I use my Cossie a fair bit around town and it was returning a cracking 8mpg

This was mainly due to the grey injectors and crappy map from a shitty local tuner (I bought the car like this) as I know it was running far too rich.
Ive now bought a set of Siemens black injectors, and was planning on going Stu's closed loop conversion to improve MPG, but would I be better off getting a live map to improve both MPG and drivability? AS Ive heard Stu can get very decent Co levels without closed loop.

What is best suggested?

Also find the car a bit laggy (well technically boost threshold) when coming on boost, its currently on standard head and cams on a T34.63. Would changing a cam make it any better?

Cheers

 

live mapped, with closed loop would be the best...

but stus so good at his software, with a .63 t34 it would be spot on off the shelf imo

 

as above

 

Not got closed loop - mine is awesome on fuel off boost so i would give karl a ring at nms for the closed loop or none closed loop depending on application

 

dingy, just curious but why don't you have closed loop if karl has the ability to do it? is there something special about your ECu that means it can't be done?

 

The base map has to be very good for closed-loop to even work, so the fuel economy difference between open-loop and closed-loop should be within 5% of eachother

 

Oh dear.

It has absolutely nothing whatsoever to do with the greys mate, only the setup and the map. Greys are fine for 30+MPG on any Std Comp YB motor. In fact, so are 83lb siemens and cams etc for that matter. click me.

You cant rule out the fact that you may well have faults as well, so unless you are certain that she is setup perfectly, and the rising rate reg etc is all set and working fine and all sensors are doing what they should do, i would recomend you do as follows:

Order the 55lb Siemens closed loop mail order chip from me.
Read the comprehensive instruction on how to set it all up and then fit it and get it working. Finally, test her for a while and then drive her to us for a setup and custom tune of the software if required. The reason i advise you fit it yourself is:

• A) You save us time welding boss in exhaust, fitting inj's etc meaning we can complete the job in a day.
  Ideal when your from London as i recall you are?.

• B) You can build up some feedback over the weeks of how it runs and any concerns you may have that we can deal with directly on the day. Cold start / cruise / throttle response / economy / etc.

Hope the above makes sense Simon. We can of course fit it all for you if you would prefer, but I simply cant guarantee to have it done all in one day if the software requires significant alterations. That said, that would only be the case if your engine spec is NOT what you think it is. If its close to what you think it is, then the chip will be within 90% of perfect from the moment you fit it.

 

Stu has live mapped my car(2wd saff) with greys, t34.63, without closed loop and its still very good on fuel mate.

 

Thanks Stu, was just about to reply to your email. Ive got hold of a set of blacks on your advice, just considering whether to just order a chip instead of the closed loop, as stated by some replies above, I'am not totally sure it would help as much as I think it would in compariosn to a decent chip from yourselves?

Does closed loop make a major improvement over one your chips for normal town driving? Or for instance can I get 30mpg without the use of closed loop as Id like to go wasted spark too very soon, so wonderig if money is better spent there?

I fully agree and intend to fit it myself then come up for a set up/check over.

Thanks for the help

 

closed loop could in theory give worse fuel economy, as you could map it to run slightly on the lean side for fuel economy whereas closed loop will correct it to lamdda = 1 (but you would not want to map it lean as the torque would be lower, temperature higher and so on).

a good chip will be very nearly as good as closed loop, but obviously closed loop has the ability to make fine adjustments to keep the mixture constantly correct (under the running conditions that allow closed loop operation of course).

if you can either afford the option of only closed loop fuelling or wasted spark coilpack, i would go for the wasted spark everytime as the fuelling will be very good anyway, and the wasted spark gets the best from the fuelling and gives benefits over the whole engine operating range from idle to full boost.

 

My chip from Stu on a poxy L6 ecu using greys gives 14.6:1 afr off boost cruising.

 

IMHO, for cruise on the motorway its normally possible to BEAT closed loop with a good map, BUT its when things change and the map doesnt adjust to it that you have the risk, where as with closed loop its a very safe way of getting your fuelling "nearly perfect"
Closed loop by default though wont ever give the best possible economy, as peak economy is nearly always leaner than the stoich value that closed loop tracks around.

 

Karl's live mapped mine on a T34.63 and siemens blacks and I can get 30 mpg at a steady off boost cruise on the motorway. Not saying he's better/worse than Stu, but I still think that's pretty impressive without closed loop etc.

