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my thinking on the mechanical secondaries is along the same lines as Carl. if you had two cars, one with vacuum and the other mechanical, the person in the vacuum secondary car can just floor it, and the car goes. the other person in the mechanical car needs to give it as much throttle as possible without bogging the thing, which takes skill/brain power. even if the person driving the mechanical secondary carb is perfect and gets it exactly right, the two cars will be evenly fast. if the driver in the mechanical car doesn't get everything right its slower.
so since you can get the vacuum (internal to the carb, pretty foolproof) to open almost whenever you need it, i don't see the point to doing mechanical secondaries.
or you can think of it like this; the car is a mess, and we have to go through the whole thing, but there is limited time to do it. is it better to drive the car or mod the carb? there is nothing wrong at all with either answer btw, perfectly fine to just have something in the garage to tinker with. i have a DD car and a car shaped thing i turn wrenches on when i'm bored.
Well that's why I couldn't find that info in the suspension section of my 83 FSM because its in the steering section! After reading that section and several posts on here about setting up a stock style suspension I made sure that the little arrows all pointed in the appropriate direction but there was no change at all in ride height. I double checked and measured and it turns out the front drivers side is 3/4" of an inch lower than the right, and the rear is about 5/8" lower as well. The whole drivers side of the car is lower than the passenger. Does anyone have nay idea what could be causing this if not the springs? My next guess would be bushings but I'm running out of ideas. The lady who owned the car before me was very large and she daily drove the car for decades so something has to be worn somewhere. I plan on replacing all the suspension bushing with Energy Suspension Poly bushings anyway, but if it's not the bushings and nothing looks bent where would I look next???
my thinking on the mechanical secondaries is along the same lines as Carl. if you had two cars, one with vacuum and the other mechanical, the person in the vacuum secondary car can just floor it, and the car goes. the other person in the mechanical car needs to give it as much throttle as possible without bogging the thing, which takes skill/brain power. even if the person driving the mechanical secondary carb is perfect and gets it exactly right, the two cars will be evenly fast. if the driver in the mechanical car doesn't get everything right its slower.
so since you can get the vacuum (internal to the carb, pretty foolproof) to open almost whenever you need it, i don't see the point to doing mechanical secondaries.
or you can think of it like this; the car is a mess, and we have to go through the whole thing, but there is limited time to do it. is it better to drive the car or mod the carb? there is nothing wrong at all with either answer btw, perfectly fine to just have something in the garage to tinker with. i have a DD car and a car shaped thing i turn wrenches on when i'm bored.
I understand all that you two are saying.That's why I'm on these forums: for advice like this!! After being told why its a bad idea I'm disinclined to mess with the carb too heavily. That being said I do have an engine in the garage I do want to start tinkering with. its out of an 83 auto and it has the counterweight so I'm thinking of building a bolt on performance motor out of it with a lightweight flywheel. That engine is already out of the car so to remove the smog equipment and bolt on speed parts would be a lot easier! I have my race car motor I can compare it to as well. I guess I'll just fix my vacuum leak and work in leveling out my suspension. The ride height issues are what are driving me nuts right now!!!
If I remember correctly from my days before having adjustable spring perches, I think the left side always sat a bit lower. I assume that the car sat lower on the left with the original springs? Are the RB springs new or used? If used, is it possible they were slightly different lengths? Probably not, but worth a thought. I am sure you also put the upper rubber isolators back in on both sides between the spring and the upper spring perch.
If you want to get it evened out, Mazda made/makes spacers that fit between the strut top hat and the body. They are a little less than 1/4" thick. I think the bolts on top of the top hat may only allow 1 or 2 spacers. If you need more than that, you can press out the studs and install longer bolts. In the rear you can double up on the rubber spacers at the top of the spring. If you want to do that I have a couple of old ones that will work and you can have. These two things were how we evened out (height or cross-weight) the car when I was racing Spec7 and did not have adjustable spring perches.
I would be surprised if the bushings in the front could have that much effect. I think the only rubber bushing there is the inboard end of the control arm. The tension rod bushing should have nothing to do with ride height. I guess the bushing in the top hat could be jacked up, but it should be noticeable if it is that far off. As far as I know, that bushing is not replaceable and you would have to replace the entire top hat.
