This is my plans for a quick 8 FB. Peripheral Port 12A with the biggest turbo I can find LOL. Hoping for mid 4's in the 8th mile. Even going with an NA set up, I'd prefer the 20B, it sounds great and they are a little easier to get ahold of then a Renesis. 8.8 rear would be perfect for nice hp numbers. a Turbo II transmission would probably be optimal or possibly even the FD transmission.

 

Ok im back.

I am a fan of my 12a and plan and doing all i can to get the power i want out of it. So i do hear where your comming from but just to give you some reasons why that 12a in my book would not even be in the same catagory of the Renisis (well maybe the Renisis) or the 20b is the price that you have to pay to make that power reliable with a 12a.

Its been proven that you can make more power with a 13b then a 12a for the same amout of investment in the motor. What you have to think about is how long a 600hp 12a going to last as compared to a 600hp 13b or a 600hp 20b.

To make it easy to see lets compare the 12a to the 20b

You would have to have a pretty descent sized turbo and you would have to be reving the motor to very high rmp in order to get that HP.

Where if you had a 20b you could use a smaller turbo not have to run as much boost and turn the engine a whole lot slower. You would be making the power in a more usable area and would have far less strain on the motor to meet those demands.

 

The difference in these two setups is Huge! Personally I think a renesis is a waste of time. NA 13b's have no torque; a turbo helps solve that. A 20b on the othere hand is known for it's torque. HP per $$$........20b. If you want to build a swap that has only been done a couple of times then do an electric FB. Otherwise, spend your money right and do what you will be happy with.

 

Dean, not really trying to be a hard ***, in fact I'm trying hard not to be one. Put the foldout of the naked rotors and housings down, quit stroking it, and start reading up on the Cosmo, Renesis, 3 and 4 rotor engines. To some of us more experienced members, your questions are silly and uneducated. You have dancing rotors in your head and they are clouding your logic and thought processes'.

Sit down and read the FSM on how to assemble a 2 rotor engine, I have yet to see a 3 rotor assembly manual in English. Once you have done that, read up on the Renesis and study how it is differs from the earlier versions. There is no 3 rotor Renesis, btw.

There are links to info on 3-4 rotor engines in the other thread, read them, take a good look at the actual cost of the engine parts. That is only a small part of the total cost of getting a mult-rotor engine installed and running. Unless you have the skills and equipment to do the work yourself, save up $20k+ to have someone install a 3 rotor for you, along with the needed supporting mods.

Since you asked what rear end should be used, that right there tells me that not only do you not know what/how to do such a swap, you also have not been doing your homework and are looking for us to do it for you. There might be 3 or 4 members in the 1st gen forum at this time that could pull off a 20B swap on thier own. I am not one of them and don't even think I would try given my present knowledge base.

 

Now to get back on topic I would choose a 20b Turbo or N/A over a Renisis Turbo or NA.

The reason why is for the amount of money you will spend getting a Renisis you can buy a 20b which is hands down better then the Renisis either way you look at it besides the factor of weight.

First of all if you want to do the Renisis swap you are going to have a lot of work to do first you will most likely need the front clip because there are a lot of electronics involved with the car (It is a modern day engine) and im sure all of those electronics communicate in one way or another to make the car function properly and make the stock ECU happy. So how much is that going to cost???

If you say you going to go with a Stand Alone System on the Renisis there's still more problems that your going to have to work out and engineer for yourself like the like the throttle that is operated by some electronics not by a regular throttle cable. So you can try and research to figure out the code and how its operated then program your stand alone to duplicate this function. You could make a regular style throttle body that is operated by a cable but again you just spending more $$$.

In my opinion only I believe the 20b will be the better swap. I have done neither of the swaps and only have information that I have read about so im not an expert. But There have been numerous 20b swaps with tons of information on these boards and other sites showing the potential of the 20b in NA form or turbo.

