SteveR Posted April 9, 2008 Author Share Posted April 9, 2008 Thanks Ash - useful input especially as you've seen the car. I'd be surprised if it's anything major or that should be addressed, touch wood! Like you say it does only seem to smoke once (per day). I'm not 100% sure as I haven't yet driven/booted it much and I'm trying to resist temptation and keep the miles down for the time being. I kindof assumed that all singles smoke (black smoke) at least a little, as the only one's I've seen - in real life or shown on youtube/etc on dynos - do! Quote Link to comment Share on other sites More sharing options...
Jake Posted April 9, 2008 Share Posted April 9, 2008 I'm almost certain it's not a valve stem seals problem. My grey Supra suffers from that, always has done in the five+ years I've owned the car, and the symptoms are very different. Steve's car (my old one) does make some black sooty smoke but I only know about it because it leaves a sooty mark on the bumper where the tailpipe is a bit shorter than most - I've never noticed it when driving the car. It's always done it and, like Steve, I believe it to be quite normal on single Supras. While in my ownership the car was mapped/remapped/tweaked 5 times and it's always been the same in respect of making a bit of sooty smoke at idle. Quote Link to comment Share on other sites More sharing options...
SteveR Posted April 9, 2008 Author Share Posted April 9, 2008 I'm almost certain it's not a valve stem seals problem. My grey Supra suffers from that, always has done in the five+ years I've owned the car, and the symptoms are very different. Steve's car (my old one) does make some black sooty smoke but I only know about it because it leaves a sooty mark on the bumper where the tailpipe is a bit shorter than most - I've never noticed it when driving the car. It's always done it and, like Steve, I believe it to be quite normal on single Supras. While in my ownership the car was mapped/remapped/tweaked 5 times and it's always been the same in respect of making a bit of sooty smoke at idle. Yeah that. It could be much worse... where's Robbie? (Robbie: you should know that I'm joking when you read this mate!! ) Quote Link to comment Share on other sites More sharing options...
bolarbag Posted April 10, 2008 Share Posted April 10, 2008 I need to upload the map you gave Jake (and he gave me on a DVD) but don't have the necessary lead - I meant ot ask what I need (MoTeC M600). You can use a Serial Cable(If you have a serial port on your laptop), wired into the CAN leads or if you have a CAN lead/wires coming off the loom, you can either buy the motec cable...which converts it to a parallel port(almost pointless in this day and age) or buy a Motec USB to CAN UTC convertor, pricey but far easier:cool: I'm sure though, if you wire a serial lead into the motec CAN connectors, you could use a Serial to USB convertor, but even they are pretty pricey Quote Link to comment Share on other sites More sharing options...
Wez Posted April 10, 2008 Share Posted April 10, 2008 USB serial adapters can be cheap http://www.ebuyer.com/product/124085 Quote Link to comment Share on other sites More sharing options...
Ian C Posted April 10, 2008 Share Posted April 10, 2008 Black = unburnt fuel. You run rich to deliver power and cool the combustion chambers and all that, you will spit some unburnt fuel out the back as if it was all burnt nicely, you'd be at 14.7:1AFR The more power you make the more fuel you inject to burn, consequently the more fuel comes out the back, eventually it's visible as a black smoke. It's more pronounced when you initially stick your foot down as you get the acceleration pump effect adding in more fuel as well. Hence black cloud on Single tubbies. Thats my thoughts on it anyway -Ian Quote Link to comment Share on other sites More sharing options...
bolarbag Posted April 10, 2008 Share Posted April 10, 2008 I'm sure though, if you wire a serial lead into the motec CAN connectors, you could use a Serial to USB convertor, but even they are pretty pricey Sorry mis-quoted myself - the serial cable can only be used for telemetry, motec can to parallel cable is about 70quid, motec can to usb is around 150(from US) Quote Link to comment Share on other sites More sharing options...
SteveR Posted April 10, 2008 Author Share Posted April 10, 2008 Black = unburnt fuel. You run rich to deliver power and cool the combustion chambers and all that, you will spit some unburnt fuel out the back as if it was all burnt nicely, you'd be at 14.7:1AFR The more power you make the more fuel you inject to burn, consequently the more fuel comes out the back, eventually it's visible as a black smoke. It's more pronounced when you initially stick your foot down as you get the acceleration pump effect adding in more fuel as well. Hence black cloud on Single tubbies. Thats my thoughts on it anyway -Ian Thanks Ian - so IF that is the cause, it's just a by-product of running a single (with its current particular map or always because it's too difficult to avoid and safer to run slightly rich Vs slightly lean?) and not something to worry about? Cable-wise - thanks guys I think I can get one sorted now, will double-check the connector. Quote Link to comment Share on other sites More sharing options...
