Archive

Archive for the ‘Jeff’ Category

What cost excellence?

August 2, 2011 7 comments

So often with a project car we find ourselves asking if the next expenditure is really worth it.  At what point do you cork the flow, put a bandage on the bleeding, or otherwise stem the tide of rising project costs?  They say the happiest two days of a boat owner’s life are the day he buys it and the day he sells it.  B.O.A.T. doesn’t stand for “bring out another thousand” just because its etymology comes from Proto-Indo-European “bheid”, which means “to break or split”.  No coincidence whatsoever.  So on to the project cars (which never break).

 
 

God, why do I keep pouring money in this thing?  (Yes, that’s me in the picture.)

Sound off in the comments; how much are you spending keeping your favorite transportation running?  If you had it to do over again, would you?  If you would, would you do it differently?  For me, the answer is ~$18,000, yes, and yes, respectively.  I bought my 2001 Audi S4 in May 2006 (Mother’s Day, actually), when it was bone-stock and had 50,000 miles on it.  It still had a certified pre-owned warranty good to 60,000 miles that the previous owner paid to transfer to my name, which restricted my modification for about nine months.  The warranty expired in January 2007, and on went the mods.  At first it was little stuff, mainly maintenance upgrades.  The big purchases have been ECU reprogramming, wheels and tires, turbo-back exhaust, and coil-over suspension.  Maintenance has been a biggie, with two timing belts, a dose of exhaust gas temperature sensors, primary oxygen sensors, and the auto-dimming rearview mirror (hundreds of dollars; I kid you not).  At first my attitude was to keep it perfect; let no quasi-failing part be allowed to live.  I preemptively replaced several engine sensors and components to keep the car at 104%.  The next step, as you have seen in previous posts, is to upsize the turbos.  This is where the nova question comes in.  “No va”, Spanish for “it doesn’t go”: do I continue to spend big dollars on this vehicle, now ten years old and with 125,000 miles (and counting, quickly), or do I start to save for my next automotive victim?  In short, is it worth putting more money into this big blue quattro bucket?  Is it worth it?  Well, that’s the question I asked the rest of you at the beginning.

(Nova Schin; for pregnant bitches that just can’t quit.  Why does she appear to be handing it to the viewer?  I’m not drinking that shit.)

The answer is: depends.  As I alluded, I would have done things differently.  The big change in my private life since May 2006 is that I had two kids.  Let me tell you, that hurt.  Man should not have children; that is woman’s work.  Puns aside, the loss of my wife’s income and the increase in domestic expenses put a cramp on my mod budget.  The loss of time control that comes from having children?  Tolerable.  The loss of income from the stay-at-home mom?  Planned for.  The increase in health care insurance premiums?  Highway robbery.  Double-digit percentage premium increases every year, and work does not subsidize dependent coverage.  My advice?  If you’re going to have children, move to Europe or Canada.  Kids complicate the modification justification equation (aka modification accounting justification equation complication consternation, or majecc).

Majecc, pronounced \’ma-jik\, is what it’s all about.  (Can you believe I make this shit up?  Isn’t linguistics fun?)  You “majecc-ly” find time and money to continue you hobby.  Usually this involves either living vicariously through your single or DINKY friends or teaming up with similarly-encumbered SITCOM friends.  The majecc continues, but so does the magic that got us into the hobby in the first place.  So bring out another thousand; excellence is made in leaps (of the wallet).

(500 AWHP?  Well sure, if you’re asking.)

P.S.  What would I do differently?  Here’s your bonus advice: if you have a range of modification expenses (assuming the cost of the upgrade is directly proportional to the value of the upgrade), save up and get the most expensive stuff first.  If that means saving $5000 for a turbo kit, at least when you’re two years into it and change your mind or move on, you can move on knowing you haven’t already committed big dollars to a stalled project.  That’s what I would do differently; I’d trade the $5k I’ve spread out over the car and focus that into the big $5k single upgrade.  Sure you can take bites at the project and it’s fun to do a small upgrade each year instead of nothing for four years or whatever, but I’m just saying that if your plans call for a $5,000 upgrade sometime in the future and $5,000 in other distributed upgrades, get the big one out of the way first.  The others will still be there.

Yeah, so BOAFT.

