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Can Overrun map cause Damage!



  R5 gtt, R27 F1 team
It is Chip!

If you map it on a spare eeprom, solder that one ontop of the original one and de-attach the 24th pin (live).
Then you re-attach both pins of both eeproms via a 2 way switch.

There you have your switchable pops and bangs :cool:
 
  AB Clio 182 FF
It is Chip!

If you map it on a spare eeprom, solder that one ontop of the original one and de-attach the 24th pin (live).
Then you re-attach both pins of both eeproms via a 2 way switch.

There you have your switchable pops and bangs :cool:

well that sounds a tad confusing aha
 
  DON'T SEND ME PM'S!!
It is Chip!

If you map it on a spare eeprom, solder that one ontop of the original one and de-attach the 24th pin (live).
Then you re-attach both pins of both eeproms via a 2 way switch.

There you have your switchable pops and bangs :cool:

it's not an EPROM, it's embeded data. What you're saying would work on a mk1 ECU, although it would be easier to run a 27c512 chip, run a double layer map, and fit a switch to earth to one pin (can't remember which it is without looking it up)
 
  182/RS2/ Turbo/Mk1
It is Chip!

If you map it on a spare eeprom, solder that one ontop of the original one and de-attach the 24th pin (live).
Then you re-attach both pins of both eeproms via a 2 way switch.

There you have your switchable pops and bangs :cool:

I don't think many people on here will want to be doing that sort of thing to their ecu, and taking the chips live pin external to the case is asking for a failure, yuck.
Also im not convinced it would even work like that as I'm not sure if the ecu moves the tables into ram when it first loads up tbh,, certainly wouldn't surprise me if it did.
 
  R5 gtt, R27 F1 team
lol, didn't know the mk2 ecu hasn't got an eprom in?

you wont be switching it to case, just back to the board trough a switch. indeed there won't be very much people on here that'll do that but i just tried to enlighten you how it could be done :)

switching is preferably with engine off anyway as i have no idea how the ecu would react when switching it while the engine's running..

Dan, how does the 27c512 eprom do that? sounds interesting!
 
  182/RS2/ Turbo/Mk1
The mk2 still stores the map in a chip so what your saying would be possible if you had two chips and a way to switch if you did it with power off (possibly +VE not just ignition though?)

You can run an emulator instead of the 27c512, which would allow you to swap on the fly so your method should work on that ecu even with the engine running in theory but i haven't ever tried it so can't say if the few chip cycles it's got neither pin connected for as you switch would cause a problem or not.

Again though not worth the effort just for some chavvy bangs, when I mentioned it's a shame it didn't switch, I meant natively rather than those sort of bodges.
 
  R5 gtt, R27 F1 team
lol, it's funny to know imo. just found how the 27c512 works:

I use that method on Delco ECUs with 27C256 by placing one 27C512 and switching 0v/5v on A16 pin. Works great!
 
Sorry to highjack, have a mate that wants to do this (personal taste), but does the pop's and bang map cause a misfire (as such) in the engine or in the exhaust. Additionaly if it is a misfire in the engine, can it not do damage to the pistons over a period of time?
 
  182/RS2/ Turbo/Mk1
Sorry to highjack, have a mate that wants to do this (personal taste), but does the pop's and bang map cause a misfire (as such) in the engine or in the exhaust. Additionaly if it is a misfire in the engine, can it not do damage to the pistons over a period of time?

Its not a misfire no, its just a deliberately inefficient burn so not all the petrol is burned which means there is still some left when it hits fresh air at the tailpipe so the rest burns then instead.

to do that at full throttle would cause massive EGTs and be very harmful to the engine, but because in this instance its such a tiny quantity of mixture involved, it isnt an issue. But the excess fuel could damage the cat if its doing it very often.
 
Its not a misfire no, its just a deliberately inefficient burn so not all the petrol is burned which means there is still some left when it hits fresh air at the tailpipe so the rest burns then instead.

to do that at full throttle would cause massive EGTs and be very harmful to the engine, but because in this instance its such a tiny quantity of mixture involved, it isnt an issue. But the excess fuel could damage the cat if its doing it very often.

Ok cheers for that... hes having new valves and re-time due to cambelt failure, unfortunatly slipped a tooth, and planning to get the map at the same time... he wants the map and at the end of the day, what he does with his money, his car is his choice, just dont want to see him spend out all his money, to then do further engine damage.

But by the sound of it, doesnt seem like an issue at all.
 
  182/RS2/ Turbo/Mk1
If he is having new valves anyway, for the extra few hundred quid it would be well worth doing supertech, they are a significant reliability upgrade.
 
If he is having new valves anyway, for the extra few hundred quid it would be well worth doing supertech, they are a significant reliability upgrade.

Is that simular to up-rated valve springs? if so, i believe he's getting it done... wasnt much more cost wise!
 
  182/RS2/ Turbo/Mk1
Is that simular to up-rated valve springs? if so, i believe he's getting it done... wasnt much more cost wise!

