That says it all, rebuilding the motor on a RX-7 than me and my friend are working on and want to turbo it. What would it take to build up the 12a to handle 20psi of boost? This car is not our daily driver so we are not worried about drivablity or anything like that. Also any companys make rebuild kits with lower compression rotors? Thanks for any help.

 

umm, not too up to date on what you guys can get over there, but maybe try to scour an importers and find a pair of factory 12A turbo rotors, whioch have lower compression, or maybe you could get the rotors decompressed by someone.

maybe it would be a better idea just to try and find a complete factory 12AT engine, they are not intercooled, but are fuel injected.

 

Actually boosting 12A's was recently discussed here, and people were having good results with upwards of 30psi. The key lies in the tuning. You could easily blow the motor at 6psi without proper fuel delivery and spark.

 

Isn't it a good idea to install an intercooler if running high amounts of boost? Granted most of my experience with turbos has been on diesels but an intercooler/aftercooler would seem like an engine-prolonguing insurance policy...

 

There are so many of these 12A turbo threads going right now. Try searching.

 

Intercooler is a MUST, another MUST is use of the search button, Nimrod is right, there's a ton of info that's just been recently discussed.

 

you know that may be the case but if every single person did a search and only a search there would never be any posts anymore. Also things change from time to time, what was done yesterday my not be the same thing that is done today. Also have done a search and nobody had that specific question came up.

 

I AGREE!!! This is a f**king FORUM. A forum is used to talk to eachother, and help eachother out. All these loosers bitching about searching... You search in the library, on a forum you ask. If you think the question has been asked too often, well, just don't answer.
If no-one asks, no forum will be left... Every question has been asked once, so you could just search the net for info, and forget about the forum. But wouldn't that be a bit boring???
So, if someone wants to know something that you know: help him/her out! It's your duty as an RX7 owner to help the others...

 

But what kind of internal mods do you need to run 20psi of boost??? Just the factory 12at rotars??? How about 30+ psi??? Would you need special rotars?!?!? Apex seals????????????????????????

Thank you

 

i have seen 28psi on a factory 12a engine with a streetport. like it was said before tuning is the key.

 

I know that information changes over time, as do procedures. But we just had 3 of these type of threads not even 10 days ago. I didn't even use the button to find them.

BOOSTING N/A ROTORS

From the archive
12A TURBO WRITE-UP

12A Turbo Setup Tips

Don't forget the sticky at the top of the page
TII swap into GSL-SE which has turbo information for all first gens, not just -SE's

Turbo Weber Information

Blow thru carbs

I think i could go on for the rest of the day posting links, a simple search for "12A Turbo" brought back lots of good stuff, and a browse through the most recent pages for the rest. I'm not a turbo guy, but i could easily have enough reading to fill the rest of my day if I wanted to. Didn't mean to be rude, but a general question like that usually won't get someone running to the computer to begin writing pages and pages of info. Unless of course your name is Sterling

 

Hey now!...

 

well ... i have not "personally" seen turbocharged 12A's running this high, but i've read about several of them. the importance of proper, patient, calculated tuning CANNOT be stressed enough. just read the threads provided and start to form an idea of what your plans will entail, then if you're still unclear or have any additional ideas or questions, post them for us to discuss then.

 

Basically you want a ample supply of fuel (at a high octane rating) for the high volume of compressed air that you will be forcing into the intake. Along with that, you want the spark to fire at the right time. And there is nothing wrong with posting a question that has been asked before, but when that question can be found on the same page as your post, or if that question is something vague that involves hours of typing to explain a multitude of options or possible combinations of components, (questions like, "How can I make my car faster?") it gets redundant.

But on the other hand, the search feature isn't really that good. If you search for "oil pump" it will bring up all sorts of threads about "oil", but not necessarily oil "pumps". Then it will show you threads about "pumps" but not oil pumps. You will get air pumps, water pumps, ***** pumps, and all other types of **** you aren't looking for. So I see the frustration in searching.

 

Well for example i know this is hard to type but you could have said, "you will need stronger bolt" or this tough one "You might need to have stronger seals" Thats really all i was after. Didnt really take alot of time. I dont want to come off like a jerk, i really am easy going, but hell this is a forum not a library. This is what you do, if it bothers people then dont reply. I have other forums for my mustang and i never tell some one to search, and trust me some of the mustang people are dumb as doorbells, but maybe the can not spend 60minutes looking over every single post. I know i dont, it is easer to just ask a question, then get to work then read what has been posted.

 

i can see what you're saying ... and to an extent, i agree with you. but there are two things i don't think you're considering ... and feel free to correct me if i'm wrong.

