High vs low gear count transmissions

[JimBill]

The only thing I have noticed with an auto transmission with more than 5 gears is that they are guaranteed to always be in the wrong gear or can't decide what gear to be in.

I prefer manual transmissions but presently do not own a vehicle with one. California just doesn't like them so they are rare here.

 

[Downs]

The only thing I have noticed with an auto transmission with more than 5 gears is that they are guaranteed to always be in the wrong gear or can't decide what gear to be in.

I prefer manual transmissions but presently do not own a vehicle with one. California just doesn't like them so they are rare here.

Not just California. Less than 4 percent of cars sold are with manuals nation wide. With only 25 or so percent of models sold in the US even being avaliable with a manual.

 

[Shakes355]

My biggest issue with 6+ speed transmissions is the programming. Proper tuning makes all the difference. Never trust the manufacturer to choose your gear for you.

 

[tjZ06]

Off the top of my head, drag racing, mud bogging, rock crawling, competitive hill climbing. you wont find 10 speed trans there buddy. Transmissions with 4+ gears or overdrive are better suited for going highway speeds while hauling stuff or if your worried about gas mileage. If you have a ton of power and you want it fast and now a 3 speed th400 is the way to go.

The reason you don't find a 10 speed auto in drag racing, mud bogging etc. is because they just haven't been around long 'enough to get worked out for those scenarios. That said, if you've ever seen a automatic 6th Gen ZL1 make a pass at the drag strip, you've seen a 10 speed drag racing. I personally know of about 10 1,000 RWHP C7Z06 with 8 speeds or 6th Gen ZL1s with 10 speeds... none have converted to TH400s. I also was partners in a low-low 9 street-race/drag '63 pickup that runs a 2-speed Powerglide. Also, you find plenty of 8 speeds in all of the 8 speeds in all the Hellcats/Demons/Trackhawks/etc. Anyway for a PURE drag or mud rig (not one that drives to/from the track/bog), I get it: you're not going to use 10 gears. And for mud-bogging and such the proven strength and reliability (and simplicity) of something like a 'glide or TH400 is king. I can agree, for those pure, single-purpose rigs the 4+ overdrive gears are useless in those scenarios.

So, I'll rephrase: "what is the Overlanding scenario, knowing that we use our rigs to go as far or further on the freeway to find dirt than we actually do in the dirt where more gears aren't better?" This is an Overlanding forum, after all...

-TJ

 

[MazeVX]

I don't get it sometimes... It's pretty simple, low gear count has its use but high gear counts, now that they are available and manageable, has its use also. Just not in the same way or vehicle
1/4 mile with a 10 speed? No way but having the right gear for every load situation and every speed on a trail or pass? Yes absolutely!
Using the engine almost all the time in the ideal rpm range is absolutely beneficial.

 

[tjZ06]

1/4 mile with a 10 speed? No way...

IDK, guys are going 9s with cars that weight nearly 4k lbs and drive to/from the track with AC on.



-TJ

 

[MazeVX]

IDK, guys are going 9s with cars that weight nearly 4k lbs and drive to/from the track with AC on.



-TJ

That's impressive and shows how good they are, I guess they don't run stock transmission software?
I had my auto transmission (wa580 jeep wrangler factory diesel) just reprogrammed and torque curve optimized about 2 weeks ago and it's a huge difference to stock.

 

[tjZ06]

That's impressive and shows how good they are, I guess they don't run stock transmission software?
I had my auto transmission (wa580 jeep wrangler factory diesel) just reprogrammed and torque curve optimized about 2 weeks ago and it's a huge difference to stock.

Stock ECM and TCM in those cars, along w/ stock operating systems on them. Yes, some tuning has been done, but that is "stock transmission software." Technology is good, and we live in a great age for crazy fast stock-ish cars.

Anyway, sorry to have taken this so far off-track. Going back to Overlanding, I really don't think there's a scenario where the new 10 speeds aren't the better transmission for us. In fact, we are probably the exact best use-case for a 8 or 10 speed. As Overlanders, we do technical off road stuff where we need deep low gears. We also do long freeway pulls and often DD our vehicles so comfortable highway cruising and MPG are key to us as well.

-TJ

 

[MidOH]

Fast dragsters don't even have a transmission. Just a clutch. If they had modern technology, drag racing would be so fast, it wouldn't even be possible anymore. Real lame axle ratios, carbs, and only 1000' tracks now.

Playing with plated street cars is cute and all. But it's just masturbating with money. Hardly autosport.

F1 has 8 speeds. And reverse is mandatory.

 

[tjZ06]

Fast dragsters don't even have a transmission. Just a clutch. If they had modern technology, drag racing would be so fast, it wouldn't even be possible anymore. Real lame axle ratios, carbs, and only 1000' tracks now.

