rotarynemesis

Im always reading about how fast rx-7s are and how they can beat all of these other cars but for some reason mine cant.
it cant even do a burn out.
its a 93 automatic rx-7 with the hks intake, dp, mp, and hks exhaust. it had a reman put in by the dealership at 76k its now at 94k miles.
ive lost to every car ive ever raced except a stock honda civic. ive been beaten by mustangs, non turbo eclipses, 240sx, crx, and many more.
my car is a joke to everyone and i want to know why. its lost to 16 second cars when its supposed to run 14s stock.
what could be wrong?

please help me out.

inis

what is your boost pattern?

And dont expect to be doing any burn-outs with the auto. Not unless you want to neutral bomb it and destroy the tranny.

rynberg

You obviously have a boost leak, which is probably saving your motor from blowing with those mods....

If you have another car to drive, do so until you've learned more about your FD. Read through the newbie stickie and read through the links that are in there. There are hundreds of hours of reading you can do.

First thing I would do if I were you would be to install a hi-flow or stock cat to replace the midpipe. Since a Mazda dealer did the re-man (worst place to take your car), there are likely several problems with the vacuum lines/solenoids. I would spend the money to take it to a rotary expert for them to do a complete "vacuum hose job", this will cost approximately $400 + expenses for any problems they might discover (such as broken solenoids, leaking injectors or worn out fuel pulsation dampener, etc). Ask in your regional forum for rotary shops close by to you. Pettit Racing is a very well known and respected shop in Florida.

Those two items will likely go a long way in solving your problems. You will also likely need a boost controller to maintain your boost to 10 psi with the stock engine computer -- once your problem is fixed.

Oh, and as you'll read in the newbie links, get a boost gauge!

Good luck!

rotarynemesis

why would i put the stock midpipe back on?
how can a boost leak be saveing my engine when ive only done intake and exhaust mods. i know rotories like to overheat but the exhaust helps relieve the backpressure and get the heat out. would a new manifold help out.
why cant it do a burn out my friends four banger has less torque and it can smoke the tires with no problem and its an auto too.
i have just looked forward to getting an rx7 for so long and it just hasnt lived up to its name. i could have bought a 240 and put an sr20 in it and still have money in the bank.

rynberg

Go back and read my post. You can't just open these cars up with full exhaust and intake on the stock ecu. You will blow the motor. Spend some time READING and you will learn the answers to your questions.

BTW, if you wanted a FD for so long, why did you settle for an automatic?

EKTwin93

A boost leak is saving your engine because the proper boost with a MP DP and CB is well beyond the stock fuel capacities. Do you even have a boost guage? How much boost are you hitting? If you don't have a boost leak you must be running terribly lean. I spike to 13psi occaisionally with just a DP and CB. I'd say put your cat back on for now...

areXseven

iTrader: (1)

The reason you're not "burning-out" at take off is cause the primary turbo doesn't really kick in till about 2300 -2500 rpm at WOT. By then,obviously, your FD is already traveling and gaining speed , (slowly but surely). In an FD stock turborized Automatic, you don't have a sudden burst of HP and torgue at launch as you do in a Manual Tranny FD (or any other stick car) . As you know, cars with manual trannys can be rev'd up, and launched at any given high RPM. This creats instant HP and Torgue at take off!!!

With the Mods you have , YOU SHOULD be boosting way above 10psi at WOT. Very curious to know what type of HKS cat-back you have. I just replaced my HKS Super Drager with a Magnaflow dual tipped muffler and it opened my boost up to 15-17 psi. With the HKS, I was "spiking" to 12 at secondary transition. The HKS was probably clogged.

IMO, you either have a clogged Cat Back (HKS) ....or.. A good sized leak somewhere, maybe the Y-Pipe coupling or plastic crossover-tube. Or a leak in the IC piping or IC pipe couplers. Many other areas a leak can develope.

If you don't have a boost gauge, YOU NEED TO GET ONE. Then you will get a better picture as to what's going on with your FD. Keep us posted on your findings. Thanks and good luck. ...OH...and don't go WOT till you get a Boost Gauge.

Louis M

get a pfc! you already have four mods and you're probably not getting optimum hp!

rotarynemesis

So I need a boost gauge and a new ecu.
What would make it run lean, how could I tell. Someone who looked at it said it was running rich.
After the warm up at start up my car likes to backfire sometimes. Is this a problem?
I bought the automatic because thats all the dealerships had around here. I read the forum about buying a 93 and all the problems so I wanted to get one with a warrenty so I got an auto. (Im also not very good at driving stick, but im learning.)

YayeR

the lack of backpressure in the exhaust would make it run lean, your car is letting the exhaust out with very little resistance, so you need more fuel to meet the demands of the increased 'air flow'. The backfire is not a problem. If you plan on modifying your car any further, get a pfc (apex-i PowerFC), if not, call up pettit or m2 and ask them about chipping your stock ecu for your mods. The reason you might want to replace the midpipe with your stock cat is that it would 1. help the leaning situation and 2. move your powerband back down into a more useful range. There is tons of information on this forum, take some time and read it, use the search option it can be very useful.

unixpilot

A dealer sold you a FD with a MP in it??? Isnt that illeagal?

Do you guys have emissions testing up there in Jax?

And there are a bunch of FD's well within a 1 day roadtrip from you, you REALLY made a mistake by blowing your wad on an automatic.

unixpilot

Also you can forget about using half of the ECU's guys are referring to in this message.

There are only a handful of ECU's that will work on a FD Auto. Again use the search.

r0gu3

I ran full exhaust and intake on stock ECU ......

areXseven

iTrader: (1)

Now that wasn't very nice.

