Nah they dont, i had them in my car for 1hr before i toke them out when my car was stg3!

 

its run 26psi all day long, every day for 7 months and never had a problem with them. i tried some champion c57's? and had nothing but missfires gapped at 6thou! thought it was a bit odd...[/quote]

WAS the miss fire mainly on tick over by any chance?

If so that's because you had the WRONG plugs in with 26psi I CANT see u with MORE than 350 bhp so you SHOULD have had Champion 59's in it NOT the c57's


ps: LOADS of people just put in Champion c57 and get NOTHING but miss fire NORMALLY on tick over and THEN slag off the plugs WHEREAS it's because they have wrongly been inform about the plug range USE c59's upto 400 bhp and after that c57's to 500/550 bhp!

 

If you're using Platinum or even worse Iridium core plugs, you will get problems with hi-boost turbo'd engined. I think its amazing how some people vendor these plugs to cars like this.

Coppper core plugs are the way to go, cheaper and manage heat transfer far better than any other metal, it just needs more regular changes than Plat/Iridiums do, but that's not a problem since copper plugs are so cheap.

 

that looks like a fueling issue,get your fuel pressure checked and your injectors flow tested

 

Based on what?

 

Colas escort melted number 4 last week. They were Denso plugs as well. Replaced them with a set of 071s and its running sweeeeeeet again now!

 

Firstly, were these the plugs that the car was set up with? It is imperative that you stick with the same plugs if you have had a live map and pushed the car to the very edge. Changing the plugs for different heat rated ones is a big NO-NO once this has been done, as it changes everything.

If the answer is yes they are the same plugs, then if the car has been mapped on the road, it is IMPOSSIBLE to replicate the full load in fifth gear driving that some drivers then do on the road . The only way you can map for this is to go to Brunters or somewhere similar and max the car out and map for that. Even then that is not 100% safe . I shall explain: When mine was live mapped at Brunters (when it was 400bhp), I did three BACK TO BACK high speed runs to ensure that the fuelling / ignition was spot on. First run (to a Stack indicated 167mph - couldn't go any faster at the time, as it was absolutely pissing it down with rain and the bottom half of the runway had been closed off for some reason), no sign of det. Second run, similar speed and towards the end of the run, the faintest murmor of det appearing just before I shut off. Third run, and towards the end of the run, det could be heard (through Ahmed's cans). I was given a choice of backing off the ignition some more to make it ULTRA safe at the expense of losing some power, but knew I would never be able to hold it flat out for that length of time on the road and also that I wouldn't be stupid enough to do three or more back to back top speed runs in normal circumstances.

Obviously the point I am trying to make, is that if you don't INDUCE the conditions that make the car det, then you don't know exactly when you should be backing off the throttle. So mapping on the road is unlikely to give you this knowledge, so you can go away thinking that the car is perfectly safe, but as I have shown, after three flat out runs, det does become an issue. A fourth run without Ahmed riding gunshot to tell me to back off, may have seen the engine lunch itself.... On the road in certain conditions, you could have even held it flat for longer than at Brunters and that is when cars tend to let go, as the heat build up is IMMENSE. You really do need an EGT gauge, as it may have told you to come off the throttle.

 

If you get your car mapped on the "ragged edge" as mike put it, then you dont ever want to run a lower octane fuel that it was mapped on.

If you dont use your car often, bear in mind that couple of month old super is only around the same octane as normal unleaded!

I get it on my mini cabrio when i dig it out after the summer, the ignition curve is fairly aggressive and on old fuel it dets, but as soon as i fill up again its all back to normal, scared the shit out of me the first year it happened as it never occurred to me the fuel had lost so much during the layup!

so thats one possibility.

Poor flow on that injector compared to the others is another (even brand new they are NOT identical IME, and with age they get worse)

Could be an oil problem on that cylinder, like valve guide or rings, as if oil gets into the chamber it effectively lowers the octane rating of the fuel.



Surprised its happened on Stu's mapping in particular though as i beleive he is normally fairly conservative with his mapping for all the above reasons (ie he will sacrifice those last few bhp you could get right on the edge of det in order to give you extra reliability as thats what a roadcar needs), so i doubt he brought it nearer to det than about 3 degrees, so whatever it is causing it i doubt its a very trivial thing as if it was i would still expect it to be safe!

 

PS. Those Denso plugs are SHIT - 071s all day long .

 

No they arent, you really think Stu would recomed a plug that doesnt work?