 – Jeff, internet profit…prophet…whatever

Categories: Cars, Jeff

Ess Ewe Vee: May I have “more than adequate”?

July 13, 2011 2 comments

We on MM pride ourselves on enjoying driving.  But what if real-world considerations impact your ability to pursue this pleasure?  I’m not talking about having to work too much or having to spend your mod dollars on baby formula, but big problems, like not driving your performance vehicle on the occasions you do find yourself behind the wheel?  Mediocre Steve drives a lowered, turbo, two-seater with race buckets so tight you barely need to wear a seatbelt.  No chance of getting a car seat strapped in that (and in Steve’s case, this is a positive).  For the family men like Alex and myself, it’s not so much the kids we have to satisfy as the wives.  There is no right answer to “how is that going to work?” when you’re trying to convince her that you’re the first person to prove beyond a reasonable doubt that a 951 is a practical car and the backseat was actually designed for children.  So that brings us to the reasonable solution: a minivan.

 

Vinyl wood siding and wire wheel hubcaps.  So much promised, so little delivered.

Fortunately, my wife does not like the idea of driving a minivan.  I must be rubbing off on her (hehe).  So we went the SUV route.  Driving a German performance sedan, I knew better than to buy another German car, and American cars were out of the question, so that left the Japanese and Koreans.  First we needed to sell the wife’s Jetta (another case against buying a German car), and we figured our family of four just needed a small SUV.  At this point I wanted something she could get in and out of the garage with the mirrors attached and for as small of an outlay of cash as possible. 

We started with the Honda CRV.  This was an entirely adequate transportation appliance.  It did exactly what it was supposed to, nothing more and nothing less.  You want acceleration?  We have 180 adequate horses to do that.  You want interior electronics and accessories?  We have what would be considered premium ten years ago as standard.  Overall I thought it was the right car for us, because there was nothing on it that I would bother tinkering with.  Then I was lured behind the curtain by Kia.  They promised value, as in I could get more for my money.  More-than-adequate is where I operate, so we test-drove a Sportage and a Sorento.  The Sportage had the turbo, which was fun (much more than adequate torque), but the build-quality was questionable.  Everything fit while the vehicle was in the showroom, but I nearly ripped the rear door off the car when I opened it.  The hinges are attached to the stamped metal, not the b-pillar structure, so the whole thing twists when the door is swung open too far by the inattentive.  Overall I liked that car better than the CRV, excluding the question of longevity (basically, it was turbo and turbo=good).  Then I wanted to look at the Sorento.  Third row seating!  Wow; I never thought I would be interested in a spare row of seating that I had no use for, but knowing you could use it ties right into my more-than-adequate attitude.  The Sorentos were bigger, but they were the same price as the turbo Sportage!  Value!  Wait a minute.  The teaser BS you see on TV where the Kias are starting at $17,988 is not anywhere near what you will pay.  Partly through disclosure and partly through the fact you want power window, you will price yourself above $30,000 for these cars.  They had loaded Sorentos at $40,000!  For a Kia!  Fook that, we’re going to Japan. 

Now I was hooked on the third-row seat “utility,” though so we went to Toyota to check out the RAV-4 and the Highlander.  The former was now considered too small, but the latter was nice, so we started negotiation.  We asked what they could give us on trade for our Jetta.  This is where they pissed me off.  They took the dealer trade-in value on the Jetta and then subtracted from that their costs to refurbish the car.  Thanks.  That’s not how Blue Book works, but I appreciate the insult.  You must think I am A) desperate, B) an idiot, or C) required by my wife to buy this vehicle.  Guessing C will not give you the right answer.  I told them forget it and took the fam to McDonalds (in the Jetta). 

 

I was sorry to see the Jetta go, but red just attracted too much attention.

