i have read that its best not to put a de-cat unless you have it mapped.
why is this?
my current setup is:
blitz lm intake
fmic
blitz bov
stock tub
down pipe
3" exhaust from tub back inc mid silencer
chiped ecu
fcd
is this gonna be a problem?
my thinking is as i have a fmic, the new exhaust will help spool the tubby quicker so therefore reduce lag. kinda cancel out the fmic.
the tub spools up nicely but the bov does not seem to make much sound when theres higher levels of boost.
ps have been driving on low boost as precautions until i find my pfc.
the only thing i can think of with that set up - is that if you ECU incorporates a FCD - and then you have another FCD - what the hell is it clamping the voltage at ????????
i ran my TII with decat ( down and main ) , cone filter , fcd , bov and it was fine
The chipped ecu guessing it is something like re-a has a higher fuel cut anyway by changeing the voltage signal with an fcd it isn\'t seeing the correct boost and not fueling accordingly.
Other than that they say you shouldn\'t use a decat without a remap because if the boost spikes or creeps the ecu won\'t give it enough fuel.
Your ecu should already be mapped for that but was done in japan so the map needs checking really, it\'s much easier and better in the long run to get a pfc.
Oh man, sounds soooo complicated tuning a turbo car! Lol!
Well, I\'d air on the side of caution mate. I work on the principle that if I change something, to remap, therefore do mods in batch\'s. You might not be able to guage what sort of performance increase you get from each individual change, but it\'ll save money, yet be safer.
hmm.. mixed opinions lol
the chipped ecu.. tbh i dont even know what its chipped for. i got it as my ecu that came with the car was not really making the front rotor do what it was ment to be doing...
i poped over to haywards n matt had a spare so i got his ecu. he said he got it chipped from rotechnics back in the days. he was using a fcd also so i assume the chip does not incorporate the fcd.
as above fitting a decat will cause boost spikes so will run lean and damage the engine.. but with the mods u already have you should already have an uprated/remaped ecu
The TII runs rich as standard,providing you are limiting the boost to 0.9-1bar then the stock pump and injectors will cope. Probably best to set the boost controller to 0.5bar, remove the FCD and then increase the boost in steps until you hit the chipped ECU\'s fuel cut - then you will know what it\'s been mapped for :wave
Quote from: Brett;565180The TII runs rich as standard,providing you are limiting the boost to 0.9-1bar then the stock pump and injectors will cope. Probably best to set the boost controller to 0.5bar, remove the FCD and then increase the boost in steps until you hit the chipped ECU\'s fuel cut - then you will know what it\'s been mapped for :wave
boost controller.. err.. i not got one yet
hmm.. maybe i remove fcd to be on safe side..
i thought it would be better to keep fcd on so it wont run lean on high boost..?!?
I\'d recommend getting something in there to controll the boost, TII\'s can spike upto 1.2bar in 4th and 5th gears on WOT - not a good thing. (Well it feels like a good thing until you get the comedy shaped apex seals after a few high pressure runs)
Quote from: BBCFC;565388boost controller.. err.. i not got one yet
hmm.. maybe i remove fcd to be on safe side..
i thought it would be better to keep fcd on so it wont run lean on high boost..?!?
In theory - the logic is revered. The standard ECU will cut fuel to the rear rotor when the boost hits 8.8 psi give or take. The idea is that it will at least try and save the engine. Never to sure whether this is such a good idea and opinions are varied.
What an FCD does is to \'cap\' the boost level seen by the ECU - so when you make 10 or 12 psi, the ECU thinks it\'s getting 8psi of boost. That means you don\'t get fuel cut, but it also means no maps for the higher boost either. Almost all chipped ECU\'s take that fuel cut away so an FCD is redundant and will in fact stop the chipped ECU from correctly fuelling past 8 psi.
If you make intake mods or exhaust mods that \'promote\' better flow then you will make more boost ;)
if theres no fuel then isnt that the same as running lean..?
Quote from: BBCFC;565555if theres no fuel then isnt that the same as running lean..?
Not quite - fuel cut is no fuel - so no combustion.