Just do some reading for your self and you will soon put this thought of the Renisis behind you. Yes its a cool motor and you can say your one of a hand full but will it be worth it to spend all that money just to say you have a Renisis But your still slower then the 20b.

"Don't take my word for it, just pick up a book and read it for your self," Reading Rainbow

 

This may make you want a 20B (http://mpsys.ca/MPSv1.htm)

Street Tuning - Short pass on closed road
http://videos.streetfire.net/video/...B892647E798.htm

Close up on Gauges - 11,000 RPM
http://videos.streetfire.net/video/5...5EAC0089B5.htm

Old video before adding the Turbo - Close up on Slide Valves with engine idling
http://videos.streetfire.net/video/7...0E7C1A1CC8.htm

Found on: http://forums.streetfire.net/showthread.php?t=5809

 

i do read the forums. a lot. ill search whats on my mind that night, even if i think i know enough about it, and read atleast every post on the first page that comes and up browse through the rest. and my question about the rear end was directed to those other then the ones using an 8.8 rear end. maybe theres something that i missed that would be better. so not all of my posts are uneducated, but u cant tell me that you've never said something stupid before. its human nature to do so. and i really dont want to be coming off as an *** here, i just want to straighten it up a little bit.

the only reason i am thinking about this massive project is because i may have a nearly unlimited source of money from a friend, who would also love to see something like this happen. and im not planning on doing this soon, since i KNOW that i do not yet have to knowledge to do so. but i figure 2 years of college might help that problem and im sure my knowledge of engines will increase over the years too.

 

Me make stupid mistakes, nah. LOL I have made a few bonehead statements in my day.

If you want to learn about the 8.8 and 9" rearends, go to the Mustang and drag racing forums. Not only will you find out how to set one up, you will find out what works, doesn't work and why.

After over 2 years of reading, I am finally getting ready to start my TII swap. At this point I feel like I have most of the mechanicals involved figured out. I might have 1/2 of the technical side figured out, which is the critical part of the overall package. Mistakes in this part can get very expensive, very quickly.

 

grannies has been thrown around quite a bit lately. and i went to thier site and it seemed pretty decently priced for a full 8.8 kit. what your opinion on them? it would probably be cheaper to get a rear end from a slavage yard and have the mounts welded on, but wouldnt it be better, and a bit safer, to pay the extra 600 or so to have everything done with new parts?

 

renisis are gay, why would you want an engine that has been factory recalled?

 

It comes down to several factors. What skill levels are available, your's, friend's or local machine shops? Final hp/tq needs. etc. Grannys isn't the only shop that builds/mods rear ends, but they are one of the few that do RX7s specifically. Hell, you can even buy the rear end compnents, piece by piece, starting with a pumpkin case, axle tubes, flanges and build one from scratch if you want. It's all in the search/research. I know, I sound like a broken record, lol.

 

well I have done exptensive research I actually went and talked to Roger Mandaville he races mazda rotarys and has bin for the past 30 years he can build some off the wall motors. He has a 20B first gen race car. The things that you have to vory aobut is you cant just stick the engine in there becouse by doing so you would put about 100lbs past you front axle and that might look like a lot but when it comes down to braking that 100 lbs just became about 500 so just take than into consideration here. To do it right you have to cut the fire wall and push the motor back about 6" that way you are closer to the 50/50 weight where you want it to be and the caracteristics of the car havent changed that much more. Other thing you need to consider wery stronglly is going with a dry oil sump that way the motor would fit easer and you would have to wory about making custom oil pans and such. The drive train will need to be upgraded to a S5 4 piston calipers and the need for bigger spindles due to added weight there is wery important. Also the rear end will have to be swaped out for eather a 9" or a 8.8" becouse the stock one just wont cut it. you will need to put some sorth of wide fenders on the car becouse your 185 tires just wont take the abuse you will give them the optimal tires would be 285/35/17 and a 245/40/17 in the front that way you have good grip all the way and its not over kill. That by doing so you still have plenty of grip but you also making sure that the frist things to brake it would be your tires loose and not a drive shaft. So after you put everything into prespective oyu are looking at a price tag of about 30K dolars jsut for the parts not including labor witch it would run you another 15K or so. But then again can ou put a price on hapiness I mean this would pur a 700bhp 20B 1st gen in your drive way and you know that there is nobody that ca ntake you down. If you have anymore questions about anything regarding puting a 20B into 1st gen I would be glad to help.

