Few days ago I have spoke with the guy from RS-Racing and he said "the limit is not a power, but the boost". Engine can be push to around 380HP and 500Nm. The boost limit is 1,6bar max. They usualy do on hybrid with 1,6bar aroud 360HP, stock turbo with 1,6bar around 330HP.
Not completly true...you have to "limit" the boost lower down as the torque is geting high for the stock engine and clutch otherwise you could runne more boost.At 1.6 bar is where hybrid 250/265 are making around 370 torque to around 4700 rpm after that you can go higher.We have a few megans that are running almoust 1.8 bar@5500 rpm with no problems on hybrid.
Does anyone know of a Mk3 R.S. with standard bottom end, letting go after(modifications/map)? i.e. being pushed to far with the bottom end. These things have been around for 6 years odd,so i would have thought that we could establish a `limit` as to what they can cope with or not?
Nope, tbf most that run a hybrid in the UK are generally on a unit that won't really trouble the bottom end and a lot of those on the continent tend to end up forged. I'm aiming for 380/360 when I go hybrid but will have it turned down a bit for longevity
Depends what spec hybrid you settle for, most will be fine although there are a couple that would be borderline on a stock engine
Hehe.I have meg 225 with GTX3071 so a bit different.I'm not new to this game and I have been around the hybrid cars when they have been maped by Paul.And I did drive them.Really fast cars with not a lot of mods needed to be fast.Spools almoust like stock with a nice increse high up.And no surge.
I would say the safe power limit is 265hp, in line with what Renault thinks as well. Everything over that is a trade-off between power and reliability or safety factor. But as history showed, a car used to go to shopping and back with 500hp will hold longer than a car races all day with 300hp. So usage is the second one. S.
100% spot on. I came here from a scene in which it was always claimed that old school Porsche were hugely over-engineered, 100% margins etc. etc. People were running anything up to 450 Bhp from a base 250 Bhp engine on the road. Then talking to those who actually raced the things and were around those who raced a lot back in the day they tell me the complete opposite and it seems that even with no more than 20% over standard they could be money pits. This is why I intend to never go further than Paul's basic stage 1 sort of mapping on my R26 as I intend to do a lot of track days in the thing and want it to last. Those tuning their 250 Megs want to think long and hard about heat management if they intend to heavily track their cars.
Going by how the vast majority of heavily tuned ones are used on the continent I have no fears running mine at XXX power. I do understand the points above and agree to an extent though
For arguments sake, does that mean companies like Ford then under tune their vehicles in order for their mount tune division to tune them? Or are mount tune pushing them past the so called safe limit?
I will try to answer this question. What tuning does is basically eating engineering margin. Doesn't matter who is pushing the buttons. My job is to develop engines for an OEM and this is the most difficult bit for us, to make the maximum performance with the same reliability targets. And in order to sign-off an engine, it needs to pass some very hard tests which tells us is ok for production and we still have issues with them (like everybody has). We need to run couple of thousands of hours without any failure. And believe the tests are very tough. This way, we can sell an engine that with withstand people who don't know how to treat them, rough conditions, bad fuel... What tuning is doing, is hoping they can trade some of this engineering margin for vehicles where the owners are going to pamper them and behave with them. But what people never think when they double the power of they're engine is the cooling side. More power means more heat! Always!!! Maybe your engine with 450hp runs ok here in UK with 70mph speed limit but go to Germany and try to run with 220-250km/h for 100km in a row, eventually going up towards Passau in order to mix altitude (and obviously no speed margin on the turbine side) and hills and inclines (and obviously higher torque demand). Then let us know how much was the towing vehicle from there to UK. People always think that engines have hidden power inside and the producers doesn't want to give it to people because of some obscure reasons, where the reality is, the OEMs always want to give the maximum power in a reliable way within the cost cap they have. And there are a lot of stories of exotics and high performance vehicles which cannot really cope with real track work because they are not designed for this. They are designer just for parade on Las Vegas strip. All the race vehicles have modified engines and cooling packs for this. Did I said Ferrari, Lamborghini, Pagani...? Oops. If anyone really wants to discuss TEHNICAL about what tuning is doing and where the gains are coming from and not "Paul's software is better than all the work Renault is able to do...", we can discuss about everything. S.
