A Stark Warning to all Modified Car Owners....

[Stu @ M Developments]

Most of you have seen my shonky old saff a few times and probably accept that, being my own daily runner, it is meticulously maintained and setup at all times, as well as teh fact it does 20Kmiles PA or more pretty much faultlessly... A couple of nights ago the Dynojet AFR warning light flashed at me when i overtook someone, signalling my AFR had leaned to 12.2 or leaner with more than 22psi. (The figures i had pre set it to warn me about) A quick datalogging run was performed yesterday that confirmed the fault did in fact exist and under what conditions: After some simple checks on fuel system, fuel electrics and ecu i decided it has to be the STD fuel pump starting to struggle with the boost or required flow, so i fitted an 044 last night and did another identical datalogging run to check results..... Problem Fixed. The point of this story? I was sat here this morning thinking about how, as most dead YB owners will tell you, a lean condition never warns you of its prescense and leads to the terminal meltdowns we all know and hate, infact, a well mapped car will normally pick up a few horsepower and feel better than ever, just as its about to let go simply because peak power is nearer to the dangerlevel where it melts than a good mapper will leave it for you in the first place... Its the slight leanoffs like this that do teh big big damage... not the component failures and other issues like that, its the ones that make her feel that little bit better than normal... I just thought it worth a mention to remind you all to be carefull out there, even the Pro's can be caught out and if it wasnt for my built in wideband warning system, i could have lost teh my own engine this week, and i do this for a bloody living!! IF YOU WANT TO HAVE A "HAPPY" NEW YEAR, GET THOSE CARS SETUP AND CHECKED OVER REGULARLY OR FIT SIMILAR EQUIPMENT TO WARN YOU.

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[Anonymous]

My 044 pump arrived last weekend, just got to fit it now, glad i decided to take the "just in case" step now


nice example stu, especially with such clear evidence.



On the subject of fuelling, i took apart an engine last night that im building for Rob for his astra as he wants 500bhp now.

When we measured the bores there was [/b]12 thou[/b] of wear at the top of them, and this was an engien that had only been built for 1500 miles.
Reason i believe was that the guy Rob got it off had been running it for most of that time on a "running in SAFE map"

all very well being safe from running lean, but not much good if its so rich it makes the rings eat the bore walls at the rate of 1 thou per 100 miles!



People REALLY need to realise how critical fuelling is!

[Rs Gus]

unchballs: i know the feeling

[S3an]

i take it mine was ok when you tuned it then stu.

[Damo V]

I am a little lost, as the second chart you put up also show lower that 12.2 above 22psi?? Not a dig, more of a question really??

Also could you put the1st 2 and second 2 images side by side so they are easier to compare

[Anonymous]

Originally Posted by sean forsyth

i take it mine was ok when you tuned it then stu.

Yes, but so was Stu's when he tuned it.

The point he is making is that you cant just look once and then assume it all stays ok.


Yours WAS fine, make sure you dont leave it too long before taking it back for a quick checkover

[dumped]

you said your car was 34 peak 30 held - its like fishing stories in here LOL

Good warning setup though

[DaveEscos]

very interesting Stu


what is the best wideband in car gauge to run?


also.. im confused at the AFR figures.. i admit i never really paid much attention to what these mean... so i guess im paying for it now but..

on your second log, after the fuel pump was replaced.. is it the higher the afr numbr, the leaner it is?

[Anonymous]

Originally Posted by Damo V

I am a little lost, as the second chart you put up also show lower that 12.2 above 22psi?? Not a dig, more of a question really??

Also could you put the1st 2 and second 2 images side by side so they are easier to compare

Lower = richer

[Anonymous]

Originally Posted by DaveEscos

also.. im confused at the AFR figures.. i admit i never really paid much attention to what these mean... so i guess im paying for it now but..

on your second log, after the fuel pump was replaced.. is it the higher the afr numbr, the leaner it is?

Yes higher = leaner



you paid more attention that you realised

[Damo V]

Originally Posted by dumped

you said your car was 34 peak 30 held - its like fishing stories in here LOL

Good warning setup though

What would you describe the charts as?? Again not a dig at anyone more of a Q?

[BlueSmoke]

Sean, you still thinking over a rebuild while all seems healthy?

[Simon Day]

Uprated fuel pump is the first mod to be done!

