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13B TII vs N/A

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Old 09-25-2012, 04:04 PM
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Default Re: 13B TII vs N/A

Originally Posted by rx_214
Also, you can get a closer ratio transmission gears, one popular mod is using the miata tranny. Aside from that, change the final gear ratio to 4:30, that will also assist in faster rev. However, horsepower will suffer a bit.
Even easier way: get smaller wheels and tires. I autocross with 15" wheels with low-profile tires, acceleration was was faster than with 17" wheels with meatier tires. Sure, top speed will suffer, but how often are you going 100+mph?
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Old 09-28-2012, 07:32 PM
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Default Re: 13B TII vs N/A

it seems to get better as it gets driven. I know it sat awhile before I bought it. I noticed putting a new set of plugs helped alot. The fuel filter is new. All the fluids are fresh. I've got an intake gasket leak. That could be holding me back too. I've got kind of a weak spot from 3700-4000. I had to idle up the engine to keep it from stalling when i let off the gas. That could also be injectors. I've gota pull the plenum off i'll check injectors while i'm there. Also i'm running the factory 15s on 60 series tires. I'm sure an alum driveshaft and some lighter wheels would aid a bit. I know i've got a bad throwout bearing so i'll invest in a clutch and flywheel eventually. It chatters a little bit too. Is there much that can be done to lighten the car? I know it's heavy compared to 240s and miatas. I can feel the weight powering out of corners
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Old 09-29-2012, 12:58 AM
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Default Re: 13B TII vs N/A

Check your secondary fuel injectors, the weak spot/hesitation you get from 3700-4000 is due to the injectors being clogged. See here: FC3S Pro v2.0:* Problems #1, Engine - 3,800 / 4,000 RPM Hesitations
And here: FC3S Pro v2.0:* Problems #1, Engine - Bogging at 3,800RPM to 4,000RPM

As for the low idle issue... there can be many things, so follow here: FC3S Pro v2.0:* Problems #1, Low idle

15" rims with 60 profile is fine, aluminum driveshaft and flywheel would help with the faster rpm you want to reach, rims wise you would have to go smaller to decrease the rotating diameter.

Miatas are different class, so you shouldn't be comparing the FC with them. 240s are about the same as FC, but the KA24DE has more torque compared to the NA 13B, therefore it would make you feel that FC is heavier.

Get the car completely restored with fresh engine, drivetrain, differential & rear end, plus new bushings and new springs & shocks, you will feel the true rotary rocket spirit coming from the car.
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Old 09-29-2012, 07:42 AM
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Default Re: 13B TII vs N/A

i know the drivetrain is pretty good. The engine (dont laugh) doesnt burn any oil or smoke. The oil has probably 1500 miles on it and is still a pretty gold color. I've put over 500 miles on the car since I bought it and havent had to add oil and i redline the car at least once while im driving it only when warmed up. I just changed the nasty tranny oil and diff oil and added limited slip addative. This eliminated my low speed accel while turning chatter. I think my biggest hickup is my intake gasket leak. I can spray brake cleaner on the front of the upper plenum and it'll bog the engine down. I have gaskets ordered but being what the car is they arent something the stores keep on the shelf or even in the warehouse so i'll be fixing that next weekend along with cleaning my secondaries because i'm sure theyre nasty. The previous owner (older fella) babied the car so i know he rarely took it over 3500rpm. On the same note tho he took care of the car. It's got new tokicos, new brakes, new radiator, new alternator/starter, new OEM driveshaft and mufflers. The underbody is rust free, the undercoat is even still tacky. The front control arm bushings are wearing but all the other rubber is in decent shape. I guess driving my sentra SER daily i want this car to be peppy. The sentra has a p/w ratio of 14.4:1 with a quick revving QR25 and 6-speed. The engine responds well to heavy load low RPM say 30-45 mph accelerations in 5 or 6 gear with ease where the rx has to be downshifted. the n/a rx has a 16:1 so it's not quite as fast. It's pretty crazy how expensive the mods can be for the rx. It's gona cost me 1500 just to get a new clutch with lighter flywheel (mine chatters and throwout is whining), a good 3" exhaust (mine has factory dual setup) and an aluminum drivehsaft. Question is, is it worth it? I read rotaries react well to mods. I know just changing my spark plugs made a huge difference. Felt like i put an exhaust on a piston engine. Also how do rotaries react to removing emissions garbage like the air pump and evap canister, egr etc

My main reason for considering miata is theyre similar. Balanced rwd great handling cars. My biggest thing is miatas are cheaper to work on and parts are more readily available. The engine is pretty much bulletproof too. Convertible is nice but i have a working sunroof on my FC. But the biggest thing is miatas can be dropped into the 1700 lb range.. that's light making any mods more effective. Their forums are much livelier too. No offense since I always find the info im looking for up here or rx7club, big difference is rx7club makes u do more searches.