Lean is too much air / not enough fuel - combustion and knock and possibly detonation
In actual fact, there is one exception to the fuel cut to the rear rotor - if you hold the accelerator to the floor (WOT), then the ECU does fuel cut to start with, then gives up and just opens the taps - it feels like a little kick in the back and is a little disconcerting - it will only happen on the stock ECU at or near the boost cut limit.
As many have said - get a proper standalone or at least a good piggy back in there and then you can be sure of what\'s going on with fuel and timing - your in the dark without some logging tools.
Totally agree with the chipped ECU and standalone FCD, I had both on my white one and had all sorts of problems, iliminated the FCD and all went away, I just never realised that the ECU had it built in. You can have a decat and all the other mods but then driving around like an old woman going shopping is hardly going to be your style. You MUST have a boost controller with all your mods, its the number one priority.
Quote from: pdtaylor18;565797Totally agree with the chipped ECU and standalone FCD, I had both on my white one and had all sorts of problems, iliminated the FCD and all went away, I just never realised that the ECU had it built in. You can have a decat and all the other mods but then driving around like an old woman going shopping is hardly going to be your style. You MUST have a boost controller with all your mods, its the number one priority.
i dont mind driving like a \'old granny sat close up to the wheel on a sunday\' when its super foggy out there lol
tbh.. my fc is more of a house ornament atm =(
trying to source a pfc from japan.. n gonna get boost controller also. not sure to go for profec b or apexi avc-r...
The top power is gained at about 6,800rpm anyhow, so you don\'t need to ever hear the buzzer lol
Quote from: m1tch;566169The top power is gained at about 6,800rpm anyhow, so you don\'t need to ever hear the buzzer lol
thats a bit random.. or am i missing sth..?
so i can boost it to say 6,500rpm n still be safe with no boost creep etc..?
i heard the buzzer go off a couple of times b4 i modded my fc.. nasty sound.. i want a ding dong noise like in initial d ae86 =p
Quote from: BBCFC;566218thats a bit random.. or am i missing sth..?
so i can boost it to say 6,500rpm n still be safe with no boost creep etc..?
i heard the buzzer go off a couple of times b4 i modded my fc.. nasty sound.. i want a ding dong noise like in initial d ae86 =p
err - no
Boost creep will happen more at higher revs, and potentially at lower RPM\'s.
You\'ll know if you are getting it - boost rising slowly - not under control and increasing in each higher gear. It\'s usually down to a mods made to the car without sorting out the wastegate on the turbo. If the wastegate isn\'t big enough you\'ll get creep.
Just read through this whole thread and its making my head hurt! I almost wish i\'d bought a fecking N/A FC! Simple case of straight through spout and air filter. Fit and forget! Lol!
So now with my Turbo II - as i understand it - if i want to upgrade the exhaust system to a 3" system straight through from the downpipe to the back box with nothing between I\'m going to need to......
(A) first fit somekind of upgraded and mapped ECU?.... Well how do i get an ECU mapped for an exhaust i dont have and how do i safeley run an exhaust without the ECU and map?:Hammer
(B) Get a boost controler to limit the amount of boost produced (is that boost creep?) and cut the fuell suply before the fuel mixture runs lean and knock occours?? What the hell IS a boost controler!? In what instance would you use one? What does it do?
Also what about a BOV? Do i need one of them too? I dont even know the diff between a dumpvalve a BOV and a wastegate!
I\'ve ALWAYS had Hondas! Lol! So i know NOTHING about turbos! I\'m also a total novice with Rotarys! I\'m quite good with regular Honda 4 bangers like the B series VTEC engines, but i\'m WAAAAAYYYY out of my depth here!
If ANYONE can explain this to me in some kind of an "exhaust tuning turbo cars for morons 101" sence making way! :D I\'d be forever greatfull!:Thumbs-up
Boost creap is when the wastegate can no longer get rid of enough of the exhuast gasses, meaning that the turbo keeps boosting past a set point, this can be sorted by porting and enlarging the wastegate flapper assembly, when you de-cat the exhuast has an easy path to get out, it just gets stuck getting out lol remember:
(http://i93.photobucket.com/albums/l49/m1tch_2006/rotarywh6.jpg)
Just remember that the above diagram will happen if the boost isn\'t controlled properly :)
from my experience:
you can run the car de-cat fine.. but the turbo spools up lots quicker n ur more likely gonna hit the boost limit so the fuel cut will kick in. when this happens the car kinda stutters.
