View Full Version : Strongly advise A/F ratio gauge on BT
ibizacupra
31-07-2005, 12:08
I would strongly advise anyone running BT seriously consider an A/F ratio gauge in-car...
ickle ibiza has melted its 2nd exhaust housing last weekend @ Castle Combe. :(
Same failure mode as Donington last year but not quite as melted, but same nett result. Laggy, struggling to make boost, exhaust housing sagged onto turbine wheel, cracked across wastegate etc...
Not happy
Donington I could explain (so I thought) that it was the massive oil breather load (1ltr consumed) running thru the intake with linking, higher EGT's on ign retard and meltdown. Since then, baffled sump, Forge breather catch tank and additional overflow catch bottle are used. No breathers go mack into intake at all these days. Intake pipes are all oil free. Also running Aquamist now. Despite all this, overheated housing and melted/distortion again. :censored:
New gauging on order for EGT, wideband AFR etc (Zeittronics) so protect my new engine coming soon. Cannot afford these failures.
Wondering... (if) S3 fuel pump is in fact not up to the job long term, and (maybe) the tested ibiza one vs new S3 one just showed new pump vs older pump effeciencies..! NOT perhaps higher fuel delivery at all!
For the interim, larger aquamist nozzle fitted (0.7mm was 0.5mm) and el-cheapo (inaccurate) AFR Autometer gauge piggy backed off ecu's main lambda as an indicator (lean - stoich - rich) to hopefully get me to the ring AND back. :blink:
Checked plugs and all cylinders are running the same (#3 looked ok) but a very gritty red coating on stuff.... Optimax syndrome perhaps like my tailpipes.
AFR gauge is essential I think now...
as said to me by a friend.. we have sensors for water temp, oil pressure, but nada for AFR but that is the most likely one to kill your engine and turbo.
So true.
I have also added additional cooling fan to blow down on shut down the turbo area (switchable and 10min timer post ign off) to see if this will make any difference to the excessive heats being seen.
On IHI's I will be doing shortly I would strongly advise on an A/F ratio gauge in-car as an indicator.
regards
bill
Got any links to decent suppliers of AF meters Bill.
http://www.demon-tweeks.co.uk/catalogue/product_detail.asp?PCODE=TRIP144&GRP=RP073&PGRP=R008&CLS=ROAD&from=search
http://www.demon-tweeks.co.uk/catalogue/product_detail.asp?PCODE=R/PDTM4007&GRP=MC057&PGRP=MP051&CLS=MSPORT&from=search
http://www.demon-tweeks.co.uk/catalogue/product_detail.asp?PCODE=LUMAFR003&GRP=MC059&PGRP=MP054&CLS=MSPORT&code=LUMAFR003&from=search
http://www.demon-tweeks.co.uk/catalogue/product_detail.asp?CLS=MSPORT&TLGRP=MP054&PGRP=MC059&GRP=MC059&PCODE=A/AAFS-1
If I were choosing one I'd want one in line of sight that was *really* obvious when it was wrong - so maybe one of the non dial type LED ones
Do you know what your peak fuel flow is meant to be Bill? I guess WOT & injectors on at x% and some maths should be ableot work it out.
Ruddmeister
31-07-2005, 14:39
Autometer ones were quite nice I thought
http://www.autometer.com/cat_gaugedetail.aspx?ref=search&gid=2817
http://www.autometer.com/cat_gaugesearch.aspx
http://www.autometer.com/img_products/4375_d.jpg
ibizacupra
31-07-2005, 14:45
Autometer ones were quite nice I thought
http://www.autometer.com/cat_gaugedetail.aspx?ref=search&gid=2817
http://www.autometer.com/cat_gaugesearch.aspx
http://www.autometer.com/img_products/4375_d.jpg
this is what I have just fitted. autometer disco gauge... cos it flashes around like a disco. :rolleyes:
its shite inaccurate but an indicator "disco" gauge. lean/rich if it stands still ong enough.
http://www.zeitronix.com/Products/zt2/zt2.htm <<< is what I've ordered
also>> http://www.dynojet.co.uk/wideband/index.html <<reccommeded to me but pricey.
