Top Gear: Roush Mustang vs. GT500

[LonghornTX]

LonghornTX and others:  Last year or early this year on a roadracing website someone was building their own version of a Mustang FR500C.  Their cost for one set of competition 3-way adjustable shocks alone was $6500.  AAARRRRRRRRRRRRRGGGGGHHH!!!  Whatever you think it might cost you to get prime grade equipment, double your estimated cost figure and hope you have budgeted enough!

That is truly outrageous!!  However, luckily I would never need that level of equipment as the car would only see autocross and occasional track time.  That is where the very good FRPP suspension comes in.  For only $1,000 you get multimatic tuned springs and shocks (made by eibach), stiffer bars, billet SB links, and a front strut tower.  If I wanted to add some adjustability to the shocks, I could buy the same pieces seperate and use Tokico D-Specs for ~$1,500.  If I wanted to go even nicer, I would probaly start looking at some of the Tein systems.

About the weight of GT500s:  Ford's planners (including Carroll Shelby) decided to give you the costly hardware--Aluminum DOHC 4-valve heads with dual injectors, variable intake timing, a 6060 Tremec 6-speed (better than the Tremecs provided on any other vehicle you can buy), a supercharger, an intercooler, big bearings, big Brembo discs in front with the Ford GT master cylinder, about the biggest tires you can fit in the wheelwells plus the aluminum wheels to mount them, oversized radiator, a lightweight air extractor hood, bigger springs, bigger shocks, bigger swaybars, etc., not to mention a chassis rigidity of nearly 7500 lbs/inch (the Gallardo AWD is considered exceptionally stiff at 6000 lbs/inch, for comparison).  This is stuff you want and need when you've got 500 HP and 480 ft lbs of torque attached to the skinny pedal.  And it's all costly ('Priced Brembos lately?  Or a Tremec 6060?)--and it's substantially heavier than the equipment that comes with a 300 HP Mustang GT. 
Ford left the lightweight non-mechanical parts up to you (and your bankroll)--carbon-fiber fenders, carbon-fiber decklid, plexiglass windows, etc.  You don't have to align bore them, port them, polish them, balance them, shot peen them, heat treat them, yada yada yada--all you havta do with those is paint 'em and bolt 'em on!  The easy stuff.   
'Ever taken the heads off an LS7 and tried to make 4-valvers out of them with your drill press and radial arm saw??
In the much more expensive Corvette Z06, Chevy gives you balsa floorpans, but a pushrod two-valve engine (I believe the engine in the 1903 Wright Brothers "Flyer" used a pushrod two-valve engine) and a transverse leaf spring suspension (which you could get on the front of Model T Fords at least as early as 1930). But the Z06 IS lighter... 

It could go either way IMO.  Sure, Ford gave us the expensive mechanical components, but at the expense of leaving the car at an unacceptable weight.  The items you listed (CF body parts) are generally very expensive and the mustang already has an aluminum hood, so it would all be in the front fenders and air screen to make the needed weight distribution change.  Plus I have heard those parts can be very expensive to paint and are useless in any kind of repair situation.

Personally I would have preferred for some additional tuning to the venerable 4.6L Supercharged from the last generation Cobra (the aftermarket has already shown the tremendous potential of that engine, and Coletti himself even sent owners letters describing how the car could be modified to accept higher boost safely through the use of different pullies).  Of course, I am aware that this situation might have kept the car from passing current emissions, and so they may have had no choice.  I wonder how much it would have been to add the aluminum block from the GT...I would be alright with a price increase if it was not too expensive.  The brakes really are not that expensive it seems, as they sell for only 800-900 on the open market.  Quite cheap for a 14' 4-piston setup IMO.  I would have also liked to see some kind of lighterweight drive shaft as the stock option is dreadfully heavy.

[gasoline]

In the much more expensive Corvette Z06, Chevy gives you balsa floorpans, but a pushrod two-valve engine (I believe the engine in the 1903 Wright Brothers "Flyer" used a pushrod two-valve engine) and a transverse leaf spring suspension (which you could get on the front of Model T Fords at least as early as 1930). But the Z06 IS lighter... 