so i drive 1/2 throttle.
best to get boost controller which can limit the amount of boost the turbo produces.
check this link for good info
http://www.turbobygarrett.com/turbobygarrett/tech_center/faqs.html
you can remap the stock ecu but dont kno anyone in uk who has the equip to do this. otherwise can go for standalone fuel management systems like apexi pfc (hard to find!! but i got one on its way from japan as we speak =D ) microtech or few others.. think maybe hks f-con pro?? (pls correct me if im wrong)
or even a piggyback system which works alongside the stock ecu (they similar to standalone ecu but limited to what they can do)
if you do de-cat then u can get rid of the air pump. if you de-cat then you need some form fuel controller else the car will run too rich on idle n fail mot.
(which remindes me my mot is due soon n i think im gona fail the emmissions due to the exhaust stinking of fuel on idle!!)
u should have a stock bov (same as dumpvalve) (not sure what a stock bov looks like on fc\'s) u can change to aftermarket one.
this is some ppls bible to tuning their fc
http://fc3spro.com/TECH/FM2W/power.htm
its a good rough guide
best advice i can giv is to follow that guide roughly and not do what i did n start from stage 4 working my way back lol
The stock \'BOV\' is a recirculation valve and yes you need some sort of pressure release in a turbocharged system else the turbo won\'t last long. When looking in the engine bay its on the left hand side just behind the big black air box, there should be a black metal pipe leading from the turbo to the intercooler, there should be a rubber pipe leading off that to a round black recirc valve, which then plugs into the back of the air box.
The options for BOVs/Dump valves are either:
Recic: Reciculates the presurised air back into the intake, these are usually quite quiet and are good if you don\'t want to get noticed
Atmospheric: These are the sort that you always see everyone with as they make the SHHH should when you lift of the throttle, they do improve throttle response...plus they sound good :D lol
The BOV I have is a Blitz dual drive, which is quiet on low boost and sounds CRAZY when on high boost lol :)
(http://i93.photobucket.com/albums/l49/m1tch_2006/DSC00058smaller.jpg)
The boost controler limits boost by controlling the wastegate, to increase boost the wastegate is held closed for longer which increases the exhaust flow though the turbine on the turbo and increases boost, once a certain boost level has been reached the controller then opens the wastegate and controls it so that its kept at that level :)
Right then i just bought a 3" exhaust system and downpipe for my TII with no cat and no mid silencers all it is is a pipe from the turbo back to the rear can!
I also have an HKS F-con piggyback ECU which i think is mapped to run with a FMIC (which i dont have, just a standard top mount) and big exhaust. I DON\'T however have a boost controler or an upgraded BOV. I will however have both very soon (funds permitting! Lol!)
So could i fit the exhaust system and plug in the F-con and safely run the car just NEVER full throttling it? (Which i cant do anyway because the roads are always sooooooo wet in the West of Scotland i\'ll just spin the damn thing! Lol!)
Or should i just wait, get the BOV and boost cont, fit EVERYTHING and THEN run the car safe in the knowlidge that all will be well?:D
REALLY dont want to spit apex seals out the exhaust ports! Ha ha!
were you still running with cats in the exhaust ??
and dont use the exhaust until you can stop it spiking - its not worth it - you suddenly get boost crazy and bang - its all gone and a empty wallet :(
Quote from: grinder;579860were you still running with cats in the exhaust ??
and dont use the exhaust until you can stop it spiking - its not worth it - you suddenly get boost crazy and bang - its all gone and a empty wallet :(
I havn\'t got anything fitted to the car yet Grinder, just i have an HKS F-con and this 3" exhaust and downpipe.
I think i will just wait and get a boost controler and BOV then fit everything in 1! The only thing i\'m panicking about is getting it done before my MOT is due in the 9th of March! :( Because it will DEFO fail on the exhaust thats on it now! More holes than metal! Lol!
You can normally do the exhaust mod without hitting too many issues except the possibility of rear rotor fuel cut when you hit 8.8 psi boost.
There are 2 cheapish solutions to that problem:
1) Get an FCD - which just lies to the stock ecu and prevents the fuel cut - the car runs progressively more lean as the boost increases - which is bad
2) Get a chipped ECU - this will have the FCD built in and usually has timing and fuel maps changed so that it can run higher boost levels safely. The downside of these is knowing exactly what the ECU\'s are chipped for in terms of mods - as they are usually ex Japan and have no documentation with them.