Is the knocklink the scooby boys seem to use a lot any good/suitable?.
ibizacupra
31-07-2005, 14:51
Is the knocklink the scooby boys seem to use a lot any good/suitable?.
dunno m8, you got a link to it?
http://stefanostadal.homedns.org/car_mods_gauges.htm
http://www.performancesubaru.co.uk/product_details.asp?id=42&cat=27
Ruddmeister
31-07-2005, 14:55
Feel had a Turbodisplay thing not sure of the cost and A/F, boost and intake temps etc were displayed
http://www.seatcupra.net/forums/showthread.php?t=46526&highlight=turbodisplay
http://www.turbodisplay.com/products.html
http://www.turbodisplay.com/P1010009.jpg
Don't know how good it is / costs though but Feel has had it fitted for a while IIRC
this is what I have just fitted. autometer disco gauge... cos it flashes around like a disco. :rolleyes:
its shite inaccurate but an indicator "disco" gauge. lean/rich if it stands still ong enough.
http://www.zeitronix.com/Products/zt2/zt2.htm <<< is what I've ordered
also>> http://www.dynojet.co.uk/wideband/index.html <<reccommeded to me but pricey.
Where did you get the zeitronix? Any uk distibutors?
Cheers
Anyone know what det cans are and how they work.
ibizacupra
31-07-2005, 17:33
I was asking about the one Feel had but its not available yet in the spe I want and I am not sure its wideband...
ibizacupra
31-07-2005, 17:35
Where did you get the zeitronix? Any uk distibutors?
Cheers
ordered it direct
ibizacupra
31-07-2005, 17:38
http://stefanostadal.homedns.org/car_mods_gauges.htm
Hmm. cant see the point of this one.
ecu already runs knock... and I dont get knock..
possible lean running perhaps to overheat things but no pinking.
Ran it just now with 0.7mm aquamist jet in it and the car got a good ragging. Seems slightly laggier than before, but maybe just playing tricks with myself.. who knows. inlet manifold was physically cold to touch afterwards, unlike the rest of it.. hot hot hot hot hot......... and auz fan blowing on it to help cool it down.
will see how things pan out I guess.
Under full boost, A/F gauge is showing rich so as an indicator it seems to work. Will have to keep a beadie eye on it tho.. Mr Paranoid now. :hide:
Hmm. cant see the point of this one.
ecu already runs knock... and I dont get knock..
possible lean running perhaps to overheat things but no pinking.
Ran it just now with 0.7mm aquamist jet in it and the car got a good ragging. Seems slightly laggier than before, but maybe just playing tricks with myself.. who knows. inlet manifold was physically cold to touch afterwards, unlike the rest of it.. hot hot hot hot hot......... and auz fan blowing on it to help cool it down.
will see how things pan out I guess.
Under full boost, A/F gauge is showing rich so as an indicator it seems to work. Will have to keep a beadie eye on it tho.. Mr Paranoid now. :hide:
Mike at jabba advised me it i was willing to sacrafice some low down torque i could fit the biggest aquamist jet so the car would have a stronger top end.
ibizacupra
01-08-2005, 11:55
bonnet vents bill?
new lightweight bonnet will have yes. :)
Scotty_b
01-08-2005, 12:09
Sounds silly bill but if your wanting to get the heat out fast and air in how about pining the bonnet and removing it for racing? Cant get any lighter than that either!
ibizacupra
01-08-2005, 12:18
Sounds silly bill but if your wanting to get the heat out fast and air in how about pining the bonnet and removing it for racing? Cant get any lighter than that either!
probably not legal to do so on track... (removal)
new bonnet and other panels will have some vents chopped out of it.. and will be pinned.
New aux fan seems to be doing the trick so far, but ring bashing is yet to occur so fingers crossed. A/F gauge shows green "rich" under boost so far and "red" lean on overrun and dances between the two at all other times.. does a kinda jig.. :D :p
finally bunged in my Denso plugs too for good measure. :hide: been in glovebox for >year now I think. :doh:
EGT's are the concern as well as A/F ratio being sound.