Ian C Posted April 11, 2008 Share Posted April 11, 2008 My reply is a completely un-useful "it depends". In fact attempting to diagnose the severity of fuelling issues by the amount of black smoke out the back is futile. If it happens a lot under light boost loads or even when cruising, yes you have a problem. under boost - rely on a good AFR reading to see if everything is OK. -Ian Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted April 11, 2008 Share Posted April 11, 2008 Black = unburnt fuel. You run rich to deliver power and cool the combustion chambers and all that, you will spit some unburnt fuel out the back as if it was all burnt nicely, you'd be at 14.7:1AFR The more power you make the more fuel you inject to burn, consequently the more fuel comes out the back, eventually it's visible as a black smoke. It's more pronounced when you initially stick your foot down as you get the acceleration pump effect adding in more fuel as well. Hence black cloud on Single tubbies. Thats my thoughts on it anyway -Ian I'm glad I came across this thread Ian. I've often wondered why I get a single puff of black smoke out the exhaust whenever I dump my foot the accelerator for the first time. (After letting the car warm up.) Your explanation makes perfect sense to me! Quote Link to comment Share on other sites More sharing options...
Homer Posted April 11, 2008 Share Posted April 11, 2008 I'm glad I came across this thread Ian. I've often wondered why I get a single puff of black smoke out the exhaust whenever I dump my foot the accelerator for the first time. (After letting the car warm up.) Your explanation makes perfect sense to me! I was just about to reply and say my old car always did this. My theory is this happened on cars with low back pressure and/or large bore exhausts. I.e. soot collects in the exhaust pipe while there's very pressure forcing it out (and the pipe is cold), then when it comes on boost the huge force of air clears all the crap out of the pipe. Quote Link to comment Share on other sites More sharing options...
vvteye Posted April 13, 2008 Share Posted April 13, 2008 Whilst mine doesn't smoke, it does like to backfire after coming off boost. I notice the AFR's are also totally lean if I'm off the throttle but in gear climbing down so to speak. Is that something to worry about? As soon as I touch on the throttle again it goes back into the mid 13's in the orange band. After a full throttle burst the other day on the motorway, I came off the loud pedal and the guy following me said there was a huge flame accompanying the big backfire. Quote Link to comment Share on other sites More sharing options...
Homer Posted April 13, 2008 Share Posted April 13, 2008 Thats normal Jon. A good mapper will add some additional fuel when the throttle is backed off to help cool the cumbustion chamber, the added fuel tends to ignire in the red hot exhaust which can cause flames from the exhaust. AFR's going off-the-scale lean on lift off is also normal, the engine isn't doing any 'work' so almost no fuel is going in + throttle is closed hence lack of O2 reading Or something like that anyway! Ryan, amoung others, will be able to explain it better. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 13, 2008 Share Posted April 13, 2008 A single should no more smoke than the stock twins should. If there's visible smoke some thing's amiss. Whether fixing it is worthwhile depends on how fussy you are and whether the cause can lead to other problems. Quote Link to comment Share on other sites More sharing options...
SilverSoop Posted April 13, 2008 Share Posted April 13, 2008 Thanks Ash - useful input especially as you've seen the car. I'd be surprised if it's anything major or that should be addressed, touch wood! Like you say it does only seem to smoke once (per day). I'm not 100% sure as I haven't yet driven/booted it much and I'm trying to resist temptation and keep the miles down for the time being. I kindof assumed that all singles smoke (black smoke) at least a little, as the only one's I've seen - in real life or shown on youtube/etc on dynos - do! Yeh i remember watching an episode of topgear when clarkson was racing the greeen murchielago with his evo 9 fq400 and that blasted out a black plume of smoke and that car was a single and was new. I thought the reason they did that was like ash said, if you dont use boost for a while it cokes up a bit and when you do, its bound to blow out a plume of smoke to clear its throat... Quote Link to comment Share on other sites More sharing options...
SteveR Posted April 14, 2008 Author Share Posted April 14, 2008 Thanks for all the input guys - I'll keep an eye on it and work out what conditions cause it - I'm pretty sure it's only happening at the first occurance of a decent amount of positive boost so that sounds like it's not a "uh-oh" definite problem and is instead just a characterisitc of how it's been set up. Like I say I'll keep watch (I'm paranoid about stuff like this so I'll now be be looking in my mirror more than I'll be looking forward, lol) Quote Link to comment Share on other sites More sharing options...
JamieP Posted April 14, 2008 Share Posted April 14, 2008 Was talking the the original owner of your car yesterday, he had a Monaro after that and now he has a VXR8:) Quote Link to comment Share on other sites More sharing options...
SteveR Posted April 14, 2008 Author Share Posted April 14, 2008 Was talking the the original owner of your car yesterday, he had a Monaro after that and now he has a VXR8:) Cool, how do you know him then Jamie? I don't know much about the chap TBH - I think he had the car from importing it in 2001 when it was ~6 months and still a stock TT, did all the mods over everal years? then sold it to Jake ~2 years ago? I always wondered what car the original owner would have gone on to own; where DO you go after having a seriously fast car that could 'beat' pretty much anything this side of £300k? Quote Link to comment Share on other sites More sharing options...
JamieP Posted April 14, 2008 Share Posted April 14, 2008 Spoke to him on pistonheads when he found out i use to have a supra, this is his profile if you want to get intouch, from what i gathered he had a lot of problems with it and it never ran right when he had it so he sold it:) http://www.pistonheads.com/gassing/profile.asp?h=0&memberId=35023&t=520766 Quote Link to comment Share on other sites More sharing options...
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