I have decat zorst, bov, induction kit and about to fit a large smic.
I will be getting a PFC about June and a remap.
What are the possible implications of running the mods without remap?
mate, if it was my car i wouldn\'t even be running the mods u are without a pfc! back box & filters are usually ok but de-cat tends to lead to boost spike n with no way to add extra fuel to compensate you run the risk of detonation!
det=blown engine!
i\'d defo hold off on the fmic n get a pfc post haste!
BANG
Your pushing you luck as it is, fitting the smic is suicide!!!!!!!!
lol i didnt know you had a decat Jim, but yeah your gunna go Boom soon without a pfc n remap.. get a cat fitted and dont boost until its on, 3k for a rebuilds not nice bud
The cat has been removed, but I do have the pre-cat still in (uk car) so it isn\'t 100% decatted. I do have a Jap downpipe to go on, but I won\'t fit it until I get the PFC.
So in theory I should be ok??... ?
Why does fitting a larger smic cause issues?
umm pass lol..
A larger SMIC cools the air better, therefore you get desnser air, which means your getting more in so if you have more air you need more fuel, e.g you\'ll run lean.
A
Alot of other Jap turbo cars I\'ve had you can get away with decatting, putting larger intercoolers on etc and without remapping it\'s ok.
Is it just because the rotarty is so much more sensitive to detonation?
I\'m gonna fit it regardless as the car isn\'t boosting 100% anyway. I\'ll then fix the boost leak and get a PCF fitted and mapped. TBH I don\'t use the car much as is, and just potter to work and back ( a few miles a day ) ... lol.
piston engine can withstand a lot more abuse. If you run lean on a piston engine it pinks/knocks but can take quite a lot. On the rotary if you get preignition you can chip an apex seal, the engine is more sensitive.
your standard ecu will not inject enough fuel as you expand the "breathing" capacity of the engine, so yuo run the risk of det. NOT NOT good, I would say the next thing you need to do before ANYTHING else is get an Apexi fitted.
I\'m on the hunt for one!
Until I get one fitted and mapped, I\'ll just potter about off boost.
Saying that, could I not just fit the SMIC without the ducting for it? That way it won\'t be working as effeciantly as it should be, and there will be less chance of det?
Either way, I\'ll be driving off boost. :)
Just buy an apexi first bud, base map on these will do all the mods you have safely, then build on that.. dont take the risk of blowing your engine.. altho i`ll giv ya a hand cus it`ll be fun rebuilding it lol
Well it would be prudent to get the Apexi fitted before doing anything else. PM Sent !!
Common theme to the posts here mate, DON\'T DO IT...................
The rx even when set up properly will inject more fuel than piston cars mate, u will have major issues if you under fuel the car.
Quote from: interloper393Just buy an apexi first bud, base map on these will do all the mods you have safely, then build on that.. dont take the risk of blowing your engine.. altho i`ll giv ya a hand cus it`ll be fun rebuilding it lol
Lol.. that\'s my thinking... rebuilding could be fun! :)
Obviously, I don\'t want to have to rebuild it!
a home rebuild costs around 1500 if new housings are needing..
Me, you, Mike... cups of tea... my shed. lol.
cups of tea??!! fook that i drink jack daniels man lol
dont understand the intercooler propblems you guys talk about. larger normally means a slight drop in boost pressure and its just like a cooler day so whats the problem?
the air temp sensor in the plenum will surely realise when its colder outside?
Mmmm... yeah. Good point.
Surely the ECU can somehow compensate if it\'s really cold outside? Ie, more boost. Or the fuelling is adequate enough for when it is very cold outside.
I\'ve never heard of a car having issues because it was boosting when the air was really cold (more dense - ie, same as having larger IC).
Any thoughts?
Quote from: Jim_rx7Any thoughts?
Seriously, you\'ll get a *MUCH* better performance increase from the ECU than any other mod you have, AND it will add safety.
There is only one logical peth here, buy your ECU (Apexi??) when you can afford it , and then fit the IC at the time of fitting / mapping.
2p :WaveBye
Quote from: Jim_rx7I have decat zorst, bov, induction kit and about to fit a large smic.
I will be getting a PFC about June and a remap.