I am pretty sure most people on this forum will say not to replace the rear control arm bushings with Energy Suspension bushings. They restrict the movement of the rear axle too much.
I understand all that you two are saying.That's why I'm on these forums: for advice like this!! After being told why its a bad idea I'm disinclined to mess with the carb too heavily. That being said I do have an engine in the garage I do want to start tinkering with. its out of an 83 auto and it has the counterweight so I'm thinking of building a bolt on performance motor out of it with a lightweight flywheel. That engine is already out of the car so to remove the smog equipment and bolt on speed parts would be a lot easier! I have my race car motor I can compare it to as well. I guess I'll just fix my vacuum leak and work in leveling out my suspension. The ride height issues are what are driving me nuts right now!!!
I owened 5 FB...two of them with Nikki carbs with mechanical secondaries and never had a problem on the street... Does it takes time to get used to mechanical secondaries? Yes....but after that it's a blast to drive.....
Carl, the car did have a noticeable lean before I changed the sprung for the RB springs; it was the lean that made me want to change the springs! I bought new RB springs and I did check and make sure they were the same height before installing. I also did install everything exactly as it came out of the car, including the rubber isolators. The FSM mentions those spacers but I haven't been able to find any via a google search because it seems I'm in need of at least one, if not two. The strut top hat seemed to be in pretty good condition and went in just fine. Next step is to source or make some of those spacers I guess.
raven12aFB considering I have an extra carb sitting around I think I'm gonna modify one just because I can! I love to tinker and I have my Pro-7 car as a reference and because its an extra carb the daily will still be together and usable as I'm messing around in the garage. Best of both worlds!!
I am pretty sure most people on this forum will say not to replace the rear control arm bushings with Energy Suspension bushings. They restrict the movement of the rear axle too much.
After doing some research it seems you're right and that the consensus is to NOT put poly in the rear. I have no problem saving a little bit of money and putting OEM style rubber in the rear. I also read that some of the Pro-7 racers ditch the lock washers and nuts in the rear for lock-nuts and barely tighten the nuts so that the nylon lock ring engages in order to allow the trailing arms to move even more. Carl, do you have an opinion on that? Does anyone else have any advice on the rear end bushings? Considering my race car and my daily have the same set-up currently I'd love to use set-up tips and tricks on both!
After doing some research it seems you're right and that the consensus is to NOT put poly in the rear. I have no problem saving a little bit of money and putting OEM style rubber in the rear. I also read that some of the Pro-7 racers ditch the lock washers and nuts in the rear for lock-nuts and barely tighten the nuts so that the nylon lock ring engages in order to allow the trailing arms to move even more. Carl, do you have an opinion on that? Does anyone else have any advice on the rear end bushings? Considering my race car and my daily have the same set-up currently I'd love to use set-up tips and tricks on both!
the nylon nut thing works, but its LOUD, probably not good on a street car.
so i've built two FB's semi recently, and both are just stock rear suspension, and both are fine? the first is Fungus Mungus's car, and he's running big A7 Hoosiers, and the thing rolls way over, but there is no snappy handling to be found (it keeps up with the 792P in the infield). the second one is the Lemons car we just did, and that one actually understeers (for 2/3 of us). it does understeer on corner exit, which kind of sucks, but its also a "new" car (lol!)
so is there a problem in the rear? yes. is it a big one? no
the nylon nut thing works, but its LOUD, probably not good on a street car.
so i've built two FB's semi recently, and both are just stock rear suspension, and both are fine? the first is Fungus Mungus's car, and he's running big A7 Hoosiers, and the thing rolls way over, but there is no snappy handling to be found (it keeps up with the 792P in the infield). the second one is the Lemons car we just did, and that one actually understeers (for 2/3 of us). it does understeer on corner exit, which kind of sucks, but its also a "new" car (lol!)
so is there a problem in the rear? yes. is it a big one? no
I understand it'll be loud, but that may not b too big a deal for a street car, I also may get tired of it QUICK! While we're talking about ease of driving as a daily, I just took my Pro-7 car out for a drive and DAMN does it drive really well. Currently it drives really well on the street, even better than my daily! It has a fully race-prepped carb set-up and a 4-puck strung clutch disc and its genuinely easier to drive on the street than the road car is to drive! I haven't had the racer out in a while and it really does feel awesome. It also has the Mazdatrix short shifter which I'd been thinking of installing on the road car when I pull the trans to service the throwout bearing and slave cylinder, but I may have changed my mind. That may be a little much for a daily. The mechanical secondaries and clutch disc, however I may eventually put on the daily... decisions, decisions!!