Mindaugas

P.S. I am currentlly worknig on a custom subframe for a 20B into 1st gen its still on the paper but its coming alog nicelly it will interchage the front suspension to a coilovers and strenghten the front end quite a bit.

 

by cutting the subframe, and moving the engine back several inches, arent you going to mess with the trans shifter positioning in the car? and instead of moving it back, couldnt u overcome the weight difference with a stronger suspension and a big brake system? or maybe i misunderstood what you were saying.

 

I'm gonna go with the Rene on this one. I mean lets face it 9k revs, 6spd trans, and 230+ HP is all you need in a little FB. It would be fun as hell to drive on the street and road courses.

 

1. 9k redline can easily be achieved by a earlier 13B

2. The 6spd tranny is crap. Go to the Rx8 forum. Constant abuse or a turbo takes it to the scrapper quickly.

3. Again, 230+ HP is not that hard to achieve with an earlier 13B.

I do understand the need to do something different. In the world of automotive performance being original brings a special kind of pride and recognition. A Renesis swap would be very challenging, not to the point of a 20B, but there is much to figure out.

For 1/2 the money I would build a 4port 13b with S5 rotors, the largest street port possible, clutch and T2 tranny to support, and a nice Haltech setup.

 

the only way for a 13b renesis to beat a 20b would be to make a 20b renesis.....

 

what I was trying to say is the fact that if you put the motor in front of the subframe when ever you go braking hard into a corner or something it will understeer like hell if you look at all the RX7s the engine is right at the subframe and its there for a reason.

 

so basicly, the rene is an awesome engine, but the wiring and setup is too much to deal with. the 20b is going to be the most reliable 300 + hp, but it would cost tons of money and fab time. so how reliable could a 4 port 13b be at 300hp? i deceided 300-400 is what im striving for.

 

A rotary will be as reliable as the build quality, upgraded parts and maintinance/abuse the owner gives it.

NA rotarys have historicaly outlasted thier piston counterparts in many forms of racing. For your goal, you will need to go turbo. NAs outlast turbos as a rule, how long an engine lasts for you, see paragraph 1.

 

well with any project, i would want new, or near new, parts for it. for me, my best bet is a t2 swap or 13b 4port with a large turbo and large SP. that could easily get me to the goal i want, and b the most efficient.

 

yes that would be more cost effective becouse since you have an SA a turbo 13B will make that thing a beast due to the significantlly leser weight than the FB I have driven a 13B 4 port sp with a light weight flywheel and a holley carb the motor made 240bhp and that thing was hell of a fast car.

 

Renesis engines suck. Didn't you guys hear they ALL got recalled. Mazda shotrened the apex seals and widened the apex seal grove in order to alow the apex seal to "wobble" in the grove and in theory seal tighter. What mazda didn't account for wa wear and the apex grove widening and the seal begining to bananna from the wobbeling. Shure it was a good idea, but poeple aren't seeing over 50k on the renesis. Hense the recall. Old 13b's can see over 250k with proper maintainance.

 

20b ftw

 

I had the same dream. With the widest tires I could get under stock fenders, I could, at 80 mph in fourth gear, step on the gas and turn the car sideways.

Fun, but not optimal performance.

I ended up adding fender flares so I could get 275 x 40 x 17 tires under the car. I can still break them loose in fourth, but the car continues in a straight line. It doesn't look like a sleeper though.