What are the possible implications of running the mods without remap?
Hi
Have a look at this link and get the Apexi PFC asap
http://www.mazdarotaryclub.com/forums/showthread.php?t=37184
You will have to get one before the smic, I personally would not take the chances you take - driving with out a PFC and a map...
Regards,
Michaelb
Quote from: allstarukA larger SMIC cools the air better, therefore you get desnser air, which means your getting more in so if you have more air you need more fuel, e.g you\'ll run lean.
A
I had a wee think....
Surely all a larger IC/SMIC does is help keep the intake temps lower, then in thoery allowing you to run more boost as long as you have sufficient fuelling.
So running stock boost with a larger SMIC/IC, I don\'t see where the problem would lie? No more fuel would need to be added, hence you shouldn\'t run lean???
Might be wrong though.
PS: I am on the hunt for PFC.
OK Jim,
Cooler air is denser air, more oxygen contained in the same volumetric space, so therefore cooler air is more air. If you put more air into the engine, you need to inject more fuel also. Otherwise, the mixture is too lean and will pre-ignite.
Really and truly there would not be a particular problem sticking on the smic and driving about, because yes the stock ecu will inject more fuel as the charge temp comes down. The point is, with your current setup you are getting a larger volume of air flow already, which the ecu will not be allowing for, so to further push the limits you are treading a dangerous line, already you are running a risk of det without further modifying the car.
Play safe, think with the head not the heart on this one :o
Hi Jim,
I am no expert mate but I can only advise you follow the advice of guys who have owned these, some what tempremental, cars for a period of time mate. They have all have a knowledge of what can go wrong, and it does not sound too good. You should defo fit the PFC before you do owt else to it, better safe than sorry mate.
My 2p\'s worth.
Another question.....
Alot of problems in other cars arise when you fully decat etc, because due to less exhaust restrictions the boost pressure rises. At this point, more boost would mean more fuel required. Although there\'s usually always a safe limit you can get to without needing a mappable ECU. Usually the fuelling is good upto a certain point.
Is this not the case in a Rx7? Has anyone wired up a A/F gauge on a slightly modded rex with a stock ECU?
(not trying to argue with anyone here.... just curious)
Quote from: Jim_rx7Another question.....
Alot of problems in other cars arise when you fully decat etc, because due to less exhaust restrictions the boost pressure rises. At this point, more boost would mean more fuel required. Although there\'s usually always a safe limit you can get to without needing a mappable ECU. Usually the fuelling is good upto a certain point.
Is this not something to do with the Fuel Cut Defencer......?????
It will stop the engine from cutting fuel in a "safe Mode" idea....??????
The stock ecu can only handle air filters and a backbox bud, anything else you`ll be running lean, dosnt matter what other cars cn do and let you get with.. rotarys are very unique and tempermental, they dont like to be messed with unless done right
These engines are all rubber seals n paper gaskets lol.. fairy fragile..
Your new to the rx7`s, all the advice above is spot one, as Neil says these guys know there stuff.. iv been reading everything i cn get ma hands on about these cars for the past 2 years, still sh!t loads i dont know n understand.. if you want advice phone a engine rebuilder/tuner like WGT, reworx ect.. ask your questions n they`ll answer in great detail lol
Cheers
Craig
FCD is a way of bypassing boost limit.
A lot of Jap cars are set to run at a set max boost, say 7 psi. The FCD is effectively a resistor which you splice inline between the boost sensor and the ecu. The ecu then thinks the car is only boostin 4 psi when you are actually boosting 7, and so you can run say 12 psi instead of 7 limit. The big prob here though is that you will run 12 psi but only be injecting fuel for 7psi. FCD like this is a big nono on Rex.
Yeah, normally you would also fit a FCD. But again, the fuelling would usually be good upto an extra point. Then it would run lean unless controlled.
Which leads me back to my previous post.
most other cars if you fit a exhaust, decat or filters, just dis-connectin the battery, press the brake to totally drain the car and re-connect the bat and the ecu will learn the new mods..usually warm the car before hand then red line in most gears to get a newish map.. well thats what i was telt lol
Quote from: strange_days_ukFCD is a way of bypassing boost limit.