 

i had low-comp 7.5:1 on a T34.55 on 55lb siemens standard 4x4 Cams once i fitted STU off the shelf chip and a brand new lambda sensor i would get 300+ miles to tank using my car for work and normal driving

 

Does closed loop have a major advantage on normal driving round town?
Or only really on a run?

 

Anywhere its active really mate.

Which is typically at low boost (say 4psi or below), and below about 4K rpm

dont know specific details of stu's though, you will have to ask him.

 

motorway driving is not what hes talking about here people, hes talking about driving a 10min drive to work and home and general driving about for short periods,,,,, i doubt closed loop will do that much for these times considering the cars almost always gonna be on the cold start map and in 3rd gear stopping at traffic lights ect

motorways i can see the benifit but round town i doubt hes gonna notice,, i had a greens chip off stu and that improved MPG just by the chip change,,, how much better would closed loop be for comuting 2 miles in a 30mph zone,,, cant see much personally but i aint totally sure about it

 

Hi Simon,
Sorry for the delay replying. My opinion is save a little and get both mate, starting with closed loop. yes, we can get it almost as good without it, but its not easy, and the slightest thing changes on your engine and it will be rich/lean. Thats the beauty of closed loop, it constantly changes to keep your mixture correct and can compensate for sensor drift and inlet depression changes with no problem at all. Running at Stoich is also great for engine logevity and oil consumption as we have far less fuel left unburnt and thus less making its way into your oil.

Our closed loop has had most of our development time devoted to it too, so as a rule you will experience a better cleaner performing engine with it as opposed to without it as at least 90% of the live maps we have done in the past 3 years have had it active in the chip.

Final point... every single car on the planet manufactured since 1994 (And a LOT before then) has had closed loop as standard. Catalyst requirements aside, Its the way forward for good emissions and fuel consumption.

 

Thanks for the replies!

Think Ive decided to spend my money on wasted spark and a decent chip.

Ginge - I admit you did say this from the start

 

simon read what stu has wrote though,, as a saftey aid its a good thing,,, personally i think ANY car should have a check up before modding the car to see if theres any issues with the car HENCE i aint touched the scoobie yet as i aint had it looked at and told what needs doing BEFORE i start ripping shite out then wondering why its gone wrong,,, then blame the mods done to the car ect

for what your asking for i cant see it being any better,, there ARE better parts of it but for the reason you need it for,,, 2 mile drive to work in traffic,,, you aint gonna notice IMO though ive never had stu's closed loop,,, i just know that when my lamda sensor in the BMW was fucked i changed it and i still had shite fuel economy round town, was a little better but not " shite, its like im driving a fiat panda" fuel economy

oh and my scoobie its fine on motorways but still shite when i use it to comute as i drive 4 miles up hill in traffic,,,, i done a test and i can get 3 times as far driving at night with no traffic as i can just driving in the morning IN traffic in the scoobie

good mod i think closed loop is for emissions ect and the engines life,,, but it aint gonna give you 30mph driving to work that people seem to talk about

 

my daily comute to work included 20miles of motorway, and 5miles of heavy traffic...and with 380bhp, i would average at 30mpg during the week....on a steady run i did see 38mpg on a few ocasions....but to acheive this i had to drive really steady, and poodle about

closed loop iis very effective imo....and its not expensive at all if you already have L8....just a sensor, and msd chip....mine paid for itself in a month

 

now jtech, driving around at 2 miles at a time in a built up central london location on a cold start map would you say theres a chance of the same 30mph ?

reality is hes not gonna get MUCH better from that compared to a new chip,, i belive he thinks hes gonna get 1.2 economy from this " closed loop" conversion that everyone keeps going on about

soon as you boot it OR do short journeys its gonna loose the great economy

 

no,i agree in part.

but they are much much cleaner at idle...i never had to clean plugs etc

it all boils down to the fact it needs a good map to start with.

but i would never own a non closed loop cossie again, now ive had one

 

i would never own a cossie with less that greys due to driving one and seeing the difference for the fun factor,,,,, but for most people a T3 cossie is more suited to them

 

at idle in traffic closed loop will enable the car to sit at idle at 0.90%...no overfuelling,no borewash, no smoke when you pull off after a 2min wait..

as i said it depends on the map as to how much benifit you see,

but a 0.90% car is always going to be cleaner than a good std map of 2.5%

my car ran 55lb injectors, considerably bigger than greys, and wasnt a million miles off a cat test pass with no cat fitted!