No its different valves not different springs that I am talking about, the standard springs are fine unless you are on very lairy cams and running big rpm.
 
No its different valves not different springs that I am talking about, the standard springs are fine unless you are on very lairy cams and running big rpm.

Ok, cheers, ill mention it to him... not sure what his full plans are, as i keeps changing lol. I think he keep contemplating either just getting new valves and re-timed ect... (be back on the road quickly), or why its having all the done, cams ect... maybe forged piston (but he's been two weeks with out it now and is missing it...) so im assuming he will go for the first option.

and let me check before i call him... its call "supertech?", any idea on price?
 
  182/RS2/ Turbo/Mk1
Ok, cheers, ill mention it to him... not sure what his full plans are, as i keeps changing lol. I think he keep contemplating either just getting new valves and re-timed ect... (be back on the road quickly), or why its having all the done, cams ect... maybe forged piston (but he's been two weeks with out it now and is missing it...) so im assuming he will go for the first option.

and let me check before i call him... its call "supertech?", any idea on price?

Just over 500 quid from ktec, or nearer to 300 if you buy them direct from supertech (take about 3-4 working days to arrive from the states)
 
  Evo 5 RS
Honestly unless you've got the cash just sitting there supertech valves on a reasonably standard engine is just throwing money away unless it's used for racing. Ok so they're friction welded, but valve failure on these is far from common and normally a result of something else.
 
  182/RS2/ Turbo/Mk1
Honestly unless you've got the cash just sitting there supertech valves on a reasonably standard engine is just throwing money away. Ok so they're friction welded, but valve failure is far from common and normally a result of something else

If you are revving the engine hard (which if he is going hotter cams forged pistons and steel rods like Joey said he might there isnt much point not revving to 7800rpm) then the chance of the standard valves failing dramatically increases.
Laine on here had his let go at only 7500rpm IIRC, and I know other people who have had them fail on even less.

IMHO 300 odd quid is cheap insurance when you are spending a couple of K on work on the engine anyway, especially compared to some unknown secondhand ones.

Not saying everyone driving around in a standard 172 should panic and start ripping the head off just to replace the valves or anything like that, but if the head is off anyway, and you are about to source valves for it, its worth the upgrade if its an engine you intend to rev a lot.

Im just about to fit some to my mrs 172 daily for example as Im going for ARP bolts and a 7800rpm limiter on it and dont want to risk the standard ones as she'll not be pleased if the extra few hundred rpm rights her engine off, lol.
Wanted to do the belts anyway as well as the rod bolts, so ordered a gasket set and set of valves too while I was at it to just get it all sorted in one go.
 
Honestly unless you've got the cash just sitting there supertech valves on a reasonably standard engine is just throwing money away unless it's used for racing. Ok so they're friction welded, but valve failure on these is far from common and normally a result of something else.

Cheers... point taken. Just spoken to him, wont tell you of his plans... as that his job at some point.

Thanks for your help and sorry to have hijacked the thread and thrown it about off topic!
 
  Evo 5 RS
I was waiting for you to use Laine as an example lol! If it's a daily I would just stick to 7,500 anyway personally. It just seems since these valves have cropped up every Tom Dick & Harry thinks they're essential. Can totally understand doing it on an all singing and dancing forged engine but for what it costs to source a standard head it seems a lot of effort. Especially for a road car
 
  182/RS2/ Turbo/Mk1
I was waiting for you to use Laine as an example lol! If it's a daily I would just stick to 7,500 anyway personally. It just seems since these valves have cropped up every Tom Dick & Harry thinks they're essential. Can totally understand doing it on an all singing and dancing forged engine but for what it costs to source a standard head it seems a lot of effort. Especially for a road car

Not sure about what you mean about them "cropping up", you make it sound like a recent thing but Ive been swapping to better valves for at least a decade on engine builds Ive been doing, its not a new thing, although I guess it might be in the context of cliosport? lol

TBH the supertech ones are still far from perfect, if I was doing a really big spec build i would be talking to someone like G&S about some one piece, as the supertech ones actually arent (despite what the ktec website tells you), but they are a lot better than standard still.
 
  Evo 5 RS
I meant on here mate, yes. And obviously these engines, not disputing it might be more worthwhile else where. I just reckon unless it's up there day and night (and standard internally), like I say, on a race car, it's not worth it. I could count on one hand the amount of valve failures I've heard about.

Maybe a specialist can come and say otherwise, like. But I just don't see it. I mean you're a different kettle anyway, I know you've done the
rounds with engines, but you just said you're fitting them to your Mrs car because you don't want to risk it lol...ARP bolts and job done!
 
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  182/RS2/ Turbo/Mk1
I meant on here mate, yes. And obviously these engines, not disputing it might be more worthwhile else where. I just reckon unless it's up there day and night (and standard internally), like I say, on a race car, it's not worth it. I couldn't count on one hand the amount of valve failures I've heard about.