The logical next step would be to sell the Jetta privately for as much as possible in order to establish our new vehicle purchase budget.  So that’s what I did.  I sold the Jetta in three days on Craig’s list for 2.75 times as much as I was offered on trade, and only $200 less than my asking price.  With cash in hand, we were much more comfortable talking to dealers.  I used a program through my credit union to “pre-negotiate” a deal with local dealers.  Most “no hassle/no haggle” programs are actually advantageous to the dealer, because he has no risk in setting a price.  You must understand two fundamentals in negotiation: 1) they are better at it than you are, because they do it all day every day and you have a real job, and 2) you should not negotiate with people who are better at it than you.  We ended up selecting a dealer who had fair pricing but minimum dealer-installed accessories (which are big money-makers for the dealer) and went to visit.  How do you know what “fair pricing” is?  Do not look at MSRP, and you can ask for the dealer invoice, but unless you know how to read it, they will use it against you.  You should bone up on this excellent site for tips and advice.  http://carbuyingtips.com/  Know what you want before you go, in terms of price, options, etc., and avoid impulse or pressure deviations.  If you feel like you’ve lost control of the negotiation or you aren’t getting what you want, walk away.  We got a decent deal, and using the car buying tips’ real price spreadsheet, I think I overpaid by about $200, but they didn’t really take advantage of me.

So what did we end up with?  A nice white SUV.  The only dealer options were wheel locks (which they insisted cost $40 to install; see what I mean about them ripping you off?) and a trim kit that I could have done without but the wife was okay with.  I installed the running boards myself and saved $500.

They see me rollin’; they ignore me.

This article is not me bragging.  It’s really the story of how I got back to where I started (Honda), having explored other options, and opting for the “adequate” choice.  See the front of the Pilot?  No projector headlamps.  See the engine?  3.5L six-cylinder with adequate mileage and just 250 hp.  I have more than that at all four wheels in the Audi.  Bottom line: you don’t get an ounce more than “adequate” with the Honda, but you do get what you need.

– Jeff, Jeff, Jeff of the Suburban Jungle

Categories: Cars, Jeff

The new turbos, part 2: Electric Bugaloo

April 4, 2011 1 comment

When we last spoke, I left you re-directing your browser to Chris Ostberg’s fantastic B5 S4 resource site, http://www.nogaroblue.com, saying he was selling something interesting.  I was on Quattroworld checking the classified when I saw a post from Chris.  Chris was selling his K04-K16 hybrids.  Holy S(4)!  His description was optimistic, that the turbos were serviceable but he personally would rebuild them before installing them (see last time’s discussion on installing used parts), and I knew I could rebuild a K04 for between $300 and $400, so we made each other offers we couldn’t refuse, and the turbos became mine.


(All the bad things we talked about last time – owner abuse (did you watch any of his videos? How about them Nurbergrings?), shaft play, foreign object damage)

What is a K04-K16 hybrid you ask?  Well, a hybrid turbo is when a company that doesn’t manufacture a certain turbo thinks they’re smarter than the company that does manufacture said turbo, and decides they’ve come up with a superior combination to what the silly engineers could.  In this case, we have a K04 (from the European hot-rod of the S4, the RS4), modified to accept a Porsche 911 Turbo (996) compressor wheel.  Why would you want to do this?  Because Porsche Turbos are fast?  Yes.  Why are they fast you ask?  Well, it’s obvious (from Chris’s site):


(Quite the obvious visual statement)

K16 is big.  Now they’re doing hybrids with 911 Turbo (997) wheels, but before the 997s came out, 996 was what it was all about.  The first thing you notice is the K16 is bigger.  Yes.  The second thing you notice is that it has more blades (12) than the Audi wheels (8).  This is important.  Size matters, but the extra blades make the K16 more efficient.  Basically, the extra blades get a better grip on the air and increase the flow rate of the wheel at a given speed.  The lower the speed, the “faster” the spool (because you’re targeting a lower speed), and the happier the bearings in the turbo.  We’re talking about speeds in excess of 150,000 rpm, so lowering that is a good idea.

Why not just put a K16 in there?  It won’t fit.  The whole point of the hybrid in my case is to accommodate the very confined engine compartment (not a lot of room to redirect the plumbing of the turbo-we can’t even fit a physically larger unit in there), while having something better than a plain-jane (PJ) K04.

Next question: why not put a couple of GT25s in there?  Yeah, about that.


From Chris’s site – I’m tired of my dirty pictures.  Well, not those dirty pictures, the pictures of my dirty unit.  Well, not that dirty unit, the filthy turbos.  Yeah.  Nailed it.