A better solution is to go with a piggy back or Standalone ECU as that will allow you to map in more fuel and change timing safely.
I only hit real problems when I had the air intake done as well, as then the Turbo spooled far too easily past 11 psi and needed a chipped ECU to reign it back in.
Porting the wastegate is a good thing to do if you run the stock turbo - it will help with controlling boost. A boost controller will not lower the boost that\'s made if you do intake / exhaust - it will only allow control of the higher point.
In short - if you mod the airflow and improve it the stock turbo will boost higher and will be far more likely to result in boost creep - a boost controller won\'t stop that happening - only a larger wastegate / ported wastegate / weaker actuator spring / clipped turbine wheel / restricted intake / restricted exhaust will do that.
Only removing the air pump will make it potentially fail MOT - a well tuned engine with a decatted exhaust will still pass.
Thanks Prof. Love this place! Replys are always soooo speedy! ha ha ha!
I have an HKS F-con piggyback maped to run with a bigger exhaust and FMIC plus other bits and bobs its good up to 300BHPish. Thats not fitted to the car yet though
I\'m going to be buying a Blitz dual something or other BOV very soon so maybe that will help out. I just have the standard Turbo II BOV and also standard air intake system with an HKS panel filter instaled.
I think i\'m going to wait and get this Blitz BOV, fit that then plug in the F-con which should make the car fuel properly, then fit a boost controler to control the high boost? and then fit the exhaust system. And finaly take it to Dasteck or something to get it all mapped up properly. Would that be a good course of action?
do you have a centre cat pipe on the car - or is it already decatted at that point ?
and i ran with a fully decatted system , air cone , bov etc.. and the MOT was fine - no probs ( although i still had the air pump )
It just has the standard mazda exhaust system on it. But fitting a full exhaust system and downpipe will remove all cats anyway.
I still have the air pump fitted so hope it will be ok.
Jimi I do have the HKS GCC which when paired with a F-Con can adjust fuel at 6 points and by 12% each way. It will only pair with a HKS item but you will need to find out how to wire it in. There is only 5 or 6 wires anyway. Few pics on the net which might give it away if not just put a thread on here, i did but then wanted to use it with a non HKS item which will not work. I am going to use an Apexi instead when i can get one cheap enough.
This will be good to get the idle right for the MOT and is easily tweaked at all 6 points from the front of the unit. I\'ll let you know a price if you are interested.
My white FC is fully decat, chipped ECU, and better intake but still retains the AFM and my MOT\'s are always very good.
Ha ha, was thinking of getting in touch with you about that thing manny.
If i got that GCC thing how benificial would it be to me?
Keeping in mind my TII is TOTALY stock right now save for an HKS panel filter. All i want to do at the moment is put on this exhaust and fit anything else that i would HAVE to fit in order to firstly, keep the engine healthy and producing optimum power, and secondly being able to pass an MOT.
It might be the difference between an MOT failure or not and ..... a blown engine or not.
However someone far better in the knowledge of these things will tell you the pro\'s and cons but to be honest i cant find anything negative about fitting one. Its all good.
The GCC is an electronic tuning component designed to add additional flexibility to the fuel tuning capabilities of the VPC, PFC F-CON or F-CON S. The GCC simply plugs into either the VPC or F-CON harness and allows the user to further adjust the air / fuel ratio at five specific rpm points. Each five points offer an adjustment range of 16% rich to 12% lean, in 2% increments, of the base value. Four different selectable rpm ranges allow maximum rpm level flexibility when tuning the fuel curve. The GCC will interpolate, or average between the rpm points of adjustment to ensure a smooth transition of fuel delivery throughout the RPM band.
Well i cant promise i\'ll take it but i\'m certainly interested.
When you have the time let me know a price for it posted to PA7 5ED and i\'ll go from there.
Thanks bud. :Thumbs-up
Blimey just do a search on ebay and see what these things are going for.
Quote from: pdtaylor18;579900Blimey just do a search on ebay and see what these things are going for.
Ha ha! Are you givin\' me a tellin\' off punk! Just following orders! Lol!
