JohnA Posted March 31, 2005 Share Posted March 31, 2005 Just got the beast in my garage, first thing is to take off the plugs and run a compression test (as you do ) What a mess these coil packs, bolts here, connectors there, it's a whole adventure to take the plugs out (compared to 4 cylinders, that is!) Anyway, 170-170-170-172-165-176 For a high-mileage UK it's not too bad, is it? My guess is that it's full of deposits, after a tankful of STP total system cleaner the valves should be sealing a bit better. Now the plugs were Denso IK24, plugged at 0.7mm and they look (to me) terrible http://www.max-boost.co.uk/max-boost/images/supra/supra_plugs1.jpg http://www.max-boost.co.uk/max-boost/images/supra/supra_plugs2.jpg http://www.max-boost.co.uk/max-boost/images/supra/supra_plugs3.jpg They also felt a bit 'loose' all of them, and their threads were dirty and full of crap. Could it be that the moron who tried to 'service' the car last forgot to tighten them up, or is it normal? (I've already ordered NGK iridiums at standard heat range, I ain't refitting this garbage) Any gen on maintaining the coilpacks now that they're on the bench? They look oily and miserable... Guess I'll have to check the valve clearances at some point, can't trust to have it done in the past, eh? Cheers in advance Quote Link to comment Share on other sites More sharing options...
Bobbeh Posted March 31, 2005 Share Posted March 31, 2005 The UK specs do run overly rich as standard, which could explain some of the mess on them. Quote Link to comment Share on other sites More sharing options...
TRD3000GT Posted March 31, 2005 Share Posted March 31, 2005 Ive seen much worse... they dont look too bad.. Quote Link to comment Share on other sites More sharing options...
JohnA Posted March 31, 2005 Author Share Posted March 31, 2005 *relief* so it's not as bad then, eh? How do you fix the 'rich from the factory' issue? AEM? I've got a wideband and boost gauge leftovers from my previous car, so I guess there's some wiring to do when I find the time... Quote Link to comment Share on other sites More sharing options...
Bobbeh Posted March 31, 2005 Share Posted March 31, 2005 Dont, it comes in handy for when you want to up the boost Quote Link to comment Share on other sites More sharing options...
merckx Posted March 31, 2005 Share Posted March 31, 2005 Look like mine! Better than being whitish grey! Quote Link to comment Share on other sites More sharing options...
Guest slow dog Posted March 31, 2005 Share Posted March 31, 2005 look good to me mate Quote Link to comment Share on other sites More sharing options...
JohnA Posted March 31, 2005 Author Share Posted March 31, 2005 So what sort of AFR do the UK supras run normally in mid-throttle positions? 10:1? Coz that how they look like, the 60 miles before were 3Krpm and just touching the throttle. Quote Link to comment Share on other sites More sharing options...
b_have Posted March 31, 2005 Share Posted March 31, 2005 So what sort of AFR do the UK supras run normally in mid-throttle positions? 10:1? Coz that how they look like, the 60 miles before were 3Krpm and just touching the throttle. I always aim for 11.8 @max boost and WOT. At 10:1 your throwing unburnt fuel Straight out the exhaust (and loosing LOTS of power) . The plugs look ok to me, the only way to get an indication by plug colour is to 'plug chop' after a hard run at high boost/rpm, Typically a dyno run. Quote Link to comment Share on other sites More sharing options...
JohnA Posted April 1, 2005 Author Share Posted April 1, 2005 I always aim for 11.8 @max boost and WOT. At 10:1 your throwing unburnt fuel Straight out the exhaust (and loosing LOTS of power) . Ah, but how do you 'aim' though? Have you got a means of adjusting injector duty or something? I take it that the supra runs closed-loop at low throttle, right? If so, after 60 miles of closed-loop I'd expect the plugs to be grey, not black and sooty like those. All supras run so very rich from the factory then, eh? .. the only way to get an indication by plug colour is to 'plug chop' after a hard run at high boost/rpm, Typically a dyno run. cutting the ignition during a full boost run just ain't gonna happen mate, not on my car anyway... That's how it's done on n/a engines, but turbo bearings get offended if their oil supply is suddenly dried out Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 1, 2005 Share Posted April 1, 2005 They look perfect to me. Unleaded fuel means plug readings are pretty meaningless, and those have seen idling before being removed. I'd probably have stuck `em back in... Quote Link to comment Share on other sites More sharing options...
JohnA Posted April 1, 2005 Author Share Posted April 1, 2005 What about the gap? Standard it's 1.1mm right? These were 0.7mm. Would there be a problem if I fit new NGKs (stock heat range) at 1.1mm? I have no idea yet about what sort of boost it does though, but the seller said that it passed (a proper) MOT dead easy, so I suspect there must be a cat of some sort in the stainless exhaust. Quote Link to comment Share on other sites More sharing options...
