dizastical

Hey guys ! I just got my 94 FD one week ago and took it to the track last night for the first time . I dont know what a FD with 3" down pipe , 3" mid pipe and 3" exhaust is suppose to run . Keep in mind that this is my first rear wheel drive car and i am a newbie to the world of RX7's . Please give all comments on my results ! Thanks guys !

reaction time .837
60 foot time 2.03
1/8th mile 8.83
1/4 mile 13.60
speed 102.86


Apexi PFC - ordered
Apexi Intakes - ordered

94touring

You probably shouldn't be driving your car untill you get the powerfc. The full exhaust is causing you to run lean, and probably making your boost spike like crazy.

93TTRX7

depending on what elevation...but if you ran it at sea level those numbers aren't that impressive...with no cats at sea level you should hit low 13's at least

UnSeeN

kabooooom!! did i hear a pop! get a power fc ive seen blown engines with a cb and dp. no cats thats how i blew my TII a while back. just dont driv ethe car man..

Brede

I drove several 13.1 runs the other day. Is that a good time, I really have no idea what my car is supposed to run at with my mods..
It was also my first time trying this, so I guess with some more experience I can squeeze down the time a bit.

-Downpipe
-N1 Cat-back
-PFC
-Unorthodox Full Pulley Set
-K&N Drop In

violator

hey im running mp/dp cb exhaust and i do have a pettit unlimited. my boost is spiking to 0.9 bar is that aight? i know only to reduce spike is to port wastegate or put a restricter on the midpipe. does a boost controller reduce ne spike at all?

93TTRX7

your pettit unlimited should be able to handle a .9 bar spike...that's around 12-12.5 psi...i believe the pettit handles 14.7 psi? Don't quote me on that

But to the guy that ran a 13.1 with just a dp, n1, pfc, pully kit, and k & n...you did really well

Freaky Monkey007

Those times arent all that impressive with the 3" all the way back. Guess that your first time to the track is showing with your reaction time... Now to Brede those times extreamly well.

spooledUP7

Just doing a public service.
Again, reaction time has nothing to do with ET. Staging does.

dizastical

Thanks for the replies . I really had no idea that running the car with those mods without a PFC was bad for the car . The shop that built the car (clean and fast) said the car was fine to race and drive every day with no PFC . I was conserned thats why i posted . Thanks for helping me out and not giving me a hard time for not knowing . What should i run in the 1/4 with the PFC using the base map and the Apexi intakes ?

Street King

Dizastical your car probably is safe to drive with out the PFC. Do you have an a/f ratio gauge and a boost guage? You can basically add almost everybolt on known to man and if your fuel is ok and your boost doesnt pass 12lbs at anytime then its safe! Your times with the new mods you might see a 12 but very doubtful. I bet you'll hit a 13.3 or 13.4. Tighten up those 60' times and you'll see a big difference!! Hey just keep trying at the 1/4 for better times. But if thats all you are worried about is the 1/4 you should have gotten a v8!

dgarvich

I get so sick of people posting that an exhaust will cause your car to run so lean you'll blow the motor.

I've been running 3" back for two years now, racing and guess what... I'm at 120K miles with perfect compression! *gasp*

These cars aren't as fragile as people would have you think. Drive your car, enjoy it.

And before anyone posts flames that say I don't know what I'm talking about please remember to provide your evidence that disproves the fact that my car has been running for two years with my setup.

No proof = no post, I'm sick of people posting on hearsay and not knowing what they talking about.

This guy is a new RX-7 owner and you're going to scare him to death that his car can't handle being driven.

dizastical

Street King, I am not only worried about 1/4 mile times . I just want to know how i can improve the car and my driving . I have only had Front Wheel drive cars and i am not used to rear wheel drive or even turbo ! The only reason why i was happy with my 13.6 is because the fastest i have ever been is 13.9 . And there was another FD running 15.1 all night . I live in Maine and there is no one here for me to talk to and learn about my car ETC . Thanks for the info . Any other recomendations to what mods i should do next or how i should tune the PFC , would be great .

rynberg

umm...ok, so YOUR car has been running for two years, but many people's engines HAVE popped running those mods.

What are your current boost levels? What are all of your mods? It's true that you can run those mods if you can restrict boost to 11 psi or so, but he doesn't list any sort of boost control.

ttpowerd

The problem is boost spike not running the mods. When you spike you will run lean and pop the engine. It is every easy to spike without any cats.

dgarvich

No boost control here, I like my spikes around 15 thank you very much.

I can't have boost control under the SCCA Street Prepared rule set.

Many people's motors have popped for many reasons, I've just yet to see proof that running lean based simply on an exhaust was the cause.

My point being, the engine can't output more air than it can take in. Whoever posted that they've seen engines pop because of a dp and cat-back is obviously running on hearsay, posting as a knowledgable individual. Not so, the cat alone provides sufficient boost control and the stock ECU can support a lot more than people give it credit for.

Do I recommend having intake and straight exhaust, no, is it possible to drive your car to and from work with it like that? Definitely.

My entire thought is that this poor guy has just gotten his FD and people are telling him not to drive it. Unless they can provide me proof of why my car is going to spontaneously combust all of a sudden because THEY said it wasn't safe then this guy will be as safe as any of us.

