89RX7VertN/A

Hello,
I just bought a 1989 Mazda Rx7 convertible. It is a Normally Aspirated car,automatic transmission and I believe it to be all stock. I am coming from
driving a 1986 Corvette 4 speed transmission, so needless to say there is a big difference in power and speed. I am looking to give the Rx7 some pep. I
do know that this can be done from what I read there are Rx7's that are 225+horsepower, so I know that there is HUGE potential here . I believe the
vette was putting out 242, and would throw your head back in the seat when you would "get in the gas". That is what I am looking for from the RX7 that
neck snapping power...How can I accomplish this? Currently I reside in Palm Beach Florida.

Below is some of the questions that I have been asked below, and the responses that I have given, that will give you a better idea of what I am looking to do.

Question) What level of performance are you looking for?

(Answer) I am looking for a few levels of performance higher that
what I currently have. At this point I cannot even spin tires coming
off a light. . I believe the car is rated stock at 160 hp. If I
could get anything 200 hp or higher that would be great! I am NOT
willing to sacrifice reliability though..THAT'S REALLY IMPORTANT.
Any Ideas?

(Question) Are you wanting to keep it N/A or are you looking to do a
turbo swap?

(Answer) Well I am new to the Rx7 arena. I would like to turbo
charged motor it if possible. That's like my dream to have a turbo
charged RX7 convertible, BUT I cannot (like I said above sacrifice
Reliability). Can anyone give me costs and parts needed associated
with modding the N/A to get it to the point of say over 200 hp and
the costs and parts needed to get it to over 200 hp with a Turbo
Charged Motor Swap.

(Question) Also are you wanting to keep it automatic?

(Answer) I would like to keep it automatic. My girlfriend has to be
able to drive it. . On a side note what is that "hold" button on
the handle of the the automatic?

(Comment) You could put a vette motor in it or another 350 ci.

(Answer) This was a funny one. If I wanted to convert the rotary to a
350 or a swap with a Corvette motor I would just keep the vette . I
am looking into getting the power needed out of the rotary motor.
That is the plan.

(comment) Add Nitrous Oxide

(Answer) I think I will pass on this modification as that compromises
reliability, in my opinion. At least it does in other normal piston
cars...Is there a difference in using Nitrous Oxide with a rotary?

Looking Forward to Hearing From You Soon!
Aaron
aaron@aaronandshara.com

neptuneRX

dunno if your gonna get what you want with a NA RX7, I have a 88NA, and frankly I'm more then happy with it's avalible power. But if you want to see HP numbers closer to your vette, you'll probably want to go the turbo route. Frankly dunno how anyone can concider an automatic a real sports car. Half the fun is shifting. That's my 2cents

-TAL-

i am pretty sure the auto tranny in that car, is very very slow.

Just the gearing of it

SpeedFreak03

Well honestly if u want to spin tires easily u should have bought a TII lol. Now of course there is ways to speed it up a bit. First, you can do a pretty good amount of modding without sacrificing reliability. You say u want neck snapping 250HP type power right? Well you have a few choices. Nitrous is one, but if you don't wanna sacrifice reliability go with a wet kit. Since additional fuel is injected with the nitrous in a wet kit, you really don't have to worry about lean conditions (although u still should get some type of air/fuel control to be on the very safe side). The good thing about nitrous is that it isn't a constant stress. The motor is only working harder for 5-15 seconds at a time! Because of this you really aren't sacrificing reliability or the life of the engine/drivetrain. But with a turbo the engine is under more stress all the time. Now if u don't overboost and have a nice amount of fuel flowing then you will be fine with a turbo. But in N/A RX7s installing turbos is a time consuming expensive process. There are no install kits for our cars, if there isn't a part available you have to custom fab it. So if I were you, I would look into nitrous, and fuel management, like an NOS (Nitrous Oxide Systems) wet kit, maybe 50 shot. About the tranny, having a manual would be a lot easier to get that neck snapping power you want, but im sure it can be done with an auto too. I know with DSMs (eclipses and talons) they sell shift kits for automatics to help out, but I don't know about RX7s. Anyway, welcome to the board, and most importantly welcome to the world of rotarys and RX7s!!!