A lot of Jap cars are set to run at a set max boost, say 7 psi. The FCD is effectively a resistor which you splice inline between the boost sensor and the ecu. The ecu then thinks the car is only boostin 4 psi when you are actually boosting 7, and so you can run say 12 psi instead of 7 limit. The big prob here though is that you will run 12 psi but only be injecting fuel for 7psi. FCD like this is a big nono on Rex.
Cheers Simon,
That\'s the point I was making Jim, they all know alot about these cars.......lol.
Well I think this is the other guy\'s point. You are already running a decat which will potentially cause you to be running lean in certain circumstances. Therefor to add your SMIC will further increase the chance of running lean and then the engine may go pop!
I have SMIC decat and induction and PFC and my PFC shows up to 90% injector duty. Therefore without fueling mods I can\'t get anymore out of her.
The mapping keeps everything within a safety margin and although we are not talking about injector duty at the moment it is also another thing to consider. ie get the PFC then fit everything else and get mapped all in one go :cool
Eddie so is that your cars using 90% of it`s output? so you`ve only got 10% more use from it? lol kinda wondered how it worked ..
Yes basically it means that the 10% remaining is like a safety margine.
ie, If on WOT for example the car needed 100% injector duty but due to a slightly blocked injector (they are 14 years old :D) it couldn\'t provide enough the car would run lean and potentially go pop :Thumbs-up
Quote from: Crazy EddieYes basically it means that the 10% remaining is like a safety margine.
ie, If on WOT for example the car needed 100% injector duty but due to a slightly blocked injector (they are 14 years old :D) it couldn\'t provide enough the car would run lean and potentially go pop :Thumbs-up
Coooool,
Mine is at 45% @ 0.6 bar on my single, loads left for more boost......lol.
Rub it in lol... how much weight have you save from the modded bumper lol
Raw nerve you hit then mate.........no need.................lol.
Well thanks for all the info people!
Hopefully will have a PFC soon!
soz dude, ack well nice reason to go shopping :) like i say cn fix it if ya wanna pop it down :)
Quote from: Crazy EddieWell I think this is the other guy\'s point. You are already running a decat which will potentially cause you to be running lean in certain circumstances. Therefor to add your SMIC will further increase the chance of running lean and then the engine may go pop!
I have SMIC decat and induction and PFC and my PFC shows up to 90% injector duty. Therefore without fueling mods I can\'t get anymore out of her.
The mapping keeps everything within a safety margin and although we are not talking about injector duty at the moment it is also another thing to consider. ie get the PFC then fit everything else and get mapped all in one go :cool
What you getting out of her at the moment mate? (bhp)
Here is dyno was originally aiming for the elusive 300bhp but well happy with drivability.
I know this is off topic now (but hey, it was my thread anyway! lol)
How would you get more out of it?
Would fitting a walbro pump enable you to squeeze more out of it, or would you need larger injectors also? Or a FPR?
Well I would go for better pump and additional injectors if I was to get more. The list of course can grow and grow.
I\'m happy with drivability and Pip has given me a safe map so will leave for now.
i am running without cat and will be putting my big smic on soon.
basically in my opinion i can see there are too sensors to detect air mass and flow etc. the important one being the map sensor which takes a reading off the back of the plenum.
if it is a cold day this will fuel in a certain way and in the warm it will compensate.
if i put the big smic on all i am doing is slightly lowering boost and making the boosted air cooler as if a cooler day. if this is within the ecus limits and map then it should be fine, perhaps if i was boosting in minus temperatures with a huge ic then it could but i cant see how. the ecu detecs the air temp in the plenum so after the ic.
as for decat if you have boost spiking just get a boost controller - i have the greddy e-01 and i set my max vaue and now it will not boost any higher thus meaning no overboosting and no running lean.
this is my opinion so you can obviously make your mind up and i would reccomend the apexi but i think it comes over reccomended sometimes.
m4drx, are you running stock ECU?
I think the same way as you mate. It makes sense in my head anyway. lol
Just not sure about these rotary engines. :)
I\'ve never heard of a car needing a map/re-map after fitting a different IC. Obviously to get the best out of it, the car would require a remap, but not essential.
