wonder if anyone know whats the expected life expectancy on a supercharged nsx? Given that all the upgrades are done correctly ie headers, exhaust, does wear and tear in the engine cams etc double? Like does a supercharge nsx engine w/ 50k miles mean theres like 100k of wear on it?
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supercharged engine life
- Thread starter nsxtacey
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No - I haven't heard anything that directly corrolated FI with engine wear. Sure - it has an impact - but so does flogging a NA car around before it is warmed up, etc.
If you show me a 50,000 mile supercharged car I will show you a 100,000 mile smile on the owner's face!
If you show me a 50,000 mile supercharged car I will show you a 100,000 mile smile on the owner's face!
well put.
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ALL NSX
92 RED/BLACK 5-SPEED
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ALL NSX
92 RED/BLACK 5-SPEED
You just can't calulate that. There is no answer. However, according to Corkey Bell (author of Maximum Boost) a stock OEM engine running 6psi of boost should last at least 90% of its standard life. I know people who have boosted 100k miles on a Honda.
Adding to the above...
Most of the things that wear out during normal use do so as a result of the number of engine revolutions. The wear rate of reciprocating parts such as pistons/rings and valves as well as their related fixed parts (cylinders and valve guides & seals) is largely dependant on the number engine revolutions if the car is properly tuned in terms of A/F ratio and properly maintained. I say “largely” because more HP means burning more fuel, and even though you might not see it in the water temp I suspect that anything in the combustion chamber is subjected to some additional heat, which likely increases wear rate to at least some degree. But then there is the reality that you are unlikely to match the precision of the stock fuel system. Running a bit too lean means more heat, and a bit to rich means more undesirable byproducts of combustion that add to wear of those parts.
I don't see the camshafts, rockers, springs as being an issue at all. Engine bearings are the other primary wear items and although they too are mostly dependent on the number of revolutions, the added load of creating more power per stroke must increase wear. Perhaps more so the rod bearings than the mains, but I wouldn't know how to estimate the degree on either one. Another possible factor in bearing life is the harmonic balancer. It is common practice on some cars to replace it with a simple pulley when adding an SC. This is a much debated issue on various cars over the years in part because there is no single answer to cover them all. The importance of a harmonic balancer depends on many factors, but I think it’s safe to say that the factory spent money on R&D before going to the expense of adding one, so at a minimum I should be assumed that removing it will have at least some impact on bearing life.
The other, and possibly most important consideration, is that unless you have a dedicated track car it is unlikely that your engine will be significantly on boost more than a small percent of total run time. So in the end I personally don't think that it is a major issue if it is a properly designed, tuned and maintained system. But that's a pretty big if.
Most of the things that wear out during normal use do so as a result of the number of engine revolutions. The wear rate of reciprocating parts such as pistons/rings and valves as well as their related fixed parts (cylinders and valve guides & seals) is largely dependant on the number engine revolutions if the car is properly tuned in terms of A/F ratio and properly maintained. I say “largely” because more HP means burning more fuel, and even though you might not see it in the water temp I suspect that anything in the combustion chamber is subjected to some additional heat, which likely increases wear rate to at least some degree. But then there is the reality that you are unlikely to match the precision of the stock fuel system. Running a bit too lean means more heat, and a bit to rich means more undesirable byproducts of combustion that add to wear of those parts.
I don't see the camshafts, rockers, springs as being an issue at all. Engine bearings are the other primary wear items and although they too are mostly dependent on the number of revolutions, the added load of creating more power per stroke must increase wear. Perhaps more so the rod bearings than the mains, but I wouldn't know how to estimate the degree on either one. Another possible factor in bearing life is the harmonic balancer. It is common practice on some cars to replace it with a simple pulley when adding an SC. This is a much debated issue on various cars over the years in part because there is no single answer to cover them all. The importance of a harmonic balancer depends on many factors, but I think it’s safe to say that the factory spent money on R&D before going to the expense of adding one, so at a minimum I should be assumed that removing it will have at least some impact on bearing life.
The other, and possibly most important consideration, is that unless you have a dedicated track car it is unlikely that your engine will be significantly on boost more than a small percent of total run time. So in the end I personally don't think that it is a major issue if it is a properly designed, tuned and maintained system. But that's a pretty big if.
