4t40 upgrade?

[rluck9277]

I have a 2003 malibu that i am planning on getting an MMS stage 2 kit for. that would give about 225 to 250 hp at the crank, the kit comes with a pcm programmed to increase shift firmness, i also planned on installing a trans cooler, i was wondering if stock transmission will be ok or if i need to modify it? thanks for any help

[prophiseer]

I honestly don't recommend a T40/45 for anything but n/a - if your going to run boost, swap the tranny with a 4T60/65; it'll hold up a lot better.

[rluck9277]

yeah, i wasnt planning on any boost, i am only going to keep this car till the new camaro comes out, but it is underpowered and want to get some power out of it but no nos or turbo or supercharger

[prophiseer]

What brand of PCM is it?

For starter's I'd recommend buying a Derale frame rail cooler (about $35)through Summit or Jeg's for the tranny, and position it in front of the condenser (you'd need to make a small connecting bracket for either side), but this is the most efficient way to run a tranny cooler, you'll end up with about 1"-1.5" between the tranny cooler and condenser. All those other kits that come with the push-through tabs to mount the cooler directly on top the condenser just turn the tranny cooler into a highly efficient heat exchanger.

Also, a tranny interceptor through either AutoTrans or Granatelli would be good also, so you can boost up the line pressure a bit and firm up the tranny's shifting. If you feel up to buying a mechanical oil pressure gauge (0-300 psi) and tie it into the line tap on the casing, you can set the line pressure a lot more efficiently than by just feel alone.

Reguarly changing the filter and tranny fluid is a must. I use Castrol DexronIII and have yet to burn their tranny fluid up (which amazes me considering how I drive). I als recommend the use of ProLong tranny additive ($15-$20 a bottle), it significantly helps reduce friction and wear inside the tranny.

mechanically, as of now, there's not much known that one can do to the T40/45. But the boosted line pressure and a cooler should really help. I think you can prob get by with the tranny, but there's always that chance . . .