The 4-speeds in current use are evolutinary copies of the Ford "top loader" (Jerico) and the Borg-Warner T-10 (Tex "T-101&quot One of the major differences is that these transmissions are available in a wide variety of ratio combinations - low gears range from ~3.5/1 to ~1.8/1.
Rear gear ratios are easily changeable as well - when DW mentions a "gear", he is talking about a removable carrier assembly, which holds the ring & pinion and the differential - 2 guys can change one in about 20 min. Available gears range from ~2.6/1 to ~7/1.
with these options available, it's pretty easy to get a gear combination that works for the particular track.

Cost is not a small issue - Quaife just introduced a new hi-torque racing transmission, to compete in the same market as the Jerico.
Jerico =$3500, Quaife = $14K Jerico has a 5 spd sequential for Grand Am & SCCA, goes for ~$7500.
How many transmissions does a Cup team have in stock, per car/driver? I'd bet a dozen...

Which is what most 5th and 6th gears are. Most cars with an overdrive high gear will go faster in their direct drive (1/1) gear than in overdrive. How is this possible? There is not enough power available in o/d!

Nascar Cup, and their other divisions are a production based racing series. -The transmissions currently used are updated versions of production transmissions.
F1 engines turn 15000 rpm plus, and do not have a particularly wide powerband - thus the need for more speeds, with closer ratios, and the paddle shifters, cuz' ya gotta shift so much to kep the little missle up in it's powerband. The big beast of a sedan has similar horsepower, but turns 1/2 the RPM, with a broader powerband.
The other thing is - 7 speed, paddle shifters would increase costs considerably (especially with the necessary sophisticated engine control software), and would not improve the show.

If NASCAR needed 7 speeds to win, they would have 7 speeds. For the ovals, the get out of the pits and get into top gear and stay there. The road courses don't need 7 gears to negotiate with the wide powerband and prodigious amounts of torque available from the pushrod V8s.

you don't need the extra gears.

And the only relationship NASCAR cars have to their street brethren, is name and approximate sheetmetal profile.

And none of it's venues is a circle. I know of a couple that are close - do you know which ones they are?

The road races are the best part of NASCAR, I wish they had a lot more of them.

Several series for tubeframe, composite body cars (aka pro stocks, super late models) like GT America, also often appear in SCCA GT1 and Super Production.
There are a couple series, allied with vintage clubs, that run older Cup cars - some in original livery. And there are enough cars to often make them a standalone race.
And quite a few time trial, "track day", "open road", hillclimb, etc cars based on stock car stuff, like the Troyer modified in the "I built the engine" post here.

Nascar transmission bare to resemblance to any current transmission. They have a striking resemblance to cars of the 60's trannies though.

With rare exception, any current production transmission would fail spectacularly the instant the clutch was dropped at full power in a NASCAR Cup car.

...it's not the lowest common denominator of motorsport without reason you know....

Witness this picture of NASCAR Hall of Fame Richie Evans'



Lowest common denominator? Can't be the lowest, without Lucas electrics and SU carbs........

...bringing a new meaning to the phrase 'completely f*cking useless'....

My buddy's Shitfire runs pretty good with a couple Italian carburetors and a spark box made in Texas. The Japanese ND alternator works nice, too.

Frequently re-labeled "Lucas, Prince of Darkness"....

Introduced to them on old Land Rovers while stationed in Britian. Good times....

Dim
Flicker
Off.


Why do the British drink warm beer?

Because the refrigerators are made by Lucas.

Just this year, NASCAR Sprint cup made the change from carbs to EFI.

so they work fine with 4 speeds. Formula1, Indy cars, and Sports prototypes make all their power in the upper RPMs, with a narrow torque band... they need the extra gears to keep RPMs up in the slow corners.

You are forgetting they use 6speed transmissions on LMP cars and the past decade have been dominated by diesels with power coming from as low as 2500 rpm with a peak of round 6000-7000 rpm but to + to his answer ? NASCAR doesn't need more gears on ovals but they prove useful on the road courses which brings us to another ? SHOULD NASCAR RUN MORE ROAD COURSES ? personally I think they should but which races to cut from the season ? They have so many great tracks and they've already cut several great tracks from the schedule to accommodate new tracks I'd rather they expanded the number of races in the schedule

Of which there is less dollars available to NASCAR. A teams funding from a major sponsor being more on par with a F1 co-sponsor.

The Nascar driver is also manually throwing the gear shift while in F1 the mechanism is powered. Making the shift take slightly longer and as drag racers discovered. There is a point of diminishing returns when each shift is a few hundred milliseconds of no power.

If money wouldn't improve the market explain how the companies continually upgrade their products almost annually.

How will adding more gears to the transmission improve the competion in NASCAR racing? please be specific......

My preference for One Huge Change would be to put a speed-measuring device that doesn't require the engine be running into the cars - they measure pit road speed with their tachometers, which can't work if you're out of fuel.