So in response to my above post that I was using just for arguments sake, you are saying even in house tuners like mount tune are trading off longevity for power?
Youre using the wrong terms to describe the issue here. Using 'safe limit' implies a sort of yes/no it will be OK answer. 'Longevity' is influenced by so many variables and not just tuning or a % power increase. Same for how any tuning is employed long term in the real world, multiple influencing factors. No set yes/no answers and trying to quantify it with a safe limit value is meaningless. For example, you can tune a stock Megane engine to 320 Bhp with a remap, but someone that never uses that extra capability isn't really increasing component failure risk other than any changed fuelling differences from the map. As eloquently discribed by bulardas, it's best to see tuning, when applied to standard components, as a potential increase in component failure risk. Failure risk and potential are the key words.
Putting everything in simple terms: increase power means more pressure inside cylinder more pressure means more stress on all components which has to contain the pressure (pistons, rods, bolts, engine head, gaskets, spark plugs, valves...) more pressure in the same volume (because engine volume stays constant) means more temperature which has to be contained (pistons, heads, valves, spark plugs, cooling circuit, exhaust system, turbocharger) more pressure and more heat means more prone to knock... increase power can also mean increased max rpm more rpm means more physical stress and more friction related failure Please find a easy escape route and you can win the Oscar in engine development. And here we are not even touching the discussion of a bad tune, inadequate sensor or un-mapped area that the engine can see. Regarding your comparison with Mountune, I'm speaking here around the OEM who actually builds the engine and still faces the same issue. So, let's brake a little tuning a little bit. What does an actual remap to your car and how can it gain anything. And for the fun of it, let put it as a discussion between two guys. BOOST: This is everybody's way of measuring they're car. - My remap makes 1.6bars of boost, more then yours. Where is this boost coming from? - Is coming from spinning the turbocharger more. - Why is not Renault doing this? - Well, first limitation is altitude margin. Because they want to have same performance like sea-level even a little higher up (usually between 500-800meters) they keep some margin on turbo speed, so the ECU can run the turbo harder when you go up. What tuners first do, is eat up this margin. Now go and try your remap car at 1000-1500 meter level and tell me how much faster is against a stock car. Second, when the tuner wants even more performance, they over-spin the turbocharger more than the turbo supplier thinks is ok. There is some extra margin as well, so you can eat that up. Usually the margin is 5%. So you are just pushing your turbo to max at sea-level hoping for the best. Also keep in mind that a bigger turbo means more lag and this is physics attached to it. You can't have a bigger turbo that spools the same!!! You just can't. Is something called inertia which plays against you! - But XXXX tuner makes a amazing hybrid. It spools the same and makes more power!!! - It can't. You think is doing this and maybe the difference is not that big in terms of spool, but the hybrid is going to increase your back pressure which goes back on the path of hotter engine, more prone to knock... - So, why can't I have lots of boost? Those guys on Youtube have 1.8bars? - You sort-of can for very short periods of time. Enough to make a Youtube clip. But if you combine track usage with altitude and high boost, that is a certain path to turbocharger failure. And don't forget you have a tiny things inside which spins 120.000-130.000rpm. Very easy to break. FUEL: Despite usual belief that for more power you need more fuel, in fact you need less. And we don't speak in absolute fuel flow terms, we speak in lambda or AirFuelRatio. Best performance you have at 13.2:1 AFR and that is physically and practically known. Is not my engine is better running leaner or richer. And I will explain why until the end. - So why don't we run that AFR all the time, this will also lower out fuel consumption and help with performance. Great! - Well, keeping engine cool and mitigating knock is the first answer. Usually AFR is limited by the catalytic converter temp. Go over 1020deg and BOOM. Proven fact. So OEMs are keeping overfuelling to give cat a fair life - Wow, so decat also helps us running better AFR and therefore the power gain from decat? - Exactly But you also have exhaust valve temperature you have to keep in check, you have engine head, spark plug, entire cooling system, hot spots and knock mitigation, so you can't run where you would like. SPARK: - Let run maximum ignition, this will give us plenty of power! - Well, ignition is very limited by knock. One degree of ignition can make the difference between a working engine and knocking engine. And because knock is limited by fuel quality, temperature and all sort of things, OEM leave a small margin there as well. So, by increasing ignition, you just eat this safety net for bad fuel. So from now own, keep an eye on that Tesco 99+ only. FREE POWER: - What that? - There is some free power in the engine. Free is just a way of saying. Usually the engine can safely do more power but it is limited by the clutch, gearbox, differential, axles so you have some limitations in the ECU. You can send those to hell and get all the safe power from the engine, but then some parts are going to slip, crack, break...so is not necessary free. But fortunately all this parts have some engineering margin attached to them. So if you get this, it is a cycle which you can't really break unless some parts are changed, some safety margin is lost, some more precaution is used in using the car.
