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Read the WELCOME ALL BMWFANATICS post.
THE N/A vs TURBO ENGINE DEBATE
- Thread starter Gizmo
- Start date
Gizmo
Banned
Race engines like the s54 and s65 use tighter tolerances to extract every last KW out of them. Race engines get rebuilt after every race so they can stay competitive, they also run very very low km on their oil before its changed out, race engines also run on the highest octane fuel available and use fuel additives to further prevent detonation.
Now take that race engine which needs constant attention and put it in a street chassis where the driver isn't a racing driver and never heard of mechanical sympathy, driving the car hard while still cold, using various pump fuels with varying octanes and putting more than 15 000km on one oil service. He uses the car for various conditions that race cars never see and he expects the car to continue running at its peak like the day it left the factory...He is absolutely shocked that the engine has eaten itself after 100 000km of street driving, I am not surprised at all knowing how engines work.
Modern BMWs use direct injection which massively reduce detonation as the piston surface and combustion chamber are cooled tremendously by the high pressure fuel being sprayed into it. That is why modern turbo engines can utilize high compression numbers and still use high boost pressures.
Now take that race engine which needs constant attention and put it in a street chassis where the driver isn't a racing driver and never heard of mechanical sympathy, driving the car hard while still cold, using various pump fuels with varying octanes and putting more than 15 000km on one oil service. He uses the car for various conditions that race cars never see and he expects the car to continue running at its peak like the day it left the factory...He is absolutely shocked that the engine has eaten itself after 100 000km of street driving, I am not surprised at all knowing how engines work.
Modern BMWs use direct injection which massively reduce detonation as the piston surface and combustion chamber are cooled tremendously by the high pressure fuel being sprayed into it. That is why modern turbo engines can utilize high compression numbers and still use high boost pressures.
sash
///Member
Gizmo said:
Are you sure BMW built a race engine, last i checked, if i raced the engine and followed their service intervals and allowed them to change the fuel filter and air filter, it probably would last 20000km and then i would be told my motorplan is void because i raced the car on a track.
What it seems like is that BMW claims to build a race engine, that cant be raced and needs to be rebuilt every so often, because its a race engine.
I would also pose the same question then to other manufacturers where they build what is essentially race engines ( in their own class). Do we see honda and toyota performance engines requiring the same amount maintenance and even then compare kw/litre output. I dont know the answers to these questions but am merely asking hoping to do some research and find them out.
Gizmo
Banned
When you have solid lifters, very high compression, high degrees of timing advance, oil cooler, ITBs, high rev limit and exceptionally tight tolerances then you have a race engine.
Motorplan is a South African marketing ploy to sell more cars, it works given the amount of BMWs on our roads. BMW see racing a car on a track as abuse because your average BMW driver will never go on a race track.
When you break your motorplan car racing beyond it's/your limit and claim from BMW for damages it costs them money, that is unfair on BMW so its no wonder they now adopt advanced telemetry to tell if the car has been raced or not. No car manufacturer with a motoplan/warranty in place will tolerate driver abuse so why should BMW be any different?
Im glad they stepped up their game and revoke motorplan claims from abusive drivers with no mechanical sympathy, good for them! It's about time they stood up for themselves and put a stop to guys from abusing the system.
Motorplan is a South African marketing ploy to sell more cars, it works given the amount of BMWs on our roads. BMW see racing a car on a track as abuse because your average BMW driver will never go on a race track.
When you break your motorplan car racing beyond it's/your limit and claim from BMW for damages it costs them money, that is unfair on BMW so its no wonder they now adopt advanced telemetry to tell if the car has been raced or not. No car manufacturer with a motoplan/warranty in place will tolerate driver abuse so why should BMW be any different?
Im glad they stepped up their game and revoke motorplan claims from abusive drivers with no mechanical sympathy, good for them! It's about time they stood up for themselves and put a stop to guys from abusing the system.