Additional fuel pump planned to make for more peace of mind for new engine, which will no doubt need larger injectors :rolleyes: and more fuel
Scotty_b
01-08-2005, 12:34
Ah ok, must just be 1/4 miles there ok for then. Wondered why i hadnt seen more doing it on the track
Would it be possible to get a group buy for zeitronix wideband gauges,make them a little cheeper?
ibizacupra
01-08-2005, 14:53
Would it be possible to get a group buy for zeitronix wideband gauges,make them a little cheeper?
we can always ask.
:cheers: for the wiring info Dan... sorted and spliced. #71 or #70 I think it was in the end.. poor eyesight had me looking at #63 and thought it was #69.. point to point buzzed it thru and found it in the end.
gauge is hunting on idle & cruising.. which is what I guess the ecu is trying to grab a stable reading, give or take a mile on a narrowband lambda.
we can always ask.
:cheers: for the wiring info Dan... sorted and spliced. #71 or #70 I think it was in the end.. poor eyesight had me looking at #63 and thought it was #69.. point to point buzzed it thru and found it in the end.
gauge is hunting on idle & cruising.. which is what I guess the ecu is trying to grab a stable reading, give or take a mile on a narrowband lambda.
Interesting - my car on TB's and lumenition ecu (which does not use lambda for fuelling) is rock steady on a constant throttle such as on motorway etc, move the throttle and it bounces about
Rob
lambda needs to fluxuate in order for cat to work(if you had one)this will be the hunting you can see. Lambda sensors only really used at idle and part load this is the only time the cat is working as well. I would expect to see .9v under full acceleration and .01v on over run depending on what percentage addaption is set at on your ecu.
Need wide band for good sensible reading.
ibizacupra
01-08-2005, 21:11
lambda needs to fluxuate in order for cat to work(if you had one)this will be the hunting you can see. Lambda sensors only really used at idle and part load this is the only time the cat is working as well. I would expect to see .9v under full acceleration and .01v on over run depending on what percentage addaption is set at on your ecu.
Need wide band for good sensible reading.
:thumbup: cheers Dan... Fountain of knowledge. :cheers:
come Zeittronix jobbie, come. :)
ibizacupra
01-08-2005, 21:29
here's another one... saw it on a vortex video..
http://www.modernperformance.com/all/aem_uego_wideband.shtml
http://www.cardomain.com/item/AEM304111
http://www.aempower.com/product_ems.asp
john banks
02-08-2005, 12:16
I've been running a Techedge WBO2 for about 3 years and it works well. There is now a good choice of wideband O2 units with cheap sensors available. I wouldn't map any turbo car now without a wideband, and on ECUs where the knock control is lazy, a knocklink as well. In car fuel pressure has saved my engine a couple of times when cheap FSE regulators have gone off.
Most ECUs run a short and long term fuel trim and you can usually see the injector pulse width ramping up and down to move the narrowband output around stoich. Using a narrowband to tune full boost stuff is rather dicey... used to use 0.89V as a safe rich level, but on some cars this was >12:1 AFR, others it was in the low 10s.
I presently run 11.0-11.2:1 AFR on an engine was cast pistons running up to 27 PSI peak, but I pull it down to below 22 PSI at the red line, and more sensibly 20 PSI because the turbo is just too small for going higher. It appreciates being rich when not using water or methanol for cooling. Can easily reach 980C in the exhaust manifold on a top gear high speed frolic, which IIRC is more than the rated exhaust housing temperature for IHI, which I am sure was about 950. The Garrett stuff is I think 1000-1100C. Warped heads, cracked manifolds/exhaust housings, preignition, pistons picking up in the bores are all risks you run screwing a small turbo to oblivion. Spewing coolant out, hot spots, detonation are all risks as well. So many vicious circles in the pursuit of a nice wide powerband :D
ibizacupra
02-08-2005, 13:52
Can easily reach 980C in the exhaust manifold on a top gear high speed frolic, which IIRC is more than the rated exhaust housing temperature for IHI, which I am sure was about 950. The Garrett stuff is I think 1000-1100C. Warped heads, cracked manifolds/exhaust housings, preignition, pistons picking up in the bores are all risks you run screwing a small turbo to oblivion. Spewing coolant out, hot spots, detonation are all risks as well. So many vicious circles in the pursuit of a nice wide powerband :D
Having melted 2 IHI exhaust housings now, this latest one for reasons as yet unknown, I am trying to suss an EGT which I will call my maximum. 950'C seems to be the max number from searching the net and looking at materials specs (guessing what IHI is actually made from)
Do you have actual IHI spec John? Is 950'C the magic number?