I agree that the stock suspension is generally fine, especially for the street. The problems may really only arise when the car is lowered a lot and you are driving really hard. In my opinion, if someone is driving hard enough to have a problem on the street, they should probably have their license taken away. ;-). I converted my car to tri-link/panhard a number of years ago, when I switched from Pro7 to ITA/STL. I feel like it really does make a difference. I think it is more predictable on the track. Directional transitions are more stable, closer to my Spec Miata (which I got rid of about a year ago). The tri-link setup is very noisy however and would drive you crazy on the street in minutes. It drives me crazy driving around the paddock before going on track. Having said that I have done lots of very enjoyable racing in RX7's with the stock suspension layout too.
I am planning on going to Willow Springs for some testing (see if I got the oil temp sorted) on either July 9 or July 23 (or maybe both), if you are interested. A couple of other local racers might be going too (RX8 and FC RX7). let me know if you are interested and I will keep you updated.
I agree that the stock suspension is generally fine, especially for the street. The problems may really only arise when the car is lowered a lot and you are driving really hard. In my opinion, if someone is driving hard enough to have a problem on the street, they should probably have their license taken away. ;-). I converted my car to tri-link/panhard a number of years ago, when I switched from Pro7 to ITA/STL. I feel like it really does make a difference. I think it is more predictable on the track. Directional transitions are more stable, closer to my Spec Miata (which I got rid of about a year ago). The tri-link setup is very noisy however and would drive you crazy on the street in minutes. It drives me crazy driving around the paddock before going on track. Having said that I have done lots of very enjoyable racing in RX7's with the stock suspension layout too.
I am planning on going to Willow Springs for some testing (see if I got the oil temp sorted) on either July 9 or July 23 (or maybe both), if you are interested. A couple of other local racers might be going too (RX8 and FC RX7). let me know if you are interested and I will keep you updated.
I agree with your assessment: if you're driving that hard on the street you need NOT be driving at all! I guess I'll replace the rear bushings with stock style rubber ones and put Polys on the front. I may convert my racer to a panhard bar and heim joints (instead of bushings) but that's not something I want to deal with on a daily basis. I'd also love to take my racer to the track with you! I'm not sure I can secure a tow out there however. I couldn't make the 9th but if you're heading to the track on the 23rd I may be able to get there! Please send my a private message or a text about it when you get the chance!
An update for y'all: This weekend I took the car up to Camarillo to see a good friend (who has a very nice hot rod BMW 2002) and do some small maintenance tasks and the hit the canyons in Malibu. The car ran beautifully!! I added some seafoam to both the oil and fuel to clean those systems and changed the oil and filter (VR1 and a K&N oil filter) before we went driving and the car seemed to love all of it! Thankfully everything seems to be working as it should and the car really is a joy to drive! I got some great pictures of the cars on a turnout on the road up to God's Seat and I'll try to post them sometime tomorrow when I get a chance.
Mechanically I don't have anything major planned for the car in the near future, but there are still plenty of maintenance items I'd like to take care of, like changing bushings and fixing an oil leak and getting the rear wiper or the windshield sprayers or the cruise control to work or converting the AC to R134a and recharging it... I still have a lot to do!
My next big plan is to start race prepping an 12A currently in my garage so I'll be posting much more on my race car thread, but as I get things done on the daily (that I still haven't named yet) I'll post all of that info here!
Last edited by IMSAaspirations; 07-05-21 at 11:13 PM.
Reason: More I wanted to include without adding a new post!
Alright, lads a new problem has developed and I'm in need of your diagnostic help and advice. My car was running very very well up until recently, but yesterday I noticed a strange behavior. Normally when I mat the throttle the car gets up and goes, but yesterday when I tried to get on the throttle the car seemed to hesitate and then eventually it would begin to accelerate. Also once it did start to accelerate the revs would continue to climb after I let off the throttle completely before coming down again. I even broke 7k RPM once as the engine kept revving another couple hundred rpm after I'd let off. I know the carb has a vacuum leak somewhere and I've yet to establish where. Also it seems that I can't get my throttle cable tight to the bracket. I can tighten the top nut with my fingers, but that's not tight enough to prevent the cable from loosing again, and I can't get a wrench on it to impart anymore force. I also can't get a wrench or my fingers on the bottom nut.