As for boost spiking, I\'ve still to fix a boost leak so it\'s not boosting 100% anyway, lol. So no chance of running lean... well not at the moment.
i am running apexi now but i was running stock with this setup before. i have induction etc also as you have seen in my for sale thread. (you reaady to swap :) )
give me a call if you get any problems with your leak and other issues mate i have been there believe me.
ah, thought I recognised your name! ... lol.
I\'ll get the IC on tomorrow and will let you know with the induction kit as to how it fits.
I\'ve been speaking to some chaps over in the US about this and this is what was said.....
Larger intercooler generally does increase boost levels unless you have an adjustable boost controller to re-adjust it. The bigger flow paths cause lower restriction.
Also, the lower intake temps do increase the amount of oxygen reaching the engine. Although this isn\'t normally a problem for the stock ecu if your boost is tuned down to 10psi.
and....
Yes. If you boost above 11psi, I would install a boost controller (manual or electrical) even though you intend to buy a PFC later. The reason why is because the PFC\'s boost control is far inferior to a separate unit. If you\'re adding flow mods one at a time, it\'s reasonable to simply use your boost gauge for a before/after and stop when you go over 10psi. Usually the boost doesn\'t go up until you after install a couple of mods.
The whole thing about temps, sensors, and crap comes down to real-world practicality - someone went to the trouble of measuring AFRs and found that as long as you keep your boost at 10psi, your afrs stay safe on a stock ECU.
You can pretty much install any flow mods you want and set your boost at 10psi with an adjustable boost controller - with one exception. The exception is a fully decatted exhaust, which will often cause boost creep. Boost creep is beyond the ability of a boost controller, and if you read the FAQ or just google you can learn more about it. As long as you leave a cat in the exhaust, you have very little risk of seeing boost creep.
Dave
Hi Jim,
I just wish to point out a couple of things.
In aggreement with the USA adding a better intercooler does mean that the engine will run lean,as more air VOLUME will get into the engine by lower intake temps which increases the volume.The stock ECU will not see any need however to add more fuel,as it runs a fixed amount of fuel based on seeing Manifold air pressure(Map sensor) revs,throttle position, and to an extent air temps,water temps.Once over a certain threshold,the stock ECU just does not put more fuel in,stock boost with stock ancillaries is safe,maybe two mods such as decat and induction can be run and be still just ok,but no more.
As for the Apexi not being good at controlling boost,this is rubbish,they just like a boost controller work in the same way,and just like a boost controller need some time to setup properly.They have the same adjustments as a seperate boost controller,only on single turbo\'s do you need a stand alone controller.
The big advantage with the Apexi is that you can also change just about every other parameter needed to make more power too.
On stock fueling with your mods and decent mapping you should be able to make around 330 flywheel hp,which is75hp over stock!
You just cannot do that safely with a stock ECU and boost controller,just put the money for the boost controller towards the Apexi ECU,they are only around £360.00,which is incredibly good value for money.
Regards
Carl
you heard the man Jim !!!
Quote from: CarlHi Jim,
I just wish to point out a couple of things.
In aggreement with the USA adding a better intercooler does mean that the engine will run lean,as more air VOLUME will get into the engine by lower intake temps which increases the volume.The stock ECU will not see any need however to add more fuel,as it runs a fixed amount of fuel based on seeing Manifold air pressure(Map sensor) revs,throttle position, and to an extent air temps,water temps.Once over a certain threshold,the stock ECU just does not put more fuel in,stock boost with stock ancillaries is safe,maybe two mods such as decat and induction can be run and be still just ok,but no more.
As for the Apexi not being good at controlling boost,this is rubbish,they just like a boost controller work in the same way,and just like a boost controller need some time to setup properly.They have the same adjustments as a seperate boost controller,only on single turbo\'s do you need a stand alone controller.
The big advantage with the Apexi is that you can also change just about every other parameter needed to make more power too.
On stock fueling with your mods and decent mapping you should be able to make around 330 flywheel hp,which is75hp over stock!
You just cannot do that safely with a stock ECU and boost controller,just put the money for the boost controller towards the Apexi ECU,they are only around £360.00,which is incredibly good value for money.
Regards
Carl
Carl, I tried to PM you, but your inbox is full!