1. you would NOT have to spend 60 minutes searching through threads to find information on putting a turbo on a 12A. i mean surely you can't think that you are the first person to consider this performance upgrade, right? (and i am honestly not trying to be facetious)

2. the question, "what would it take to build up the 12A to handle 20psi of boost?" is open to a lot of opinions, speculation and black magic. you mentioned lower compression rotors, and that is good ... it shows what direction you're thinking, but aside from that, the question is just vague. what kind of budget are you working with? what type of fuel system do you have in mind? that sort of thing ... your answers will be based on all of that.

now ...

to get to the question, again ... regardless, of budget, it's all about TUNING. you don't NEED low compression. you just need to focus on building a strong, balanced, ported motor ... and then supply it with sufficient intercooling, fuel and ignition at (or beyond) your targeted boost level. anything that deters heat, and deters detonation is your friend.

 

No one sentence answer is going to give you all the information and direction on how to get your 12A to boost to 20PSI. What were you going to do? Take one sentence like "You need stronger apex seals" then boost like there is no tomorrow? You might as well flush your money down the toilet. Regardless of what you think of your question, it is vague. And yeah, you may have saved yourself time in searching, but asking a vague question results in time spent by someone else asking you questions about your budget, fuel system, overall expectations as far as HP, elapsed time if you race, do you want carb or EFI an so on. You are 110% right, this is a forum, but it is also a library because there is an awesome amount of information here, and to help us help you, at least be more specific when you post questions like these.

 

Will all you lil' whiney pussies shut the **** up and answer the mans question?!?!?


I personally dont know. I would go with factory eveything, yet with a HV oil pump...lol... and then get an EK6 or whatever the best haltech is... and then a TWM induaction.... and take it to a tuner, and pay lots of money, for the perfect tuning.....


Thats me, and a Million dollars!

 

Thats the point I'm trying to make. I haven't even mentioned boost controllers, rising rate fuel pumps, and all that crap. But he wanted a one sentence answer, and when he wasn't told what he wanted to hear, he start making smart comments about how hard it is to type "Get better apex seals" and **** like that, as if 1 new part will let him boost to high heaven. But he rather be told that instead of searching....

 

My exact typed words were "rebuilding the motor on a RX-7, and what would it take to build up the 12a to handle 20psi of boost." That right there is not asking anything about EFI or turbos or anything what so ever. I was asking what do i have to do to BUILD the ****** motor. I ******* know i need more gas and all of that ****. If you can not tell i am new to this site and new to the rotary motor. I have build piston motors before and i know that if i wanted to run 20 pounds of boost on my mustang for example, then i need to replace my pistons and rods with forged stuff. I would need a main baring girdle, and a copper head gaskit. If you were not so quick to flame ever single person new to your site, and actually read were they were saying. I am not some one to get upset easy, but come on i never asked anything more than what i need to build my motor, and i am getting ****.

I dont want to get all of you guys hating me, i didnt think that i was asking a vauge question. I do, have plenty of time to ask questions right now, I have got a RX-7 that will not be for transpotation but for racing in autoX and drag, i am going to build the motor, i need to know is there anything that has to be done to the rotors as in machine work, or anything like that before i put stuff back together. I could not find anything about replaceing studs or bolts but i would think that i have too, with that much boost. I have read that the 12A is very durable, but will it last long if i dont build it up somewhat? I know that tuning is important but for the time being that is not going to be an issue since this car is going to take some time to get going.
If you dont want to answer then please dont i am not here to **** people off.

 

Your original question right there, says nothing about your knowledge of having built piston motors for mustangs, your knowledge of needing to properly tune a boosted motor, or that you even know how to change the oil. This constitutes a vague question. I'm not trying to flame you, I just wanted you to see that point, which I think you finally do because you are asking more specific questions.
You will see a lot of responses to vague questions that simply say "search" or "do a search, theirs lots of info on this topic". Don't take it personal, but the less you say, the less people will assume you know.
There are different port configurations to maximize fuel delivery. Rotary engines don't have valves, so instead of increasing the duration of the open valves, you can widen the ports. There are all sorts of thing you can do. What is your overall goal? Obviously this ain't going to be a grocery getter, but are you racing in the 1/4, you auto Xing, or are you trying to break the land speed record?

 

Well the main goal for this car is to be fast, but the plan is for drag, and depending on how the car feels at this point autocross. I did search and found that there has been some people that are boosting 30psi, i dought that is on same stock rotors and seals, am i right on that? Is there any forged that i should use? Basicly tuning and cooling aside, can the 12a take 20psi of boost with out blowing 10,000 miles down the road?

 

The simple answer is: nothing. This is under the stipulation that you know how to tune it. If you want to know recommended mods, reliability mods, mods so that you can rev it high, mods that will make the most power, porting mods, or whatever: PLEASE DO A SEARCH, then do another.