At first I thought that the sluggish revving and dieseling were caused by the vacuum leak getting worse, but i it perhaps a loose throttle cable? Also how do I tighten that damn cable down!? I'm getting quite frustrated over this problem, gents. Please aid me in any way you can!
Vacuum leaks are easily detectable... get the motor running and spray carburator cleaner around the area...the idle will change when you hit the area with the leak....
The throttle cable should have two nuts...one for the front of the base and one for the back...
Vacuum leaks are easily detectable... get the motor running and spray carburator cleaner around the area...the idle will change when you hit the area with the leak....
The throttle cable should have two nuts...one for the front of the base and one for the back...
I've detected one with that method and I am aware that one exists, I have yet to figure out where the leak is exactly as in what hose or gasket on the carburetor may have the leak. I'll have to gain access to a smoke machine or som slow burnish incense to find the exact cause.
I'm aware there are 2 nuts, but I can't seem to get a wrench on the bottom nut at all, and the top has a ton of crap in the way. Does anyone have any advice on tightening it? Or do I have to remove everything around it to gain access with the 12mm wrench?
I recently rebuilt my carb, when reattaching it I had to deal with the throttle cable also... I found that I could use a set of pliers with rubber hose over the tips to hold the cable in place (keep it from spinning) and a stubby open ended wrench could get on the top nut (at about a 45 degree angle) with enough bite to tighten it. Since I was keeping the cable from turning I didn't have to have anything on the bottom nut. Worked for me, hopefully will for you as well. Good luck.
This is the stubby wrench set I was using: https://www.harborfreight.com/12-pie...set-97383.html
For $12 worth a shot...
I figured I'd likely have to go and grab a stubby wrench or two. I was going to heat up and bend a 12mm wrench to use to get my carburetor off so that wrench may come in handy as well to tighten the cable. I'll get on that and see how it goes. Right now I'm searching the forums to see if I can find the common sources for vacuum leaks. I know I have at least a small one, but I'm trying to see if someone else has previously posted what spots are common leak points so I can begin there.
Hello all! Life really has been kicking my *** for the last month and I'm sorry I've been AWOL. The biggest news I have on the Black Daily, which I think I've decided to call Carasu or Crow in Japanese, is that I discovered the cause of my carb problems... a MASSIVE fuel leak coming from the rear float bowl!! Suffice it to say I swapped that carb out for my spare immediately upon finding that and the thing seems to be running way better now. I still need to fine tune the idle mixture a little but it seems to be much happier. I also finally replaced the leaking o-rings in the beehive and soon I'll drop the oil pan to replace that gasket as well.
oh and I was also rear ended... Thankfully it was a very low speed impact and the car and I are ok. His insurance will be covering it all and a trusted shop will be doing the repair work. Insurance estimates $1000 but we won't know until the shop has the car apart. Thankfully it just need some bodywork. It could have been so much worse!
It's been a busy few couple months! In car news I finally got my race car on track (my thread on that read car talks about that) and I had the rear end bodywork damage on my car fixed finally. I've really really enjoyed having this awesome little car as my daily, and now I really want to give it some restoration work, and seeing as that's a major part of that I do as a job I feel I'm up to the task. I've decided that I'd like to build a nice "day 2" car, a car with simple period-correct mods that would have been done back in the day. My goal is a half cage for side impact and roll-over protection, 15' mesh wheels, rear window louvres, a restoration of the bodywork and interior, a glass moonroof, and mechanical fixes and upgrades to things like headlights and brake pads. Here's a screenshot of a good chunk of the to-do list, but it's by no means exhaustive. I recently found an old 2-spoke RX7 steering wheel and that went in today, but the other projects have yet to be started in any way.
Also I have a glass moonroof, but it only has one hinge. I've spent hours trying to find info on the fasteners used to hold the hinges on but I've had no luck at all. Both google and the forums haven't been too helpful lately. Does anyone have any info or ideas on where to get those weird fasteners that hold the hinges onto the glass itself??
06-29-21, 09:16 AM
