Rod-Tarry

Wow !!

Reading this makes me wonder why some of you are running Cossies.
Ive probably had more conversions than anyone else on here & none had cheap chips from Harry Ramsdens. . All my engine were Dynoed & then live mapped.
My 330 conversion when checked gave about 24mpg on a run average around 20. At 500ish the average was around 18 although a tad over 20 was coaxed out of the old girl on a run. With the latest ECU at 640 ish bhp the average was about 17 although I once saw 22 on a long trip. Im expecting sub 15 on my new engine but probably still near 20 on a run.
If im really trying (we checked it at Brunters on a Topspeed run) it was less than 4mpg.
My wifes Proton Duo is around 30mpg average & some of you are claiming this from a non-standard Cossie, .
Cossies are meant to be driven hard its the only way or buy a 1.3 Ka, mind you in my hands that would also be less than 20mpg. .

Rod

Stu. The only engine ive killed was because we were running 950bhp on a Block that had done over 40k miles & the horses cracked it.

4x4 ste

iTrader: (1)

You drive your car hard on the road and you still have a license Surely not all the time

Stu @ M Developments

iTrader: (12)

So your mapper only lost 2mpg average going from a standard YB to a low compression T4 with head and cams generating 500+bhp. Good work Mark. My point proven very nicely, cheers Rod.*

Thankfully, nowadays we can probably coax more out of them to start with, and we still only lose about the same percentage (Depends how you work out your average.) as mark will confirm if you ask him Rod, hes set a lot of engines up running my software.


Rod, there are a lot of people on here use their cars daily, and do thousands of miles a year. For over 15 years i have done a minimum of 16K PA in mine. Why the hell would anyone want to toss fuel away for nothing? Its ok in a weekend toy, like say our Lancer Makka, but not if you intend to use it daily. Anyone who says otherwise is just being the big i am and trying to show everyone how much money they have. lol



*= Best of all though, im sure Rod didnt actually INTEND to agree with me.

charlie luciano

iTrader: (3)

In answer to your question my cossie does shit fuel consumption and drinks like a fish hence why its not driven that often



Luciano

4x4 ste

iTrader: (1)

roflol

dovboy

nobody else being you! all i am saying is that the normal use for a high power cosworth is not motorway cruising only but a mix.

i'm sorry to say but with me it is mostly(at least 70% of the time)hard throttle driving

as i said in my first post ,if you want good mpg go see stu at msd!! why? cos we all know what you can do with these cars

out of interest stu could you get more power from a higher bhp cosworth if you chose to ignore fuel consumpsion? as i know you like to put out great allround cars

rapidcossie

Surely no tuner looks for mpg over bhp

pete mcrash

iTrader: (1)

i'm with dovboy on this,i use and abuse mine everyday....its all about the pure pleasure you get when flooring it..............when i'm on a run i get better fuel econony,but day to day.....who cares!!!!!.....i didn't buy it for its m.p.g.........

cossiedave

iTrader: (1)

my cossie is 523 bhp and dose about 18 to mpg think your self,s lucky

Stu @ M Developments

iTrader: (12)

Count teh people in this topic NOT talking about flat out, then come and tell me again its only me.


Sadly, we cant all live in scotland and be able to drive to work and back as fast as humanly possible. Nor can we drive to all the shows we attend, as fast as humanly possible. Sadly, down here, we also have police and speed cameras. So i am happy to assure that driving your daily drive 400bhp saff, flat out, for 70% of the time, is impossible where i live, and indeed, where most of these forum members live, so i guess your just very lucky with your motoring and my input and experience (Bear in mind i drive fast cars "Fast" for a living, 6 days a week) is likely of more relevance to the majority reading.



No. Fuel economy and BHP have no relation to each other whatsoever in a fully mappable EFI system as theya re totally and utterly seperate part of the mapping, in fact they are at totally different ends of pretty much every map you care to mention.

It makes me laugh when people turn out "One setting for economy and one for power" ROFLOL. These people prey on the un informed.