See that funky flange?  That’s where the turbo connects to the exhaust manifold.  The downpipe flange is also unique (to everyone but VW, Audi, and Porsche).  Changing all that to get a Garrett in there is not worth it (because now I need headers and a new turbo-back exhaust system?  Why?  I thought I was upgrading the turbos?), so most guys make do with K04s, hybrids, RS6s, weird “eliminator” combos that advertise a Garrett cold side on a Borg Warner/KKK hot side, and now the new Frankenturbos (which is what Chris was trading up to).  Anything that’s not BW/KKK will have fitment (and potentially quality issues as have been reported on the forums), so I wanted to stay with the tried-and-true (even if it is tired-and-true) K04-based system.  RS6s are a safe choice, but they cost more, and they start to border on a selection too large for my platform.  Too large you say?  How do you know?  Well, because of the turbo sizing calculations I did of course.  Oh, you don’t know how to do that?  Why didn’t you say so?

– Jeff knows all about how to blow bigger…

Categories: Cars, Jeff

The new turbos, part 1

March 29, 2011 2 comments

I got new turbos for the S4.  The B5 S4 (2000-2002) came stock with a 2.7L bi-turbo (that’s German for twin turbo) V6 engine rated at 250 hp and 258 ft-lbs of torque.  In typical European fashion, the “peak” torque is available over a wide RPM range, like from 1850 rpm to 5500 rpm.  This is accomplished by truncating the boost curve so that the manifold pressure stays constant over a wide RPM range.  Lost yet?  An engine makes torque by exerting a force on a rod that turns a crank.  The “force” is the expansion of combustion air, heating from the burning fuel, acting on the piston, pushing on the connecting rod, and turning the crank.  It’s pretty much what you see on an old-fashioned steam locomotive, except the on the train the crank is integral to the drive wheel.  If you want more torque, you need a bigger engine so more air is acting on the piston(s).  The airflow into the engine is directly proportional to manifold pressure on a forced-induction engine, and torque is directly proportional to airflow, so a flat boost curve makes a flat torque curve.  One of the easiest (and often first) modifications to an engine with this behavior is to remove the “artificial” limit on the manifold pressure by reprogramming the ECU (or removing the ECU control of waste gate duty cycle and putting a manual boost controller in its place if you are a caveman – Hi Alex!)


Technically not fair; Alex’s hair is spikey.

This procedure allows the turbo to provide a higher peak manifold pressure, with a natural increase and decrease on either side.  The ramp-up in manifold pressure comes from the time it takes for the compressor to spin up to a useful rpm (between 100,000 and 200,000 rpm – hey, these things take time!), which is usually mitigated as much as possible by reducing intake restriction and optimizing turbo sizing and construction, and the taper at higher RPMs is the result of the engine sucking in more air than the turbo can compress (the manifold pressure or boost is a pressure, which corresponds to a volume in our fixed-volume intake systems, and at higher rpms the engine is consuming more air than can be supplied by the turbo at that manifold pressure, thus pulling the manifold pressure down).  The spool-up and taper down usually come from the physical limitations of the turbo-engine combination, although some ECU programs control the taper to protect different components.


Here’s a before-and-after dyno (at the wheels) of my chip tuning.  Note that wheel HP on a stock S4 is registering at 171 on this dyno, which is 250 hp crank????

Are there any downsides to raising the manifold pressure on an otherwise-stock engine?  Potentially, yes.  Like just about any other “performance” modification you can do to a car, modifying only one component in a system stresses out the other components in the system.  Removing the artificial cap on boost allows/commands the turbo to spin faster.  A good ECU program will prevent the turbo from rotating too fast and killing itself (and a manual boost controller may or may not, depending on how ham-fisted the guy setting it is – Hi again Alex!), but increasing the maximum speed of the turbo may cause it to wear out faster.  This brings me to the title of this article.  No, I didn’t blow my stock turbos, but I was concerned that I could, so when a cheap replacement came along, I picked it up.


K03 replacements: K03-16 and K03-17

These K03s are the stock size and reportedly have about 60,000 miles on them.  New they’re about $2000.00 for the pair, and I paid $300 shipped.  They have a little shaft play (heh heh) in the lateral and axial directions (heh heh…huh?)  Unfortunately, replacing turbos on the B5 S4 requires removing the engine.  This is nuts and bolts work, but it’s more than most owners will do in their garage.  So when the stock turbos die either through owner neglect, mis-use, foreign object damage (FOD), or otherwise, you start calling the shops and checking the forums.

