6-speed vs Automatic

teal32 · October 19, 2007, 06:21:18 PM

I'm starting to see allot of hot rods with 6-speeds. Is this the new trend, or am I just starting to notice them more? Not sure I want to shift more in my old age. But, it would be fun to drive a stick again. Will the 6-speed get that much better gas mileage over, let's say, a 700R4, or an overdrive tranny? In the back of my mind, I've thought about changing the TH350 out, so maybe this is the way to go.

Carps · October 19, 2007, 08:12:11 PM

Why not a six speed automatic? Most of these come with a manual function just no clutch pedal.

Generally 5th and 6th are overdrive ratios in these transmissions, so yes on highway fuel mileage should be much better thanx to the higher top gear.

I also have an 8 speeder which again has only two overdrive ratios. As a result first is slightly lower and all the others up to the 1/1 6th are closer together which translates to less effort toget the car moving and even better fuel consumption. It's also designed for manual shifting if I desire and it's very clever being able to skip ratios and choose only what's appropriate for any given driving situation.

But in my hot rod? There's three pedals and four forward ratios,

And my Kustom has everything in multiples of three, six pistons, three pedals and three forward gear ratios.

When it all boils down, go with what suits you best, you'll never be happy otherwise.

1FATGMC · October 19, 2007, 10:40:49 PM

Quote from: "teal32"......... Will the 6-speed get that much better gas mileage over, let's say, a 700R4, or an overdrive tranny? ................

Probably not as the final gear is very close to the same and that it the gear you will be in the most if you are talking highway driving. The 6 speed would offer performance rewards in acceleration. GM now has a 6 speed auto much like Carps talked about, but I'll bet they are very expensive at this point. Have to wait a few years for them to show up in the salvage yards.

I'd love a 6 speed in my truck, but it is just too tight for the pedals and the rest of the stuff that goes with a standard.

c ya,

Sum

jaybee · October 19, 2007, 11:34:08 PM

I'm happy to see an increase in manual trans cars. I enjoy driving them but then again I don't see a lot of stop and go driving, either. The T56 six speed is a really strong unit that is well suited to today's higher horsepower engines. It's also very heavy and physically large.

dragrcr50 · October 19, 2007, 11:36:36 PM

we have a 2000ss camaro convert with ls1 6 speed . it gets about 26 mpg on the road on a long trip and will run a 12.99 qtr... not bad for a gm pig in todays world

Crosley.In.AZ · October 20, 2007, 12:56:01 AM

Quote from: "Carps"Why not a six speed automatic? Most of these come with a manual function just no clutch pedal.

Generally 5th and 6th are overdrive ratios in these transmissions, so yes on highway fuel mileage should be much better thanx to the higher top gear.

I also have an 8 speeder which again has only two overdrive ratios. As a result first is slightly lower and all the others up to the 1/1 6th are closer together which translates to less effort toget the car moving and even better fuel consumption. It's also designed for manual shifting if I desire and it's very clever being able to skip ratios and choose only what's appropriate for any given driving situation.

But in my hot rod? There's three pedals and four forward ratios,
And my Kustom has everything in multiples of three, six pistons, three pedals and three forward gear ratios.

When it all boils down, go with what suits you best, you'll never be happy otherwise.

those trans bolt to a GM engine?

:?

Carps · October 20, 2007, 09:18:17 AM

No reason they can't be made to fit any engine.

We are hot rodders aint we?

Crosley.In.AZ · October 20, 2007, 10:01:50 AM

Quote from: "Carps"No reason they can't be made to fit any engine.

We are hot rodders aint we?

I was curious if an expensive adapter was needed. looks like that answer is yes.

jaybee · October 20, 2007, 12:02:32 PM

I seem to have something lodged in the back of my memory about a Toyota 5 speed that was plenty sturdy, available at a reasonable cost, and adaptable to a GM engine. Can anyone enlighten me on this?

enjenjo · October 20, 2007, 01:33:53 PM

Supra 5 speed Real popular in Oz. There are adapters available from Castlemain Rod Shop in OZ, or Advanced Adapters in the states. I've picked up three of them.

Crosley.In.AZ · October 20, 2007, 01:48:40 PM

Quote from: "enjenjo"I've picked up three of them.

are they very heavy weight?

1FATGMC · October 20, 2007, 05:53:59 PM

Quote from: "enjenjo"Supra 5 speed Real popular in Oz. There are adapters available from Castlemain Rod Shop in OZ, or Advanced Adapters in the states. I've picked up three of them.

Have you installed any yet?? How much do they go for at the salvage yards?? How much is the adapter?? And yes I'm interested in the answer to Tony's question -- how much torque/HP are they rated for???

c ya,

Sum

jaybee · October 20, 2007, 06:13:28 PM

Seems like there's a real spot for an overdrive transmission that will take some torque but not be overkill. As an example, a 6.0L LQ9 from a GM truck has enough torque to be a questionable match with a T5, but a good, low mileage T56 can run $1500. At 4-5x the cost of a used T5 it's a considerable bite. If you're running a really strong motor a T56 is a great option but a box that'll take 700hp seems like overkill if your target is 400. Wonder what the availability is of the Supra trans, or do any of the Toyo pickups come with something that would work?

Carps · October 20, 2007, 08:07:14 PM

Quote from: "Crosley"
Quote from: "Carps"No reason they can't be made to fit any engine.

We are hot rodders aint we?
I was curious if an expensive adapter was needed. looks like that answer is yes.

I'd imagine so but since I haven't tried it yet, I dunno how expensive or complicated. I'd say the bigger issue would be getting the engine and trans RCUs to communicate in the samme language.

1FATGMC · October 20, 2007, 09:08:20 PM

Quote from: "Carps"...............I'd say the bigger issue would be getting the engine and trans RCUs to communicate in the same language.

These people.....................

http://www.powertraincontrolsolutions.com/content-4.html

...................make transmission controllers for transmissions that need them like GM's 4L80E and 4L60E and say they have them for:

Toyota, Lexus:

·A340E*, A343E*, A650E*, U140F, U240

Are any of the transmission you were thinking about in that list?

They also say they are interested in working with customers to cover more transmissions.

I'm looking at one of their computers to control a 4L80E that I have and that I want to put into my truck. I'm going to talk to them this next week.

c ya,

Sum