Maybe a specialist can come and say otherwise, like. But I just don't see it. I mean you're a different kettle anyway, I know you've done the
rounds with engines, but you just said you're fitting them to your Mrs car because you don't want to risk it lol...ARP bolts and job done!


At 7800rpm which is where I will be setting the limiter, no I dont want to risk it and I think its bad advice for you to say the standard valves are safe for that, they just arent from what I have seen, especially once they are old and fatigued from years of heat cycles etc (141K miles in this instance). A new set I would have no issue with revving to that level TBH if racing in a series where it had to be standard parts, but I would want to "life" them, but in the case of not having such rules to need to stick to, it just seems pointless to risk it for the sake of an extra couple of hours work next time you are doing the belt to just swap over to some better ones, especially if like our car it does a lot of trackdays.

Dont forget her car is an RS2 one, so doesnt suffer from the usual "feck all point revving it anyway, its rubbish up there" syndrome that a standard engine does, lol
 
  Evo 5 RS
141k is pretty high but meh. Well how about you don't fit them, and when in a years time it's still alright after a few days on circuit you can buy me a set ;)


I txt James last week btw I'm popping up to give him his fecked wheels back (even more off topic), not heard back from him so I'm going on a hunt for an F1, if not I can give you a red one lol :eek:
 
  182/RS2/ Turbo/Mk1
141k is pretty high but meh. Well how about you don't fit them, and when in a years time it's still alright after a few days on circuit you can buy me a set ;)

And if it isnt then you'll pay all the parts and for my labour to fix? Sounds like a plan to me :)
If so I'll put these valves to one side for you ;)


I txt James last week btw I'm popping up to give him his fecked wheels back (even more off topic), not heard back from him so I'm going on a hunt for an F1, if not I can give you a red one lol :eek:

Flol, no thanks to a red one.
 
  Evo 5 RS
And if it isnt then you'll pay all the parts and for my labour to fix? Sounds like a plan to me :)
If so I'll put these valves to one side for you ;)




Flol, no thanks to a red one.


I'll get back to you on the former, and to the latter, I had a feeling that's what you'd say, so didn't mention them before lol
 
  DON'T SEND ME PM'S!!
It's not revs that are killing valves in my opinion/experience, it's valve bounce caused by being too rev limiter happy. Everyone I've seen have it happen to has had an intimate relationship with their rev limiter
 
  182/RS2/ Turbo/Mk1
It's not revs that are killing valves in my opinion/experience, it's valve bounce caused by being too rev limiter happy. Everyone I've seen have it happen to has had an intimate relationship with their rev limiter

Im not convinced that hitting the limiter is going to cause the valves to bounce (thats more a case of the phsyical strength of the spring being upto the job or not of keep the valve in contact with the lifter and hence cam profile really), but what will of course happen on a car with a fuel cut limiter is that you'll run lean on the limiter and potentially see EGTs rise as a result.
So I definately agree that zinging off the limiter for long periods is a very bad idea.
 
  Cooksport Fleet
Paul is running std valves with 510bhp. And i was running std on 380bhp at 7800rpm with high egts.

Same std valve as the meg iirc.
 
  120d M Sport
Get a 106 gti/ saxo vts...all you need is a decat (even on standard exhaust!) and it pops/bangs on demand...by that I mean when you want it to, rather than when you don't.

The Clios I've seen with the pop n bang map sound silly, do it way too much which sounds contrived (well I guess it is)
 
  182/RS2/ Turbo/Mk1
BHP isnt a massive issue generally speaking in terms of valve reliability (although there is a relationship between BHP and EBP of course on a turbo car which can lead to increased valve temps, so it does have some effect still), its EGT and RPM and amount of duty cycles as a combination that normally causes valve fatigue.

Often parts survive in race cars that dont in road cars just due to the lack of hours they see in use etc.

So its not always directly relevant what one car or another is doing if they are used differently.

Lastly of course, (like most things renault) the production tolerances are unlikely to be tight, pistons are the obvious example where there will be lots that are fine, but if you are unlucky and get one with big air bubbles in the casting you are screwed for getting big power, so its a bit of a lottery, and I am sure that the valves vary too.
 

tadas

ClioSport Club Member
  RS Clio 172 Ph1
Just my opinion on this overrun map thing, I believe that RS clio itself is silly to begin with, so adding more character to it seems just right. When I show up in it saying it is my weekend fun car people react with disbelief, however, it all changes after I start the engine or pop up the hood. So I do think since the car at hand is a (grey/silver at my case) clio, having something exciting added to it is great. Furthermore, it is top of the line sport model, not a riced out ford or something of that sort.

So OP I wonder if you run this map to this day, for half a year, or did it get boring after a few days?
 
  Renault Clio 172 Cup
I know it's a different car, but ALL 106 GTI's will pop and bang on the overrun with a decat, it's the way they are mapped from the factory

It's fantastic fun and always puts a grin on my face

Never heard of a 106 blowing up because of it? So I'm sure if you had it properly mapped and didn't go stupid it shouldn't be a problem
 


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