From what I understand of harmonic balancers unless your engine has been balanced and blueprinted you should use it.
Crankshafts vibrate with a twisting motion due the torque variation that results as each cylinder fires. This vibration is at its worst at some critical RPM. A harmonic balancer modifies the vibration characteristics of the crankshaft and flywheel assembly. They are made from of a heavy steel ring mounted over a thin layer of rubber on the outside of a center hub. The rubber acts as a spring. The ring twists on the rubber to cancel out crankshaft torsional vibration. Some energy is removed as heat in the rubber but the balancer's primary function is to store energy and return it to the crankshaft at just the right time to suppress vibration. This is a generic explanation of a harmonic balancer.
Crankshafts vibrate with a twisting motion due the torque variation that results as each cylinder fires. This vibration is at its worst at some critical RPM. A harmonic balancer modifies the vibration characteristics of the crankshaft and flywheel assembly. They are made from of a heavy steel ring mounted over a thin layer of rubber on the outside of a center hub. The rubber acts as a spring. The ring twists on the rubber to cancel out crankshaft torsional vibration. Some energy is removed as heat in the rubber but the balancer's primary function is to store energy and return it to the crankshaft at just the right time to suppress vibration. This is a generic explanation of a harmonic balancer.
That about covers it, except that even an extremely well balanced engine has such resonances. I've long since forgotten the details, but as best I can remember the 90 degree V6 design is inherently better balanced than most and of course the super short crankshaft length is a plus.
I should noted above that many people also replace them as part of a set of under drive pulley set to save HP, also probably not worth the risks, but very trendy. I am unaware of any recent scientific studies on the topic but I'd like to find one.
Well put nsxxtreme. We highly discourage the replacement of the harmonic balancer with a non elastomer part. With the elastomer part removed the harmonics will not be absorbed. Those harmonics could then be a detriment to the engine (ie. oil pump). If the vehicle is being used as a track only car where it is inspected on a reg. basis there should not be a problem. However, we do not reccomend it for the daily driver.
Speed Safely,
Factor X Engineering www.factorxengineering.com
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I wouldn't assume you couldn't just because nobody has racked up that kind of millage. The CompTech unit wasn't really availible until 98' and my recolection of the Bell units was not much before that. That means you would have to find someone who has put 100k in 5-6 years on an NSX. How many people period have put 100k miles on an NSX in 5-6 years? There are a lot of more realistic ways to measure engine life and people have torn down boosted engines (CompTech and Mark B comes to mind) and have had metalurgic tests done on the block to see if their applications were safe before risking problems with customers and lawyers.
You probably won't find anyone here with a 100k+ boosted NSX, but there are simple answers for that. I don't think I have to go over those reasons, but If you are suggesting that an NSX or any other car can't go over 100k turbo/supercarged miles you must not have a good grasp on the topic. There have been hundreds and thousands of OEM turbo cars...do you think there is a 100k mile limit on those cars? There are obviously different designs between an NA and turbo OEM application, but if you design your forced induction system properly, you will have NO problem going over 100k on a stock nsx motor. If you want to talk details let me know, but sounds to me that you've already made up your mind. We'll just have to wait for someone to drive their car enough to see it. I'll be happy to be the first to show you when I get an NSX.
[This message has been edited by true (edited 08 December 2002).]
EDIT: I'll type the exact quote written by a turbo expert Corkey Bell, the author of Maximum Boost.
Under his FAQ.
Will the turbocharger affect engine wear and maintenance?
"Certainly the turbo will affect engine wear. Do you really expect to add power and not increase wear? No miracles here either. If you drive vigorously but with some respect for the equiptment, you can expect about 90% of normal engine life."
If he is not an expert, who is? You? Maybe you can give us some reasoning as to why it's NOT possible? Thanks.
Note: I finally ran into a posting problem that seems to have been reported before. Trying to append the above as edit and the submit would just hang forever. Last night I upgraded to the latest IE6 service pack. Hrm.
[This message has been edited by true (edited 08 December 2002).]
Under his FAQ.
Will the turbocharger affect engine wear and maintenance?
