CRX7

Hello everyone, i have been checking out the site for about a month now, going through all of the helpful posts and have come to realize there are some creative people on here. Very nice forum as well. My name is Reese and i live in Arkansas. I have been drag racing hondas for a few years and primarily building my CRX. Today i finished my purchase of a 93 RX-7 with 39,000 original miles. Twin Turbo rotary that has not been modified and is an absolute beauty. I bought the car for 13,000 from a nice neighbor whom has had it for some time and finally gave into my demands. I got a loan from the bank for 16,000 so i could have some play money.

Mind you, I have plenty of Honda experience as i am a Honda tech here in AR, but have dealt with rotaries very little. I am absolutely excited to begin this project as well as join your community.

So here is the question, besides a turbo timer, intake and exhaust work, what sould I be spending my extra 3000 on? What are the most common problems with the FD(and what does that stand for) and also the best things for preventive upgrading.

Thanks again
Reese

EDIT: One more question, i have noticed that there are a lot of people swapping their motors before the 100k mark, are these not long lasting engines all the sudden???

diablone

iTrader: (2)

Turbo Timer is a waste unless you really can't keep your foot off the last few minutes before you park. You should start with this thread ( https://www.rx7club.com/showthread.p...threadid=68640 ) which gives a good start to modifying your FD (Which stands for nothing, it is part of the chassis code). Definitly start with the reliability mods, not going for the highest power output.

All of a sudden? You've got alot to learn. This has been going on since day one.

CRX7

what i meant was do the rotaries not last as long under pressure? I have read a few posts where people generally are swapping new motors arounf 100k or even less.

cloud9

iTrader: (4)

depends how reckless people are with their cars, this is not a honda the motor doesn't get 300K miles, these motors need good tunning as the mods progress with out that you can kiss the motor byebye

vchacon

Boost Gauge... and if you're getting over 10 psi a boost controller.

CRX7

Already installed the boost gauge, would an AVCR do the job enough. What is the most common problem some of you are running into with the FD?

fd3s93

extreme heat .. also youll find out that lots of 7 had fire in the engine bay. so anything that can cool the temp down...

kingcornflake

Hi CRX7

Well, this is easily explained...the coolant seals tend to brake if engine gets overheated. Not only that, but if you forget to change coolant regularly this will also blow your engine.

The thing with the seals is the following: Due to the rotary principle you have to seal the water circuit very well from the combustion chambers; if it breaks you have a wet engine, that means overhaul. Most common problem to make you notice a water damaged engine are severe starting problems.

You see, the rotary engine itself is very reliable. The difference is N/A or Turbo...only because of the boost you're able to crush it...the coolant probs mentioned above are a result of that.

I'd go with diablone and fd3s93...a good start are reliability mods, a boost gauge and, as mentioned, heat dissipation mods.

Reliability mods (as I do have on my R1 1993) include:

- Boost gauge
- All the important coolant and air hoses changed to sth more resisting heat (mine are Samco)
- Definitely a Downpipe

I consider a modified airbox not as essential, though. Opinions are wide spread as it comes to necessity. One says it just sucks hot air from engine compartement, the other says I really makes a difference...

These are basics only.

Good luck man (and trade in your HONDAs in order to get even more $ for FD mods )

cheers
Patrick

Broken09

iTrader: (1)

Check your vacuum hoses too. That was one of the first things I had to change on mine. Along with that check plugs and wires.
Aftermarket Radiator is good too to address the cooling issue.

CRX7

What kind of hoses should i get for the vacuum and other lines for replacement and where can i get them

CRX7

Just ordered a greddy intercooler kit and will go with a new koyo radiator as my turbo rex has one and has performed flawlessly for over two years of hard drag raing.

"Good luck man (and trade in your HONDAs in order to get even more $ for FD mods )"
I was waiting for a honda joke, thanks for indulging me, but i dont plan on getting rid of either the drag crx or my 2000 accord with 90,000 miles and a value of 18,000 still.
Where are these coolant seals at?

It is understandable that a car under constant boost since day one would be more liable to get into trouble but i would think mazda would have beefed the engine up a little more.
As far as sealing the water curciut, does this mean some kind of rotary head gasket?
Thanks for all of your help as well.

AntiVenom7

just my two cents, but with 3gs for the just the engine/performance. sounds like you already got the boost gauge, intercooler, and radiator, which musta set you back about $1200-$1500. I would go with the following.

-change the oil and get new sparks ($50-60)
-downpipe ($150-$300)-reliability & performance
-turbo timer ($115 w/ harness) - personal opinion it is gonna give you some extra life on your turbos.
-highflo cat (or midpipe, but watch for boost creep) and catback ($800-1$$$) for both)
-intake($200-$500)-more air = equal more power-my preference is the blitz SUS($300), but I am not sure how well that works with the greddy intercooler.
-Greddy Profec B Spec 1 Boost controller($300) - not pretty, but simple to use.

This puts you somewhere around $2000. I think personally I would have put my money into and fuel management system/upgraded ECU before that intercooler. you can do reprogrammed ECUs for like $500-700 or do something like the Apex power FC and commander for about $1200. This will become crucial if you are gonna start turning up the boost. you gotta keep a rotary supplied with fuel, detonation is very bad.

