RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   3rd Gen General Discussion (https://www.rx7club.com/3rd-gen-general-discussion-322/)
-   -   Who else appreciates a stock FD? (https://www.rx7club.com/3rd-gen-general-discussion-322/who-else-appreciates-stock-fd-1137342/)

Montego 07-09-19 03:52 PM

Stockish yes. 100% stock hell no. The SMIC heats soaks too easily and the stock DP converter really chokes power above 70MPH.

IMO the perfect FD is:
  • Sequential
  • CAI
  • Upgraded SMIC
  • RB exhaust
  • Upgraded radiator
  • AST delete
  • Max boost set at 12 psi
  • ECU
What you get is a decently fast, comfortable (quiet), rock solid car that you can beat on without a care in the world.



Originally Posted by Johnny Kommavongsa (Post 12357624)
The weather has been super-hot and I was stuck in traffic a few times. AC kept me cool, stereo kept me entertained and I wasn’t too worried about the car overheating, although I was nervous a few times.

FYI - there is no reason for a stock FD to overheat under normal driving conditions. The reason we upgrade the radiator is because the plastic end tanks on the rad have a nasty habit of cracking.

pd_day 07-09-19 08:10 PM

That's exactly what I have, but with efini y-pipe, Ohlins, RZ Recaros and some BBK.


Originally Posted by Montego (Post 12357850)
Stockish yes. 100% stock hell no. The SMIC heats soaks too easily and the stock DP converter really chokes power above 70MPH.

IMO the perfect FD is:
  • Sequential
  • CAI
  • Upgraded SMIC
  • RB exhaust
  • Upgraded radiator
  • AST delete
  • Max boost set at 12 psi
  • ECU
What you get is a decently fast, comfortable (quiet), rock solid car that you can beat on without a care in the world.




FYI - there is no reason for a stock FD to overheat under normal driving conditions. The reason we upgrade the radiator is because the plastic end tanks on the rad have a nasty habit of cracking.


Montego 07-10-19 01:08 AM

^Nice :)

arghx 07-10-19 07:00 AM

Besides the 3000 (?) rpm hesitation, which is better on newer ECUs (my old '95 that Johnny bought has almost zero hesitation), you can't beat the stock ECU for liveability. And I say that as someone who has done a lot of tuning and given a lot of tuning advice, on both Rx-7's and piston powered vehicles.

Stock ECU:

1) Starts consistently under all weather
2) Doesn't overboost lean out or otherwise blow up, no matter the altitude or ambient condition (winter, heat soak in summer, etc), provided you don't over mod it.

Also Stock airbox and stock intercooler are fine for reliability, just give up some power vs aftermarket units, and the stock ECU can handle heatsoak. Stock ECU can handle mild reductions in backpressure (downpipe and catback) no problem, especially if you keep stock airbox to help maintain boost control.

3) Controls the sequential twins better than other ECUs due to gear based boost control and sequential staging (transition point is higher rpm in 1st gear), as long as you overhaul all the vacuum lines and solenoids (as I did with Johnny's car)
4) Idles much better than most aftermarket ECUs as long as you keep the main cat and underhood emissions controls (as I did with Johnny's car).
5) Has a simple on board diagnostic system (OBD 1) that throws codes when sensors fail and goes into a failsafe mode. If you lose a sensor in an aftermarket ECU, you could blow a motor.
6) Allows the convenience of the oil metering pump and won't blow the motor if it fails (no need to premix unless you really want to eke out a little more engine life).
7) Good tip in throttle response that is difficult (but certainly not impossible) to achieve with aftermarket ECU.

A lot of these can be overcome with a Power FC or better, newer/more advanced ECU, but it takes a LOT of real world tuning to get it right, and the aftermarket ECUs will never have a real OBD system or some of the advanced logic of the stock ECU (unless you go hardcore with custom code).

The main reason for aftermarket ECU is more power. You won't beat the liveability and convenience and safety of the stock ECU as long as the engine hardware is kept close to stock.

FourtyOunce 07-10-19 07:20 AM

I foresee a lot of WTB threads for stock parts ....

Johnny Kommavongsa 07-10-19 07:36 AM


Originally Posted by FourtyOunce (Post 12357946)
I foresee a lot of WTB threads for stock parts ....

Ha, one can convert back to stock but there is something awesome about an unmolested FD. The door panels, center console, and other plastics fits great and feels solid.