The Wright Brothers also had wings and propellers.



You know, I never understood why leaf springs and pushrods were any less modern that rear-engine layouts:


That has got to be one of the more primitive layouts of modern time.

[SVT666]

Like I said, you would definately have to install many things yourself? :P.? Your idea is very cool indeed and I wish that cars like the ones you outlined existed in the market? .

Thanks, but the prices I give would include labour.  What it wouldn't include are the huge mark-ups for the name and for body kits and paint which all add up quite a bit.  It's entirely realistic.

[SVT666]

I truly do not understand why there are so many pushrod haters out there.  I do understand that there is a lot brainwashing going on, but come on, even some of our most intelligent posters are falling for it.  As far as I'm concerned a well engineered and built pushrod actually has the advantage of being lighter (in some cases) and more compact and smaller then the OHC variety, but other then that I really don't see that either one really has an advantage over the other.  It's just two different ways of achieving the same thing.

[omicron]

I truly do not understand why there are so many pushrod haters out there. I do understand that there is a lot brainwashing going on, but come on, even some of our most intelligent posters are falling for it. As far as I'm concerned a well engineered and built pushrod actually has the advantage of being lighter (in some cases) and more compact and smaller then the OHC variety, but other then that I really don't see that either one really has an advantage over the other. It's just two different ways of achieving the same thing.

Agreed.

[r0tor]

I was at the wright brothers museum this summer... i think i considered their design OHC after seeing it in action

[Nethead]

My posting was not directly a Corvette bash--those of us who were once huge fans of the '63 fuel-injected 327 Stingray coupe are saddened to see Corvettes failing to benefit from the many automotive advances that have been out there for decades--coil springs and OHCs are the two that stand out.? The pushrod is not dead--after all, the greatest sportscar of the last century--the Cobra 427--used an iron-block pushrodder, as did the Ford GT Mark IIs that won LeMans outright in 1966 and the Ford GT Mark IVs that won LeMans outright in 1967.? And in 1968, an iron-block pushrod 302 propelled a modified street Ford GT-40 to outright victory at LeMans and repeated the performance in the very same pushrod 302 GT-40 again in 1969.? And pushrod Ford flatheads of less than 300 cubes have reached over 260 MPH in tiny streamliners at the Bonneville Salt Flats.? All this is well and good--the twin turbo Saleens and twin turbo Viper Venoms can surpass 200 MPH in less than one mile from a standing start (the Saleen even does it while emissions legal).? This, too, is well and good.? And I believe the Goldenrod Bonneville streamliner that used four 426 Hemis to set the wheel-driven speed record of over 400 MPH at Bonneville back in the late 'Sixties still holds that record--although to my knowledge no one has built a wheel-driven turbine-engined streamliner to go after that record.?
But, except for the '68 and '69 outright wins at LeMans by 302-cube Ford GT-40s, all these pushrodder achievements have one thing in common--they are all huge-displacement engines:? the four 426s in the Goldenrod, the 427 in the Saleen, the 522 (or bigger) in the Viper Venom, the 427s in the Ford GT Mk IIs and IVs.? And the 427 in the Z06.? When someone decides to come out with a true performance car with a really big OHC engine, get your pushrodders out of its way!? Can anyone here say "Veyron"? Can you recall how 1,000+ horsepower Porsches obliterated the 427 & 427+ cubic inch aluminum pushrodder Chevies in the CanAm some decades ago? As I recall, those Penske Porsches were DOHC, 5-liter, air-cooled flat-12s and dominated the series so totally that the series folded!? And back in the days when USAC was trying to get pushrodders competitive with the OHC engines that were dominating open-wheel racing, all manner of advantages were given to pushrod engines to no avail.? An occasional event was won by a pushrodder that caught the yellows lucky, but they never were a threat until Mercedes introduced "pushrodders" that had the cams mounted so high in the blocks that the "pushrods" were about one inch long.
Racing tells the story, but any scenario where extreme performance is demanded of piston engines will tell the same story--note that over sixty years ago the P-51 Mustang wasn't competitive in the skies until the British canned the P-51's huge Allison pushrod V12 and put in a DOHC Rolls-Royce V12.? And in Road & Track magazine's "The Standing Mile" competition in the September, 2005 (maybe the greatest automobile brawl in history) issue, the fastest vehicle from a standing start to 5,280 feet down the runway was a CART open-wheeler with an 800 HP 2.4 liter DOHC four--beating substantially even the mighty 1000 HP twin-turbo V10 stroker Viper Venom as well as all the streetcars and all the other tuner cars and pure racecars that dared to show up.? To be fair, the CART open-wheeler did not beat the Navy F-18 to the mile, but that wasn't a pushrodder either.? When's the last time anyone got a reliable 800 HP out of a 2.4 liter pushrodder?
Soooooooo, OK, these cars were racecars.? What about street cars?? Well, back in the old AutoWeek forums, some dudes researched what was the last pushrodder that held the Guinness record for proven (not alleged) fastest production car on Earth.? What was it?? The last pushrod production vehicle that held the proven title of fastest production car on Earth was the 427 Cobra of four decades ago.? Note the displacement of that pushrodder, by the way.? And many would argue that the 427 Cobra was a tuner car and not a true production car (an AC Ace with a monster NASCAR V8 dropped in).? They may be right about that.? All holders of the title since have been powered by OHC engines.? Coincidence??