And to give you all the one million point question: WHO IS WILLING TO RACE his stage X car with 5 people inside and luggages for half an hour at 250km/h (any weekend night in Germany), eventually with a sky-box on top of the car full of skis going towards Passau (between 800-1000 meters altitude) against a stock car??? I put my money on the stock one!!! You know why? Because I tested in this conditions and I know it works. Who did this with his Stage X???? S. If you desire special power levels and/or race engineered motors for endurance, high stress or Vmax type events, please keep in mind that the laws of physics and thermodynamics apply. The candle that is twice as bright, only burns half the time. This is motorsport!
Wow, this all got a bit negative a bit fast did it not? Surely the majority of users on here are running cars that are at least re-mapped? The guy's question has already been answered, so no need to go on about the bad points of modifying. I'm really tempted to light a fuse about Renault themselves releasing the same engine as a 250, 265 then 275 when essentially its the same engine but I don't care, like the original poster, I'm just here to get advice on how to improve my car (and maybe see lots of pictures of other peoples also).
My OEM 2009 CBA GT-R out the factory with 480bhp and 430ft-lb torque ran on stock turbo and internals 670bhp and 650ft-lb torque for 3 and a bit years, 250+ Nurburg laps, a good few Alpine runs across Switzerland and Italy (high up) and never missed a beat. In fact it was literally only ever driven hard but services without fail every 6 or less months sometimes with only 1000-2000 miles done. Thats over 33% power increase over stock. It's pot luck I guess and no I'm not trying to compare a Megane to a GT-R but in general on most cars I've owned I've never surpassed 33% increase in power on OEM items. In fact I only did with the GT-R because my INDY warranties the car for there work should it have a mishap and go boom. With a Megane taking roughly the same mark up that would be 352bhp / 335ft-lb torque. I certainly wouldn't surpass those figures personally and even then there is an element of luck.
Yes Andy, GTR is not the best example, as Nissan wanted to build an icon from beginning. But even so, we have to keep in mind that a bigger, more powerful engine is less stressed than a smaller one, because let be honest, how long can you keep foot down in a 700hp car and how much in a 350hp car. S.
Not negative at all. The OP asked what was 'safe power' and just got a random answer to a non specific question as there is no such thing as a safe power limit. More power equals extra risk over stock. Even when Renault went from 250 to 275. A few people then qualified tuning with a few caveats. Thinking you can knock out 360+ bhp on stock internals with no mention of component failure risk (including drivetrain) is hiding potential issues.
Ok maybe I just read it as negative then, sorry. What would you say was a safe limit for the car on stock internals then, as I think this is really what he meant? Lots of people run around 300-320bhp without forging and seem to have no problems so personally I will only look at forging if I ever go above maybe 320bhp. The clutch and gearbox seem to be able to take a fair bit more but I'm definitely no expert. From everything I have read I would go with whatever advice RS Tuning give. They also mapped mine (previous owner) but I have a copy of the graph and I can see that they actually turned it down a bit on the last run rather than stressing it as far as it could go.
