Figured this could be an interesting thought exercise after seeing the resurrection of the 200k+ mile thread, and reading some impressive stories within.
My 1997 BMW M3 racecar has 157k miles, and was turned into a time trial car, then racecar when I bought it five years ago at 144k. Take a few thousand miles off of that accumulation given I drove it to the events for the first year or so, and the rest of the miles (let's call it 11k) are at or near full throttle on road courses.
How much extra wear is that generating? I have most of the records for the thing. Original engine, trans, clutch, axles, brake calipers still on the car. One rear wheel bearing may be original. Been in some wrecks so the only body panels original to the car are the passenger side doors and the roof, and I guess the rear quarter panels.
Anyway, thoughts?
Maybe make it a factor of 10? So 10 track miles are about 100 road miles?
Not sure. My experience with rally has been roughly 100x for suspension- 10 stage miles at speed equals 1000 road miles. Track use has to be a lot nicer than that, but might actually be harder on the engine.
¯\_(ツ)_/¯ said:
Maybe make it a factor of 10? So 10 track miles are about 100 road miles?
Not sure. My experience with rally has been roughly 100x for suspension- 10 stage miles at speed equals 1000 road miles. Track use has to be a lot nicer than that, but might actually be harder on the engine.
That is definitely a good start. We are probably (far) nicer on suspension than you guys are, but still end up popping over kerbing and such which I can't think is too good on shocks and bushings. Granted, most of those are all upgraded by now anyway.
Seems to me that it varies on type of engine? My ZX-2 has ONLY ever been driven on track (5k miles worth of it), the oil comes clean and internals (that I've seen) look fantastic. It might pass as a 50k engine? Looks and runs newer for me however - **most track cars see maintenance never neglected, so they have that going for them?
Suspension and friends are a different story me thinks.
I was also thinking a factor of 10.
For a rotary engine, maybe a factor of -5 (or should I say 0.2)? 
I think it's nearly impossible to quantify. Type of racing? Driving style? Track layout? So many variables. Small autox course vs. huge road course are two different things.
I haven’t found engine wear to be a major issue on track. Since track guys are careful about warming engines up before beating on them, paying attention to oil level/quality/pressure, etc. etc. I suspect wear and tear may actually be better than you’d get on the street.
In my experience, transmissions, diffs, wheel bearings, and bushings take the real abuse on track.
I'm assuming track days/practice/time trial on a track with a smooth surface (so little to no curb-popping, sliding, or locking up, and no worrying about damage from other cars). Course size doesn't matter as much as the prevalence of heavy braking zones and extended acceleration zones, although there is some correlation between the two. Theoretically you could copy-and-paste Ebisu's touge course to be bigger than Road America.
Autocross is very easy on brakes and not too hard on engines or tires, but is actually harder on suspension and especially steering than driving around a track, it's mostly the serving size (and the accompanying lack of heat accumulation) that makes it a low-wear form of racing.
LanEvo said:
I haven’t found engine wear to be a major issue on track. Since track guys are careful about warming engines up before beating on them, paying attention to oil level/quality/pressure, etc. etc. I suspect wear and tear may actually be better than you’d get on the street.
In my experience, transmissions, diffs, wheel bearings, and bushings take the real abuse on track.
Agreed, I see more suspension issues than anything.
LanEvo said:
I haven’t found engine wear to be a major issue on track. Since track guys are careful about warming engines up before beating on them, paying attention to oil level/quality/pressure, etc. etc. I suspect wear and tear may actually be better than you’d get on the street.
In my experience, transmissions, diffs, wheel bearings, and bushings take the real abuse on track.
Engine wear's not a major issue but track use definitely accelerates wear, especially on the rings of piston engines. Engines that commonly see track use usually start smoking in half the time that one that sees just healthy street driving would - but that's not something the Average Joe practices.
A set of Hawk Blues lasted about 500 miles on my Neon IT car. Normally, I would expect about 50,000, so thats a factor of 100. A set of tires was good for about one weekend, 175 miles, and I would expect 20,000 gentle street miles out of a 200tw ties, so...
Engines on a left turn biased track were good for several thousand miles, but I discovered that a right turn biased track drops the crankshaft life to an hour or so.
I have an accusump now.
I did break a crankshaft in half once, but I might blame that on a very aggressive clutch and some harsh shifts about 20 times a lap.