-Josh

PS if you have any questions about some terms I used then right back, because I know a couple things might not be used with domestics cars like Corvettes. lol ur on the good side now!

STR8BALLIN - R

there is extensive conversation about the issues you raise here....
i will just say that with an n/a you are limited and with an automatic transmission attached to it you are slightly screwed. the vert is heavier than the coupe cars and there was no increase in horsepower to compensate for the added weight. From what I have read ( ive got an 88' n/a vert manual) you can throw quite a bit of cash at an n/a engine and setup and get about 220 horse or so but thats about it..... from what i hear the best bang for the buck would be to do a t2 swap but then your risking your reliability.
many on this board will tell you to scrap the auto vert setup and buy a t2 coupe.....
if you want a vette beating vert your probably gonna have to do a v8 swap (bignono in the rx community) or dare i say 3 rotor...... cheapest would be the t2 swap but i dont know if it will give you the performance your looking for.

SpeedFreak03

Yea I was thinking man, either convertible automatic or neck snapping turbo 5-speed. They will both cost about the same. Honestly I think a neck snapping turbo 5 speed would be more fun. Of course u could drop money into the N/A automatic but is it worth it?

neptuneRX

one factor you left out is how much you're willing to let this set you back. Frankly, if money isn't a factor, get a 20B with a fair size turbo attached dropped in by RP, RX-7 Store or the many other highly qualified rotary specialist in the community. Hell, if it's setup right it can probably out run your vette, and **** on it at the end. :-P

Kai

Your girlfriend should learn how to drive a manual, because bolting an automatic to a 200+ whp 13BT will sacrifice the reliability you demand.

A manual swap, an S5 13BT swap, and a few light mods (fuel pump, FCD, downpipe, SAFC) will take you well over 200 wheel horsepower with "average RX-7" reliability.

89RX7VertN/A

Can any of you go over pricing on what you think it will cost me in different scenarios?


Thanks!

89RX7VertN/A

Well I forgot to say this in my Original Post.


The reason why I got a VERT is because I collect convertible cars .

So the object for me is to take this car and make it fly


Any Ideas....

Thanks!

ultradef

I decided to go with a full TurboII conversion on my vert. This entails taking the turbo engine, transmission, rear end, ecu, wiring harness, etc out of an 89-91 TurboII coupe and transplanting it into the convertible. Since TurboIIs only came with 5 speed manual trannys, you would not be able to keep your auto tranny. IMO, this is the easiest and best option for making the heavy vert relatively quick. If you buy a donor car with a recently rebuilt engine your car will remain reliable. The swap itself is pretty much a direct bolt-in and can be done in a weekend. The hardest part is finding a suitable s5 (89-91) donor car or piecing together the necessary parts if a donor car is not available.

Here is a good resource: http://www.rotaryresurrection.com/turboconversion.htm

V8RX7com

IMO – if you are going to compare the power of your N/A automatic convertible RX-7 to your previous owned 1986 corvette, you will never be happy with your RX-7. The reason can be answered with one word:

Torque


A 1986 corvette has about a 90 horsepower advantage over your RX-7, but the corvette also has twice the torque over your n/a RX-7 (RX-7 140 lb ft vs. Corvette 330 lb ft)


Also, the C-4 convertible corvette weighs about the same as your auto convertible RX-7 and the C-4 hardtop vettes weigh less than your vert


Comparing the 2 cars is like comparing apples to oranges. One was built for straight-line performance and the other was built to go around corners.

89RX7VertN/A

V8RX7com,
Thanks for your VERY informational reply.
I read your website and now understand why I am not getting the desired power out of the RX7..You are right TORQUE plays a significant role of "off the start" power.

So lets look at things another way...and please leave your biases out of this . Which is less expensive and which is more reliable to go with the V8 Swap or the Turbo Motor Swap.... Anyone on this? I would like to hear all opinions.

