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I have a 2002 RSX (Integra) manual. It has 160BHP which generates 141 lb/ft of torque @ 4000 rpm. The Type-S version has 200BHP which generates 142 lb/ft of torque @ 6000 rpm! Please help me understand this. That means to get the extra 40HP in the S you have to rev each gear to 6000 and higher? I would much rather get all my torque down lower at the 4000 point. For driving around in every day life, around the neighborhood and cities streets it would be awful to have to rev all the way to 6000 in every gear, my neighbors would have called the cops on me a long time ago! Plus it just seems that in the 55MPH or less speeds the car with the lower torque would be a lot more zippy and fun. Am I missing something? It seems like the very high redlines that Honda has been making is at the sacrifice of low RPM torque. So unless you get to drive on a race track to work everyday these engines are rather boring in the real world. The S2000 is even worse redlining at 9000, you have to go up all the way to 6800rpm just to start to get your power! They have lowered the reline in the 2004 S2k to the 8000 point. Maybe Honda is starting to realize this problem?
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You don't say at what rpm the max power is generated for each engine - usually it is a little lower than the red line. Max torque is usually generated at considerably lower rpm. You need to look at a graph of the power and torque curves of each engine to get the full picture. The flatter the curves the more useable the power/torque.
If it quotes 200 bhp at 6000rpm then to get the full extra 40bhp you would need to reach those revs. But you may get, say, an extra 30 bhp at 4000rpm.
The great advantage of modern turbo diesels and the traditional American V8 lump is they produce masses of torque at low revs and are thus easier to drive. Often 90% of max torque is available at 2000rpm.
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For driving around in every day life, around the neighborhood and cities streets it would be awful to have to rev all the way to 6000 in every gear
For every day driving you don't need 200bhp. 20 would probably be enough, so you don't have to scream it.
My main vehicle generates max bhp at 11500rpm but toddling along a quarter of that is enough.
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I looked up the power curve charts and it is very interesting. My base RSX has the same power; actually it?s a little faster all the way to 6000rpm. It?s only 6000 and above that the Type-S has anymore power at all! So Honda and other 4s are offering more power but it is almost totally unusable in the real world. The only time you could ever really use that extra power would be at speeds of 80mph and up! I mean how much time do you spend above 6000 in 1st through 3rd? Maybe .5 seconds at the most? This hardly lives up to the hype. I don?t think they tell people that the 40 HP difference in the S can only be felt above 6000, if they did, would anyone really care?
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I doubt it's any consolation but my diesel van-with-windows produces significantly more torque at 1700 revs than your car does at 6000. Plus it carries five adults in comfort and gives me about 48 miles per gallon.
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Haha that?s cool. So can you explain the advantages to diesel? I asked this once before in a different thread but didn't really understand the answer. How would my car and a similar engine be better if it were diesel?
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Well as you may know in the UK we pay a lot more for fuel than you do in the USA and the better economy used to be the main advantage for diesels. In most cars a diesel engine should use 25% less fuel than the equivalent petrol. Diesels also lack the high voltage electrics needed to make sparks so they are arguably less prone to irresolvable damp starting problems as they get older. The downside was that in performance terms diesels were quite slow and rather noisy. I've liked driving them for quite a while because apart from the economy they do everything at lower revs and are generally more amenable in everyday use.
Modern diesels however are a completely different beast. They retain the reliability and low revving characteristics but are much more powerful and more economical too. They are still 25% better on fuel than equivalent petrols and often have equal or better performance. All the major European manufacturers produce excellent diesels these days but BMW in particular have done very well with performance diesels: the BMW diesels are within a whisker of the performance of their petrol equivalents--so near it makes no difference on the road--but you get to use all that power at 3500 revs rather than 6000. At 70mph most modern diesels run at 2500 revs or less, which I suspect actually makes them quieter on a long trip. I don't think your car, which I think is essentially a sports car, would benefit from a diesel in that it's meant for the track so high revs, fuel economy and relaxed driving style are not an issue. But the diesel powered Volkswagen Golf TDI 150 would certainly give it a run for its money.
In Europe there are also tax breaks for using diesels because they are perceived as less polluting overall.
I hope that helps.
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What speed limits are in force in your area ? In the UK the highest limit is 70 mph. Most of the cars here are normalised to 3000 rpm at 70 mph. If you are safety minded and keep within the law the use of higher revs. would be limited to going up through the gears to overtake or engine braking downhill. I sometimes go up to 5000 rpm downhill in 2nd gear.
One of the factors in the development of power in an engine is the MEP (mean effective pressure) in the cylinder. This is related to the compression ratio. In petrol engines it is perhaps 9:1, and in diesel double that. The other factor is the revolutions. Petrol engines rev at up to 6000, and diesels 4000. Thus the diesel, although turning more slowly can generate the same power, but with much more torque. This makes for a relaxed ride.
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BRSXM, if you want to find out more about diesel cars you'll probably find Fred's TDi forum well worth a look - the majority of contributors there seem to be from the US, so there will be less potential confusion for you as to the range of diesel engines available in the US, different names for the same car, etc.
forums.tdiclub.com/cgi-bin/ultimatebb.cgi
I used to drive petrol cars, but would never go back - I love the way a diesel engine works, all the benefits you describe for everyday driving in terms of getting power out of the engine without having to have it scream at you. Much better for overtaking as well.
If you decide you want a diesel, you may want to consider something else, particularly when (as I understand it) diesel fuel in the US is generally of a lower grade than here in Europe. An alternative that's not as bizarre as you might first think is biodiesel. Hundreds of people make their own, and many sell it commercially as well. You might find the information on this forum interesting:
biodiesel.infopop.cc
and on this site:
journeytoforever.org/biodiesel_mike.html
I started a thread in the Technical section of this forum called "First fill of biodiesel" which might have some useful stuff too. I've done around 58k miles on the stuff by now.
andymc
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I read recently that some people in Wales have used cooking oil to bulk out their diesel fuel. Anybody heard anything recently about that ?
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That was around a year ago or so, AFAIR. They were prosecuted for not having paid the fuel duty on the vegetable oil they put in their cars - sounds ludicrous, but in this country, more or less whatever you use as a fuel in your car is subject to duty. If those people had declared to C&E that they were doing this and had paid the duty, they wouldn't have been prosecuted.
In any case, there's a difference between biodiesel and vegetable oil - biodiesel is the end product of a chemical process which alters vegetable oil to make it more suitable for use as fuel. Vegoil can be burned in a diesel engine so long as it's warm enough, but in cool temperatures (like what we have now anywhere in northern Europe) it's usually too viscous to use unaltered in an unadapted diesel engine. Biodiesel doesn't necessitate any engine alterations and can be used at least down to -10 degrees C. I know this because I've done it! However, this can also depend on the type of vegoil used as a source feedstock for the biodiesel - some (like palm oil) are solid at ordinary room temperatures, so the biodiesel derived from them wouldn't be as good for cooler climes like ours. Where Growler lives, palm-derived biodiesel wouldn't be a problem!
Anyway, I didn't intend to hijack this thread, so perhaps any further comment/query about all this can be posted to the biodiesel thread - www.honestjohn.co.uk/forum/post/index.htm?t=9764&v...f
andymc
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LOL Well I did start this thread and I don?t mind it being ?hijacked? at all! I find all this info about diesels to be very interesting!
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