This is a regional championship winner, run as hard as it will go, at the pointy end of the pack. I also ran in the same class as a guy who got a full season out of one set of tires, so somewhere between those two should be average.
Regarding the engine, over ten years ago, we put data acquisition on an MGB race car for a 20 minute race and then on an aggressively driven MGB street car for 20 minutes. With some extrapolations, we figured that the race car had as much time above 5000RPM that 20 minute race as the street car would have in 20,000 miles. We also found that the street car was idling or coasting almost 30% of the time and the race car was idling/coasting less than 1% of the time. So it's all apples to oranges, but it points to at least an order of magnitude of difference. On the other hand, engine are so robust in modern cars that they don't seem to mind being revved for long periods of time or other abuse...I agree that other parts of the car are where the issues may come in.
You seek an overly simplified answer to a highly complex problem.
Remember the grm camry project that kept toasting engines on track, grossly different to perhaps an nsx.
Depends on far too many details.
The answer is 42.
Totally depends on the type of car and driver. Some guys do HPDEs and keep it at 8/10 and some go full retard, banging rev limiters and jumping every curb like it's Turn 3 at Road Atlanta. (We know who we are.)
The platform has a lot to do with it...your M3 is a car that I would consider a very good platform for eating up track miles. A Porsche 996 is not.
Based on anecdotal experience (and, if the internet has taught me anything, it's that the plural of 'anecdote' is 'data'), the appropriate factor is approximately 4*pi.
aw614
Reader
12/11/18 8:18 a.m.
When I had an oil analysis done on my integra that was driven 2-3 times a week to work, plus autocrossed 2-3 times per month, averaging 6-10 runs for most events, blackstone mentioned that for the 1,500 miles I had driven, the engine saw wear of examples of daily driven cars that went 4,500 to 5,000 miles per oil change. Since then I've just done 1,000 to 1,500 mile oil changes on the car, even post motor swap. At the time I was using high mileage syn blend oil, vs synthetic, so I am curious to see if that type of wear would change.
aw614
Reader
12/11/18 8:21 a.m.
GameboyRMH said:
LanEvo said:
I haven’t found engine wear to be a major issue on track. Since track guys are careful about warming engines up before beating on them, paying attention to oil level/quality/pressure, etc. etc. I suspect wear and tear may actually be better than you’d get on the street.
In my experience, transmissions, diffs, wheel bearings, and bushings take the real abuse on track.
Engine wear's not a major issue but track use definitely accelerates wear, especially on the rings of piston engines. Engines that commonly see track use usually start smoking in half the time that one that sees just healthy street driving would - but that's not something the Average Joe practices.
Sounds like why it seems every honda at the track as a puff of smoke from the tail pipe and is considered "normal"
Tyler H said:
Totally depends on the type of car and driver. Some guys do HPDEs and keep it at 8/10 and some go full retard, banging rev limiters and jumping every curb like it's Turn 3 at Road Atlanta. (We know who we are.)
The platform has a lot to do with it...your M3 is a car that I would consider a very good platform for eating up track miles. A Porsche 996 is not.
Every time you miss a curb God kills a kitten. 
Although even my local track, Hallett, you don't want to touch the curb in 10.
3 words to answer that question (on the engine/trans/diff): Used Oil Analysis. Seriously. I see a lot of track cars get sampled. They are all different. I can safely say there is no 1 answer for this question.
For engine usage its a super tough call. Most cars never have an internal engine failure from wear - they usually meet their demise from an accident, neglect, or other component so there really isnt a good datapoint to compare a track engine to.
Carl Heideman said:
Regarding the engine, over ten years ago, we put data acquisition on an MGB race car for a 20 minute race and then on an aggressively driven MGB street car for 20 minutes. With some extrapolations, we figured that the race car had as much time above 5000RPM that 20 minute race as the street car would have in 20,000 miles. We also found that the street car was idling or coasting almost 30% of the time and the race car was idling/coasting less than 1% of the time. So it's all apples to oranges, but it points to at least an order of magnitude of difference. On the other hand, engine are so robust in modern cars that they don't seem to mind being revved for long periods of time or other abuse...I agree that other parts of the car are where the issues may come in.
This is the kind of answer/data I was hoping to get! I know it's entirely anecdotal and dependent on the driver, car, and track conditions but it's still fascinating to see the diferences.