Raymond - what are your thoughts on ecus such as Pettit or M2? From what I understand, they are supposed to be just reflashed stock ecus. I had the pettit and thought it did a good job, just idled a little too rich for my likings.

arghx 07-10-19 09:00 AM


Originally Posted by Johnny Kommavongsa (Post 12357947)
Ha, one can convert back to stock but there is something awesome about an unmolested FD. The door panels, center console, and other plastics fits great and feels solid.

Yeah, you gotta go as long as you can without removing anything. And don't touch that passenger handle!


Raymond - what are your thoughts on ecus such as Pettit or M2? From what I understand, they are supposed to be just reflashed stock ecus. I had the pettit and thought it did a good job, just idled a little too rich for my likings.
Did you run with the air pump and ACV working like stock?

I've never driven one and have only heard general things about what's changed inside the ECU. I don't think it's a good idea to run one without the air pump and ACV, especially from an idle perspective, same as totally stock ECU. The air pump air is primarily directed into the exhaust ports, where it backflows into the intake charge air during overlap, for better combustion stability and leaner mixtures, and also to oxidize the HC and CO. Thus the stock ECU logic with the stock ECU accounts for this; I'm not sure how the Petit handles it. Based on what I've seen on old canned tunes for piston engines, somebody probably changed either an injector size value, a target AFR table or volumetric efficiency table, or some other setting in there that's kind of a sledgehammer to make the tune safer.

Remember that a 13B-REW and all the other older side intake port rotaries have the equivalent of a mild cam from the factory due to the port timing (Rx-8 is different). That leads to more recirculation of exhaust gases, which hurts combustion stability. To maintain idle, the mixture is made richer, and secondary air is applied through the air pump and ACV. On a modern piston engine, the internal EGR rates are controlled by the variable cam phasers. At warm idle (cold is different), the cams are parked to a low overlap position to eliminate the exact issue we are describing, unstable combustion due to high internal EGR rates. The older rotaries really need the secondary air to idle correctly at a stock idle speed without being rich.

spintriangles 07-10-19 10:45 AM

My back window did fog up. Other than that it was a decent drive. My car is not oem but the drivability is pretty good. My car was done correctly by Kilo Racing with quality mods. Nothing is like oem I agree but a will built rx7 can also be a joy to drive.

IRPerformance 07-10-19 10:49 AM

Nice find. Add some wheels and coilovers, do any necessary maintenance and leave the rest alone.

TG888 07-10-19 10:50 AM

The FD3S is the quintessential sports car with a timeless shape and great driving dynamics. Of the 90's sports cars (E30 M3, 964 C2, NSX), this is the one I always come back to. My first one was a stock 93 CYM purchased from the original owner back in 2000. I ended up replacing her with an Alpine White E46 M3. Since the CYM, I have owned 5 other FDs, always in Base or R1 trim.

As I have gotten older, my taste for aftermarket mods outside of exhaust and suspension have diminished. A well maintained, stock FD (not modified and brought back to stock) is a rare treat to drive. As Johnny and others have mentioned, Mazda knew what they were doing. Sure with the advancements in technology over the past 25 years, the platform can be improved based upon an owner's specific needs, but there is still much to appreciate in a stock FD.

Over the years, I have returned to the FD because they presented such a great value proposition. I also rationalized the decision by telling myself I would be saving another FD from either a life of neglect or poor modding decisions by the previous owner(s). After sorting it out, I would lose interest and move on. (A major part of the ownership experience for me is working on the car.) My keeper though has been my 95 CW Base with mods.

Now, I am after an original, completely stock, never modified CYM. The hunt is half the fun!

j9fd3s 07-10-19 10:53 AM


Originally Posted by Johnny Kommavongsa (Post 12357947)
Raymond - what are your thoughts on ecus such as Pettit or M2? From what I understand, they are supposed to be just reflashed stock ecus. I had the pettit and thought it did a good job, just idled a little too rich for my likings.

the M2 didn't seem to do much except change the boost, ie you'd put the thing in and the car would run exactly the same, it would just boost to 12psi instead of 10.

i have an Re Amemyia ecu in my current car, and they quite obviously remapped the whole thing, it runs so much better its kind of amazing.