I'll take credit for starting the searching argument because I'm the one who said it first. But you have to keep in mind that people don't like repeating themselves a million times just because the newest person to come on the board didn't want to go through the trouble of searching and piecing together the information they needed. Instead they decide to have all the info come to them for virtually no work on their part. I personally am tired of saying the same thing over and over again. Moreover I'm tired of reading the same thing over and over again.

I didn't mean to be rude or snotty, but all the answers to every question you asked are on this board somewhere. How do I know that? Because I could answer them all, I could give you two or more sides to each question. All because I come to this site almost everyday and I read the points and the counterpoints that these wonderful people make. Oh, and I use the search almost every time I'm here.

 

I plan on supercharging my 12A (stock) with an Eaton M-90 blower. It can produce a very high amount of boost, but I had planned to keep it rather subdued comparably speaking, for fear of my engines longevity. But maybe not- deepending on what I learn in the future about it. I havn't actively researched it, but when I saw this post, I wanted to follow it.
I had alot of interest in this thread. However, I've been busy, and havn't checked the board in two days.

This is the piece of crap post I come back to check on?
You girls waste more space and time bitching about other peoples "netiquette" than you do answering the question.
I'm posting because I'm pretty pissed that I spent my time- wasted my time looking for this thread, and then reading it, only to find that nobody had anything useful to say.

People, you gotta problem with someone and you want it fixed- Like this person needs guidance as to when the search function should be used, or needs guidance as to clarity of his questions...******* PM HIM!!!! You ALL know GAWD-DAMN RIGHT WELL you'll get a better responce if you let him know without publicly chastizing him.
...Unless of course, you want to start ****.
Shall we time how long it takes to PM someone? I ventur to say it takes less time and energy to shoot a PM to someone than to keep on a bitch-war.

Hell- I'm all for a good flame-war. But it's got to be about something worthwhile.

...buncha little girls.

 

you know something??? this thread IS starting to become BS ... and not because of people doing the right thing and telling him to research. not because of the bickering back and forth, but because the question WAS answered several times, by various people ... NanaimoRx7, Project84 and myself, included (sorry if i forgot anyone else) ... either he did not understand what was said (in which case he should have pinpointed more specific questions), or he refused to believe the answers given to him, and who can do anything about that, but him?

i was new here once, and even though i didn't ask about turbo 12A's or 13B's swaps or how to circumvent the 4x110 bolt pattern ... i do remember asking a few questions that were covered in detail (fusible links is the one i remember) ... my point is this. i was told to search, and then i realized that there's a wealth of info. it may take piecing together 2 or more threads, but if the info is here you will find it. AND I KNOW 12A turbo and engine building info is here, because i contributed to writing some of it!

well, okay ...

one more HERE
and, one more time ... (1) streetport the motor, (2) upgrade the oil system, (3) upgrade the cooling system ... (4) DO ANYTHING THAT IS GOING TO DECREASE THE THERMAL LOADS ON THE ENGINE UNDER BOOST CONDITIONS!!!! take the time to blueprint it. use the best bearings you can afford and carefully monitor the clearances. research the use of ceramic apex seals - unfortunately, i'm still learning about them, so i can't give you the info on them. however, from what i've researched and read, if you don't build the motor and grenade it by some tuning **** up, then they will prove to be a great asset in terms of future rebuilding headaches, and functional reliability. AGAIN, THAT IS ONLY IF THERE ARE NO SERIOUS MISTAKES IN TUNING! if you choose not to use them, then you're stuck using the stock seals, because the carbon seals are not for forced induction applications. this also means that you need to keep the power band at 8500 RPM or less!

as i said, it is not a necessity to run low compression rotors, the stock compression will take it just fine! if you feel you really MUST have them, then good luck finding them in good shape or take my advice and use a 13BT.

well, okay, he targeted drag racing and autocross as his uses for the car - that's good, but it still leaves many things unclear. as far as i can see, he still has not answered what type of fuel system he's planning to run, and what kind of budget he's planning to run. both of these pieces of info are critical to the remaining steps for keeping the motor alive at 20PSI! here are some reasons why ...

- which turbo are you planning to use? what trim?
- liquid intercooler vs. air
- nitrous oxide (not necessarily for combustion purposes, but for extra temp control)
- distributor vs. distibutorless ignition
- number of injectors and sizes vs. carbie

WHAT??????

building the motor is going to be the EASY part and aside from the link i provided (on top of NanaimoRx7's links) you have several threads on motor building tips to choose from in this forum, as well as the Gen II and Gen III forums. anything that applies to building a reliable, strong 13B will apply to builidng a reliable, strong 12A! and more often than not, the 12A will accept the 13B part without hassle.

YOUR MOVE ...