Ratslaaf
///Member
Oh boy, another bearing thread on the internets.
As I said before, there's many things contributing to the failures. Yes, BMW isn't innocent here, and yes the bearing / crank clearance is smaller than what other manufacturers use. And for a long time I also believed our fuel quality was the root cause. But it's not the only issue: the TWS oil used by BMW is kak, I can show pics of the severe caking this sludge made on the tappet cover of my S65. And yes, this motor is at the bleeding edge of destruction already, further compounding the issue.
What I don't believe in is the concept of changing to hardened bearings, as this is more likely to cause other damage. Some of the guys in the US have designed a bearing that improves oil flow through the bearing/crank gap, and I believe that this is likely to be the best route to solving this issue. As many experts have stated; the most likely cause of accelerated bearing wear is oil starvation and it makes sense when you look at how these fail.
I went for OEM bearings on my car. I'm not likely to ever do 100k km with it and I'm aware of the temperamental nature of these engines, so I use proper oil and pamper the motor till it's up to operating temps. I use an octane booster and I frequently change oil, with the addition of CeraTec as well. I believe that these small measures on my part, compounded, will drastically limit future risk on my engine. That, of course, is my opinion and is in line with current thinking internationally.
As I said before, there's many things contributing to the failures. Yes, BMW isn't innocent here, and yes the bearing / crank clearance is smaller than what other manufacturers use. And for a long time I also believed our fuel quality was the root cause. But it's not the only issue: the TWS oil used by BMW is kak, I can show pics of the severe caking this sludge made on the tappet cover of my S65. And yes, this motor is at the bleeding edge of destruction already, further compounding the issue.
What I don't believe in is the concept of changing to hardened bearings, as this is more likely to cause other damage. Some of the guys in the US have designed a bearing that improves oil flow through the bearing/crank gap, and I believe that this is likely to be the best route to solving this issue. As many experts have stated; the most likely cause of accelerated bearing wear is oil starvation and it makes sense when you look at how these fail.
I went for OEM bearings on my car. I'm not likely to ever do 100k km with it and I'm aware of the temperamental nature of these engines, so I use proper oil and pamper the motor till it's up to operating temps. I use an octane booster and I frequently change oil, with the addition of CeraTec as well. I believe that these small measures on my part, compounded, will drastically limit future risk on my engine. That, of course, is my opinion and is in line with current thinking internationally.
Gizmo said:
Gizmo .... I do not agree with this statement ... the N54 engine won awards ... without turbos on the N54 it is just an ordinary engine ... even with OEM turbo's this engine is limited to 8/9 PSI .... most people that runs a JB4 piggyback, increase boost to well around 20PSI (even higher in some instances). Going Single Big Turbo, even make these N54 engine to perform better.
So, when the N54 finally gives in, what would the options be? Get another N54 (2nd hand) at R35K or get a 2JZ engine at R18K with so many aftermarket performance options?
Turbo technology has become the future, we cant ignore that. Any little engine as small as 600cc in the smart cars are turbo technology ....
sash
///Member
Gizmo said:
How does one go racing beyond its limit? I was under the impression that the rev limiter is the safe cut off for the engine revs. I would understand issues with manual gearbox where a driver slams into 3rd instead of 4th.
Can you define what is racing within the 'limit'?
Ratslaaf
///Member
I think it might be what's called a 'de-rating curve'. Basically, the engine is designed to run at its limit for a short period of time, not all the time. I'd imagine this is what would make a pure racing engine different to a vanilla engine. Both can put out the same power, but only one can do so for extended periods.
When one considers that 90% of people will never push their engines to the limit all the time (or ever), a manufacturer will design a vanilla engine to take an occasional beating in order to save manufacturing costs, as opposed to having an engine that can sustain full power indefinitely but make it unaffordable and prohibitively expensive.