[SVT666]

Racing tells the story, but any scenario where extreme performance is demanded of piston engines will tell the same story--note that over sixty years ago the P-51 Mustang wasn't competitive in the skies until the British canned the P-51's huge Allison pushrod V12 and put in a DOHC Rolls-Royce V12.? And in Road & Track magazine's "The Standing Mile" competition in the September, 2005 (maybe the greatest automobile brawl in history) issue, the fastest vehicle from a standing start to 5,280 feet down the runway was a CART open-wheeler with an 800 HP 2.4 liter DOHC four--beating substantially even the mighty 1000 HP twin-turbo V10 stroker Viper Venom as well as all the streetcars and all the other tuner cars and pure racecars that dared to show up.? To be fair, the CART open-wheeler did not beat the Navy F-18 to the mile, but that wasn't a pushrodder either.? When's the last time anyone got a reliable 800 HP out of a 2.4 liter pushrodder?

The race car also weighs half as much as the Saleen.  The new Hemi and LS Engines from Chevy produce more power in their trucks then the equivalent OHC truck engines in their competitors.  THey also get better mileage then their OHC competitors.  A pushrod V8 can easily spin just as fast as their OHC competitors.  My Hemi has an aritificial redline of 5700 rpm.  I have read several articles from Hot rodding magazines where they have succefully and safely raised the redline to 7000 rpm.  Swapping the cam and installing long tube headers while raising the redline to 7000 rpm has also garnered 120+ crank horsepower gains from the 5.7L Hemi.  I have an article from popular hot rodding to prove it.  The Z06's engine easily spins past 7000 rpm.  GM is even currently working on multi-valve pushrod powerplants right now.  I'm really interested in seeing the result.  In street applications, there is no way anyone can convince me that OHC holds a definitive advantage over pushrod.  Racing?  Sure, they can spin a tiny displacement OHC V8 or V10 a lot faster therefore creating more power from such a small engine, but there are plenty of forms of racing where pushrods do just fine.  Drag Racing and NASCAR are just two.  Top Fuellers and Funny Cars that are running 320+ mph in the 1/4 mile producing over 5000 hp are pretty impressive too.

[TheIntrepid]

Does anyone have the link to the site with the downloads for Top Gear episodes?

[The Pirate]

Does anyone have the link to the site with the downloads for Top Gear episodes?

http://www.car2max.com/topgear

[SVT666]