[S3an]

Originally Posted by chip-3door

Yes, but so was Stu's when he tuned it.

The point he is making is that you cant just look once and then assume it all stays ok.


Yours WAS fine, make sure you dont leave it too long before taking it back for a quick checkover

well unfortunately i dont thinks the doors of msd will be open on boxing day unless he fancies going over to do some festive tinkering. I DONT THINK SO. your right though need to get there asap for my post tuning check up.

[Anonymous]

If thats in a lowish gear and its only hitting 34 psi for 1500rpm on the way up. thats pretty much just a peak by any standard surely?

So 34 peak 30 held sounds fair to me on that

[Damo V]

Originally Posted by chip-3door

Yes higher = leaner



you paid more attention that you realised

Right I got it now... It literally only just tipped over the edge of 12.2 ... sweet

I want one

[DaveEscos]

a couple of q's then

what are the bounderies for a top end fueling run.. ie.. when should the alarm bells start ringing and waring lights start flashing in terms of afr

also, at what boost.. do engines only melt at high boost AND revs, or can hey melt at lower ranges, ie 15 psi to 22 psi but at low revs)

basically.. what should the alarm bells be set too

[Anonymous]

Originally Posted by sean forsyth

well unfortunately i dont thinks the doors of MSD will be open on boxing day unless he fancies going over to do some festive tinkering. I DONT THINK SO. your right though need to get there asap for my post tuning check up.

If you arent confident in it right now, just keep the boost down till you get it looked at mate

The most dangerous thing your car can do tuning wise is running a LITTLE lean on big boost.

thats where it slowly melts the pistons away!

[dumped]

34 peak and in my opinion more like 25/24 held as this is the top end - but thats how i read it.

It was only the lightest of joking digs as I'm sure stu will appreciate

[S3an]

Originally Posted by BlueSmoke

Sean, you still thinking over a rebuild while all seems healthy?

well the car is gonna hit the 70k mark sometime later on next year so was thinking about it.

[BlueSmoke]

Personally, I would.

[DaveEscos]

Originally Posted by sean forsyth

well the car is gonna hit the 70k mark sometime later on next year so was thinking about it.

dont fix what 'aint broke!

[Anonymous]

Originally Posted by DaveEscos

a couple of q's then

what are the bounderies for a top end fueling run.. ie.. when should the alarm bells start ringing and waring lights start flashing in terms of afr

also, at what boost.. do engines only melt at high boost AND revs, or can hey melt at lower ranges, ie 15 psi to 22 psi but at low revs)

basically.. what should the alarm bells be set too

Depends on spec entirely mate.

anything in the 11s is generally nice and safe for on boost fuelling though.

and its often in the middle of the range that people melt things due to a mapping problem (its where you make most boost normally) but its at the top end that you will always kill it if its a fuel pump issue as its at the point of max bhp not max torque that the pump is working hardest.

[Mike Rainbird]

Originally Posted by dumped

you said your car was 34 peak 30 held - its like fishing stories in here LOL

Good warning setup though

He obviously never usually revs the car above 5984rpm .

[Anonymous]

Originally Posted by sean forsyth

well the car is gonna hit the 70k mark sometime later on next year so was thinking about it.

I believe you are looking at 4 grand for a properly built fairly basic spec engine from Stu.

Given your current financial situation and how much you love that car, i would do it mate

[Damo V]

So presumably following on from Chips first comment many things affect the "ideal" fuelling level??

I mean for eg mine could be lets say for example, 12.4/12.5 @27 /28psi Peak/held

Presumably thats stil ok?? Or do different tuners like their own different figures??

[S3an]

Originally Posted by chip-3door

If you arent confident in it right now, just keep the boost down till you get it looked at mate

The most dangerous thing your car can do tuning wise is running a LITTLE lean on big boost.

thats where it slowly melts the pistons away!

to be honest im just driving it sensible at the min as the new 6 paddle clutch is getting fitted on tuesday(big thanks to paul seveneigths) ive no complaints with the set up boosting at 29 psi and holding 25psi. better than the so called GGR 335 bhp conversion that was on it. even after fitting a pro alloy cooler it was struggling to get 21psi.

[DaveEscos]

hmmm.. my dyno plot is full of 12's! ??

