what's up guys? i just installed a megan racing down pipe and midpipe on my 95 fd, and it has a hi power titanium exhaus from hks. now the problem is that im getting this back fire everytime, a loud back fire....its just the downpipe, midpipe, and the hks exhaust, there's no cat or resonatorin between. can anybody tell me what the hell is wrong and why it is backfiring? oh yeah, i just got back from the freeway also, and on 3rd and 4th gear, when i hit around 5 and a half or 6 thousand RPM, the damn thing kicks me out like im already hitting redline. somebody please tell me what the heck is wrong?

 

its probably fuel cut. I'd put that stock cat back on if I were you..

 

I agree. If you continue like that, you won't have that problem any more... you'll have bigger problems.

 

so can i just get rid of that fuel cut? instead of putting the stock back?

 

GET A PFC!!!Your gonna blow the car up running a mid-pipe on stock ecu.

 

im guessing if u are, running stock fuel programming. The exhaust is too open without proper fuel enrichment.

 

yea sure, call chuck at rotaryextreme , you'll need 1300 CC secondaries and 850 CC primaries, a new fuel pump and a power FC, have fun !

 

yes and no.

no you will not blow your car up with the stock ecu and a midpipe.

yes you will blow your car up from too much boost that is the result of a midpipe and the stock ecu.

if you cant get a PFC or some other ECU, get a boost controller and a boost gauge. if you cant keep your boost at 10 psi, put the stock cat back on until you can.

 

boost controller will NOT keep the car from over boosting with full exhaust. ESPECIALLY WITH winter coming, and the temps just getting colder and colder. ONLY WAY is to restrict exhaust.

The reason a boost controller wont work is because the stock wastegate is being maxed out and can no longer keep the boost at the stock level due to the extreme upgrade in airflow with no cats. you COULD port the wastegate but its a bitch, easiest thing is to just restrict the exhaust some how (high flow cat)

 

i have same setup but have greddy cb and hks rs intakes. alot of back fireing buy i dont let it get past 6grand still pulls like a mo fo but dont want to lean out(no bost guage)............pfc/defi/greddy BC plans on the way

 

thanks guys, this really opens the page up, im new to rotaries and i really appreciate your inputs...this car will be staying in the garage this winter...so a PFC, Injectors (850 primary and 1300 secondaries), high flow cat, boost controller, are some stuff that i need. oh yeah this car is daily driven and also a show car...what are your thoughts about that?

 

[IMG]C:\Documents and Settings\Mike\My Documents\My Pictures\Picture[/IMG]

 

this is the only car you'll own that will be this much of a bitch. boost control is very hard to fine tune on the stock twins and wastegate

 

 

I said if he cant keep it at 10 psi with a midpipe then put the stock cat back on. I was able to keep mine at 10 psi with a full exhaust on the stock ecu with a manual boost controller...in December. I didnt see where he specified he had boost CREEP and not just boost spikes. it is most likely boost creep though and will need an exhaust restriction or a ported wastegate.

 

nice man heres mine

 

then why would he be getting fuel cut? obviously he is boost spiking or he wouldn't be posting this thread at all.. mister

 

if he is spiking, a boost controller can cure it. it is boost creep that is a wastegate problem.

nice car, BTW...both of them...I wish mine was white.

 

that's a nice FD man. and thanks for your input...now im thinking of just putting the stock pipe back on until i get the rest of the fuel, ecu and the boost controller upgrades...its off season anyway. if you have any more advice, i'd be glad to hear them...thanks again. here's another pix, its pearl white with blue pearl tints.

 

off topic...who smoked the reverse lights, etc. for you?

 

you too man, if you have any questions feel free to PM me or im always on AIM at nopistons93 so either or.

 

all the lense smoking I did on my car

 

You smoke too much j/k

 

Read the FAQ. https://www.rx7club.com/3rd-generation-specific-1993-2002-16/faq-3rd-gen-other-useful-links-68640/

You are probably looking at boost creep followed by fuel cut. Just because they sell those pipes together on eBay does not mean they are a good idea.

I suggest you put the main cat back. If you really want the midpipe, you'll need to take apart the turbos and port the wastegate, and also add a boost controller and ECU.

You also need to add a boost gauge so that you can know when things like this are happening.

Dave

 

Too true... I never managed to tame the boost on the twins....

Either be prepared to spend big bucks on a proper ECU and a Single conversion and all that entails, or put some restriction back into the exhaust.

And do it NOW - you're sitting on a timebomb!!!