My car has bad manners at low speeds and while on very light throttle, it makes me look like a learner driver sometimes !! :spank
Here\'s the spec...
Mild Street Port
T04R Single Turbo
External Wastegate
Standard Injectors
Uprated Fuel Pump
Sard FPR
Apexi ECU
I guess I\'m talking about two seperate behaviours here...
Firstly while driving along in traffic , i.e. when idleing in gear (0% throttle) the car can sometimes begin to hunt slightly which causes a kangaroo effect, very annoying as I sit in traffic with her every day :reallymad
Secondly, when cruising in any gear ( but it\'s more obvious in the lower gears) and on very light throttle (especially downhill ) the engine seems to stutter and cough, as if to say either put your foot down or back off completely. :xconfused
My question is this, are either of these behaviours likely to be down to the mapping of the car or is it the modifications I have causing the problems ??
Car was tuned by Reworx before I owned her and goes like stink when I\'m brave enough :god but I wish I could iron out these niggles :xconfused
May be way off here, but it *might* be that as you\'ve uprated the fuel system its not possible to dial down the fuelling enough at very low revs so runs a bit rich, i.e lumpy :)
Keep providing guesses to your threads but I must get an A for effort :D
Hey all guesses are more than welcome, thanks for your input :D
It must run very rich because it stinks of petrol at idle etc etc. :rollin
QuoteHey all guesses are more than welcome, thanks for your input
lol, no worries, without being patronising are you 100% that your running standard injectors, might back my guess up if you\'ve got some big old 1680cc\'s in there :D Seems a little strange that everything else fuel wise is uprated bar them...
Secondaries will only be in the equation when the engine is at WOT, should not affect low revs / crawling in traffic.
The thing you have to remember is your car is modified, and the modifications are such that it is not conducive to be subjected to chugging along in trafic :rolleyes: you will be clogging up the plugs with carbon and at every opotunaty you should be trying to clear those plugs.
If you have to use your car as your daily commute I would look to be getting it de-tuned, seems an awfull waste to be sitting in traffic with that spec.
HTH
QuoteSecondaries will only be in the equation when the engine is at WOT
lol, good point, im tired...
Quote from: John YorkeSecondaries will only be in the equation when the engine is at WOT, should not affect low revs / crawling in traffic.
The thing you have to remember is your car is modified, and the modifications are such that it is not conducive to be subjected to chugging along in trafic :rolleyes: you will be clogging up the plugs with carbon and at every opotunaty you should be trying to clear those plugs.
If you have to use your car as your daily commute I would look to be getting it de-tuned, seems an awfull waste to be sitting in traffic with that spec.
HTH
Thanks John,
I clear the plugs as often as I can :chat
She gets redlined regularly ( at least twice every trip ) and at least once with WOT if the weather permits.
I don\'t "have" to use my FD as a commute, but I enjoy driving it so I do :chat
Just wishing to iron out the bugs.
Quote from: ScuttleRXlol, no worries, without being patronising are you 100% that your running standard injectors, might back my guess up if you\'ve got some big old 1680cc\'s in there :D Seems a little strange that everything else fuel wise is uprated bar them...
I know we\'ve ruled the secondaries out of the equation, but regarding your other point...I know, it is bizarre. :spank
Nice thing is, all it needs is bigger injectors for plenty extra horses :chat
QuoteNice thing is, all it needs is bigger injectors for plenty extra horses
Yes you\'ve got a nice set-up to build on there :)
Dont know wether this helps or hinders but I have both of those \'problems\' and the mota\'s standard! :confused:
Quote from: Ricco_04Dont know wether this helps or hinders but I have both of those \'problems\' and the mota\'s standard! :confused:
hmmmmmmm interesting..... :rollin
Now I\'m confused !!
you had a service lately chaps? sometimes it the simple things like old plugs....
Servicing is pretty much upto date, so should be ok on that front...