Naturally, the forums are full of enthusiasts and they say “It’s going to cost you $1000-1800 to do the work, so why put the same-size turbos back in, and worse, why put used ones in?  The clock’s ticking on those things and you’ll just be pulling the motor in a year; don’t save a few bucks now just to have to go through the exercise again in a year or two.”  Point taken.

Like I said, I haven’t blown my stock turbos yet, so I set my new used K03s on my desk and didn’t think much about it, until I saw a post from this guy  www.nogaroblue.com.  He was selling something.  Tune in next time to find out what.

– Jeff, overlapping data with inuendo since 1932.

Categories: Cars, Jeff

Guest Editor Jeff: Winter wheels and tires

December 6, 2010 4 comments

La Nina winter is settling in on the PNW, and I find myself asked “What makes a good winter tire”? If you live in a place that has more than on season, chances are you would benefit from having a dedicated set of tires for your warm season and a different set for your cold season. In some climates that may mean studded snow tires in winter and all-seasons the rest of the year, or maybe ultra-high-performance (UHP) summer tires for some months. It’s a sad reality that a single tire won’t be the best at every type of driving condition. Those tires that are great in the summer, due to chemistry, size, tread pattern, aspect ratio, etc., won’t be as effective in rain, snow, or icy conditions.

Tires that purport to made for “all-seasons” are really just compromises, a classic jack-of-all-trades, master-of-none situation. UHPAS (ultra-high-performance all-season) tires are a little cul-de-sac of tire engineering, but they still can’t provide the summer driving of a true Extreme Summer tires plus the winter performance of a dedicated snow tire. Plus, you basically get what you pay for, so if you want a great all-around tire to replace having to buy a summer set and a separate winter set, expect to play double what a comparable summer or winter tire would cost, since this special tire is essentially two-in-one (today is hyphen-day, if you hadn’t noticed).


Continental ContiExtremeContact D(ry)W(et)S(now) tires. Non-hyphenated.

So let me offer you this advice. If you’re going to pay for two sets of tires (and you are, whether you physically buy two sets or just pay double for one all-around fail set), don’t spend more than about $100 per tire. That price point is just about at the inflection point of the value-price derivative. Weird sizing notwithstanding, you can get a good name-brand tire that’s good in summer (for your summer wheels) and one that’s good in winter (for your winter wheels). What’s that? You don’t have dedicated rims for your summers vs. your winters? Okay, let’s look at that.

If you live in a place that is disproportionally “wintery”, then what I’m about to say may not apply to you. If you live in a normal place, chances are you show off your car in good warm, dry weather in the summertime. It would then make sense that you would dress-up your car with some aftermarket rims for summertime driving, and those rims will need tires, so this is a great time to pick up some Extreme Summer tires to go with them.


Scion tC video game picture nonsense

Problem half-solved! Now you have summer rims and summer tires. What about winter driving though? Would you buy winter tires to put on your nice new BBS rims? Here are some reasons not to:
1. Those rims are probably bigger than stock size, meaning the tires have a smaller side-wall than stock size. This provides less protection to the rim from road impacts (pot holes, etc.) and firmer ride.
2. Those rims were expensive. You’ll want to take care of them. Washing your car in winter weather may not be an option.
3. If you had winter tires in the same size as the summers, it would cost you about $25 per wheel every time you wanted to switch back and forth. That’s $200 per calendar year (summers on in spring, off in fall).
4. You have the stock rims sitting in your garage.

You could sell your stock rims and recover some of your funds, but chances are they wouldn’t bring in enough scratch to cover another set of BBS rims for winter, plus a second set of nice rims for winter doesn’t compute with issues 1) and 2) above. If you’re into charity however, you could give them to your less-fortunate friend.


The Prius owner got tC rims and a white chick. Not sure what the Scion could have gotten in return.

Instead of all that (and by now this should make sense), buy winter tires for your stock rims and keep your summers on your nice aftermarket wheels. If you hate your stock wheels (i.e., they are steel and have a horrible two-piece plastic hubcap), get some in-the-family wheels from a nicer trim line, nicer vehicle, or whatever. Got a Jetta? Get GLI wheels (or TT wheels). Got a 325? Get M3 wheels. Got a Prius? I’m so sorry.