The race car also weighs half as much as the Saleen.? The new Hemi and LS Engines from Chevy produce more power in their trucks then the equivalent OHC truck engines in their competitors.? THey also get better mileage then their OHC competitors.? A pushrod V8 can easily spin just as fast as their OHC competitors.? My Hemi has an aritificial redline of 5700 rpm.? I have read several articles from Hot rodding magazines where they have succefully and safely raised the redline to 7000 rpm.? Swapping the cam and installing long tube headers while raising the redline to 7000 rpm has also garnered 120+ crank horsepower gains from the 5.7L Hemi.? I have an article from popular hot rodding to prove it.? The Z06's engine easily spins past 7000 rpm.? GM is even currently working on multi-valve pushrod powerplants right now.? I'm really interested in seeing the result.? In street applications, there is no way anyone can convince me that OHC holds a definitive advantage over pushrod.? Racing?? Sure, they can spin a tiny displacement OHC V8 or V10 a lot faster therefore creating more power from such a small engine, but there are plenty of forms of racing where pushrods do just fine.? Drag Racing and NASCAR are just two.? Top Fuellers and Funny Cars that are running 320+ mph in the 1/4 mile producing over 5000 hp are pretty impressive too.

Not to mention the CART engine is spinning at 18,000 rpm to produce that power.  What is the point in producing all that power at such a high rpm if you can produce the same power at a 1/4 the engine speed?  In an F1 or CART application I can understand it, but in a street car I don't.  Flexibility is the name of the game in street cars and larger displacement engines are far more flexible and peak a lot earlier...pushrod or not.

[nickdrinkwater]

FYI, this clip isn't from Top Gear.  I think it's from Clarkson's new DVD, The Good, The Bad and The Ugly.

[Raza]

I don't know enough about engines to be a pushrod hater.

[Nethead]

HEMI666: Solid, informed, articulate response from Hemidude, as always!  It's not the time to cart the LSs and the Hemis off to the smelters.  But there was a time when flatheads were not useless, yet the world moved on to OHV engines and vehicles became better as a result.  That process is going on today, but now it's moving on to OHCs, modernized diesels, multifuels (those that run on regular or E85), hybrids, fuel cells, batteries, yada yada yada.  Displacement on Demand isn't what those seeking genuine fuel economy are going to settle for--they're going to get a non-DOD four or non-DOD V6, and probably in an Asian vehicle. 
Sean Hyland was chassis-dyno-testing a boosted Ford modular (whether a 4.6 or a 5.4 the Nethead here does not know) a few years ago when a shaft that connected the modular to its transmission broke, essentially removing all load on the crankshaft in a nanosecond.  Before the folks at SHM could shut down the engine, it had soared to 11,000 RPM.  Disassembly of the engine found no damage!  If it had had pushrods, there would be sixteen new craters on the Moon...I believe the details are in Hyland's manual on performance modifications for the modular series.
Now, the Nethead here is not a pushrod basher--my Bronco has sixteen of 'em in its 289--but I ain't blind to better, either.  I'd trade anyone with a current Ford GT even for his or her engine if they want to get their Ford GT more authentic and drop a 289 into it (the fifty-five Ford GT-40s built by Eric Broadley's shop around 1966 all had 289s, which the Mirage folks modified with cranks from later 302s to win LeMans in '68 and '69).  I'll probably start looking for a pushrod engine for my Focus when I read of a new Ferrari with a pushrod engine, or a Veyron, or a Koenigsegg, or a Mercedes, or a Porsche.  Can you imagine how fast a Porsche would be if they scaled up one of their many killer OHC engines to seven liters???  Even the French can build a 252 MPH street car with 6.2 liters!  Sheeeessshhh! 

[SVT666]

Nethead: I think we both made great points and neither of us will change their mind, but I think we can agree on one thing...nothing sounds quite as good as an old pushrod V8.

[sandertheshark]

I'll probably start looking for a pushrod engine for my Focus when I read of a new Ferrari with a pushrod engine, or a Veyron, or a Koenigsegg, or a Mercedes, or a Porsche. Can you imagine how fast a Porsche would be if they scaled up one of their many killer OHC engines to seven liters??? Even the French can build a 252 MPH street car with 6.2 liters! Sheeeessshhh!

The Bugatti actually has an eight-liter engine.  That's sixteen cylinders, four turbos, 1001hp.  Impressive, yes?

Compare to a Saleen with a seven-liter twin-turbo pushrod V8 making 1000hp.  Much more impressive than that OHC Bugatti engine, yes?

[SVT666]

The Bugatti actually has an eight-liter engine.? That's sixteen cylinders, four turbos, 1001hp.? Impressive, yes?