Steven_RW

What a prime example of people arguing about nothing.

Why oh why adding a slightly lower comp or a bigger windmill should automatically make ur fuel econ, on cruise hurrendous is beyond me (and stu and AVA).

At the end of the day its still a 2 litre 16v engine. Why pore petrol in off boost? Im sure some injectors are a little better for standard cruise conditions but surely not to the point they have to just pore in petrol even off boost.

RW

Stu @ M Developments

iTrader: (12)

Of course they do.
In Formula 1, an extra 1mpg is worth some horsepower due to the pit time wasted adding fuel and of course its weight. They tune for the ultimate compromise, and interestingly, they are also the ultimate tuners. You would be shocked how lean they run those motors, its immensely impressive.

Rally teams also do the same of course... the less fuel you need to finish a stage, the better your power to weight.

Mind you, if you lot were tuning Hamiltons F1 car this week he would have come last as he would have wasted an additional 38 seconds coming in for fuel 3 times. "Who care about MPG? If its empty, fill it up"

AlexF

Why are you people not listening to stu?!

bhp is related to the amount of fuel you put in. You do not need to much fuel to get a certain number - its all about the right amount!

Take two similar cars, say one is std and one is at 500bhp, they will need to produce about the same bhp to cruise at 70mhp..... so the fuel consumtion should be about the same.

As soon as you boot it, even a little but, thats a whole different ball game

Alex

Stu @ M Developments

iTrader: (12)

Indeed, but it is at least entertaining in between wrioting articles and watching some prime time Tv with the girl.

Interestingly, my article is about tuning AFR and spark lead.

rapidcossie

why do you take EVERYTHING i say out of context?

I mean in this small world of ours where we tune cosworths.

rapidcossie

Im not, not listening to Stu if that makes sense

Nick.

I think my dad said he used to get around 9-11 MPG while thrashing around donington

dovboy

i have to agree with euan,,you are getting a bit defensive stu

Stu @ M Developments

iTrader: (12)

Chill Euan, it was simply an extreme example, but why just look at the small world of Cosworths? Its a bloody boring place as far as tuning goes... there are far more interesting tuning projects if its really tuning your interested in, and F1 is the pinnacle. You can learn things from F1. You will learn sod all from ropey old Cosworths.

If talking flat out power, there arent many cosworths running decent enough management to pull it off as EGT's become uncontrollable on teh YB if you try it, but with a decent managament like Motec or T6 2000, then we can actually run a decent thermal management system and tune for more economy and still keep the power, yes.

What your probably missing, is, your car at a guess, runs about 11.8:1 flat out.

It would make more power at 12.7.
It would also give more MPG.
So why exactly arent you running 12.7:1?


because without some thermal strategies in place, which of course your autronic can in fact deal with i believe, it would melt.

Does that help?

Dannn

I dread to think how much money I spent on fuel when I had the piece of shit on the road.

It would do 150 miles on Ł60 optimax no matter if I drove like miss daisy or drove like I stole it.

You could literally see the fuel coming out the back on tick over - fucking piece of shite.

rapidcossie

I actually replied before reading your whole reply, and kinda jumped in a bit

Sorry Stu

Stu @ M Developments

iTrader: (12)

No problem pal. Its actually an interesting and informative topic underneath it all, which is good for everyone.

rapidcossie

I understand that the leaner you can run that the power "should "increase, if in fact you can manage the other factors you mention.

How would you do it as it something I have never looked at?

rapidcossie

lol I keep re-reading what people have written and have to write more

One of the mods we did to my car after looking at the data logs fromthe runway was to fit the twin cooler to try and help ACTs.

when you say thermal stratigies...what do you mean?

Dannn

He mean a thermocouple to measure the EGT and then dynamanically increase the fuel the hotter it gets at a guess..

rapidcossie

kinda thought it would be something like that Dann.

wee spot of NOS would do the trick too

Stu @ M Developments

iTrader: (12)

Well, on top flight management we have a few options.