Cracked manifold also been like this for > year now, but then again my std one was cracked in the K03 also. Same as ur Quattro's cracked their manifolds for a passion. Hot and design material and geometry having its effect.
My Zeitronix unit is with UPS now on its way, with optional EGT sensor and additional MAP sensor for all in one display with wideband A/F ratio.
Not sure I want to rely on tuning on just logging CF from factory sensors as this has let down one guy with meltdown on a cylinder and nothing logged out of the ordinary. Its not fool proof.
john banks
02-08-2005, 14:05
After I posted I was trying to find some hard data, but I can't.
Another thought... some wideband sensors don't work well at high exhaust pressure - ie you need to fit them after the turbine wheel. Some will give a simulated narrowband output that you can then give to the ECU to save you running the factory narrowband, I run mine like this with a single NTK L1H1 sensor at the top of the downpipe, it only gets exhaust gas that has come through the turbine not the wastegate but it should be homogenous as long as there are no leaks I think.
Ibiza sport man
02-08-2005, 23:14
I should be getting one of these next week.
http://www.plxdevices.com/R-500_productinfo.htm
Seems pretty good spec but not seen one yet, it's only been out a couple of months.
Bernard
ibizacupra
03-08-2005, 09:01
dare I ask how much?
looks nice.. but wondering how visible in bright daylight it will be on that screen.
Ibiza sport man
03-08-2005, 09:59
dare I ask how much?
looks nice.. but wondering how visible in bright daylight it will be on that screen.
It's about £360, with Lambda sensor and EGT probe.
As you say, maybe not too clear in strong sunlight. But I will be using it mainly for logging data to a laptop.
Bernard
Dormouse
03-08-2005, 10:02
dare I ask how much?
looks nice.. but wondering how visible in bright daylight it will be on that screen.
LOL, it really will be 'Startship Badger' with all the dials and gizmos soon :).
She canna sustain this kind of fuel / air ratio captain! :bleh:
Dor.
ibizacupra
03-08-2005, 11:40
LOL, it really will be 'Startship Badger' with all the dials and gizmos soon :).
She canna sustain this kind of fuel / air ratio captain! :bleh:
Dor.
It might not... fuel pump concerns.. which I need to evaluate to be 100% confident. S3 pump *might* be a red herring, as used ibiza pump vs NEW S3 pump might have actually showed new vs 2 year old pump. My S3 pump is now ~2 years old and maybe back to Ibiza pump delivery..?
*maybe*
Pending testing on supply volume and pressure with an 'eagle eye' on A/F ratio on track this coming weekend.
Dormouse
03-08-2005, 11:45
It might not... fuel pump concerns.. which I need to evaluate to be 100% confident. S3 pump *might* be a red herring, as used ibiza pump vs NEW S3 pump might have actually showed new vs 2 year old pump. My S3 pump is now ~2 years old and maybe back to Ibiza pump delivery..?
*maybe*
Pending testing on supply volume and pressure with an 'eagle eye' on A/F ratio on track this coming weekend.
Electric fuel pump right? Would have thought that was a yes or no device. Unless efficeiency of motor reduces due to winding / brush deterioration....
Dor.
you could get really boring & work out if the fuel lines can supply the levels of fuel required. can't recall the diameter of the fuel line, but you should be able to work out the peak flow & whether the diameter is sufficient.
take the hose off the fuel rail and see how much it pumps out ina given time - and i guess there is some calc you can do for consumption rate - if pump is not delivering 75% then I would start to worry
Rob
ibizacupra
03-08-2005, 13:18
Electric fuel pump right? Would have thought that was a yes or no device. Unless efficeiency of motor reduces due to winding / brush deterioration....