Alex Posted April 1, 2005 Share Posted April 1, 2005 John, have a search on IK24's and you'll find lots of useful info. Quote Link to comment Share on other sites More sharing options...
tDR Posted April 1, 2005 Share Posted April 1, 2005 Plugs look fine John, stick em back in IMO too. Denso irridiums are pre gapped to very small gaps usually 0.7mm - they are designed to work like this because of the super thin electrode design. IK24s are colder than stock grade, think they are like an NGK heat grade 8 from memory. What gap and heat grade you choose to run depends very much on what boost you want to run and how efficient your IC is at keeping air temp and thus EGT down. Quote Link to comment Share on other sites More sharing options...
JohnA Posted April 1, 2005 Author Share Posted April 1, 2005 John, have a search on IK24's and you'll find lots of useful info. you mean lost plug tips? lol... That's why I ain't putting them back, NGK I trust (well, haven't yet lost part of a plug due to high boost) Quote Link to comment Share on other sites More sharing options...
tDR Posted April 1, 2005 Share Posted April 1, 2005 you mean lost plug tips? lol... That's why I ain't putting them back, NGK I trust (well, haven't yet lost part of a plug due to high boost) lol, I'm of a similar opinion. There is also the NGK Iridium option which are pregapped - BKR7EIX and BKR8EIX I think are the codes. Not heard such bad press about them although I would always stick to coppers because they do the job just fine and are cheap. For slightly increased boost with a standardish setup I'd fit BCPR7ES or BKR7E and gap at 0.9mm. Quote Link to comment Share on other sites More sharing options...
JohnA Posted April 1, 2005 Author Share Posted April 1, 2005 I've seen from up close Denso plugs with missing bits of porcelain and tips, not nice. I've got a pic on my site under 'ignition' I think... Quote Link to comment Share on other sites More sharing options...
Alex Posted April 1, 2005 Share Posted April 1, 2005 A BPU car running Denso Iridium's will be fine, the porcelain only ever breaks cause of detonation/pre-ignition. Unfortunatly unlike the NGK's they don't melt in a detting engine...but then the engine shouldn't be detting anyway. Quote Link to comment Share on other sites More sharing options...
Ian C Posted April 1, 2005 Share Posted April 1, 2005 The Denso plugs are apparently less resilient to det. People are blaming a symptom rather than a cause, I wouldn't like to see an urban myth kick off about IK series plugs being dangerous to the engine under normal running conditions because of this. -Ian Quote Link to comment Share on other sites More sharing options...
Guest Usmann A Posted April 1, 2005 Share Posted April 1, 2005 I agree with Ian, its better not to have any DET in the first place. We ran 2 bar+ on IK27s and they were gapped aswell(cant remember to what, I didnt gap them), and all plugs look in Top condition.(regardless the thing blew to peices,lol) I can see from the other prospective tho, a plug which can take detonation occurance, but then if you detting in the first place, you can say "BYE BYE" soon anyway. So its a kind of no win situation. I for one will be using the IK27s again this time, and keeping a stock of NGKs, very cheap. Guys that are loosing plug ends shouldnt be dissing the plugs, either your detonating slightly, and pre-ignition is a aftermath of DET,which most likely be losing the ends, but look to the reason of why the hell your loosing plug ends first!!!! Quote Link to comment Share on other sites More sharing options...
JohnA Posted April 1, 2005 Author Share Posted April 1, 2005 I agree with everything here, but remember that detonation is a cruel mistress. My previous car could hold 30psi without a hint of detonation, and yet some day decided to kick the bucket at less than 1 bar. Same setup (apart from the upgraded ignition during the fookup) You never really know what's gonna happen, fuel quality can vary, who knows --- who cares when you're sitting on the hard shoulder waiting for the AA truck I'd play it safe, urban myths or no urban myths. Why don't NGK plugs disintegrate so easily, are Denso users somehow more likely to push the envelope? Quote Link to comment Share on other sites More sharing options...
Ian C Posted April 1, 2005 Share Posted April 1, 2005 I'd play it safe, urban myths or no urban myths. Why don't NGK plugs disintegrate so easily, are Denso users somehow more likely to push the envelope? Possibly yes. I don't know why they fall apart easier otherwise. Perhaps the smaller electrode. How far do you play it safe though? I'm going sort mine for the highest it'll go on Optimax (best I refit the NGKs for that lol) and then run it at 1.2bar most of the time. That way I know it's not gonna det unless I accidently put diesel in -Ian Quote Link to comment Share on other sites More sharing options...
b_have Posted April 1, 2005 Share Posted April 1, 2005 Ah, but how do you 'aim' though? Have you got a means of adjusting injector duty or something? I take it that the supra runs closed-loop at low throttle, right? If so, after 60 miles of closed-loop I'd expect the plugs to be grey, not black and sooty like those. All supras run so very rich from the factory then, eh? cutting the ignition during a full boost run just ain't gonna happen mate, not on my car anyway... That's how it's done on n/a engines, but turbo bearings get offended if their oil supply is suddenly dried out I have a wideband and make fueling adjustments with an SAFC (signal fudger). Yes, I find that stock TT's run VERY rich. My plug chops ALWAYS allow for turbo timing. The 2 mins or so of idle soot can be removed with a splash of acetone revealing the true colour for reading. (IMO) Quote Link to comment Share on other sites More sharing options...
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