So when the weather’s good, throw your summers on. When it’s bad, throw the winters on. It’ll save you money in the long run and provide superior driving over a single “all-season” tire.


This time-lapse photograph, read left to right, shows the transition from stock to OZ to BBS.

-Outro-Jeff has his winters on stock rims. Yes, they’re contiextremecontact.

Categories: Cars, Jeff

Guest Editor Jeff: What’s your favorite number?

November 11, 2010 7 comments

Mine is 72.  72 is a weird number that keeps coming up.  Did you know:

  1. You can determine the synchronous no-load (natural) revolutions per minute of an (electric) AC induction motor by dividing the number of poles on the motor by 7200?
  2. You can estimate the peak torque (foot-pounds) of a naturally-aspirated gasoline engine by multiplying the displacement in liters by 72?
  3. You can calculate the optimum vee-angle of a V-engine by dividing 720 by the number of cylinders of the engine? 

Let’s look at the first one.  A two-pole electric motor has one north pole and one south pole (if I’ve lost you, go back to elementary school) on the permanent magnet (probably the rotor), and the same on the stator.  Let’s say electricity provided has a frequency f of 60 Hz.  Let’s say N is the motor speed in RPM, and P is the number of magnetic poles (note that P must always be an even number; you will have as many north poles as south poles).

By the equation N=120*f/P, you can determine the third variable if you know the other two variables.  Assuming you’re talking about line voltage in the United States, f will always be 60.  Therefore the N/P relationship will always be equal to 60*120=7200.


(Got it?)

Okay, car stuff now.  #2 is my gift to you.  I got into a conversation with my little brother (He has a PhD in Astrophysics.  No bullshit.) and he was trying to complain about how “inefficient” American cars (Cadillac CTS-V with the LS6 5.7L 400 hp Corvette V-8) were compared to Euro porn-stars like Ferrari 612 (5.7L V-12 530 hp).  He said something like “Dang the Americans, why can’t they make a 5.7 liter motor with more than 400 hp if Ferrari can make one with over 500 hp?” 


(Hey, I could have given you the picture of the CTS.  Booooring)

He was missing a fundamental relationship between displacement and horsepower: torque.  It goes like this (queue the Geek).

Horsepower is (always) the rate at which torque is “generated”, governed by the equation HP = Tq*RPM/5252.  Any engine, whether electric, Diesel, or gasoline, makes a given horsepower at a certain engine RPM based on the torque at that RPM, divided by a constant.  That’s it.

The Cadillac peak HP is generated at a lower RPM than the Ferrari (400 hp at 6,000 rpm vs 530 hp at 7,250 rpm).  The torque of the two motors is remarkably similar: 395 ft-lb at 4,800 rpm for the Cadillac and 434 ft-lbs at 5,250 for the Ferrari, a difference of only 40 ft-lbs, not the same magnitude of the 130 hp difference.  Yes there are probably deficiencies in the American design, but the difference could easily also be attributed to differing methods of measurement, manufacturer over/understatement, etc.

How can YOU, the wide-eyed consumer, be prepared to properly evaluate engine horsepower and torque?  Is there a convenient rule of thumb you can use to impress your friends when one says he just got a new Corvette and you don’t remember the HP figures from the brochure?  Yes.  Try the “rule of 72” that I’m inventing.  It works like this: engine displacement in liters, D, times 72 equal torque Tq, or D*72=Tq.  Let’s try it.  Ferrari 612 had a D of 5.7.  Multiply by 72 and you get Tq equal to 410 ft-lbs.  They claim 434, so we’re within 5-6% of MFG stated torque.  Cadillac says 395, so our estimate is 4% high (395 vs 410).  Overall you’re VERY close to the actual (crank) torque of the engine.  With that ballpark, you can ask intelligent questions like “at what rpm is peak horsepower generated?”, and you throw that RPM back into the first equation, and viola, you have a musical instrument.


