dxacer01

Does Anybody know where I can get a six speed tranny for my 2.8 v6? Does Gm even produce them? I see hondas and crap that have them, so I figure someone will make one that will fit my bird

Thanks

crazy3rdgen

iTrader: (1)

why would you want one for alittle 2.8

RTFC

Let me be the one to remind you that this is a tech board and thats not your concern.

Either answer his question or please do not respond- its not you job to oversee his opinion.

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Dx, I don't know much about the manul trans in these cars but I do know that alot of guys are doing T56 swaps and I assume the V6 bellhousing wthat bolts to a T5 will also work for a T56 just like the V8 T5 bellhousing work with T56's

Dean

crazy3rdgen

iTrader: (1)

just playin

RTFC

I made another friend I see.

Xophertony

i am also very interested in a six speed. and i will tell you why....
i figure if you add another gear it will both allow the car to achieve a higher top speed. (or in my case allow me to do 75MPH, my top speed, at less then 3.5k) and lower the gear ratios slightly for 1st 2nd and 3rd gear. making for better acceleration off the line. both of these things i am a fan of. my dads haundai tiberon has a six speed. he hates "all the shifting" i like it.

dxacer01

I really want it for gas more then anything, I am already getting around 25-30 city and 34-38 on the highway, I want to be able to do around 80 at 1.5 or 2 (thousand) rpm I am near 3 when i am doing 80 now.

Ps. I drive slow which gives me alot better gas, I usealy do near 60mph at 2000 rpm, but i am tired of having to leave early because i want to save gas, I think the six speed would help out alot.

dxacer01

Also what parts would I need from a donor car? I read the article on here about doing the swap.

TechSmurf

Yeah.. you're pretty good at that occasionally... I'm not sure I even want to see what his reply originally said.

Honestly with a fairly stock 2.8, it's quite probable the .5:1 overdrive would be totally useless. Gas milage could go down from the throttle setting required to generate enough torque to maintain speed... but since nobody has tested this...

What you'd basically need is a "retrofit T56" and a custom clutch to accept the 1 1/8" 26-spline input shaft, and a custom pilot bushing, to adapt to the V6. Doward should have access to all of the above fairly soon for his V8 T5 swap (I give his existing tranny one good 1-2 or 2-3 shift with the T61+Zexel Torsen). Getting the retrofit version to work will be interesting enough, using a normal LTx/LSx T56 on the 60 degree platform may not prove remotely feasable.

Doward

Gee, thanks for letting the cat out, TechSmurf!

Yes, I'm working on being the first guy to run a V8 tranny behind a V6. I got a V8 WC T5 (.63 overdrive baby!! No need for 6 speeds here!!!) that I'm working out all the measurements and all for the clutch to work.

As soon as I get the $175 to rebuild the V8 T5, It'll be going in - I'm building a clutch kit for anyone that wants to use a 26 spline V8 tranny in the 60V6.

ScrapMaker

wow I get 15 city, and no more than 20 on the highway...

even though my tranny lets me sit at 2200rpm at 80mph... seems like I'd get good mileage... oh well...

i got that 20 mpg when I kept the engine at 2,000 rpm all the way to the coast... 3 hour drive. I didn't accel for hills or anything... I was astounded to get that mpg too!!

rebuilt motor... no bad sensor readings either... is it my tranny? I have never heard of any thirdgen getting as high mpg ratings as you... 25-30 city is better than a lot of new cars... and nearly 40 highway??? I don't believe it.

the optimum speed to travel is around 40-50mph to get highest mpg out of a vehicle... is that what you are doing?

dxacer01

I drove from Palm Bay FL to Houston County Ga and then back, I filled up in Houston County then drove back to palm bay. on the way up i drove between 65-75 taround 2.5 - 3.0rpm i went 431 miles I put in 13.9 gallons on the way back I did 60mph at 1.9 - 2.0 rpm the way back had no stops or slowing down it was almost perfect conditions way back went 443 miles when filled up 12.8

Trip there 31mpg
Trip back 34.5 mpg

I thought i read somewhere that GM was going to be producing a 6 speed for the v-6 in the first quarter of the year? anyone know anything about this?