Compare to a Saleen with a seven-liter twin-turbo pushrod V8 making 1000hp.? Much more impressive than that OHC Bugatti engine, yes?

Yes. 

[Raza]

Now, mind you, this is simply speculation, but perhaps there is more to an engine than its maximum output?  Maybe the Veyron engine is smoother or more efficient, or has more torque available at lower revs?

(This is me coming to the defense of the Veyron.  I never thought it would happen.)

[heelntoe]

Now, mind you, this is simply speculation, but perhaps there is more to an engine than its maximum output?  Maybe the Veyron engine is smoother or more efficient, or has more torque available at lower revs?

(This is me coming to the defense of the Veyron.  I never thought it would happen.)

displacement is a major factor for torque, and i can't see how an 8 litre 16 cylinder engine makes more torque than a 7 litre 8 cilinder engine.

[Nethead]

HEMI666: Hemidude!? The Nethead here isn't swinging an avenging sword in behalf of OHC 2.4 liter four-cylinder engines!? I'm only pointing out that you ain't likely to see that kinda power from a 2.4 liter pushrodder--especially one that's built to stand up to several CART races, even if you could get a 2.4 liter pushrodder to hit 800 HP briefly for a dragrace or even a few laps around a track.? You're free to think whatever you choose, but meanwhile OHC engines are probably in ninety percent of the engines of the cars sold in the world every year and OHV engines are in ten percent.? Fifty years ago, those percentages would probably have been reversed.? Trucks would be less so, but I don't know enough about trucks that aren't imported to the US to have any clue what percentage of truck engines worldwide are OHC and what percentage are OHV.? I can't think of a four, five, or six cylinder pushrod gasoline engine still being offered in cars in the US.? Diesels and trucks still offer a variety of pushrod designs, and in configurations other than these I've mentioned.? But that percentage reversal over fifty years lets you know which way the wind is blowing, and I think you'll see OHC engines becoming a little greater percentage of the gasoline engines equipping cars as every year goes by.?
sandertheshark:? Sander, you hear rumors about a 1,000 HP Saleen twin turbo, but every car mag that tests a Saleen always has the 750 HP version.? The story of a 1,000 HP Saleen came out before Christmas of '05 but what's happened to this beast is still unreported.? What is a fact is that the second-fastest production car in the world is the DOHC 4700cc modular V8 in the Koenigsegg CCR at a certified sustained 241 MPH around the instrumented loop track at Nardo, Italy.? 806 HP, 678 ft lbs of torque, and emissions legal for sale in the US as the blunter-nosed version of the CCR that is designated the CCX.? 241 MPH from 287 cubic inches.? This ain't no 1500 pound CART racer, either, but a genuine street car with the usual accessories.? At around a third of the cost of a Veyron.
Lots of specialty manufacturers and tuner manufacturers make awesome claims for their vehicles, but Nardo is where those that can truly walk the walk take their cars to be inspected & certified that they meet the stock specifications--and if they aren't found to have non-spec equipment at inspection they are then sent out on the instrumented loop to show what they can do.? Lingenfelter, Hennessey, Calloway, and Saleen love to talk that talk--but so far none of them have taken their products to Nardo to show that they can walk that walk like Bugatti, Koenigsegg, McLaren, and even the Ford GT have done.? The last three owners of the title of world's fastest production car at Nardo have been powered by DOHC engines, and probably the dozen before them.? The pushrod contingent mentioned above is still talking the talk, but notably absent from Nardo...hmmmmm.

[sandertheshark]

sandertheshark: Sander, you hear rumors about a 1,000 HP Saleen twin turbo, but every car mag that tests a Saleen always has the 750 HP version. The story of a 1,000 HP Saleen came out before Christmas of '05 but what's happened to this beast is still unreported.

http://www.fast-autos.net/vehicles/Saleen/2006/S7_Twin-Turbo_Competition/

That's no rumor, nethead.  That's an honest-to-god production car.   Saleen hasn't released the final product for sales or testing yet and the 250mph top speed is just a rather conservative estimate, but that car's the real deal.