(Unrelated musical instrument)

Horsepower is a function of torque AND rpm.  The Ferrari made more horsepower because it had higher rpm.  You see this behavior a lot with small-displacement engines that you have to “rev-up” to get any useful power out of.  That’s simply a function of utilizing the RPM side of the equation to calculate out to big horsepower.  Check out the following table.  Here’s a mix of engine configurations, displacements, and countries of origin.  Note that Diesels are not included because they use a different fuel, and the Mazda rotary engine is shown to have much higher torque than a piston engine of the same displacement would.  Go Felix (Wankel).  This is due to having three combustion “strokes” per rotor rotation instead of one combustion stroke every two piston strokes (as in a four-cycle piston engine).  Overall, my “rule of 72” seems to be a good rule of thumb for calculating torque based on a given displacement.

The third thing “72” does for me is provide the ideal vee-angle of a vee-engine.  This however has gone on long enough, so go read the article in this month’s Car and Driver for details.  If you have questions, let me know.  Let me leave you with this picture, the typical 80s Ferrari owner.  Honest.

(Actual Ferrari Owner.  I am not making this up)

Here’s your bonus picture.  This blows the “rule of 72” out the window unless you calculate the approximate equivalent engine displacement based on the manifold pressure multiplier to ambient.


(Forced induction changes everything) 

Jeff likes his forced induction.  Strangely, his engine displacement is 2.7, an anagram of 72.  Weird!


Categories: Cars, Jeff

Guest Editor Jeff: Troubles in car rental land

November 4, 2010 5 comments

Occasionally I travel on business and am obliged to rent personal transportation at my destination.  I don’t usually have a say in the rental; the administrative assistant supposedly does me a favor by booking the car rental for me.  I don’t think she likes me very much, because last time I traveled to Charleston, SC, she rented me this:


(Grey; it’s more than just a color, it’s an attitude)

You are forgiven if you don’t immediately recognize it as a Vauxhall Cavalier Opel Vectra Vauxhall Vectra Holden Vectra Chevrolet Vectra Saturn Aura.  This is the XR version, which is rated neither X nor R, but I am ashamed to say is the top-of-the-line model.  It uses the 3.6L V-6 from the Cadillac CTS and has a six-speed automatic transmission.  The latter is significant because it also comes with paddle shifters (called TAPshift; I had to look it up.)


(A steering wheel that means business)

I was excited when I saw it; my last rental here had been a Yaris (which tried to kill me by cutting throttle due to traction control issues while making a fast U-turn in front of much traffic).  This time I was travelling with my boss (a GM product owner) so I guess we warranted something bigger than the Toyota.  I got in the car, adjusted my seat, got excited about the paddle shift, started the car, and was surprised how quiet it was.  I exited the airport rental area discreetly, assuming 250 hp and lots of cogs would be a good combination once the road opened up a bit.


(Three “sporty” gauges placed in the one-size-fits-all dash opening.)

It did however turn out to be a disappointment.  The paddle shifters are as lame as you should expect from GM; this is not a DCT, it is just the latest Hydromatic, so “selecting” gears with the paddles is just like clicking 1>2>3>…>6 on the automatic gear selector.  The delay between command and executed shift is measured in whole seconds, not  milliseconds (150 for an Enzo sequential manual transmission, or 8 for an Audi DSG) like a true “flappy paddle” gearbox.  This ruined the car.  Yes, I realize it is a rental and therefore not treated with the love and devotion of an “owned” car (example, the keyless entry system could not unlock the car.  It was possible to lock the car and arm the anti-theft system remotely, but not unlock the car remotely.  Therefore one would set off the car alarm whilst unlocking the car with the key.  The alarm was silenced by actually starting the car with the key.  So basically the anti-theft does not actually prevent you from starting and stealing the car.  Nice feature.)  I doubt it was really making 250 hp (200 wheel?  I think not.)  Front wheel drive is a disappointment on dry paved roads, but none of those niggles compared to the failure to execute driving pleasure through control of the transmission.  Whoever approved this feature at Opel GM obviously had dreams bigger than their budgets, but who doesn’t?  I guess the bottom line is, if you’re going to do something wrong, should you do it at all?

I could go on about the interior materials being lower quality than I am used to, or the fit and finish being inferior, but you should already expect that from GM.  For all the compromises a designer or manufacturer has to make to satisfy all the vested interests, it’s irritating to see no bad idea wasted.

– Jeff is sitting in his Audi, smelling the leather, selecting his own gears, and ratcheting up his douchebag score enjoying the PNW sunshine.

Categories: Cars, Jeff