 

fair comment on that i guess,,,,, but what actual MPG difference is there in reality when hes gonna be on a cold start map most of the time driving to work till the cars upto temp

driving for a little longer he would be better off but hes a 10 min drive to work in the morning

thats the difference hes looking for,, will he notice that with the closed loop

motorways YES DEFFO as he drives like a pussy on motorways as he wont break 70 for fear of getting points ( yet he will do 130 in a 30 which is ironic )

its a GOOD thing for hes car,, just he needs to understand what its gonna do for him,,, its like taking diet pills,,,, they help loose weight IF you control the diet and excercise,,,, keep eating the pies and bacon double cheese burgers they you wont notice the REAL benifit

ps: thats made me hungry pmsl

 

They only flow about 10% more than greys (static) - however the Siemens injectors have fantastic low duty-cycle performance which makes them better for this kind of thing

 

Well thats confused me further

Thanks for input Jtech, does help.

Ginge - I have actually bought that run around so I dont have to do the commute to work in it, I just dont want to have a Cossie and think 'its too juicy to take here or there etc...'

So its not nesscarily doing short journeys.

Great thread btw, think Iam swaying towards Closed Loop again now.

 

If Ginge is right and 90% of the time you use your Cosworth its going to be below 70 deg C and out of closed loop, my advice would be to sell it in all honesty as A) its not good for it B) You shouldnt realky use boost hard when its cold so stuck with a slow car C) A TD is FAR better at what your trying to do. It will do 45+Mpg stone cold.!!

 

Thanks Stu, my old XR2 was used every day and could get around 25mpg which was ok in my eyes.

The Cossie will NOT be used everyday, ive bought a run around as I am aware a Cossie is not ideally suited for such things. However I will be doing a lot of round town mileage which will NOT consist mainly of 10min journeys.

IVe bought a runaround for this reason.

 

So basically, Ginge has filled this topic with rubbish to be ignored?

 

simon most places you go to will be max 10 min drives on average due to where your located just like me

for runs yeah its gonan be good, for general health/caution thats also gonna be good

its the " ill get 30mph round town" that you aint gonna get with closed loop as most of the people on this forum live in the sticks with nothing but roundabouts or junctions on there drives and need to drive 10 miles to work in industrial areas ect ect ect

london is full of hills, speed bumps, traffic lights and traffic,,,, count how long you stay in 3rd gear every day before meeting corner and needing to change down,, you will be suprised as i know i was

 

stu remember i KNOW simon, where he lives, works and how he drives based on being in hes car

these are things ive been trying to tell him, he wants closed loop to get " 30mpg" as hes fiesta was good on fuel,,, hes got a cossie that SHITE on fuel and thinks that closed loop IS the answer,,,, but in reality a good chip will help him just as good based on where hes located and drives

stu also i drive a car around every day on a similer basis to simon as i live realativly local to him so also see the benifits of a scooby on closed loop to a cossie on greens running 26psi and remember the difference JUST A CHIP MADE from you for round town driving

 

after using my car as a daily driver round london i can honestly say i saw very little difference between the PE map and the MSD closed loop map round town.

this is because the car never really has time to get up to temps and just loses loads of fuel in the warm up stage. you also have to consider that the amount iof distance you actually cover in traffic is sweet FA with alot of starting stopping hill starts etc.....average journey from my old house to my folks in traffic, 15 mins 1.5 miles!

on the motorway though there was a vast difference, a jump from 220 miles (PE) to over 300 miles (MSD) to a full tank so this is where i saw the benefit

for a london commuter, either put up with the crappy mpg, or get a new car, closed loop wont solve your problems for short journeys.

 

I,ve seen great improvments with closed loop and coilpack(wasted spark)
and with a co of 0.8% which my MOT man said have u a cat

One of the best conversions imo which is why i have them on both my cossie powered cars


Paul

 

ginge, 10 minute journeys? where you live? where you going, the end of the road?

it often takes me 45minutes to get from work (City) to Regent's park thats about a mile

 

why not just walk???

 

because i can't fit the car in my pockets?

i wont drive to central london unless i have to, i'm a rail commuter

 

get a scooter

 

The definitive answer to the original question is BOTH