Ive used denso IK series plugs in some REALLY nasty environments (like during 100% increases in power on nitrous and right at the lean esge where its not especially safe)

 

melted plugs is down to heat(if the plugs are up to the job)yes/no??
so whats causing the extra heat in the cylinder?
lack of fuel??

 

So if they're so good, why did it melt then, but on Colas car, 071s spot on? .

They're SHIT AFAIC, and I wouldn't put them in YOUR lawn-mower, let alone my own .

 

i used ngk 8s then densos missfires meltin galore spoke to mike and guzzler they both said 071s no probs since

jay

 

I used 071's on my 400 engine and they were spot on!
I have ngk9's in my 500 engine with no probs and their in there for the past year or more!!

 

Couldnt possibly comment without know more about the details.

Perfectly possible the failure was caused by a set of conditions that hasnt been replicated since.

 

nope, it gets ragged everywhere

 

its on page 34 of the unwriten rule book thou must thrash ur cossie within a inch of its life u no right next to when u hire a car drive it like u stole it


jay

 

 

LOL

Fair point, the accelator and brakes on my 3 door could be binary and it wouldnt make any difference

But by same conditions i meant more than just how its driven, like it could have been some old fuel or similar.

 

nope, fuel gets replaced daily as well



sometimes every few hours depends on traffic

 

Still may be older in the petrol station.

Thats only one example of course of how running conditons can be different though, im not saying thats the case here specifically.

 

Just got me set of 071's through the post, put them in and guess what. The fooking thing fired up no bother . I was expecting a melted piston in there also tbh. 5Thank fuck for that

 

Gapped at 6 thou!?


I've got C57`s gapped at 25thou and I'd never change them for any other plug

(stage 3 btw)

 

Didn't realise this thread was on 2 pages and so I was responding to the last post on page 1

 

Mike, Rod uses those Densos so they are hardly shite....

BUT I am a fan of 071's as you know and run them in Sierra with no problems It used to EAT NGK9's and C57's

 

I personally think they are and I'll stick to that. Ł60 for a set of plugs that regularly cause problems in Cossies? That's shite in my book .

 

Nobody has answered my question. Why is it that cossies do this???????
Is it something to do with the design of the head???????????

 

I answered on Page 1 .

 

Alps , i am in linthorpe and to be honest the only moonstone saff i seen is some times parked up out side the hair dressers on oxford road now and then.
See toddy around now and again,know jacko too ,and there is a nother black 3 door allong with mine ,and have heard that there is a new white 3 door just in the area.
come up to the next meet mate ,its at 7 ocklock this time cos of the AGM second sunday of the month at the dalton lodge.
Or you could pop allong to the kart track at south bank on the 2nd at 7pm ,we got an evening organised

 

righthooker
My mate is allways about in his moonstone 4x4 standard as they come. I have seen you once over the summer, but the sight of a cossie is very rare around boro and going to get rarer as mine might be going to torquee(spelling )

 

there only rare if you dont know where t look .
ther was a cheap saff in the paper last week 3800 i think it was ,.
What you going for next then??

 

Going to have a look at a nova 2.0 16v tonight

Just as a daft toy and possible trackcar. My choice to replace the cossie is a dc2 integra type-r. Nice motors standard without the worry of melted plugs and pistons

 

a good mate of mine lives on st marys walk was telling me about someone selling a saff,Bradshaw ! could he have been talking to you??

 

Na not me mate i go by the name of Whiteley. My mate just lives of saint marys walk right at the top end near the cooper. I live just behind the corra on the other side.

 

car ran fine on tickover, only had problems at peak boost. the car's still on a t3, so it really shouldn't do that, surely? like i said, i stuck a set of motorcraft plugs back in it and it's been perfect since!

 

CRAIG! the day that car costs us thousands on a rebuild, is the day it gets scrapped, love u hahaha

 

Nowt wrong with Denso the only plug that lasts in mine 5k miles & numerous 200+ runs at 2.5bar. Can i suggest respectfully that whoever specced your plug grade got it wrong. If correct Denso plugs are used they are simply the best. Ive seen the grade that other big bhp Cossies use & they are miles away from the correct grade & will give probs, unfortunately i cant give this info away.
Rod

 

Rob probably wouldnt hepl much if you did give it away, as unless they have the same sort of strength ignition as you they may get other problems.

 

mines melted a plug three days before it melted a piston. early warning that there is osmething wrong with the engine/set up?

get it back to stus to be checked over

the tip of the plug has got to go somewhere, so i would be worried....sorry man