Playing with plated street cars is cute and all. But it's just masturbating with money. Hardly autosport.

F1 has 8 speeds. And reverse is mandatory.

Are you suggesting Funny Car/Top Fuel run carbs? They've been (mechanically) injected for as long as Funny Car/Top Fuel have been a thing. I'd hardly call the technology in the top-tier of drag racing not-modern. And what about all the door-slammers and pro-mods? They ALL run a transmission (whether it's a 'glide or TH400 based auto or a clutch-assisted manual such as a Lenco or G-Force). I know Street Outlaws has a ton of "reality show" BS built-in, but some of the cars are impressive. The Fireball Camaro is in the 3s at over 200 MPH in the 1/8th... I'd call that both QUICK and FAST (drag race people will understand) with a TH400-based transmission.

Are you familiar with Drag Week? Guys are going 5's in the 1/4 mile with "cute" street plated cars that have to put in hundreds of street miles between tracks, and some have finished with averages in the 6s.


I think Drag Week is one of the TRUEST forms of AutoSport left right now. Mostly regular guys, very few sponsor-dollars, tons of rule-book-bending-all-American-ingenuity. Drag Week always has lots of breakage and interesting track-side repairs. It's really, really good auto sport and I'm really not even a drag-guy myself (I did AutoX and Road Course for years). F1, NooseCAR, and most road course stuff just isn't great to watch anymore.

Even daily-driveable street cars have gotten into the 9s commonly now, even 8s. My girl's DD only runs 11s, but the 8 speed is a big part of why it does it.



So... ummmm, agree to disagree?





Back to Overlanding, more speeds is mo-bettah!

Anyway, sorry to have taken this so far off-track. Going back to Overlanding, I really don't think there's a scenario where the new 10 speeds aren't the better transmission for us. In fact, we are probably the exact best use-case for a 8 or 10 speed. As Overlanders, we do technical off road stuff where we need deep low gears. We also do long freeway pulls and often DD our vehicles so comfortable highway cruising and MPG are key to us as well.

-TJ

 

[Billiebob]

A lot of people consider the auto better offroad.

the modern automatic is better everywhere !!
it only loses when things screw up. a clutch and a mechanical selection of gears will run forever.
a simple glitch in an automatic can shut it down and demand a deck truck to the stealership.
but when they work, even tho I love a clutch and have a million miles driving 18 speeds....
a modern automatic does it all right,,,,, until it fails 100 miles from civilization.
I swear by a clutch only because they are bulletproof if you know how to drive.
and if something fails??? a pair of vicegrips can get you mobile.

 

[Billiebob]

Fast dragsters don't even have a transmission. Just a clutch.

No they don't....
The fastest dragsters have been 2 speed automatics since the 1960s, 2 speed GM Powerglides at that.

Back in the 1970s I saw a stat for Top Fuel..... zero to 100mph in a car length, before the rear tires cross the start line.
I used to think the world must be slowing down.
The quarter mile is still the standard.
Anything less is just fake news for the wanna bees.

 

[MidOH]

No, I was making an example of archaic rules created to keep speeds down. Some classes, last time I gave a darn had a spec carb. Might have been a local thing.

It's just a money game now. As bad for the sport, as midget jockeys in motorcross.

Top Fuel and funny are direct drive. Centrifugal slipper clutches with some automation. Cool article:

Inside a Fuel Car’s 3,700°F Slider Clutch

We hung out with Corey Lee, Del Worsham’s clutch guy and McLeod Clutch’s Paul Lee to find out how they’re tuned and rebuilt between rounds.

www.hotrod.com

 

[Billiebob]

In 20 years trannies and fuel choices will be nostalgic conversations as we rejoyce in the fossil free world of pure electric propulsion with direct drive to each wheel thru individual motors and the ability to have 100% power at sea level or 10,000 feet above it, plus the ability to refuel with a solar panel.

As for racing......... just as it did 100 years ago..... electric energy will kill the fossil fuel competition.

 

[MidOH]

The automobile saved horse hobbies.

Racing, trail riding, whatever. Horses are mostly pets now.

 

[JimBill]

My favorite workhorse was a 99 Silverado with a 5 speed manual and 4.8L engine. 1st gear and low range and it was a crawler. Pulling a loaded car trailer was no problem either (3rd gear over hwy 58 to Mojave at 70 mph easy peasy). I got way more work out of the 4.8L/5 speed than my later 5.3L/ 3+OD automatics. More gear choices the better. But as I said earlier, although I have not driven many high gear count autos, the ones I did sucked simply due to poor programming. But.... if control is right then experience says the more gears the better for crawling, hauling, accelerating, and cruising.