I need to change the fuel filter and the plug leads as they are the only things not recently (i.e. within 1500 miles) changed.
hhmm, just thought id check :) its always the simple things you think of last, well in my case anyways :)
Seem to really notice difference every time you get new plugs in these cars, supposed they get coked up fairly quick
My rx does this sometimes and its getting close to plug changing time so i would say you guys might well be correct on the plug issue.
Quote from: ScuttleRXhhmm, just thought id check :) its always the simple things you think of last, well in my case anyways :)
Seem to really notice difference every time you get new plugs in these cars, supposed they get coked up fairly quick
Hmmm...
May be worth me changing the plugs every 3K with the oil and filter given my daily crawl in and out of work.
Quote from: gsb876My rx does this sometimes and its getting close to plug changing time so i would say you guys might well be correct on the plug issue.
Right then, thats it... 1st plug change coming up :)
Where is best place to get said plugs chaps ??
Cheers :cheers
try one of the vendors mate, probably cheapest as they must buy loads of them :D
If the car was tuned on the rollers it was probably mapped at wot and medium to high load areas. You need the light load and cruise set up also by the sound of it. :)
my plugs have been in since it\'s rebuild 6k now, i need to do an oil change too,and i am a bit worried about belts, so i was thinking of going for the Dragon service kit, do they do 9s plugs ? anyone know? i have never redlined the car ever myself, it runs very well but tickover is a little unstable now, which i think maybe plugs,
cheerrs Bob
First things first, get that buzzer going, your missing out on the best part of a rex :)
Imagine they would be 9\'s mate, reckon they might even have 7\'s if you want them
oops, just noticed recently rebuilt, but 6k, should be into play time now :) :cool
Yes it\'s me scuttle! i was thinking of changing my name to Lightfoot! lol,
the plugs in there are 9s and i havent cleaned them yet, my car has been redlined by the engine builder to check everything, i think the trouble is i\'m too used to slow running v6 engines, but anyway wrong time of year now, maybe in the spring i\'ll give myself a treat! or a fright!
Bob
Yeah i suppose the v6\'s a lot of your power will be low down :) roll on spring, this weather sucks, why is it always dry all week then miserable at weekends :(
Red and Single, you say "Street port?" Its most likely the port modification thats causing the roughness. Thats why Mazda made the standard ports like they are - for idling and smoothness.
Quote from: MartinyRed and Single, you say "Street port?" Its most likely the port modification thats causing the roughness. Thats why Mazda made the standard ports like they are - for idling and smoothness.
I did wonder, although we\'ve (myself or re:worx) no idea as to the extend of the port work as the engine\'s not been apart.
Re:worx said it appears to be ported by examining the power graph.
I\'m interested to see if someone with mapping skills could take a look at it for me ???
best post up the graph :)
If this works, here you go, sorry it\'s a photo of a piece of paper !!
even with a pretty seriously modded engine and porting it should be possible to tune the low rpm and light throttle areas of the map for smoother running.
Regards
Carl
Seeing as you are peaking @ 6800ish would suggest to me as a \'mild\' street port, nice smooth graph :) must be quite progressive powerwise no big hit as it were, If you are having a lumpy ride in your commute I would suggest giving it a bit of WOT at least once a week. These cars run rich and need the carbon buildup blown away [seems like a good excuse to me anyway :rollin ] either that or shorten your service intervals [whip the plugs out once a week / fortnight and give them a good clean] to 2k. HTH
Quote from: Carleven with a pretty seriously modded engine and porting it should be possible to tune the low rpm and light throttle areas of the map for smoother running.
Regards
Carl
Would these areas be better tuned on the road or on a dyno in your opinion ??
In fact I wondered if tuning in general is better on the road or dyno ??
Opinions anyone ???