Dor.
original one would spool supply pressure for a while then an internal bypass/relief valve would creep and the delivery pressure would drop.
I have been sent some info on how to calc delivery from return line to which I need to compare my injector sizes etc..
Not sure if it will be volume short or pressure limited.
john banks
03-08-2005, 15:17
Tired pumps that only drop pressure and flow after high pressure and flow use, as well as unpredictable regulators, inadequate fuel pump wiring (usually for beefier pumps resulting in voltage drop) can all be problems on some setups.
I'm using a Walbro 255 lph pump. I run it at 5 bar pressure (3.5 bar differential pressure) at 1.5 bar boost with 740cc (rated at 3.0 bar differential) injectors running at 85% duty cycle.
So I have 0.85*4*740*((3.5/3)^0.5)*60/1000 = 163 lph at 5.0 bar. At 221 lph at 5.0 bar at 14V (you can find the Walbro replacement pumps and graphs all over the net) it has at least 20% spare capacity as per general recommendations, and the GS34x series is available for VAG fitment.
A rule of thumb for turbo motors is that you need about 5.5cc/BHP.
If you want to allow for 400 BHP then you need to allow 132lph with a margin, at your given fuel pressure and supply voltage.
Jeff Lucius has a great page on fuel pump current, pressure, flow and selection http://www.stealth316.com/2-fuelpumpguide.htm
Another caveat - on some OEM fuel pressure regulators running a return system, the hole in the regulator limits the return flow and raises the pressure at low injector demands. SX fuel regulators are nice, and I have found them to be more reliable than cheaper FSE boy ricer type regs.
ibizacupra
03-08-2005, 19:29
cheers John.
all good info.
thankyou. :)
got sent this by a friend who's building a nice spec race ibiza 20Vt.
"Working on a theoretical over-supply of 30%, the formula is: HP x K = Fuel pump flow (cc per minute)
Where HP=maximum horsepower
K= 7.3 for forced induction.
That is with the fuel pump at system pressure, so you'll need to pressurise fuel regulator to simulate max boost using a tyre valve and a bit of tube. You'll have to bypass fuel pump relay so you can run pump for 2 minutes with the tank return line into a graduated container then run pump for 2 minutes then divide by 2 to get CC's per minute.
280 hp requires 2044cc per minute inc 30% over-supply.
Stock type fuel pumps reduce fuel flow by up to 40% when run at 4bar, compared to flow at zero pressure.
Also fuel flow can be estimated to drop by 12% for every 1 volt drop in battery voltage at the pump, so good wiring to the pump is worth having.
"
john banks
03-08-2005, 22:14
Fuel pressure and AFR gauges in cabin whilst under boost (especially if you can datalog them) will tell the story of the system on the car nicely I think. Why not just stick a known overspecced, reliable and cheap Walbro on it?
ibizacupra
03-08-2005, 22:36
Fuel pressure and AFR gauges in cabin whilst under boost (especially if you can datalog them) will tell the story of the system on the car nicely I think. Why not just stick a known overspecced, reliable and cheap Walbro on it?
why not indeed. sorted then..
added to the to-do list.... :)
this look ok for what you run John and price reasonable?
http://search.ebay.co.uk/walbro_W0QQfcclZ1QQfclZ4QQfltZ9QQfnuZ1
£85 buy now price 255ltr/pm jobbies
why not indeed. sorted then..
added to the to-do list.... :)
this look ok for what you run John and price reasonable?
http://search.ebay.co.uk/walbro_W0QQfcclZ1QQfclZ4QQfltZ9QQfnuZ1
£85 buy now price 255ltr/pm jobbies
surely thats per hour???
