Autoxrx788

ok so. we'll start with all the problems with my car at the moment.

-speedo stopped working
-just replace my waterpump because of a leak but my coolant buzzer keeps alarming and it still leaks. Koyo radiator. i personally think it is the cap leaking because my overflow tank is full but it won't go back into the radiator so i think the cap isn't creating a vaccum and leaks.
-for some reason the car sometimes doesn't want to start but if i sit long enough and turn the key without the clutch depressed then press the clutch in it will start.
-NOT ENOUGH POWER!
-cheap suspension upgrades?
-possible 302 swap? or any better suggestions

i race auto cross and i am a driver. not a mechanic.....i like to work on my car but only when there is something wrong with it. but it is coming to the point where i am getting tired of the car and i need some new things to bring the rx7 back to life. THANKS. =)

Aaron Cake

iTrader: (1)

What year and model is your car?

RTRx7

iTrader: (2)

A 302 swap sounds like an excellent idea.

Kentetsu

According to his profile, he's got an '88.

For suspension upgrades, take a look over at www.re-speed.com

I would start with a new radiator cap, and see if that takes care of the issue. Otherwise, there may be a chance that you have exhaust gases getting into the cooling system (which would be a bad thing).

Good luck man. Nice to see another autocrosser around.



.

Aaron Cake

iTrader: (1)

Make sure the speedometer cable is plugged in at the back of the instrument cluster and nice and tight.

Make sure there are no pinholes in the tube from the pressure cap to the reservoir. Just replace it if in doubt. Also make sure you have properly bled all the air out of the system because sometimes it can be stubborn.

More info is needed. Does the car just crank and crank? Does it start and then stall? Does it not even crank?

Isn't a 302 an iron block designed sometime in the 50s? If you must go V8, then a modern aluminum block LS-whatever is a far better choice. Nice EFI system or even a stock ECU from the donor vehicle, no slushbox, etc.

Then rethink a V8 swap because you need mechanical ability to perform any engine swap.

Autoxrx788

i am very mechanically inclined. dis-regard what i said earlier. the 302 i would use is out of a mustang 5.0. it is a cheaper route it seems rather than getting a new turbo II engine and all of the electronics needed for the turbo to run properly. this is the first "tuner" my family has ever owned...we have always worked on and raced muscle cars. but maybe i am wrong about the hassles of the turbo II. inform me.

Autoxrx788

yea i was gonna do that next. yea definitley. where do you normally race?

Aaron Cake

iTrader: (1)

The 5.0 Mustang made what, 165HP from the factory? I'm not a Mustang person so I may be wrong on that, all I know is that stock, they are slow. So unless the engine is hopped up it will be slower then the rotary the car came with.

A TII swap is a direct bolt in.

Kentetsu

Naw, stick with the lightweight rotary you've already got in there. As far as power to weight ratios go, it can't be beat.

I've got the 12a, and with only 1100 cc's of power I'm always beating Mustangs, S2000s, supercharged Miatas, and damn near everything else out there when it comes to Autocross.

Good luck.

FatMatt

my speedo stopped working also, any ideas?

fastboy2468

I am a new rotary owner myself and it's a little discouraging trying to figure out whats wrong with these cars but i do know you wont get the power to weight ratio from a V-8 that you can from the rotary. Stick to the rotary and you will be surprised at the hp that one can generate.

I have been tuning V-8's and V-6's for over twenty years but even I went out and bought a rotary. Do the math! And good luck...

rxtasy3

iTrader: (2)

no to mention the extra weight u add to the front by doing a v8 swap.

fastboy2468

Exactly! A V-8 weighs? With how much horsepower?

and a rotary weighs? With how much horsepower?

I'm with you Rxtasy3

w.sen

iTrader: (8)

if u wanted a v8 get a camaro.....

Autoxrx788

Wow I can see it makes people a little angry me saying that I want to put a v8 in my car. But truthfully it is just an idea. And if you have a problem with leaving factual messages instead of opinianted ones please refrane from posting anything. With a turbo II it would have a little over 200 horsepower without any tuning right? Plus I would have to buy many electronics and other added things required to make the turbo run. If I'm wrong let me know. I love the rotary just from what I hear and see it is much more expensive. What are some cheap things I can do to my n/a motor to gain big power.

Aaron Cake

iTrader: (1)

Did you check your speedometer cable as described in this thread?

Meh, doesn't bother me if you put a V8 in the car. It's your car. What does bother me are iron block, carbed, slushboxed engines designed 50 years ago that are swapped in out of ignorance and convenience. I've seen some awesome EFI LSwhatever modern V8 swaps that I would be proud to own and probably thoroughly enjoy. But it does turn the RX-7 into a totally different car, which may be your thing, it may not be.

Just ignore the people that instantly bash V8 swaps.

Yep, a TII swap is an "easy" 200HP. Bolt on all the stock TII stuff following the step by step in he FAQ and with an exhaust you can do 200HP with no other mods if everything is in good shape (maybe a fuel pump rewire). After that, you're going to need to add fuel which starts the slippery upgrade slope. You don't need to buy any "things" (not sure what you mean there) to make the turbo run. But a full turbo upgrade requires a lot of supporting mods.

Autoxrx788

ok well i've educated myself a little bit on my car since my last post and come acrossed some different cites that say i can get around 230 or 240 to the wheels with my N/A motor. but some people say the synchros in my transmission will go at about 250. but i am a little confused weather they are talking rwhp or bhp. what would i need to get this kind of horsepower?

RHDthirdGen

i had the same problem in my old car

Aaron Cake

iTrader: (1)

Syncros on a transmission are not a load bearing component. They are of little consequence here. The NA transmission certainly is weaker but it will handle 250HP on a street driven car without issue.

In order to reach 250HP with that NA engine, you will need a healthy bridgeport. This requires disassembly and essentially a rebuild. You'll also need a tunable standalone EFI system to run the engine, and the stock intake manifold won't do it so you will need to fabricate something or get an off the shelf ITB kit. Additionally a nice open exhaust is required.

This all adds up to quite a bit of money and a car that will be very, very loud with abysmal fuel economy. Sadly, it is often uneconomical to make big power out of an NA rotary when compared with the easy path a turbo rotary is.