For the original poster, get a boost gauge, keep it under 15 if at all possible. You don't HAVE to spend thousands to enjoy your car.

dgarvich

Maybe everyone needs to understand the difference between a boost spike and boost creep. A boost spike, if it is truly a boost spike is not that dangerous. So your turbos spun fast enough to make 15PSI for 1/10th of a second, the 13B can handle that much boost in stock form. However, holding that level of boost, or starting at 12 PSI and creeping to 15PSI is what's dangerous.

Holding a car at 15-18PSI for an extended amount of time will not necessarily kill an engine because of it running lean, but you *will* hit fuel cut and it will scare the pants off you. Enough so that you won't do it again.

I've got the fuel map for the stock ECU around here somewhere in Excel format if someone would like to take a look at exactly what the stock ECU will and will not do.

I just think it's important that people who don't know what they're talking about don't continue to downgrade the value of our cars. Consider for a moment what might have just happened.

Some happy camper paid $14,000 for a car in good condition. Took it out once and now people who are supposed to know their stuff are telling him it's about to explode. Let down, yet needing transportation he turns around and sells the car because he can't afford to spend the $5,000 that people here say he would need to spend to have "reliable horsepower." BTW - those people also replace their engines every 30K, just ask em. In turn, the value of our cars continues to drop and the reputation our cars have for unreliability just got worse.

A Supra, from the same year, demands roughly 130% the price of an RX-7. Why do you think that is? Because people understand pistons, not rotors? Which car is *really* better?

If people actually knew rotaries better, they would know that the little keg that could is an EXTREMELY sturdy example of an internal combustion engine. Talk otherwise baffles me. For proof, compare the frequency at which a Formual V or Formual Ford has to replace/rebuild their engines as opposed to a Formula Mazda.

These cars aren't fragile, if you understand them.

94touring

Why risk it? Fact is, a high flowing exhaust and no ecu upgrade is right on the edge of blowing a seal. Boost spikes are horrible for the stock ecu, since it hits a fuel cut of some sort after 12psi. Every car is different when it comes to tuning, just because someone is ok with those mods doesn't mean the next guy will be. If it was a highflow cat I wouldn't be worried, but a midpipe is a big performance mod.

dgarvich

I have no more to say on the subject, I feel my point has been made sufficiently in saying that I encourage the original poster to enjoy his stay in the FD community.

Drive your car, enjoy it. Worrying about popping a motor every time you unlock your doors isn't a lot of fun, so I choose not to do it.

You should continue to bask in the infinite knowledge contained in this forum and learn from all those who seem to know so much about blowing seals and body kits. Please ignore anyone with proof that differs from the popular opinion, that person must be incorrect. **hopes the sarcasm isn't too thick to walk through**

I'll continue to believe proof, not opinion and not hearsay. Popular opinion isn't always correct, don't be a lemming.

Now I'm going to go replace my fuel filter... the one that's on there is new but it's just so much damn fun. It's 2:00PM, do you know where your fuel filter is (99% of the members on this forum couldn't find their fuel filter in 10 minutes or less, this contributes to fuel filter delinquency and raising levels of A in the A/F ratio)?

94touring

Well thats fine, but when he blows his engine cause his boost spikes, I hope he sends you the bill for repair. Not that his car will, but it is a known fact that boost spikes can occur when you run a full 3" exhaust. My car use to spike badly back when I had a straight exhaust, twin turbos without a modified wastegate, and a boost controller.

dgarvich

And oddly enough, it appears that you still have the same engine? Curious isn't it? Thanks for supporting my opinion.

93TTRX7

You can't flame him because he seems pretty intelligent...but anyone who doesn't blow a seal with 3 inch piping all the way is pretty damn lucky too.

94touring

Oddly enough I didn't mention that I blew that engine after it hit fuel cut on me. I cracked a seal, lost compression, then blew it sky high months later after a single turbo conversion and 20psi. These engines are stronger than people give them credit for, I have been running 18psi on pump gas for a long time and have managed to keep the engine together. But you can’t be stupid when modding and tuning, there are rules to follow to be safe. You must have proper fuel delivery, that means no FUEL CUT. Fuel cut occurs when you BOOST SPIKE on a stock ecu, or go past what your map sensor can handle, boost spikes can occur when you have a downpipe, MIDPIPE, catback…..its just common rx7 knowledge to live and die by. And oddly enough you act as though just because your car with x amount of miles and x amount of mods can handle it, then everyone else motor should too. Well that’s not how it works, there are different variables car to car. I’ve seen motors that boost spiked and caved the rotors in, cracked end plates, and spit apex seals out the exhaust…….so I think that should say something to you and others who think its ok to boost spike.

dgarvich

No, I say that no one should tell Mr. Original Poster to run and hide from his car because of his current mod set up.

Mine is a I can do it, so can you! Type story.

Take it for what it's worth. I never blew my engine...

Everyone knows the best form of boost control is achieved with the right foot.

94touring

Who said he should run and hide from his car? All I said was "probably", he should "probably not be driving it untill he gets the power fc. He "probably" is boost spiking. Your making this thread way to complicated by adding comments no one ever said.