Also dont forget the KA weighs as much as the rx's whole driveline. Also nissan didnt focus on balance like mazda does. The KA powered 240s are very front heavy making them abuse tires and lose traction when braking into corners. Most guys swap in a SR due to it's factory build for turbo, ability to handle 300hp without internals and about 250-300 lbs less. The guys i work with have SR 240s exept one who just got his but he plans to stick KA. I'd love to get the TII with all the lighter mods and put it up against the stock SR 240. All he has is the stock setup with 1-piece driveshaft and super low springs

Last edited by recian; 09-29-2012 at 07:58 AM.
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Old 09-30-2012, 12:38 AM
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Default Re: 13B TII vs N/A

Check the OMP to see if it's working properly, that might explain why oil is slowly getting lower. I drive mine daily at a pretty spirited fashion, so pretty much I have to check almost once a week or two weeks. It really depends, I have heard others who say their engine don't consume oil.

You've done a quite a bit of research, which is good... I spend a good portion everyday just reading up a lot of different stuff on both the forums and websites. And since we are also drivers, it's easier to know what is actually right or wrong based from our own experience. Also getting connections with local rotary specialist would be one of the most helpful thing, get familiar with them and raise your questions, these mechanics love to share their thoughts with us who are passionate about rotary.

Removing emission related stuff will make the rotary run smoother and quicker... after all, rotary is intended for racing, not daily driving (see the owner's manual, DD is consider 'special driving' that requires a different maintenance method). A lot of people remove the emission stuff, but to be honest, is it necessary? Depending on where you are, law enforcement are bound to give you hassle, given that rotary is loud by nature, removing emission just makes it more obnoxious or high profile, may not be worth it. So this is going with your question, is it worth it?

Worth it or not really depends on you, I say that not to throw the question back at you, but more so everyone has a different direction they pursue after. For my case, I'm working towards the streetable race car that runs on pump gas, DD mostly but track worthy; my mechanic and I are working towards on NA larger streetport, ITB, Microtech, custom one piece exhaust, and a bunch of other things. So the fine line to reach the balance I want is not easy, but it's an on-going project that I insist on pursuing, even though I have doubt myself many many times, is it worth it? (I've spend up to five digits now, and it's still growing)

Miata is nice, I've driven the NA, NB, and NC, even considered to get a NA myself at one point. But I know down the road I will switch to either FC or FD, so may as well just go with it from the start. But that's a different talk all around with the Miata, I'm not a fan of convertibles so it's simply not for me, even though it's a great fun car to drive.

rx7club can be messy, I've been on it since I first got my car, there are way too much useless information on there, and idiots who simply just throw out crap that won't help anyone, not to mention misleading information. But here is pretty dead though... you can see a lot of threads are not active, and there aren't a lot of people around sharing opinions, there are more questions than answers here. I just try my best with my limited knowledge, at most I'm just a more experienced driver and an amateur mechanic, nothing more.

240s are really fun cars, I've driven S13 and S14, both fascinates me with how much potentials can be brought out. But you know what, FC also has lots of potentials against them, just gotta restore it and work on putting in the right upgrades to have it tuned. It gets down to what you want as a whole, cause if you know you will not be satisfied with something, best to just switch to what you will want to have and sick with it, don't settle for something when you can just go with the full package.
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Old 09-30-2012, 08:39 AM
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Default Re: 13B TII vs N/A

If i was in your situation i probably wouldnt have any issues. There arent any rotary guys in my area. Only one has one and he's part of the omega drifting crew around here. He's running a TII and his is ok not a wow kind of car. I love the engine and how it responds to upgrades and the fact that i can put 3 ppl in the car and it doesnt bog down like my 4 banger does but i hate the lack of support in my area. I'd love to have a rotary powered miata tho. light, convertible and rotary powered
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Old 10-01-2012, 08:04 AM
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Default Re: 13B TII vs N/A

Also ive noticed my hesitation is gone after driving it harder going over 4k more. However i dont have secondary injectors being NA. But the information was interesting
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Old 10-01-2012, 11:33 AM
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Default Re: 13B TII vs N/A

Do this to clean the 5th and 6th port: Cleaning The 5th and 6th Ports
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Old 10-01-2012, 12:24 PM
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Default Re: 13B TII vs N/A

Originally Posted by recian
Also ive noticed my hesitation is gone after driving it harder going over 4k more. However i dont have secondary injectors being NA. But the information was interesting
Yes, n/a has 2 primary and 2 secondary injectors.
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Old 10-01-2012, 05:41 PM
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Default Re: 13B TII vs N/A

ah i see theyre hidden. Theyre closer together on turbo models. I may play with those actuators when i do the intake gaskets. I may end up taking the air pump off. I'm just worried the engine may not run right without all it's emissions components since the ecm is tuned to run them... However megasquirt is looking for 86 RX7 N/A models to test ECMs and will give you a free tuned ECM when theyre done. Only catch is I cant drive the car to their shop in GA and leave it for 2 months.
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