Forget the term 'safe limit'. It doesn't exist. How much extra power? You have to decide yourself based on the data out there. RS Tuning is in the business of making money out of tuning, so take their input and factor it with other info and inputs. Many years ago RS Tuning was pushing the boundaries on the MK2 and engines were going pop. They wound it back and capped torque.
Yeah but that would imply that anything over 275bhp is unsafe, which I would argue is untrue given that the Megane 3 has been out long enough now for people with say, just a re-map for example, to have tested it over long periods of time with high mileage without any issues (that I know about anyway). I hadn't heard anything about their issues with the MK2 to be honest but hopefully they have learnt from it.
Nope, anything over 275 is less safe. You just have to quantify that yourself based on your own circumstances, usage, what you want to achieve and the risk associated with it.
Exactly. But don't forget Bullardas's excellent point about heat management. Decide if you are going to use that power over a long period (hard track laps or racing) or just for the occasional 5 second blat. If its the former its my humble opinion that you always need to think carefully about heat management. On the mk3 Megane I personally wouldn't tune one without including Paul's intercooler and turbo cooler package, on my R26 I added the GPI intercooler to go with his basic sort of stage 1 mapping. Maybe I am paranoid but at 41 seen to many people kill engines over the years.
I totally agree on alot of points Bulardas mentioned but actually there is one big mis assumption he makes! Some of that safety margin used by OEM's actually stresses the engine more! Also a Megane won't run the same power at altitude. add on top of that basically every m2rs and m3rs runs more power than the book says!
Tutuur, The only safety margin that actually stresses the engine is the catalitic converter. We all agree is a bad thing but we can't do it without. 2 years of my life I made engines for Renault (K4M RS, H4Bt, F4R) so I know how Renault thinks and calibrated. I'm doing engines now as well. If I would not be under a No Disclosure Agreement, I could back everything up with graphs and data. S.
I'm fully aware of everything going on in the ecu so that's why i say it doesn't run the same power at altitude, also i wasn't talking about the cat. it's ignition advance i was talking about, which does indeed create safety margin, but also causes the egt's to be higher than needed, that's why they overfuel in standard form, which isn't a good thing either. so simply saying having a safety margin is better for the longevity of the engine is a wrong conclusion. It does however enable the engine to operate on lower quality fuels which is exactly what oem's design for.
Yes Tutuur, but on the other side of the spectrum is running more ignition and leaner mixture takes you to higher peak cylinder pressures and knock. Which is worse than egt and overfuelling. This is why I don't take this as good. S.
This is how I see it: 1. The components in your car will wear out, as standard. 2. Increasing the engine output will make the components wear out faster. 3. Increasing the output too much could cause catastrophic failure. The OP asked what is the safe limit. As has already been answered, there is no such thing - the components will wear out even at the mfg standard map. If the OP is not bothered about the difference between point 1 and 2 above, then crack on but be wary of point 3. If he is bothered, stay at point 1. Renault and others demonstrate this with the 'sport' buttons and modes - they don't want the car running on this map constantly for a number of reasons, reliability notwithstanding.
You all talk about the components when running high power for long time. That's right, but let's say that for me, running 20% more than the stock power for something like 2 years and then having the clutch need to be replaced, with some more stuff during this time is a good tradeoff for the value i'm getting with the performance during the 2 years. However, if I know that going above 30% more power may cause the engine to break, it's not worth the power I'm getting. So basically the less power you add, the less risk you're taking and knows that it can cost you more money soon. But hey, Buying a 350bhp car that handles like the Megane will cost us much more And don't forget, components and the engine can crack and break even with the stock power. Keeping an eye on your car, maintaining it as often as you can, for me at least, is the most important thing no matter how much power you get.
