Blown and Injected: A stock Forester XT weighs 45 lbs more than a WRX, and has a softer suspension (more energy eaten up by body lean), and a slightly worse coefficient of drag. A stock Forester XT can do the 1/4 in 13.8 seconds at just over 100 mph. 0-60 in 5.3. Both numbers are better than what a WRX can manage, which doesn’t make sense if a Forester really has only 210HP and 235 ft-lbs of torque.
I know where you got the Subaru data - a Car and Driver test. And I have a lot of respect for their testing. However, in this case, I think Subaru may have slipped them a “cheater” model. The official acceleration for the XT (from Subaru) is 0 - 100 km/hr in about 6.4 to 6.8 seconds, depending on country and transmission. All the other tests I have seen found times around 7 seconds or more. In fact, CARkeys in UK clocked it at 7.9 seconds. The standard Forester has 170 hp and takes about 10 seconds 0 to 60 so the 7 second number seems optimistic if anything. Going from 10 seconds to 5.3 would generally take a lot more than adding a turbo.
Exactly - all we have are anecdotes that it “must have been true”, and yet, no citations.
By the same token - under the TOS of my car insurance policy, I believe I’m required to tell them if the “physical condition of the car changes”, because this directly affects the coverage level in case of body damage. But nowhere does it say that I am supposed to tell them if I increase the power of the car, or even replace the engine entirely.
To accept that “sleeper” cars were made to get around car insurance rates means the following assumptions must be true:
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That car insurance companies break down accident, theft, and coverage rates with engine horsepower as a primary independent variable.
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That there were actual actuarial tables cross-referencing rates to horsepower. Note we’re talking early 1970’s here, so they must have had it in hardcopy. No PC sitting humming away in most offices.
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That policies were written to say that “coverage and rates are impacted by horsepower”.
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That somehow the insurance companies would be “fooled” by a well-known “insider fact”, and would not just raise the rates as soon as word got out. They have the right to raise their rates on any basis that results in a higher possibility of claims or higher claim amounts, after all.
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And finally, it has to be shown that this “power” adjustment was independent of the car being a “special edition” or collectable.
Thus far, I’ve seen no evidence other than half-remembered anecdotes that any of these 5 things would qualify. Now note, I’m not saying that early on “sleeper cars” weren’t made - the note from Philster earlier is a good example. Just that I see no evidence that it was driven by insurance rates.
Enola, I’m afraid I don’t agree at all with the claim of cars being purposefully made heavier by lead sheets being added to get around insurance rates. I can find no actual reliable cite or reference in any book or manual I have to that, in none of my automotive engineering books, nor anywhere on the web. Does anyone else here think its plausible that lead sheets were added to cars to increase their weight for insurance purposes? 
I’m thinking that those “lead sheets” were actually sound deadening material. Heaven knows AMC products could use it (speaking as a proud Rambler owner).
A little nit to pick that could be causing confusion. HP today is rated as net, in the past it was gross.
Think of how much money you make. Gross is what you say you make, net is what you take home after the government gets their share. Same with engines - gross is what the engine can produce all by itself, net is what you get when you actually put it in a car and have water pump, alternator, intake, exhaust, etc dragging it down.
There is no direct correlation between gross and net, but a quick rule-of-thumb is to knock about 15% to 20% off the gross to get net, or add 20% to 25% to the net to get gross. So 282 SAE net HP would probably be in the range of 335 to 350 gross HP.
So the 5.7 liter 400 hp mill in the Z06 Vette today made comparable actual rear-wheel power as a 60s era 426 Hemi?
(note: I hay horsepower, not torque)
If you assume the 426 hemi put out 500 gross HP, then yes, that’s in the same ballpark as 400 SAE net.
One little nit, though… SAE net does not include drivetrain losses (otherwise you’d get different HP for manual vs. automatic, or different tires, or …), so on both of these cars you’d see somewhat less HP at the rear wheel. Probably in the ballpark of 320HP (i.e. 20% drivetrain losses).
As for torque vs. hp, you can always create more torque than the engine will put out (that’s what gearing is for), but you can’t create more hp. If you want power, you want to look at HP. See this article http://www.boston-bmwcca.org/bimmer/1999/03/horsepower-and-torque.asp for details.