I have one of these (http://www.innovatemotorsports.com/products/lm1.php) with one of these (http://www.innovatemotorsports.com/products/lma3.php) and one of these (http://www.innovatemotorsports.com/xcart/customer/product.php?productid=16143&cat=250&page=2)
That gives me an indication in the car plus 44 minutes of logging of AFR plus 5 other parameters. Lastly it talks to my engine management (Autronic SM4) to allow it to tune itself :thumbup:
ATP sell 255l fuel pumps that fit.
http://www.atpturbo.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=ATP-VVW-019&Category_Code=VVWFE
ibizacupra
04-08-2005, 08:25
mines a round in-tank pump... wondering how that ATP arrangement is actually bolt in replacement.?
ibizacupra
04-08-2005, 08:26
I have one of these (http://www.innovatemotorsports.com/products/lm1.php) with one of these (http://www.innovatemotorsports.com/products/lma3.php) and one of these (http://www.innovatemotorsports.com/xcart/customer/product.php?productid=16143&cat=250&page=2)
That gives me an indication in the car plus 44 minutes of logging of AFR plus 5 other parameters. Lastly it talks to my engine management (Autronic SM4) to allow it to tune itself :thumbup:
nice :)
mines a round in-tank pump... wondering how that ATP arrangement is actually bolt in replacement.?
I wondered that too. Looks a odd shape. Round vs Square
How does the walbro in tank fuel pumps fit into the tank?
Cause i though that the pump and sender unit are one.
Also Bill few guys on vortex say there can be fuel starvation on hard right turn this true?
I wondered that too. Looks a odd shape. Round vs Square
How does the walbro in tank fuel pumps fit into the tank?
Cause i though that the pump and sender unit are one.
Also Bill few guys on vortex say there can be fuel starvation on hard right turn this true?
eek! no accelerating on roundabouts then!!(maybe this is why the LCR pulls to the left :roflmao: )
eek! no accelerating on roundabouts then!!(maybe this is why the LCR pulls to the left :roflmao: )
Could be you never know. :D
Going to try some runs with vag com with hard right turns and see. Or can you even measure fuel pressure?
ibizacupra
04-08-2005, 11:25
Also Bill few guys on vortex say there can be fuel starvation on hard right turn this true?
not experienced it but thats not a good sign as most tracks are clockwise... so right hand turns
I dont run low fuel tho typically myself, but have been known to get a petrol light on at the end of a session... :-o
john banks
04-08-2005, 11:35
Bill, the Slowbarus the are a nightmare at the hairpin at Knockhill as all the fuel runs to the left side of the tank and the pickup is towards the right. Even worse with the Walbro upgrade with the filter sock as supplied which is too short - that would surge on half a tank and give a nasty lean misfire & detonation coming out the hairpin. Refitting the original filter sock to the Walbro works fine - doesn't surge on road tyres until under quarter of a tank. Just compare the pick up points if you are changing the pump. There is talk of different relief valves that may help if you are running high fuel pressure, some sell these as the "Motorsport" version.
On another point, if not already considered I would check carefully the oil pressure if making a lot of lateral g depending on your pickup/baffling/sump arrangements.
Maybe adding a fuel swirl pot could help Bill?
not experienced it but thats not a good sign as most tracks are clockwise... so right hand turns
I dont run low fuel tho typically myself, but have been known to get a petrol light on at the end of a session... :-o
You can get an inline swirl pot which keeps the pumps fed by gravity in the event of fuel starvation.
Edited: didnt read you Post Rob :redface: To slow
ibizacupra
09-08-2005, 19:26
Bill, the Slowbarus the are a nightmare at the hairpin at Knockhill as all the fuel runs to the left side of the tank and the pickup is towards the right. Even worse with the Walbro upgrade with the filter sock as supplied which is too short - that would surge on half a tank and give a nasty lean misfire & detonation coming out the hairpin. Refitting the original filter sock to the Walbro works fine - doesn't surge on road tyres until under quarter of a tank. Just compare the pick up points if you are changing the pump. There is talk of different relief valves that may help if you are running high fuel pressure, some sell these as the "Motorsport" version.
On another point, if not already considered I would check carefully the oil pressure if making a lot of lateral g depending on your pickup/baffling/sump arrangements.