This reply is so long i lost track of everything. if anyone else has something to add. knock yourself out. I am sure there are people that will disagree with what I say, but I have all of this put the Power FC on mine and I am happy with the results. The PFC is coming soon. with an FM intercooler to follow.

kingcornflake

@CRX7

For the coolant/air hoses I prefer Samco's. Probably there is sth better around but that wouldn't be too affordable (for the value you get), see below.

For the vacuum hoses I'd go for hoses made of "Viton". "Viton" is a material that is extremely resistant to heat. On the other hand, this is expensive, too. But for the Turbo vacuum lines (if you decide to stay "Twin" -> original setup) it is definitely the material to get. There are like 200 of 'em and if one goes bang you'll lose boost by an instant...therefore: One time set up with these "Viton" things you would not have to worry the heat prob when it comes down to the TwinTurbo control mechanisms. And for the diameter needed, you can afford them (that's why I go for Samco within the large diameter things).

cheers
Patrick

Scrapiron7

Sounds like you intend to mod it quite a bit. I would throw down some of that $$ on a Power FC and save yourself any headaches in the future.

CRX7

Thanks for the help guys. I dont plan to go all out on the car as i already have on the CRX, the RX7 is for reliablility.

kingcornflake

@CRX7

See the attached file.

The seal is a "lip" which seals the surrounding chambers (for coolant) from the combustion chambers (that is where the rotor turns into it).
And yes, that's right, the seals are a type of "head gaskets". The material used differs (I think some kind of special rubber).

As far it concerns beefing up a boosted engine: This was the weak point Mazda engineers did not pay attention too well.

XSTransAm

You have got that the WRONG way around. But thanks anyways I was in a bad mood and needed a good laugh this morning

XSTransAm

https://www.rx7club.com/showthread.p...+engine+popped

moehler

iTrader: (12)

If your seven is for reliability I think your in for a surprise . If you want a "reliable" FD here's what you should do (I know you have some of these already):

1) boost gauge
2) Down Pipe
3) Koyo radiator
3) Aluminum AST
4) Eventualy replace the coolant and vacuum lines

I'm just warning you that your going to want to mod the hell out of it (i'm saying this b/c you like to mod other cars)... at that point keep the CRX for the reliability .

AntiVenom7

if his CRX is running 11s it is probably about as reliable as a rotary. i know hondas are tough, but not indestructible. you gotta be running some good stuff to be turning those numbers.

Andrew

iTrader: (1)

Did you have a white turbocharged CRX with a gutted interior? I went to MoKan a few times with some of my brother in-law's (Adam) friends. If so, I'm the guy with the black Turbo II that beat you and blew out his clutch.

Nice to see that you got an FD, I bought one a couple of years ago.

There are plenty of posts about reliability mods. Generally what you need is a downpipe, boost gauge, temp gauge, fan mod (search, it's easy), aluminum AST.

Only replace the radiator and vacuum lines if you need to. I put in a Koyo radiator because the factory one sprung a leak. I'm replacing the vacuum lines because I have some boost problems.

The engine itself is very reliable, it's all the crap that Mazda puts on it (like twin turbos) that kill reliability. The FDs have a bad reputation for being unreliable because of the restrictive twin turbo system and pre-cat that keep so much heat in the engine, and the engine compartment is so tight, and rotarys generate so much heat anyway that all of the other stuff (wiring, hoses, etc) start to deteriorate. Also, the factory ECU could've been designed to be a little more forgiving. Not to mention the fact that the dealers have no idea how to work on them.

The keys to reliability on an FD are to manage the heat, keep the boost down to 10-11 psi with no spikes, replace the plugs every year, do the reliability mods, in addition to general automotive maintenance.

diablone

iTrader: (2)

That was great.

devlman

iTrader: (13)

I don't think anyone explained that FD refers to the VIN on 93+ RX7s. All these VINs start with 1JMFD... (as yours should ). Second gen 7s are FC and first gens are FB for the same reason.

Nice pickup, by the way. Keeping the damn thing cool is key, so make sure you have a temp gauge. The intercooler will help, as would a bigger radiator. I run my fans all the time and sit at about 83 celsius without fail 'cause I'd rather spend a couple hundred on worn-out-fan-motor replacement than a few grand on a rebuild.

Enjoy

devlman

iTrader: (13)

I don't think anyone explained that FD refers to the VIN on 93+ RX7s. All these VINs start with JM1FD... (as yours should ). Second gen 7s are FC and first gens are FB for the same reason.

Nice pickup, by the way. Keeping the damn thing cool is key, so make sure you have a temp gauge. The intercooler will help, as would a bigger radiator. I run my fans all the time and sit at about 83 celsius without fail 'cause I'd rather spend a couple hundred on worn-out-fan-motor replacement than a few grand on a rebuild.

Enjoy

Androidmj

http://www.rx7turboturbo.com/robrobinette/

http://www.scuderiaciriani.com/rx7/index.html