Tranny Rebuild + PI 3K = More fun but lower mileage?

[Svashtar]

A few weeks ago finally had the PI 3000 and full tranny rebuild from Dennis installed. My mechanic also upgraded a couple of additional parts as well while he was in there. Also did his rear engine cooling mod at the same time.

Had to get used to the new shift patterns, but the car is a lot more fun to drive. Very firm shifts. You know how the stock MM loads up a little and the RPM jumps when you take OD off? Well, now it kind of feels like that all the time, like the car is pulling harder. No more of that "coasting" feeling I used to get, but still the car is quicker.

I think my RPM at most speeds is up a bit as well, as I seem to recall the car running at about 2150 ROM at 70 mph, and now it is about 2400. (?)

Anyway, does it make sense that after beefing up the tranny and installing the TC that my mileage would drop 1.5 mpg?

Not complaining as the trade off in performance is well worth it, just trying to figure out the mechanics of why it's happening.

Thanks as always for any info.

Norm

[KillJoy]

That milage drop sounds normal.

Your foot is in the Pedal more :D

KillJoy

[LVMarauder]

My gas milage improved with just a 3k TC, lighter weight, smaller diameter= more efficient. If I drive it like a geratric anyway. But launching is too fun and Im always on the pedal as stated above.

[Stranger in the Black Sedan]

A higher stall converter is going to be slipping below its stall speed (when the TC is not locked of course) so a loss of gas mileage is normal

[RVT04]

been 10,000 miles since dr did mine and i had the 4.10's installed at the same time so i can't say mpg was/ is lower just because of the tc or the tranny but i lost about 2 mpgs at hiway cruise control no foot in it drivin, course i don't care as the instant downshift hammered butt in seat feelin at wot is so worth it, and in town is not much different still go about 310-330 miles on a tank of gas and just drive like always, don't beat it a bunch, but never can seem to resist the opportunity to roast em occasionally JBIC!!!:burnout:

[magindat]

A few weeks ago finally had the PI 3000 and full tranny rebuild from Dennis installed. My mechanic also upgraded a couple of additional parts as well while he was in there. Also did his rear engine cooling mod at the same time.

Had to get used to the new shift patterns, but the car is a lot more fun to drive. Very firm shifts. You know how the stock MM loads up a little and the RPM jumps when you take OD off? Well, now it kind of feels like that all the time, like the car is pulling harder. No more of that "coasting" feeling I used to get, but still the car is quicker.

I think my RPM at most speeds is up a bit as well, as I seem to recall the car running at about 2150 ROM at 70 mph, and now it is about 2400. (?)

Anyway, does it make sense that after beefing up the tranny and installing the TC that my mileage would drop 1.5 mpg?

Not complaining as the trade off in performance is well worth it, just trying to figure out the mechanics of why it's happening.

Thanks as always for any info.

Norm

Yes, it's normal. The engine is allowed to spin up more and is pumping more tranny fluid before a given speed. Plus, usually the tune leaves the TC unlocked longer. And you're right, the performance and feel is worth it!

[Svashtar]

Thanks very much guys. My MPG dropped a couple after the 4:10's and SCT tune, the first round of mods, but then rose a bit and stabilized. I used to refill at 300 miles, but now it's about 280 or so.

Couldn't figure out if it was anything mechanical, or just me hammering it more! Sounds like a combination of both. The whole tranny is just so much tighter now it's unbelievable.

Thanks again.

Norm