JONSKI

First off, work on your launch technique. Intuitively, one will think, "It's AUTOMATIC! All I do is stomp the accelerator, right?" Wrong. Ever notice that the car has almost no power when you stomp the accelerator? If you gradually depress the accelerater, then you will get a much faster launch. A great AT (Automatic Transmission) launch requires both practice and know-how. Listen up.


This is just about the fastest way to launch the AT FD.

- Put the transmission selector in the "L" position.
- Activate the Hold feature by pressing the Hold button on the top of the transmission selector.
- Press FIRMLY on the brake with your left foot.
- Carefully depress the accelerator with your right foot until you just about reach your stall speed. Your stall speed will likely be at or above 2500rpm. If you don't know what the stall speed is, scroll down to the end of this post. You are now doing what is called "Brake Torquing". You will hear creaking sounds as your revs increase. This is normal. Don't do this for longer peroids of time (1 minute MAX!), because you are drastically raising the temperature of your transmission fluid.
- When the light turns green, release the break, but DO NOT stomp the accelerator. GRADUALLY depress the accelerator as your car gains speed. You should not reach WOT (Wide Open Throttle - accelerator fully depressed) until about 5000rpm.
- At 6500rpm press the Hold button again to disable the hold feature and allow the car to shift automatically.


--- STALL SPEED ---
This is the maximum rate at which your TC (Torque Converter) can spin while your brakes are locked. The stock AT FD TC usually stalls the engine anywhere between 2500rpm and 3000rpm. Stall speed is affected by temperature, TC design, TC condition, ECU, and probably other stuff. You can find your stall speed by brake torquing until the engine seems like it is struggling to run (i.e. it seems like the engine is on the brink of stalling). Try not to stall your engine.

areXseven

iTrader: (1)

JONSKI: Is an aftermarket "Stall Converter" available for the FD?? Like the Hole Shots sold by B&W?? Some can be stalled to 3500 rpm!

Icemastr

iTrader: (2)

Aftermarket torque converters are available for any car, but the problem with making your automatic fast isn't the torque converter. A high stall torque converter is not going to benefit a stock twin sequential RX-7 much, because it makes plenty of power on the low end, high stall torque converters are used on cars that dont make power until high in the power band, such as a car running a huge single. If you have a 4000rpm stall on your torque converter, and you step hard on the gas, your car will instantly be at 4000RPM and climbing. However this also causes the transmission fluid to get really hot, especially if you are launching and holding the car just below stall for much longer than a couple seconds. However putting a high stall on stock twin FD isn't going to help your launch much. An upgraded more efficient torque converter where you can launch at 3000RPM or so would help the launch, but thats only part of the problem. The FD automatic transmission is not capable of handling much power. 300RWHP seems to be about the limit. In order to do more power and shift faster your going to need an entirely new automatic transmission, such as a TH400, TH450, or 2 Speed Powerglide. With an upgraded version of these transmissions you will stay in your powerband long, shift much faster, and be able to handle 1000+hp. However, I don't know of any companies that make a turn key bolt up kit for the FD. On my current project I am planning on using a modified TH400 with a 4000RPM stall converter and a big single turbo, but it is not cheap, the transmission and drivetrain will be over $8000. I think Rotarynemesis has some serious problems with his car besides just the transmission.

Snook

iTrader: (12)

If you bring all tools like a wrench set, screw drivers, pliers, silicone hoses of the 3 different sizes on the car and your car I will check it out and we could fix it in a day. Everyone's right, you absolutely can't have a full exhaust and intake on the stock ecu unless your wastegate is ported. Your boost will go over 10psi at the higher rpms even at the lowest settings. Also bring a boost gauge along. I'm in gainesville near the University.

-Snook

NorthwindHost

Do your homework on this car.

If you have no patience, then this car is not for you. Honestly if you don't see your self working on this car when its sick, I would sell it before you blow an engine.

Also, mazda warrenty. Ha. Takes them about 3 months to replace a engine, turbo, etc...

Mahjik

iTrader: (1)

You can also drive with your feet, that doesn't mean it's a good idea just because you can do it.

Everyone is just trying to give him safe advice.

unixpilot

Sorry if I sound brutally honest, but given the fact that his primary concern appears to be the ability of doing a burn out and street smacking hondas, I'm not sure if he's "FD worthy"

You could read this forum for a week and have more Rotary / FD sense than he's got.

Here my advice, sell the FD and get a SRT-4

fdeeznutz

When I was looking for my FD all I could find were AT's. It took me quite some time to find a nice low mile 5 speed FD. I just don't understand an auto in these cars

Oh well, atleast they didn't offer it in a non-turbo version........like the supra,300zx,3000gt

shred

Sure hope that you are not someone out there just joking around to see if you can get a bunch of RX7 owners comming up in arms over a slow RX7. Stock you should be able to beat quite a bit, even with the (ahhheemmm...cough....) automatic. I would suspect boost issues. Hook up a gauge or get that dealership that you bought it from to do a test. If that isn't the problem I would suspect the engine isn't performing as it should, check vacume, maby missing spark, something. Does it jerk or anything under boost??

What does it feel like when you are driving it?

Jasooner

I got beat by a 4 door Civic EX when I first bought my car :gasp: It was embaressing. Then I found I was making 0 boost, there was a HUGE split on the y pipe hose coupler. Actually, it was so bad, the y pipe wasn't even connected to the ic pipe. I'd check there first.

But AFTER, man I ate my neighbor's 5.0

r0gu3

I can drive with my feet ... but the 1 - 2 shift is difficult.