We will always have accurate AFR monitoring and Det monitoring (although its worth noting that the latter is extremely hard to make reliable out of OEM conditions.)

We will push the motor to peak power, say around 13:1, and then monitor what happens with the spark required. Normally it will decrease as the thermal load increases and will require backing off in a relatively linear fashion as the temperatures generated in the cylinder block increase.

Quite often, and interestingly, the power will sometimes remain the same as the spark lead is dropped back to avoid det. This is due to the fact that our BSFC can actually improve as the temperatures get higher. This is one of teh reasons modern engines all run hotter than they used to do... improved thermal eficiency. You need to retain as much heat as possible as thats one of the energy's we are using to create power. Anyway, thats another story...

So, weve got our 500bhp motor, and she is running 13:1 and making great power with minimal boost (Thus controlling ACT) but getting damned hot at the same time. A strong motor like yours Euan could have EGT's in the 1100+C range before you got out of 4th at 13:1 on a warm day BTW.

So, we need to decide on a thermal EGT limit. I normally choose to start controlling heat at around the 750C mark, thats because we need a lead time to get control as temps can be rising very fast and i would rather not exceed 850 for any long period of time. So lets say we will start to control temps actively at 750C.

We now go to our fuel trim with EGT map.
And add a percentage of fuel with EGT. So say.

750 +2%
775 +3%
800 + 4%
850 + 8 %

More fuel, for those who dont know, will cool the combustion and thus the EGT's...

And so on and so forth, and this way, the management will keep the engine running as lean as it can do without running into dangerous thermal conditions that will lead to other problems, such as turbocharger core failure. (Or random hose/soundproofing/wiring meltdown on most cossies ) So if EGT is cool, it will leave her running lean, and if its too hot, it will richen her up until she is cool again.

The spark with AFR and Spark with EGT
Maps are used in a similar way as descibed earlier to control the ignition as you require different advance with different mixtures and EGT's, so again this stays active.

We also have boost with EGT and a coupe of other interesting maps if all else fails. LOL

I could go on, but your likely all nodding of now and im sure you get the rough idea of how its done.

JonnyBravo

Interesting read that Stu

Stu @ M Developments

iTrader: (12)

thanks, just edited it quite a lot so may be worth a quick re-scan.

glancy2081

interesting topic here

rapidcossie

I do know there is a point where the pistons will melt even if there is no det or leaning out etc.

So at this point we could add more fuel or an additive like methanol to cool it down ?

dovboy

seconded

JonnyBravo

Hell of a lot goes straight over my head but bit by bit I have more of a understanding of how these things are working.

rapidcossie

On my recent mapping and test runs on the rollers Alan monitors EGT on my car as he mentioned that things can get extemeely hot and actually start melting the blades of the turbo etc.

dovboy

i know what you mean as i have been trying to take stu's articles in fast ford in for months but as homer says "when i learn new stuff it pushes old stuff out!"

rapidcossie

Engine mapping, specially on mega powered cars is SO complicated....must take years to become good at it.

Stu @ M Developments

iTrader: (12)

Fuel added around peak power will normally cool the combustion process by a usefull amount, but what you have to beware of is the fact it also changes your spark lead requirements. So you can add or subtract fuel and then melt it by retaining the original spark map... Doh, what a hurt that would be!

Its a similar issue that afflicts people who add bloody octane booster to engines mapped for pump fuel... And this is a fact you may all wish to consider for a while, especially when you think how many do it...

"If your map was actually correct for pump fuel, adding octane booster to it will LOSE YOU POWER"

Same situation. But in reverse.

rapidcossie

would running a higher octane fuel lose you power too?

dovboy

i would think yes if it wasnt mapped for it

rapidcossie

yeah thats what I mean.

Alan told me not to run the 102 ultimate PF had on offer at the daddy thrash and I wondered why.

Stu, how many cars utilise this kind of thermal management on the road?

Not many would need it I guess?