kyrx7

i have a 93 rx7 automatic. i have heard that the auto transmission cant hold alot of horsepower. is this true? im doing 290 to rear wheels. is there a way to beef up transmission or is there a way to convert to manual and what all is envolved in that

purerx7

iTrader: (61)

search. auto to 5spd is becoming a common day thing and is very well documented on this forum. The stock auto tranny I believe is good for 320whp.

kyrx7

can the stock auto be beefed up to hold more horse power. and do you know alot about a car running lean and rich

weaklink

yes the stock auto can be rebuilt for higher horsepower but it is expensive. Close to $5K parts and labor for me. For that money you can get a 5 speed swap. If you are dead set on the auto I would call a local tranny shop and talk your concerns over with them.

oh yeah, at the very least, if you are not using a synthetic atf then you should do so immediately.

weaklink

mine broke with 268 to the wheels. I don't think you can assign a horsepower at which it will break. Depends on how you drive it too. Don't brake torque-I think it's what killed mine.

kyrx7

my cars running rich when i get the right ratio and get it not running rich will this add more horsepower?

weaklink

i don't have any idea what you are talking about. I'm guessing the ratio you are talking about is the air fuel ratio. Unless you have a wideband/lambda meter I would NOT jack with the air fuel ratio. Even then I think it's a bad idea to do if you have to ask if you should do it.

kyrx7

dont u have to tune the car when u make mods to it? when you put on the apexi computer and its making alot more boost than factory then dont u have to tune the car? its running rich. getting to much gas. you never heard of a car running rich or lean?

dustinchen

is there a power difference between the automatic and the manual rx7s?

rynberg

1. Tranny info and swaps are covered in the FAQ thread.
2. You aren't running "much higher" boost than stock just by putting in the PFC.
3. Yes, the PFC needs to be tuned for your car.
4. Unless you have a wideband o2 sensor, you have no way of knowing what your AFRs are. You can search for the AFR values people tune to with different octanes/boost levels.

rynberg

NO.

dustinchen

so they should run the same tines etc?

rynberg

No. An automatic is slower than a manual due to higher gearing and the losses through the torque converter, just like with 99% of other street cars.

bajaman

A good running automatic is going to be around a half to one second slower 0 - 60 simply due to the initial lack of response when you mash the gas. And it takes an EXPERIENCED automatic FD driver (like me! ) to really wring THAT much performance out of one.
The quarter mile will be a longer ET but it is possible to have a faster trap speed; once an automatic is under a full head of steam it has a constant and linear boost pattern and accelerates like a rocket.

There are literally countless threads about the auto-to-manual conversion, as others have said it is WELL DOCUMENTED.

It is also well documented about using aftermarket ECUs or standalone engine management systems like the PowerFC. If you want to retain the 'hold' feature of the automatic you basically are limited to using a Peter Farrell Supercars "Purple" system.

And lastly, the entire air-fuel ratio physics is another well documented subject. Just keep in mind that the 13BREW rotary is NOT forgiving AT ALL if you run it lean. More engines have been killed this way, a lot of them while "tuning" to try and wring out that lasssssssst little bit of horsepower. It is quite frankly not something you want to mess with unless you know EXACTLY what you are doing. And don't even think about tuning if all you are using is a stock O2 sensor-ed air/fuel ratio gauge. A wideband is ESSENTIAL.

weaklink

yeah I've heard of that, it's just that your syntax makes it very difficult to decipher what you're talking about.

Also, how do you know that you are running rich? If you are making more boost then you would be getting more AIR, therefore you would be LEANER.

It's clear to me that you should not be adjusting anything. Please stop before we have to puzzle over your "is it blown?" posts.

jeff p

get a good tune on a dyno by a rotary shop. add 4.3 rear end gears and keep the auto in the car. when the car is in top condition the auto will be fine and a lot of fun for street driving.
Jeff

kyrx7

here is the deal. when i bought it it was not making any boost. it had a few mods large intercooler. when the rx7 shop hooked the hoses up correctly and installed the apexi computer and monitor. it was making 13 pounds of boost. he told me to get it back to my home town and get it on the dyno. i brung it home and added a down pipe and midpipe my friend who owns the shop is a mustang man. he put it on the dyno but didnt have time to tune it. the car was doing 280 to rear wheels and was doing 16 pounds of boost. i dont know if it is running rich but i know that sometimes when you are idle at a stop light sometimes it floods out and sometimes the gas is so strong it burns your eyes. i lost my license and the car has been parked. i get them back in 6 months and want to get this lined out. what does the flooding and smell of gas mean?

weaklink

I think jeff p is on the right track here. If I were you I would do the following. Turn the boost down to 10psi (until you get tuned), change the atf to synthetic, get the car to a rotary tuner, or see about having one come to you (Steve Kan), and have a shop swap the rear end to a 4.10 or 4.33.

I wouldn't go more than 12-14 psi on the stock twins.

rx_obsessed

My opinion:
I would not spend 5 cents on an automatic transmission, other than to rip it out of the car and throw it off a cliff. It has no business in such a great sports car to begin with. It burns my *** that Mazda even made autos to begin with. I have no idea what they were thinking. On the other hand, I'd spend thousand to convert to 5-spd if I had to. Who cares if it can or can't handle power or if it will break or not? It's just not the right experience or setup for a sports car. Throw it out!!

Mark

kyrx7

i agree i just called the rotory shop and they said they convert them all the time. he said the labor was around 700 thats not bad. maybe i can find good deal on the parts. im hopeing that if the labor is 700 then maybe i could get it done for no more than 3000. i wanted a stick but couldnt find one in my price range at the time so i seattled and i wish i wouldnt have. the car is fast but its not near as fun as a stick. so hell with it. im saving my money to convert it. should have it in the next 6 months. then it will be like getting a whole new car.

'87 turbo II

iTrader: (1)

here's my automatic question.
Why did such a diehard sports car have the option of an automatic?

rx_obsessed

that's what i asked too 87.....

good choice kyrx7..good luck with the conervsion bro....

lotta-boost

Ya what they said, I was like you I was putting down around 280 to the ground, and did a swap to a 5spd, the car is a different animal!! plus it is alot more fun to drive!

dgeesaman

iTrader: (7)

Rynberg is right when he said you got tooled. Never ever let another non-rotary shop touch the car again.

Dave

bajaman

Evidently because the market was there. While I own one and love it, one DOES want to scratch one's head and say "What the ****?" when one knows that the FD was made from Day One to be a no-holds-barred sports car. I remember the original goals that were hyped in pre-production, things like sub-5 second zero to sixty, a 1.0 G skidpad, etc.

Now funnily enough, automatics are coming back in a BIG way in the supercars from Mercedes, BMW, Aston Martin, Jaguar, etc. In Europe these days you are considered pathetic if you have to shift with anything other than your fingertips!