ECU number 3, is the 280ps one, my friend had one running in a car and it makes a HUGE difference, car just ran better everywhere. interestingly emissions, with this ecu were within 1ppm of the Rx8

moral of the story, stock ecu's work, and 32bit stock ecu's work better

jhaffner 07-10-19 12:24 PM

STOCK FD's
 
I have been driving my stock '93 Turing ever since I bought it new in '93. It has been a pleasure. The only real problem I ever had was when the radiator expansion bottle split and I lost coolent, overheating the engine causing the rotor housing to warp. There was a service bulletin about removing the expansion bottle, which I did while having the engine rebuilt. Never had another major problem. Oh sure, I have replaced the Tach and Speedo, and now my stereo is getting a little dodgy, But after 26 years of service you have to do a little maintenance. Then nice thing about the stock FD's is they are rapidly appreciating in value. Hagerty has the stock FD as number two on its top ten list of most desirable cars.
John

H_M 07-10-19 12:50 PM


Originally Posted by Johnny Kommavongsa (Post 12357841)
You still happy with the bridgeport or would you put in a new engine with stock ports if it was given to you?

I still like the bridgeport. I've gotten the idling and cruising tuned well enough that it's smooth. It's not perfect yet but I can drive multiple hours without it tiring me out and I can sit in traffic for a long time without the car getting weird. When I put the engine in, I wanted to make the car more streetable than before. I put in a six puck sprung clutch (much easier in traffic than the unsprung clutch that was in there) and I got a Tanabe Medallion Touring exhaust. I also installed Banzai Racing's Street motor mounts.

I still have my street ported engine as a spare. The primaries are stock and the secondaries have a medium street port (pretty close to stock). I can go back at any point but probably won't.

yurcivicsux 07-23-19 03:38 PM

couldn't agree more, nice to see like minded owners on here. as you get older you appreciate things for what they are and not what they could be. ......stock is best for me with a few quality mods. oem ++ all the way,

gmanpie 07-23-19 08:18 PM

I've owned two (JDM) FDs now:

#1: Full exhaust, high flow cat, intake, and a tune for power. Otherwise stock. Ohlins suspension and then some interior stuff (roll cage, bucket seats, etc.).

#2: Totally stock except for a newly installed lightweight flywheel with new OEM suspension

Suspension-wise, the Ohlins was superior for daily driving and much superior for track driving, but the gap isn't as much as I would've thought. OEM is definitely good enough for country roads if it's new(ish).
Power-wise, stock is enough to have fun, but I definitely notice the turbo lag. Although I hated the noise that came with an almost open exhaust, it really drove great with just stock twins.

I'd probably go for something like this in the regular course of replacing old, worn-out parts on an FD:
Replace dampers with Ohlins, replace exhaust with a racing beat or similar to OEM type. OEM clutch is fine, but I'm really enjoying a lightened flywheel even for daily driving.

spintriangles 07-23-19 10:55 PM

Gman I agree I have the ohlins on my car and they are superior to the oem especially on a roadcourse. Although my pet 6262 divided manifold turbo boost pretty quickly the two twins did a better job at low rpm. My exterior and interior are oem. It's only under the hood that you notice there are some mods. I do like the vmount over the oem smic also. The twins are what I miss sometimes. I will not go back to twins because of heat and complexity. I the near future I would like to go for the 8374 iwg Borg Warner turbo.

Montego 07-24-19 12:03 AM


Originally Posted by gmanpie (Post 12360609)
Power-wise, stock is enough to have fun, but I definitely notice the turbo lag.

Turbo lag on a stock setup? :scratch:

If anything, the main attribute of the stock sequential system is the instant boost response.

spintriangles 07-24-19 09:25 PM

Nothing
 
Nothing seems to boost as fast as the twin turbo. The borg warners are close though. I live in Orlando where there are open highways and very little elevation changes. Even the tracks are high speed in this area. Single turbos medium size seem to rule this area. The twins are good for autocross around here but that is about it. I was just in the Smokey mountains and if my car was driven there I would prefer the twins. I would go with the bnr twins though

PeloNZ 07-25-19 05:17 AM

It's been two years and I'm still glad i bought a stock FD. It came with some nice 17" Racing Beat wheels and a quiet Fujitsubo catback. I swapped the wheels for stock 16s with summer tyres ust to get the original feel of the car.
Now I've spent a fair amount on maintenance, plus a Greddy SMIC and boost/temp gauge. The car drives so nicely, despite the odd hiccup from the sequential system.
I constantly daydream about track day mods, nice wheels, and a respray. But the money vs satisfaction doesn't add up for me.
I do appreciate the heavily modified cars seen at meets and trackdays, but my car is in turn praised for it's stock condition.

djseven 07-25-19 02:10 PM


Originally Posted by arghx (Post 12357942)
Besides the 3000 (?) rpm hesitation, which is better on newer ECUs (my old '95 that Johnny bought has almost zero hesitation), you can't beat the stock ECU for liveability. And I say that as someone who has done a lot of tuning and given a lot of tuning advice, on both Rx-7's and piston powered vehicles.

