mr corsa

hi guys not much of a poster but im looking into doing a auto 4t65e conversion on my car and if you guys knew to much about then and wot to look out for
cheers tony

USMCFieldMP

iTrader: (1)

No one has really ever done one.

The GM Build Book is pretty much your only guide on how to do it.

HunterKiller89

iTrader: (1)

do you guys know if the 6T70 or 6T75 will bolt up? its a random question, but i dont think anyone has ever asked before. 6sp auto wtf! FWD is still FTL tho

celicacobalt

why not use a built 4t45? That fits perfect.

HunterKiller89

iTrader: (1)

i may have answered my own quesion. the staurn aura XR uses the 6t75...and im pretty sure the aura XR uses a LE5, which means it can bolt up to an ecotec. I wonder if there is any modification tho...

its rated at 315hp 300tq too
if my tranny ever gives out...im upgrading

Sharkey

iTrader: (1)

the 4t65e would be your best bet, but still not easy. getting the tranny in there may take some clearancing, it is rather large. you will need to use a bates flex plate and adaptor plate. mounts will be custom most likely. axles, well there are the gm race stuff but its very expensive, aside from that it may be custom. run an aftermarket controller, itll simplify the wiring.

the 6t75 would be a tough swap. yes it will bolt up. no clue on the alxes working, nor mounts. the biggest issue is controlling this beast. the transmission has the tcm mounted on the valve body inside the transmission and you only have power and 2 seriel data wires comming out of the tranny. the stock pcm will not comunicate with it, you would need to fit the entire wiring harness and all modules from the car the tranny came out of for any hope of this working. aftermarket controlls are non existant yet.

Maven

iTrader: (1)

Neither the 4T65 of the 670/5 will bolt up to the ECOTEC There is an adapter plate available for the 4T65, and it would work for the 6T70/5 as well.

BOTH would require an adapter plate, custom mounts, custom axles, custom flywheel, custom cooler lines.

The 4T65 I think requires engine relocation, so that means custom engine mount too, and custom exhaust. You could in theory get the stock TCM to control a 4T65 as they both use 2 shift solenoid, a TCC solenoid and a PWM Pressure Control Soleoind, but...the trans's use different range logic so that would even be difficult, not to mention fluid temp input, Park/Neutral detection and on and on. A 4T65 is for race use.

A 6T70/5 would be extremely difficult and isnt really even worth discussing.

The 6T40 is available in an ECO friendly model. This trans comes on the LE5 powered high end G6/Malibu/Aura sedans,

It will bolt up, flywheel isnt an issue either. You would still need custom mounts, custom shift cable, custom cooler lines and custom axles. And of course youd have to have to switch to an '09 LE5 PCM and fabricate/modify engine trans/harnesses. And then hope your BCM will like everything your Z-car PCM has to say.

If you want an ECO powered 6 speed auto car, wait til the Cruze or the Alpha/Torana sedan comes out.

qwikredline

both you and sharkey have a good handle on this i can add that no way in hell will you be able to get the bcm to communicate with it so its clear anything is possible but in this case you cant pay what it would take to do it and the result is clearly not worth it....tens of thousands of dollars to do a workaround on this project....

HunterKiller89

iTrader: (1)

so basically...upgrading to the 6t75 would probably be easiest if using something like a stand-alone system?

Maven, could you possibly elaborate on the PCM/BCM issues related to the 6t40? Hoestly, this is probably way outside of any future price range i have, but its all info that i'd like to know and i like to research all options

Sharkey

iTrader: (1)

all the new gm 6 speed autos have the tcm (transmission controll module) in the pan bolted to the valve body. again, with the 6t40 there are only 3 wires, power and 2 seriel data. its the same issue as the 6t70/5. there is no stand alone controller that will work with these transmissions. to even attempt something you would need to madify the tranny and run wiring for all the solonoids and speed sensors out of the transmission to a stand alone tcm.

the 4t65e is still the best swap thats going to hold massive power. as far as running a stock pcm using the 4t45e logic to control a 4t65e, the amount of work that is isnt worth it, a stand alone controller will plug in and work out of the box.

if your under 400hp, build up a 4t45e, they can hold a lot of power when built right.