Quote from: John YorkeSeeing as you are peaking @ 6800ish would suggest to me as a \'mild\' street port, nice smooth graph :) must be quite progressive powerwise no big hit as it were
Yeah, on song she is awesome, great little turbo, spools up really quick and early on, no scary moments from massive power spikes :chat
Big can or worms there fella, in an \'ideal\' situation sure tuning is best carried out on the road, problem with the rex you will find to do the mapping you have to exceed the national speed limit and I\'m afraid there are not many tuners out there that are prepared to do this, if however you have access to a private road / airfield I am sure it would be the best way to tune for your day to day driving/ commute.
Quote from: Red and SingleWould these areas be better tuned on the road or on a dyno in your opinion ??
In fact I wondered if tuning in general is better on the road or dyno ??
Opinions anyone ???
Since your car is a road car and already well tuned in the high power and speed areas then there should be no problem tuning the problem areas you have on the road as there is no need to get up to any excessive speeds.
Also you should not really have a problem with the spark plugs carboning up all the time as at cruising and light throttle loads there is no need to run rich.
And lets face it,unless you have a racing car most road cars spend 95% of the time in the cruising and low rpm areas off boost.
Regards
Carl
I\'ve got what sounds like exactly the same problem, and have had for a little while since doing some major upgrades. Car\'s with one of the specialists at the moment trying to sort it out...
Current thinking for a number of reasons (including the fact that nearly all of the other parts in the engine bay bar the wiring loom have been changed) is that it\'s a fault on one of the primary injectors and that it could be fouled and needs cleaning. I believe the injectors are being fault/flow tested at the moment and am awaiting results. If it\'s not one of the primaries - which I personaly think it is - then I\'m absolutely full out of ideas. I believe they\'re quite pricey to replace so unless I know it\'s one of them I\'ll be stuck too. I\'ll let you know how it looks later in the week.
HTH
H
Have you tried setting your throttle position sensor(T.P.S.) up? Simple little fault, that often gets over looked. The ecu could be thinking the throttle is shut when u still have it open or the oppersite.
Tuning. All these people that say "It\'s a rotary you need to clean your plugs" are wrong. With proper tuning you should not need to CLEAN your plugs EVER, you should just need to replace them when they are worn. I\'ve run big turbo half bridged motors on the street, and the only time I ever cleaned plugs was when the tuning was off.
Can\'t comment on the changing of plugs bit (although mine have been changed twice), however the TPS has also been replaced and adjusted with a brand new Mazda part - it made no difference. Hense the reason for suggesting it\'s the primaries. As mentioned previously, everything bar the primaries and the wiring loom have been replaced and haven\'t resolved the issue...
Cheers
H
I\'ve got similar specs to you expect running twins and have uprated injectors.
I get both types of effects also which I didn\'t get when standard so I put it down to being tuned for WOT. Hasn\'t really bothered me that much.
1. I tend to free wheel in traffic in neutral.
2. Cruising on light throttle - I either pop into neutral or drop it down a gear to increase the revs / engine load.
So I\'ve just adapted my driving style to suit the car.
Rich :D
Quote from: Rich Cheung1. I tend to free wheel in traffic in neutral.
2. Cruising on light throttle - I either pop into neutral or drop it down a gear to increase the revs / engine load.
So I\'ve just adapted my driving style to suit the car.
Rich :D
Hi Rich,
I have similarly adapted my driving style to suit the car, but it results in the car using even more fuel :rolleyes:
Just what the FD needs....help being uneconomical :rollin
I have similarly adapted my driving style to suit the car, but it results in the car using even more fuel
LOL I never thought about that.
Least it means I get to see the hottie that works at the local Shell garage more often :D
No such hottie\'s at my local Shell :(
Well, picked the car up on Friday and all the injectors have been replaced and low and behold the car is much smoother than before. I wouldn\'t say the problem has totally gone, but it\'s barely noticeable and happens randomly, however I put this down to the fact that the 550\'s have now been replaced with 850\'s which aren\'t the best for light throttle action/idle situations...
One happy customer :o)
HTH
H