Stock ECU:

1) Starts consistently under all weather
2) Doesn't overboost lean out or otherwise blow up, no matter the altitude or ambient condition (winter, heat soak in summer, etc), provided you don't over mod it.

Also Stock airbox and stock intercooler are fine for reliability, just give up some power vs aftermarket units, and the stock ECU can handle heatsoak. Stock ECU can handle mild reductions in backpressure (downpipe and catback) no problem, especially if you keep stock airbox to help maintain boost control.

3) Controls the sequential twins better than other ECUs due to gear based boost control and sequential staging (transition point is higher rpm in 1st gear), as long as you overhaul all the vacuum lines and solenoids (as I did with Johnny's car)
4) Idles much better than most aftermarket ECUs as long as you keep the main cat and underhood emissions controls (as I did with Johnny's car).
5) Has a simple on board diagnostic system (OBD 1) that throws codes when sensors fail and goes into a failsafe mode. If you lose a sensor in an aftermarket ECU, you could blow a motor.
6) Allows the convenience of the oil metering pump and won't blow the motor if it fails (no need to premix unless you really want to eke out a little more engine life).
7) Good tip in throttle response that is difficult (but certainly not impossible) to achieve with aftermarket ECU.

A lot of these can be overcome with a Power FC or better, newer/more advanced ECU, but it takes a LOT of real world tuning to get it right, and the aftermarket ECUs will never have a real OBD system or some of the advanced logic of the stock ECU (unless you go hardcore with custom code).

The main reason for aftermarket ECU is more power. You won't beat the liveability and convenience and safety of the stock ECU as long as the engine hardware is kept close to stock.


A whole lot of truth^. Im a big proponent of the Pettit and M2 modified factory ECUs. Even with emissions deleted, the stock ecu offers the best driveability and comfort for stock twins if you have a healthy engine. It can even handle minor porting before the overly rich idle becomes obnoxious. One thing you mention that most ignore is the tip in issues with aftermarket ecus. In my opinion, its more annoying then minor 3k hesitation that happens on stock ECUs. The stock ecu/modified ecus do have their limits but overall driveability is unmatched. The only reason I like the PFC as well is because of the commander and its ability to display so many different readings without having aftermarket gauges displayed in the car.

gracer7-rx7 07-29-19 11:44 AM

The problem with those stock-like ECUs is that you can't run them with a street ported motor :(

Testrun 07-29-19 02:17 PM

I can admire a fully stock FD. Do I want one?
Nope.
The FD for me was a must have for a long time. A fantasy car. I have always liked and appreciated the under dogs. (Almost got a damn lotus esprit instead, but I couldn't get the rotary bug out of me). There are not too many cars sub 80k that interest me, but the stock fd lacks the power I want. To keep up with the more modern cars it needs more power. I think a good solid twin sequential FD putting out 325-350ish rwhp could be as solid and reliable as a fully stock car and keep up with most things on the road. At least damn close to it with all the supporting mods. Fast enough to have fun? For me? HELL yeah!

ptrhahn 07-29-19 02:26 PM

The thing that always gets me about a stock FD, is how high you sit (and then how huge the wheel is). I've had race seats fixed-mounted on the floor and a 330mm wheel forever, and I can't remember the stocker. I think I'd need some Spirit R seats or something for a daily driver. I'd love to have the space for one though.

Narfle 07-29-19 02:27 PM


Originally Posted by gracer7-rx7 (Post 12361543)
The problem with those stock-like ECUs is that you can't run them with a street ported motor :(

I believe @BLUE TII was able to get a specifically tuned daughterboard box from KnightSports in Japan, if that's what you're really after. May be an option for owners with setups outside the scope of Pettit/M2 standards, who want to retain the benefits of the stock ECU.

TomU 07-29-19 02:40 PM


Originally Posted by ptrhahn (Post 12361576)
The thing that always gets me about a stock FD, is how high you sit (and then how huge the wheel is). I've had race seats fixed-mounted on the floor and a 330mm wheel forever, and I can't remember the stocker. I think I'd need some Spirit R seats or something for a daily driver. I'd love to have the space for one though.

2nd FD = $35k
House with 2 car garage = $1.3M :lol:


All times are GMT -5. The time now is 02:21 AM.


© 2024 MH Sub I, LLC dba Internet Brands