HunterKiller89

iTrader: (1)

i would look to upgrading to a 6sp for the closer gearing more than for holding power...as you said, i would rather build the 4t45 to take more if it was merely just trying to hold more power.
There also appears to be a slightly beefed up 6t40 aka 6t45
all i can find is the 6t40 is rated at 177tq, and cant find anything on the 6t45
the main differences between the two is the 6t45 has a thicker ribbed case to make it stronger, a 1.25" output chain opposed to the 6t40's 1" chain, and the 6t45 uses a 5 pinion gearset for the input gearset opposed to the 6t40's 4 pinion gearset.

im not really sure what this means the 6t45 can hold....but it seems like a fun project to build up a 6t45 and have a 400tq handling 6sp automatic

the only downside i see to this transmission is its very widely set... which makes for great economy with a very tall overdrive gear, but 1st gear has a 4.58 ratio....thats waaay to short for a blown car....no traction at all.

1 4.584
2 2.964 2.95
3 1.912 1.62
4 1.446
5 1.00 1
6 0.746 .68
R 2.94 2.14
F 2.89 3.63

1st with 4t45=10.7085
2nd with 4t45=5.8806
3rd with 4t45=3.63
4th with 4t45=2.4684

1st with 6t45=13.2772
2nd with 6t45=8.5660
3rd with 6t45=5.5257
4th with 6t45=4.1789
5th with 6t45=2.89
6th with 6t45=2.1559

Maven

iTrader: (1)

The 6T7X DOES NOT attach to the ECO, and it would most likely require large amounts of cutting and repositioning to get it to fit in the Cobalt engine bay.

The 6T40 DOES bolt to the ECO but youve still got the issue of needing custom just about everything. And of course youd have to basically convert your Cobalt over to a G6/Malibu electrical system.

The 6T40 as you pointed out is not intended for high power, The LE5 is most likely the most powerufl engine you will EVER see it bolted to. I wouldnt say they are delicate, but They do use relatively small clutches and small gear contact areas. The 6T45 isnt available in any vehicle sold in the USA, In fact the only vehicle I think it comes in at this time is the Chevy/Holden Epica, which used to ba available in Canada, not sure if it still is. The main reason for the 45 isnt for high power though, the 6T45 is the version used for AWD platforms.

And as far as having too much gear for a blown car.....you need to pull out the ratios on an F23, the 6T40 has nearly identical first gear.

HunterKiller89

iTrader: (1)

you're right....of course the F35 first gear produces a ratio of 13.689...even shorter than the 6t45

well, again, this is something i would never be able to afford anyways...

tru2nrtt777

iTrader: (1)

So in theory by what I just read it seems asthough I could use a manual 06 ecm with the 4t65 and a stand alone tcm?

Omega_5

... you can.
Talk to the Fiero guys... they've done it many times.

tru2nrtt777

iTrader: (1)

Cool, and they say hondas are the only ones who can swap components with no problem.

Omega_5

You still need to adapt the tranny physically, though.

Maven

iTrader: (1)

And we still come back to the whole WHY do you need a 4T65???

Is it to be unique. OK.

Do you think you NEED it? the 4T45 when built can EASILY handle 400hp, and F23s if not abused have held up to well in excess of 500hp.

HunterKiller89

iTrader: (1)

QFT. the only way i do a tranny swap on my car is to add more gears...and i cant even afford to do that! lol but the 4t45 is a beast. harden the axles, get some blue plate special clutch packs, and cryo everything and your good to go for massive power Dont forget a tune!

tru2nrtt777

iTrader: (1)

My buddy has been dyno'd at 675 hp in his GTP with that trans and it has held up great... so far.

Maven

iTrader: (1)

GTP? as in Grand Prix? That shold have a 4T65.

HunterKiller89

iTrader: (1)

thats what he's saying. Hes saying since his friends GTP's 4t65 can take the 650hp that his friend is throwing at it, he wants one too.

Sharkey

iTrader: (1)

the 4t65e is whats used in the gm pro fwd cars, built right it can take 1450hp.

HunterKiller89

iTrader: (1)

unless your planning on pushing that kind of power, which i highly doubt, its much cheaper and more sensical to build the 4t45 to take 500hp

Maven

iTrader: (1)

Well he quoted my post where i was discussing the capabilities of the f23 AND 4t45, and he said "my buddy dyno'd with that trans" Hence my confusion.

As far as I know the 4T65 stops getting used at about the 1000hp mark. The ProFWD guys use XTRAC sequential manual transmissions and multidisc slipper clutches.

And while it may be obvious I feel it needs mentioning that a 4T65 that will hold upwards of 1000hp is very expensive, very serious piece of custom built race equiptment that isnt suitable for the street, and as a side note, no longer even a 4 speed(they convert it to 3spd) It looks like a 4T65, and thats about all you can say