Quote from: pdtaylor18;579900"I\'ll let you know a price if you are interested
Quote from: Jimi_Hendrix;579869Thanks Prof. Love this place! Replys are always soooo speedy! ha ha ha!
I have an HKS F-con piggyback maped to run with a bigger exhaust and FMIC plus other bits and bobs its good up to 300BHPish. Thats not fitted to the car yet though
I\'m going to be buying a Blitz dual something or other BOV very soon so maybe that will help out. I just have the standard Turbo II BOV and also standard air intake system with an HKS panel filter instaled.
I think i\'m going to wait and get this Blitz BOV, fit that then plug in the F-con which should make the car fuel properly, then fit a boost controler to control the high boost? and then fit the exhaust system. And finaly take it to Dasteck or something to get it all mapped up properly. Would that be a good course of action?
You won\'t be able to get 300bhp from a stock turbo, well you might be able to, but it won\'t last long! plus the injectors will max out before then anyhow lol
Quote from: m1tch;580021You won\'t be able to get 300bhp from a stock turbo, well you might be able to, but it won\'t last long! plus the injectors will max out before then anyhow lol
Just saying its capable of dealing with power up to 300BHP. Thats what i was told anyway. I dont really want anymore than 250-260BHP.
Quote from: Jimi_Hendrix;580028Just saying its capable of dealing with power up to 300BHP. Thats what i was told anyway. I dont really want anymore than 250-260BHP.
Thats ok then :D just remember to port the wastegates!
You will get that just by decat, filter and ECU with boost controller.
Mines on 210 with decat, freeflowing (although not 3") exhaust and filters and a wastegate that doesn\'t seem to like to stay closed, so it boosts to 0.6 bar then drops to 0.4 bar lol
Is that it !!! You can get an extra 30+ HP just by an exhaust and 20HP by the ECU alone let alone all the other mods. Think your car is not pushing the right HP me old matey.
I think in Mitch\'s case the exhaust is the problem - it isn\'t big enough so it\'s throttling the turbo, plus he doesn\'t have the FCD and is therefore subject to fuel cut
just out of interest.. if you use a piggyback f-con, do you still need a FCD?
Yes
And by way of eplanation - the stock ECU looks at the signal coming in on it\'s MAP sensor, and when it records 8.8 PSI or higher boost, it completely cuts fuel to the rear rotor. The FCON just allows you to alter the fuelling by changing the airflow meter signal to add/subtract a small amount of fuel. This means that any fuel cut you get will be in effect regardless of the FCON settings.
A chipped ECU actaully removes this piece of code in the ECU hence providing the FCD function, and will then supplies different maps to provide more fuel at the higher boost values.
question ... does the FCON need a FCD there too? cause the cables are prepaired for the HKS FCD
and can the boost controller controll the overboost? or just porting up the wastegate (damn work xD)
and the last question... HKS F-con V (not pro) with ignition/fuel mapping ... or Panspeed chipped N374 ecu?
Quote from: spidy-RX;580147question ... does the FCON need a FCD there too? cause the cables are prepaired for the HKS FCD
and can the boost controller controll the overboost? or just porting up the wastegate (damn work xD)
and the last question... HKS F-con V (not pro) with ignition/fuel mapping ... or Panspeed chipped N374 ecu?
Fcon does need the FCD or a chipped ECU
Boost controller cannot control boost creep - only the wastegate (porting of the wastegate or a larger one) can control that - or you have to put a restriction back into exhaust or intake to prevent it happening
The Fcon will give you more options - chipped ECU\'s aren\'t mappable - they just have fixed maps to support some modifications
thx prof
the point of wastegate porting is my opinion too. cause some other guys said its possible to stop boost creep with a boost controller... but i think it can´t!
so i hope my F-Con will run this afternoon :Hammer
Quote from: Prof;580153Fcon does need the FCD or a chipped ECU
All i have is an Fcon. My ECU is standard Mazda. So will i need to get this FCD thing as well in order to make the Fcon work?
thanks prof :)
I don\'t think my ECU has a limiter on it lol charlie reved it past 8k on the dyno pull apparently lol there isn\'t a fuel cut so mine might be one of those ECUs without a limiter, you know how rich my system is running lol :D
mate have you sorted out your cooling issues yet?