Which torque converter won't affect my mileage by more than 1 MPG, but will provide decent gains? Will the truck run like crap afterwards, or will I need to tune it then?

 

Around here it seems the Yank TT2600 & 3000 are the most popular.

 

I 3000 rpm would murder MPG in town big time especailly with tall axles and big tires. I would say maybe 2600 tops if that high.

 

Sno seems to be the new resident converter expert but most people have been running 2800-3000 stalls with NO loss and lots of gains
If you only wanted "2600 tops" stall, maybe look at a stock Trailblazer veter.

Hey sno where do you get all your converter experience from? Just curious.

 

Well, the original question asker was concerned about MPG and regardless of snoman's level of experience, he is right on in this regard. When I talked with Chingon he said his mileage went through the floor with his Vig 3200.

 

Someone just recently posted they got better gas milage with a 3000 stall than their stock verter.

Kinda goes with the discussion that was made about engines not being as efficient at 1300 rpm as they are at 2000. Just because the rpm is higher doesnt mean your gas milage is suffering.

If you cant figure out why Chingons gas milage went through the roof, you should drive around with him someday His stall is also 3200 and pretty loose. If it was a vank 3200 it would be alot different so ive been reading.

 

Yeah, I took a ride with him....I kind of know why.

I have a hard time believing an increase in mileage going to a bigger converter. By definition, you are less efficient with a higher stall converter - the motor is spinning faster than the tranny, and you are generating heat instead of motion. If you want to overcome this 'slippage' to get normal speed, you have to step on the gas (which is more fun, anyway, hence Chingy's problem...).

So while I don't doubt an increase in power and fun from a higher stall, it does come at a cost (nothing is free) and I think the price of admission in this instance is gas mileage. I would really be amazed if mileage doesn't incrementally go downward as the size of the converter goes upward.

 

I dont know much about converters but lemmie throw some thoughts out there...

What Naked said about bigger stall = less efficient I can understand, but isnt there more to it than that? Like, the STR. From what ive read that kinda rates the amount of multiplication going on in the verter. So say a stock verter has 1.5 or something and you get an aftermarket stall with say a 2.5 STR, isnt there more power being multiplied compaired to the stock verter?
Also doesnt yank rank the efficiency of their verters? What is stock efficiency?

And as far as gas milage goes, I would think its pretty common to loose milage with a higher stall, but as far as like highway driving, would it change much? As long as the verter locks up, should be the same right?

Like I said I dont know much about converters, im sure you guys can school me

Naked - I remember you doing alot of reasearch on the trailblazer verter, think it would be ok in this application?

 

Actually larger converters are more effiecent at lower speeds because less fluid pressure is needed (hence less energy lost to heat too) to transmet torque through it. THere are no free lunchs here as some have observed.

 

I can't help you with choosing a converter that will stay within a 1MPG range compared to stock, but I can tell you about my PI Vigilante 3200 since it's the only one I've had.
First of all, you will need a tune. I would imagine that the higher/looser the stall is, the more you'll need a tune because the PCM will think the tranny is slipping and go into this mode where it feels like a 5000 stall. Right after I had the converter installed it felt VERY loose but my truck also felt totally different. After about an hour of driving something happened and I thought my tranny crapped out because I would gas it and if felt like it was in 3rd gear or something. The RPMs went up to about 5000 and it barely crept forward. I found out later it's because I needed tuning. After the tuning the stall felt tighter/more streetable.
What do you mean will the truck run like crap? My truck runs the same as before the converter except now when I step on the gas, it launches a lot harder than before.
On the freeway I don't notice a mileage decrease, it's the streets where it's gone to ****. Like Mac and NakedAV said, it's my driving habits.
The thing is, the higher the stall, the more annoying it will be in bumper to bumper traffic, at least to me. Because the truck doesn't really move until above 2000 RPMs, you have to give a good amount of gas to get it going. Since I'm impatient I just stomp it and it goes, hence the MPG decrease.

Bottom line: Converters kick ***. It's in my top 3 favorite mods along with nitrous and a tune. Get one, you will love it