Bad manners !!

[John Yorke]

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

[Red and Single]

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

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

[Red and Single]

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

Yeah, on song she is awesome, great little turbo, spools up really quick and early on, no scary moments from massive power spikes :chat

[John Yorke]

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.

[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

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

[Spotlamp]

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

[Andy_k]

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.

[igy]

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.

[Spotlamp]

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

[Rich Cheung]

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  

[Red and Single]

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  

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

[Rich Cheung]

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  

[Red and Single]

No such hottie\'s at my local Shell

[Spotlamp]

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