I have baffled sump already and yes you need them when generating some G
john banks
18-08-2005, 20:51
Another Walbro plot.
http://www.johnbanks.dsl.pipex.com/Walbro.jpg
ibizacupra
19-08-2005, 08:23
14amps... hmmmm
tiny poxy wiring on mine to std pump... :(
tiny silly pins too.
Shock_Xe
19-08-2005, 10:24
Adam has a warlboro inline pump for his as well as a drop in tyrolsport, Im sure he will post up about it, spec etc.
makes me worry bout my pump cause of age
Quick question on the subject of running lean. when leaving the car in gear and you are not using the accelerator pedal so its going on its own momentum are you causing any damage because no petrol is going through?(according to jeremy clarkson anyhow)
jonathanp
19-08-2005, 13:32
Been doing some logs this week of the timing and I'm getting CF's up to around 9 so does that mean I'm running lean and possibly getting high EGT's?
john banks
19-08-2005, 14:31
No petrol is going through because the injectors have cut off (over-run fuel cut), so there is no combustion. What damages the engine is the heat or knock from lean combustion under high load, especially with a high compression ratio (or dynamic compression ratio with boost). Spark plugs are usually still being fired on over-run though.
ibizacupra
19-08-2005, 15:51
Been doing some logs this week of the timing and I'm getting CF's up to around 9 so does that mean I'm running lean and possibly getting high EGT's?
Not neccessarily lean but overadvanced for the fuel you're running or simply too much boost as well in combination.
The result from too high a CF would be ecu retarding ignition but that in turn raises EGT's if you leave the boost high.
Too lean and exhaust valves etc start to suffer. Valves are an issue on these engines as it is. (crack and Breaking)
jonathanp
19-08-2005, 15:54
boost is no more than 19/20PSI fuel is optimax on the APR hi-flow program
No petrol is going through because the injectors have cut off (over-run fuel cut), so there is no combustion. What damages the engine is the heat or knock from lean combustion under high load, especially with a high compression ratio (or dynamic compression ratio with boost). Spark plugs are usually still being fired on over-run though.
thanks. :thumbup:
boost is no more than 19/20PSI fuel is optimax on the APR hi-flow program
maybe it's advanced too much?
Do you have V-Tune? or the ability to switch to the 95Ron program which will be less advanced
Is it on fourth gear runs in the mid-range, or higher gears higher up the revs?
You need to stalk yermother, I know he was getting some timing pull - I think he played with v-tune.
Just seen this thread on A/F ratio meters.
I'm running the AEM kit - very happy with it (on the left in the piccy below)
http://www.ttoc.co.uk/gallery/clived/AF1a.jpg
I've heard the AEM gauge is one of the best. How do you hook one up?
Just seen this thread on A/F ratio meters.
I'm running the AEM kit - very happy with it (on the left in the piccy below)
http://www.ttoc.co.uk/gallery/clived/AF1a.jpg
That look very good Clive!
Cheers for the mani btw :thumbup:
We actually just piggy-backed the OEM wideband sensor - worked a dream :-)
Wish defi did A/F ratio to hook up to their link system :(
this ones the closest match I can find to e seat dash
http://www.demon-tweeks.co.uk/catalogue/product_detail.asp?CLS=ROAD&TLGRP=R008&PGRP=RP073&GRP=RP073&PCODE=TRIP144
ibizacupra
22-08-2005, 12:12
Wish defi did A/F ratio to hook up to their link system :(
this ones the closest match I can find to e seat dash
http://www.demon-tweeks.co.uk/catalogue/product_detail.asp?CLS=ROAD&TLGRP=R008&PGRP=RP073&GRP=RP073&PCODE=TRIP144
This DT one wont be wideband tho. not for £40
Isn't the AEM wideband gauge something like $400?
ibizacupra
22-08-2005, 13:27
http://www.rpmoutlet.com/aemgauge.htm
yep that kinda money.
:thumbd:
would look ok in black mode though
For anyone that's interested, Thor Racing near Kenilworth are the UK auth distros.
i'm running twin pumps on mine,running a tt pump+ a bosch high flow pump as used by hpa in the states on vehicles above 400bhp. it's a bit noisy though