When one considers that 90% of people will never push their engines to the limit all the time (or ever), a manufacturer will design a vanilla engine to take an occasional beating in order to save manufacturing costs, as opposed to having an engine that can sustain full power indefinitely but make it unaffordable and prohibitively expensive.
sash
///Member
This is also a blanket statement claiming that all ///M drivers dont know about mechanical sympathy and how to drive. THe octane issue should be considered by BMW as they normally do when they detune engines for our climate and the oil services are determined by BMW, where in most cases they dont change what they claim to.Gizmo said:
You then state that he does not use a race car for racing and expect it to be perfect, then in another of your posts you state that drivers who do use it for racing go beyond its limit.
Now I am very curious to know what is considered to be the desired life of an ///M vehicle.
What was it designed to do?
How was it designed to be driven?
Who was envisaged to be the driver?
And lastly, as mentioned in my previous post, what is considered racing within the limit?
cOlDFuSiOn
New member
Ratslaaf said:
This is exactly it... And this is usually why things go wrong when people boost a stock turbo engine too much.. Most engines can handle a small tune here and there, but if you drive it hard each day (redline) you are in for a bad time.. Then the engine gets blamed, etc.. I always maintain if you want a strong car as a daily, buy a strong car and tweak it a bit.. Don't go boosting a 135/Focus ST/GTI/whatever to 2+ bar (3-400kw+) and drive it like a race car each day, nothing will last.
On an aside, we are running a CA18DET engine with a T3/T4 turbo on the project car.. Low boost, fun little car to drive, damn good engine for the era, not a daily, just a fun car to make noise with as it has a screamer pipe.. :rollsmile::roflol:
Again my 2c on owning a few boosted cars here and there so far.. Can't comment as I honestly have never owned a 6cyl NA BMW even!!
That got heated quickly! But actually some good info here too.
Bearing issues suck, glad mine have been recently done. Loads of factors seem to be to blame, crap oil and crap fuel seem to play the biggest part, but clearly not the only reason. The thing the sucks most about the bearings is how BMW seem to deny it.
Turbos vs NA? Turbo is better I would have to say with all the modern tricks etc. Which would I prefer? NA hands down. The down side to the NA engine to me is actually its upside. Having all the power much higher in the rev range makes you have to drive the car "harder" to get that power and there in is the fun part for ME. I really appreciate how engineers were squeezing every last inch of power out of these NA engines (maybe downside being bearings etc). I liked the simple ideas, wanna go faster, make it bigger and add more cylinders!!!!!!
I've noticed that it feels like I'm going faster with a higher revving engine. If the revs are higher it just gives more sense of speed. The turbo car is giving so much power low in the rev range it lacks excitement, but has much more speed. NA has the excitement for me and I can live with being a bit slower. Day to day, city, start stop driving, the turbo car does make more sense having so much torque on tap. But I would sacrifice that all for the excitement at 7-8000rpm in NA engine.
Bearing issues suck, glad mine have been recently done. Loads of factors seem to be to blame, crap oil and crap fuel seem to play the biggest part, but clearly not the only reason. The thing the sucks most about the bearings is how BMW seem to deny it.
Turbos vs NA? Turbo is better I would have to say with all the modern tricks etc. Which would I prefer? NA hands down. The down side to the NA engine to me is actually its upside. Having all the power much higher in the rev range makes you have to drive the car "harder" to get that power and there in is the fun part for ME. I really appreciate how engineers were squeezing every last inch of power out of these NA engines (maybe downside being bearings etc). I liked the simple ideas, wanna go faster, make it bigger and add more cylinders!!!!!!
I've noticed that it feels like I'm going faster with a higher revving engine. If the revs are higher it just gives more sense of speed. The turbo car is giving so much power low in the rev range it lacks excitement, but has much more speed. NA has the excitement for me and I can live with being a bit slower. Day to day, city, start stop driving, the turbo car does make more sense having so much torque on tap. But I would sacrifice that all for the excitement at 7-8000rpm in NA engine.
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