[Raza]

displacement is a major factor for torque, and i can't see how an 8 litre 16 cylinder engine makes more torque than a 7 litre 8 cilinder engine.

Torque and torque availability are two different things.

And Saleen needs to go ahead and get the car in a bowl and on the press circuit.  Clarkson has gone on and on about how there will never be a car faster than the Veyron; I'd love to see his reaction to the Saleen.  "The ride is so stiff, it's like Paul Reubens at a porn theatre!".

[SVT666]

http://www.fast-autos.net/vehicles/Saleen/2006/S7_Twin-Turbo_Competition/

That's no rumor, nethead.? That's an honest-to-god production car.? ?Saleen hasn't released the final product for sales or testing yet and the 250mph top speed is just a rather conservative estimate, but that car's the real deal.

I read an article that quoted Steve Saleen as saying that 270 mph is not out of the question.

[LonghornTX]

Pushrod engines have their place in many applications IMO, just not most.  For example, most small engines run much better (make more power, are smoother, etc) with an OHC system in place  (this would probably be why Nethead says 90% of cars around the world have ohc setups as most cars around the world are small and need a small engine).  But for some applications, like sports cars and large pick up trucks, push rod designs still hold relevant positions in the market. 

And, if I am not mistaken, that article about the Saleen S7TT competition states that it is only pushing 5.5 PSI.  That is certainly not a huge amount of boost if I interpretted the article correctly and it certainly seems that the engine probaly could take more if they wanted it to.

[JYODER240]

?

And, if I am not mistaken, that article about the Saleen S7TT competition states that it is only pushing 5.5 PSI.? That is certainly not a huge amount of boost if I interpretted the article correctly and it certainly seems that the engine probaly could take more if they wanted it to.

I think that maybe 5.5psi through each turbo.

[LonghornTX]

I think that maybe 5.5psi through each turbo.

Even if that were the case, 11psi is still not a huge amount....

[Nethead]

sandertheshark: Sanderdude!  Thank you for the link to the Saleen S7 Competition!  The Nethead here was beginning to wonder if Steve Saleen had run into technical difficulties--or perhaps into a customer affordability issue!  I want Saleen to put it to the test--at Nardo, and equipped exactly as any S7 Competition would be sold to any (rich, very very rich) customer.  Nardo is tough--the McLaren F1 that held the speed record for a decade was able to reach 240 MPH at VW's 9 km straight strip in Wolfsburg, Germany.  The McLaren folks ain't chickenshit, so they later took the F1 to Nardo.  It was 13 km/hr slower there on the loop track, and that is considered a typical drop in speed when switching from VW's long, long, loooong dragstrip to Nardo's loop track.  Even at 13 km/hr under 240 mph, it was still the fastest production car until the Koenigsegg CCR set a new record at Nardo in 2005.  If the Saleen S7 Competition can walk the walk, let it do so at Nardo and it will get the worldwide recognition it would deserve by setting a new production speed record there.  Gooooooooo, Steve!

[Nethead]

HEMI666: Hemidude, the Nethead here took in the Grand American Cup season opener at Daytona International Speedway this year as the spouse and I were through there on our way to Miami.  The spouse actually enjoyed herself at the race, which was cold up in the grandstands even in the Florida sun.  The thing that may surprise you is that the FR500C sounds just like a NASCAR stocker, only quieter because of the mufflers the Grand Am officials penalized them with--whereas the Mini Coopers were horrifyingly loud, raucous, noisy bastards!  And they were as slow as they were loud.  As Churchill said, "Never in the field of automotive competition has so much noise resulted in so little speed."  Or he would have said that if he had been there. 

[sandertheshark]

I think that maybe 5.5psi through each turbo.

It's actually 5.5psi on top of what the 750hp S7's turbos were making.

[r0tor]

displacement is a major factor for torque, and i can't see how an 8 litre 16 cylinder engine makes more torque than a 7 litre 8 cilinder engine.

true, but in forced induction engines the boost curve becomes a much bigger piece of the torque puzzle -

you could have something with a constant boost pressure and flat torque curve like a roots supercharger, or have a turbo setup that either trades top end power for no lag and down low torque or is sized for max power output and lots of lag.