The bottom line on this post, is that currently I am not getting the power I want out of the car and I want to do something to change that

Thanks!
Aaron

Icemark

what i did:
https://www.rx7club.com/showthread.p...hreadid=260972

NCGNETO90

iTrader: (3)

I am going with an LT1 in my vert when the engine is goin down quick. But that is only becausei am going to TII my 90 GTU. So i will still have a fast rotarty 7 and an extremely fast boinger 7.

V8RX7com

A Turbo II swap or a V8 swap are both labor intensive, and both will cost a lot to do properly, but here are some pro and cons of both I can think of.

Turbo II swap advantages:

The main advantage of a Turbo II swap is that you can take a Turbo II coupe and bolt in the whole drive-train and engine wiring into a convertible (very little custom fabrication required compared to a V8 swap)

You are keeping the RX-7 rotary powered (if that is important to you).

Turbo II swap disadvantages:

The Turbo Rotary is not exactly known for it's reliability.

Rebuilds are expensive (you can't just rebore a rotary)


V8 swap advantages:

V8 parts are cheap and plentiful

A V8 can be both powerful and reliable

V8 swap disadvantages:

Even though a Chevy V8 fits and works remarkably well in a RX-7, you will spend a lot of time, effort and money to get the conversion to feel like a factory installation.

DigitalSynthesis

I'm doing the TII swap, with a few little secrets . Naturally, once you do that, you have access to any of the performance-increasing mods the TII guys have, as well. Of course, a TII is by nature slightly less reliable than an NA. But let's be honest: they are both sports cars that require MUCH more care and TLC than a honduh, right? [small rant] I mean, the reason we buy an RX-7 is NOT reliablity, its the sportiness, the handling, the ROTARY engine , etc. Its not an RX-7 if its got a V8, that's my personal opinion. Its another car that happens to have an RX-7 body. And if I wanted a V8 I wouldn't have bought an RX-7 in the first place, there are a number of import piston-engined vehicles which perform very well to choose from. [/rant]

Anyway, "religion" aside, a TII is still (for its year and engineering) a formidable engine with a lot of power potential whilst retaining a very reasonable amount of reliability. Streetports, different turbo/intake/exhaust setups, various intake/intercooler choices, and a number of engine management computers mean you have a lot to choose from, and a lot of power you can unleash safely. And there's always the 20B to go to if you want and have the time to do it right. Pettit has a great setup on the 20B that they put in a 3rd gen which would probably be able to be modded into your car as well. Its something like a $30k swap if they do it, though.

In my personal opinion, also owning and heavily modding a 'vert, you will NOT get your neck-snapping power in one of these cars unless you do some very drastic things to it, all of which will either cost a LOT or sacrifice a lot of reliability. Icemark has a shining example of a fairly powerful peaked-out NA, short of going with a very nonstandard porting arrangement which would probably be sub-optimal for daily driving.

I think I will end up very happy with my TII setup, once I get it tuned right. I've upgraded the suspension massively and am expecting to do a little bit more body stiffening (strut tower bars, perhaps a 3 point engine bay + torque brace) and once I get it on the road I'll be able to write up a little more about it. I'll take it to the dyno once the rebuild is broken in nicely.

Good luck, and welcome to the community!

DigitalSynthesis

Umm, just wanted to say, that last post was NOT directed in any way AT V8RX7. He's got a VERY nice example of a V8-powered '7. I just personally wouldn't have chosen the '7 as a base for a V8 conversion in the first place, and don't consider a V8-powered '7 an 'RX', by definition.

Peace...

Sideways7

iTrader: (7)

About the only way to get torque like a vette without major mods on a TII is to get a 20b. Those have assloads of torque. Also, the autos in the US rx-7s are pretty crappy, to say the least. I think JDM autos are better, or at least more sturdy, since they are all made for TII's.

t2greddyrx7

If you want 225+ you want to get a T2 swap and put on a few add ons for 225

89RX7VertN/A

Yes but will that 225 give me the power that i am looking for?
Aaron

Here is a pic of my vert.
http://www.aaronandshara.com/images/89RX7.jpg

For now thats all I have, but I will post more as i take them