ScrapMaker

still.. what do you other guys get?

here's from Edmunds.com the EPA ratings.. which are always optimistic

"Fuel Tank Capacity: 15.5 gal.
EPA Mileage Estimates: (City/Highway)
Manual: 19 mpg / 27 mpg Automatic: : 18 mpg / 27 mpg
Range in Miles: (City/Highway)
Automatic: 279 mi. / 418.5 mi. Manual: 294.5 mi. / 418.5 mi."

somehow your car is godlike compared to others

man it sucks that a new trans am gets the same or better mileage than our v6s... for shame

"Fuel Tank Capacity: 16.8 gal.
EPA Mileage Estimates: (City/Highway)
Manual: 19 mpg / 28 mpg Automatic: : 18 mpg / 26 mpg
Range in Miles: (City/Highway)
Automatic: 302.4 mi. / 436.8 mi. Manual: 319.2 mi. / 470.4 mi."

Doward

I knock down 20-22 with the turbo, and my heavy lead filled foot.

If I'm being easy on it, 24-26mpg

ScrapMaker

will the turbo give you better gas mileage if it alows your car to work at lower rpms with higher torque output?

mw66nova

iTrader: (13)

i use to get 28 or so highway with my v6, get around 22 now with my carbed 305.

86Chicken

Putting a 6sp with a 0.5OD behind an otherwise stock-ish 2.8 would be pointless. My guess is that the gas mileage would drop for the reasons mentioned above.

Even my 90 Vette 6sp w/ 3.33 rear gears (my Bird has the stock 3.42) has trouble from time to time - the 2.8 would never be able to use it. The gearing would be fighting it and the V6 would lose.

A turbo'd 2.8-3.4 would probably be a different story. I have never driven a turbo car so I cannot comment on how it would react during cruise w/ little to no boost. It would be an interesting experiment.

BTW:
Bird 2.8 5sp-> 30-32 Hwy
Vette 5.7 6sp -> 28-30 Hwy

The Bird gets MUCH better city mileage tho.

Doward

Cruise would be fine. If you give it an additional 30% throttle or so, you start to build boost - aka torque

ScrapMaker

how the crap do you guys get such good gas mileage!!??

20 max on the highway for me... 3.1

is there a huge difference between 2.8 and 3.1?

bah I should be getting at least 25-27 on the highway... I just can't figure out what's wrong... can an old tranny really rob like 30% of my power/efficiency?

im running 2200rpm at 80mph... seems pretty efficient... this is weird... regardless of transmission efficiency, I AM getting that engine output, and speed at the wheels... or close to it, anyways.

dxacer01

I agree i think putting a tranny made for a v8 in the stock 2..8 would be pointless. Thats why i wanted to know if they made one for the v6's. I am sure they do, I just can't find where to get one. I have seen 6 speeds on geos, little mazdas and such that are 4 cyl. 's and have six speeds that work just fine.

Geyservillebob

22 max for me on the highway with my 3.1L.

I thought mine ran pretty damn good but listening to people pulling nearly 30 makes me thing something is wrong with my motor.

Frank

ScrapMaker

I don't think they are getting that much... that's like a brand new car pretty much... 35 mpg?? dunno I'd love to drive that car for a whole tank and we'll see...

qytum

30 mpg is very possible, had an 88 bird with 2.8 that could do 28 mpg. Obviosly that is with no driving it hard. My 91 bird now with the 305tbi gets 23 to 25mpg. You should definately get over 24mpg without flooring it with a 2.8. If not you must have some sort of problem.

Black85sport

my 88 2.8 hardtop bird will knock down 26 on the highway at 75 mph

ScrapMaker

I think its the 2.8 that's giving you guys the mpg, because my 3.1 is rediculously worse on gas mileage than your motors.

camaro_junkie

You should also check out this section of TGO: https://www.thirdgen.org/newdesign/t...ulations.shtml

There are some tranny gear ratios here for different years/engines. So you might be able to obtain a different gear set and get the results you want. For instance, for some reason the T5 for the V6 in 1986 (my car's year) has the first gear at 3.50, whereas for other years it's 4.03. I would rather have had the 4.03 set.