Whoops!!!
Brain fart
Good catch
I recal reading C&D making a comment about their test Subaru (I thought it was a WRX - but then I thought the WRX was the fast one) being lighter than any other one they have tested
And I will use the ATI Power-Speed Calculator, which seems to work very good with almost every weight/power/car times I have been able to make at the track. To go 100 mph in the 1/4 with 210 HP, the calculator says 2,750 lbs - so based on weight and MPH (the best figures for measuring power) something does seem to be off. However, the MPH and ET do not seem to jive especially for a Subaru. The Suberu’s, because of the AWD, do not have the launch problems that can through off elapsed times (ET), and the 100 MPH should be good for a low 13 second run.
And yet another good catch about SAE net power.
I will, however, have to further the debate on the torque vs. HP.
When HP is stated above 5252 RPM’s, the engine power* is being overstated as a result of the equation used. When the torque range is mover to a higher level the area under the curve is increased. Gears will only help so much. Typically once a car is in 3rd gear (for an automatic) and 4th gear (for a manual) the gears are 1:1 plus the final drive ratio.
the car I lusted after was a 1967 Camaro…and a few years ago, I was actually able to drive my “dream” car. What a disappointment -the car rode like a buckboard! Oodles of power (I could burn rubber in 3rd gear), but the handling was terrible-no road feel at all, and the rear end would break loose on the gentlest of curves.
Shows you how automobiles have improved in the last 37 years…my 2001 Saturn is a far superior vehicle, in every way (save that V-8 rumble!)
What was the condition of the car: shocks, springs, bushings (body and suspension) and tires! There is a huge difference between original, very old, equipment and modern shocks and tires.
There is all manner of aftermarket goodies to make the old Corvette drive like a dream.
My AMX with a 401 probably has around 400 HP if dynod out of the car. My 1/4 mile ETs and trap speeds show that the car is working with about (rearwheel) 260 HP.
The original 401 was rated at about 330 HP. 1/4 mile times would show the original car to have about (rearwheel) 190 HP. The tested ET`s back then were much slower than my current times.
There is nothing magic about 5252, it is just the constant that is used to keep HP at a reasonable number. Would you prefer 10,000 pennies or $100? It’s the same, right? If I defined MongoHP as torque * RPM / 1000, would that make 1000 RPM somehow special?
The point is, to go fast, you want to keep the engine as close as possible to the point where it produces maximum horsepower. Take 3 cars as examples:
- torque peak 2000 rpm, horsepower peak 3500 rpm
- torque peak 4500 rpm, horsepower peak 5500 rpm
- torque peak 6000 rpm, horsepower peak 6500 rpm
The first one is like an old big block. A two/three speed transmission will work just fine with it, because it produces decent power anywhere from probably 1500rpm to 4000rpm. You have a lot of range there, starting at 1500rpm you’ve got 166% rpm gain until you’ve gotta shift.
The second one is like your typical modern V6/V8. Probably produces decent power from 3500rpm to 6000rpm. Starting at 3500rpm, you’ve got 75% to go until you’ve got to shift. You need a 4 or 5 speed transmission to get the same range of speeds as car 1 and stay in the power band, and you’ll need to shift twice as often.
The third one is a typical fast revving 4-valve engine. You’ve got decent power between 5000 rpm and 7000 rpm. Starting at 5000 rpm, you’ve got 40% rpm gain until you need to shift again. You’ll need a 6 speed (ok, really an 8 speed) transmission to get the same range as car 1, and be able to stay in the power band. You’ll also have to shift 3 to 4 times as much.
Rear end gear doesn’t enter into it, other than you have to match the rear end to the torque you expect to come out of the back end of the transmission, for whatever performance you want (acceleration, top speed, or some combination).
There is a practical limit. 50 speed tansmissions aren’t practical, and even if they were, you’d be shifting way too much. The power to the ground during a shift is trivial to calculate: 0. 10:1 rear ends aren’t trivial, either.
Pushkin,
The way I heard it, BMW & Mercedes set 155 as a kind of “truce” so that they wouldn’t have a top-speed war between their high-performance sedans. After all, no matter how good your handling is, your car will take a loooooooooooong time to stop from 155, and even loooooooooooooooooonger from higher speeds.