"Certainly the turbo will affect engine wear. Do you really expect to add power and not increase wear? No miracles here either. If you drive vigorously but with some respect for the equiptment, you can expect about 90% of normal engine life."
If he is not an expert, who is? You? Maybe you can give us some reasoning as to why it's NOT possible? Thanks.
Note: I finally ran into a posting problem that seems to have been reported before. Trying to append the above as edit and the submit would just hang forever. Last night I upgraded to the latest IE6 service pack. Hrm.
[This message has been edited by true (edited 08 December 2002).]
Larry Garcia tells me he has 90,000 miles on a Comptech SC 9 PSI car (in response to my question about whether one of these can be used as a reliable daily driver). Of couse, you may believe it or not.
The reason for my orginal inquiry is that I am in the market for an nsx. There are a few sc nsx for sale and I just wanted to know about mileage on the car in relation to engine wear on a sc nsx. A stock nsx is very nice still but a tricked out one demands respect from the rest of newer more powerful sports cars. (I refuse to lose to my friends new m3). However, im still weary about buying a used modified car. The engine warrenty is no longer good on modified engines so I'm approaching my purchase carefully. Anyone know why that yellow sc nsx in south florida by exotics4less has been up for sale for over a year now?
Thanks for everyone's input.
Thanks for everyone's input.
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At my current rate I should hit 100,000 miles around the year 2025. I'll be sure to give you an update then....
Seriously, the reason people don't have that many miles on their forced induction cars is, as others have pointed out, is a combination of the fact that there weren't very many forced induction NSXs until the late '90s and the fact that most of us don't put many miles on our NSXs.
There is obviously a real misunderstanding of how the systems even work if someone thinks you can't put a lot of miles on a forced induction car.
Most importantly, the majority of boosted cars spend a very small proportion of their time under any serious boost. I just put over 2,600 miles on my NSX going to NSXPO, but outside of the track event it was probably only boosting for the equivilent of 10 miles worth of driving. The vast majority of those 2600 miles were just cruising on the Interstate. And I was only boosting maybe 10 miles off the track because I gave some test rides/drives in my car for people interested in feeling an NSX with the CTSC... Even if I accelerate hard, the car is only boosting for maybe 5 seconds until I am at or well above the speed limit.
So even if being under boost doubled the wear and tear on the engine, which it certainly does not in a properly designed kit, that would still only be like adding another 10 miles to my 2,600 mile trip.
Is it starting to be clear just how little additional wear is produced by a properly designed forced induction kit in normal street driving?
Revving your engine high wears it faster as well. People who cruise around in a low gear because they like to keep the revs up are wearing their engines faster than someone with a forced induction car who generally keeps the revs down under typical street driving.
At the track you can use it a lot more, but any track car goes through a lot more wear and tear all around.
Seriously, the reason people don't have that many miles on their forced induction cars is, as others have pointed out, is a combination of the fact that there weren't very many forced induction NSXs until the late '90s and the fact that most of us don't put many miles on our NSXs.
There is obviously a real misunderstanding of how the systems even work if someone thinks you can't put a lot of miles on a forced induction car.
Most importantly, the majority of boosted cars spend a very small proportion of their time under any serious boost. I just put over 2,600 miles on my NSX going to NSXPO, but outside of the track event it was probably only boosting for the equivilent of 10 miles worth of driving. The vast majority of those 2600 miles were just cruising on the Interstate. And I was only boosting maybe 10 miles off the track because I gave some test rides/drives in my car for people interested in feeling an NSX with the CTSC... Even if I accelerate hard, the car is only boosting for maybe 5 seconds until I am at or well above the speed limit.
So even if being under boost doubled the wear and tear on the engine, which it certainly does not in a properly designed kit, that would still only be like adding another 10 miles to my 2,600 mile trip.
Is it starting to be clear just how little additional wear is produced by a properly designed forced induction kit in normal street driving?
Revving your engine high wears it faster as well. People who cruise around in a low gear because they like to keep the revs up are wearing their engines faster than someone with a forced induction car who generally keeps the revs down under typical street driving.
At the track you can use it a lot more, but any track car goes through a lot more wear and tear all around.
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