mentioned fuel injection as a replacement for carbs, DJ (Sam?) I think. But what fun would an RX-7 be without a carb to play with?

Ray

 

I wouldn't go much higher than 32 on your tires. Overinflating them too much leads to premature tire wear in the middle and bad traction.

32 is what I keep mine at, though I may go a little higher since my tires are larger than stock and seem to give more than I'd like in corners.

We once sequenced yeast DNA in General Bio 1.. that was kinda fun.

Jon

 

Sequencing DNA is easier than tuning a Nikki or working on cars. But it is a cool technique.

On the tires, yeh those are good points, but I want to push it as far as I can. I have a nice set of Yokohama Avid Touring tires on there, stock size, so I think they probably don't mind being pumped up a bit. And almost all the driving is straight ahead at highway speed, so there should be minimal lateral wear. I think I can get away with 36 at least, maybe 40. Anybody tried that?

I'm getting more curious about that coasting valve, I keep popping when I decelerate at high speed or down shift hard. For some reason it's worse on the ride home in the hot afternoon than the ride in in the cooler morning, maybe temp related?

I think I'll take a look at the diagrams and see if I can hook the shutter valve solenoid back up and reactivate the beast. Anybody tried that?

 

Ray:

Does Al Gore know what the hell your up to? He'd **** an ice berg.

No really, it looks great, at least it does on paper.

I'm still stuck in an EPA police state county. So when you get finished you can help me figure out how to get mine to pass the Enviro Gestopo requlations.



Greg

 

Al Gore knows all about it, have you heard about the carbon tax? If I can get 400 miles on a tank (that's 15 gallons for you friggin SUV drivers), what are the SUV's gonna say?

Ray

 

Al Who?

I love being Canadian

(And Canada Day is coming up!)

Jon