[BlueSmoke]

Originally Posted by sean forsyth

to be honest im just driving it sensible at the min as the new 6 paddle clutch is getting fitted on tuesday(big thanks to Paul seveneigths) ive no complaints with the set up boosting at 29 psi and holding 25psi. better than the so called GGR 335 bhp conversion that was on it. even after fitting a pro alloy cooler it was struggling to get 21psi.

What like when we were tearing up and doing Blackpool seasfront doing fly bys?

[Anonymous]

Originally Posted by Damo V

So presumably following on from Chips first comment many things affect the "ideal" fuelling level??

I mean for eg mine could be lets say for example, 12.4/12.5 @27 /28psi Peak/held

Presumably thats stil ok?? Or do different tuners like their own different figures??

Its all dependant on spec, if you have forged pistons not squeeze cast you can get away with more heat for example.

running leaner means more heat, so its all down to what your components can take and what measure you are using to combat heat, like for example if you have water injection you can get away with running leaner than without it

[frog]

Nice one Stu.

Worth checking the wiring too, as it gets old and isn't quite so able to carry the requisite power and voltage to the pump

PS: Any offers on wideband kits over xmas ???

[Garage19]

Good thread witha great example.

[TIFF]

Pop a new fuel filter on while your there

[Stu @ M Developments]

Originally Posted by sean forsyth

i take it mine was ok when you tuned it then stu.

Yeah, very healthy and tons iof fuel pal... just like mine last time i datalogged it, just over a month ago

Originally Posted by Damo V

I am a little lost, as the second chart you put up also show lower that 12.2 above 22psi?? Not a dig, more of a question really??

Also could you put the1st 2 and second 2 images side by side so they are easier to compare

I think you are confusing teh numbers a little.
AFR figures are a ratio of fuel to air, the larger number being air..

Example: 11.5:1 is RICHER than 12.5:1

Originally Posted by dumped

you said your car was 34 peak 30 held - its like fishing stories in here LOL

Good warning setup though

It is essentially, it peaks around 34 at 3500 and falls to 30 at 5900, dropping to sub 20 by the rev limiter as even the HKS EVC V cant overspin teh turbo anymore

Admittedly that run was in 4th and it DID hold a tad more boost than it normally does. probably more impending doom on teh horison... look out for teh next topic

Originally Posted by DaveEscos

what is the best wideband in car gauge to run?

Pretty much any of teh ones you read on here are impressive, also see PF next month for a back to back test with my own IS ECM1200... interesting results.

I like teh dynojet for its instant datalogging at teh flick of a switch, as seen here, and its ability to WARN you of danger, so no need to EVER look at teh gauge itself.

[Anonymous]

Originally Posted by DaveEscos

hmmm.. my dyno plot is full of 12's! ??

I dont like the look of that personally.

I cant see why you are richer at low rpm at 15psi than you are flat out at 28 psi


Were the EGT's being monitired too though?

[dumped]

Stu - why is the fault away once the boost goes down/revs up as presumably peak power is up at 6500odds so peak fuel should be needed there?
Looks more like some sort of regulator fault than pump from the 1st charts but then your new pump sorted it minted Just seems odd - I would ask if the problem was repeatable through rev range like that but after seeing it once i doubted you wanted to know lol

[DaveEscos]

ok, stu's alarm went off at afr 12.1 up to 12.4



my dyno chart shows my entire air fuel range at 12.4 - 12.7

whats going on there then?

or is it different rules for dyno runs?

[S3an]

Originally Posted by BlueSmoke

What like when we were tearing up and doing Blackpool seasfront doing fly bys?

thats why its getting a 6 paddle fitted ask jamsport dan about the traffic lights launch wid the evo sat behind me to be fair though when stu set the car up he did say there was a issue with the clutch and this confirmed the voice of reason

[Anonymous]

Originally Posted by dumped

Stu - why is the fault away once the boost goes down/revs up as presumably peak power is up at 6500odds so peak fuel should be needed there?
Looks more like some sort of regulator fault than pump from the 1st charts but then your new pump sorted it minted Just seems odd - I would ask if the problem was repeatable through rev range like that but after seeing it once i doubted you wanted to know lol

Once the boost drops the injector duration drops too, so its not such an issue for flow on the pump.

His car must be making peak power lower than you suggest i would think from that.

[DaveEscos]

I know chip... maybe someone can explain dyno afr's??