Reliability of modern high gear count transmissions is my only question. Each time an automatic shifts, to make the transition pleasant, it slips between two gears for a moment. This builds heat and is the wear point. Us old guys are used to installing shift kits to speed the gear changes up, and if we don't go too stupid with it performance and reliability are greatly enhanced. With a high gear count, the transmission is shifting many more times per any given activity than a low gear count, resulting in increased heat and clutch disk wear (or so I would think, anyhow). How is the reliability these days? A few years is one thing, but I am used to running 15-30 year old vehicles and offering them no mercy.

So my question to those that drive and stress modern vehicles is: Is the reliability on par yet with the traditional workhorses (TH400, 727, C6, etc)?

IMHO- My ideal gear count is 7 gears. 1 granny, 4 speeds ending in direct drive, and a double overdrive. Make me one as strong and reliable as a TH400 with solid programming, and any gas engine I am likely to be interested in will come alive with it.

 

[tjZ06]

My favorite workhorse was a 99 Silverado with a 5 speed manual and 4.8L engine. 1st gear and low range and it was a crawler. Pulling a loaded car trailer was no problem either (3rd gear over hwy 58 to Mojave at 70 mph easy peasy). I got way more work out of the 4.8L/5 speed than my later 5.3L/ 3+OD automatics. More gear choices the better. But as I said earlier, although I have not driven many high gear count autos, the ones I did sucked simply due to poor programming. But.... if control is right then experience says the more gears the better for crawling, hauling, accelerating, and cruising.

Reliability of modern high gear count transmissions is my only question. Each time an automatic shifts, to make the transition pleasant, it slips between two gears for a moment. This builds heat and is the wear point. Us old guys are used to installing shift kits to speed the gear changes up, and if we don't go too stupid with it performance and reliability are greatly enhanced. With a high gear count, the transmission is shifting many more times per any given activity than a low gear count, resulting in increased heat and clutch disk wear (or so I would think, anyhow). How is the reliability these days? A few years is one thing, but I am used to running 15-30 year old vehicles and offering them no mercy.

So my question to those that drive and stress modern vehicles is: Is the reliability on par yet with the traditional workhorses (TH400, 727, C6, etc)?

IMHO- My ideal gear count is 7 gears. 1 granny, 4 speeds ending in direct drive, and a double overdrive. Make me one as strong and reliable as a TH400 with solid programming, and any gas engine I am likely to be interested in will come alive with it.

The nice thing w/ a modern trans is the TCM can vary the shifts a lot. In the "auto" mode the Trackhawk has barely perceptible shifts... in "track" the shifts hit HARD... really hard, like an old school TH400 w/ a shift kit, like you described. You can have both in the same trans. Of course, like you said those soft shifts do mean a little bit of clutch "slip". But it's not like a soft-shifting trans taking lots of HP like the old days where you wanted a smooth-shifting trans but had a lot of HP. With a modern setup you only have those soft shifts at light throttle, resulting in a little sip but very little heat/wear. When you're WOT the shifts are quicker, keeping you from having lots of slip under big power. With the ZFs in BMWs they call the fluid a lifetime fill, there's so little wear/slip causing so little contamination. Now, I don't buy that lifetime fill BS... but that's how confident BMW/ZF are in their shift strategies.

-TJ

 

[MazeVX]

The nice thing w/ a modern trans is the TCM can vary the shifts a lot. In the "auto" mode the Trackhawk has barely perceptible shifts... in "track" the shifts hit HARD... really hard, like an old school TH400 w/ a shift kit, like you described. You can have both in the same trans. Of course, like you said those soft shifts do mean a little bit of clutch "slip". But it's not like a soft-shifting trans taking lots of HP like the old days where you wanted a smooth-shifting trans but had a lot of HP. With a modern setup you only have those soft shifts at light throttle, resulting in a little sip but very little heat/wear. When you're WOT the shifts are quicker, keeping you from having lots of slip under big power. With the ZFs in BMWs they call the fluid a lifetime fill, there's so little wear/slip causing so little contamination. Now, I don't buy that lifetime fill BS... but that's how confident BMW/ZF are in their shift strategies.

-TJ

That lifetime fill is pretty easy, if the oil is "done" to old, whatever, the life will end.
So it's a lifetime fill...
That's pretty often the case, but honestly I do not believe that the oil will work as good as new after 100000 miles.

 

[tjZ06]

That lifetime fill is pretty easy, if the oil is "done" to old, whatever, the life will end.
So it's a lifetime fill...
That's pretty often the case, but honestly I do not believe that the oil will work as good as new after 100000 miles.

Haha, fair point. When I had my 335i I changed the fluid at 75k, even though it was "lifetime."

-TJ