COMPLETE LS SWAP MPG

[oldsmobile joe]

i calculated with lock-up. at 70mph, engine is turning about 1700 rpms. so you have a pretty good ear for this. you said 1800.

i used this for the calculator http://www.grimmjeeper.com/gears.html

 

[20Grand]

i calculated with lock-up. at 70mph, engine is turning about 1700 rpms. so you have a pretty good ear for this. you said 1800.

i used this for the calculator http://www.grimmjeeper.com/gears.html

Going to have to check this out. I just overheated again tho going up a mountain pass. Going to make a new thread. I have quite a few to pass to make it back home.

 

[20Grand]

i calculated with lock-up. at 70mph, engine is turning about 1700 rpms. so you have a pretty good ear for this. you said 1800.

i used this for the calculator http://www.grimmjeeper.com/gears.html

Do you have a similar setup?

 

[fleming442]

You might benefit from just holding it in 3rd gear. If it's constantly downshifting and locking and unlocking the converter, that's a whole lot of unnecessary heat being created.

 

[oldsmobile joe]

Do you have a similar setup?

Not yet, but soon. I have the 5.3l, holley system, and car. I was going 6spd, but my wife wants an auto. Go figure.

 

[pontiacgp]

Yes, 4l60e with stock 2.73s I believe is what it is. I drove 2005+ Cad STS’s and even their v-6 couldn’t do that. The best I ever got with those 8s were 18 and I’d have to do 65 to get it. The only thing I’d like to do is increase the gears. I overheated going up a mountain in Utah and I wonder if that had anything to do with it. But, posted this so people knew what was going on. I’m a stickler for efficiency and mpg.

have you done the engine and transmission conversion but never removed the cover on the rear end to see what the ratio is and to change the 30 year old lubricant?

 

[olds307 and 403]

Change the gear oil to 75w90 and check the ratio while in there.

 

[20Grand]

Change the gear oil to 75w90 and check the ratio while in there.

I checked 6 months ago. I believe

have you done the engine and transmission conversion but never removed the cover on the rear end to see what the ratio is and to change the 30 year old lubricant?

Well, this is assuming the previous owners never replaced the lubricant, then yes. Do you think this could cause the overheating?

 

[20Grand]

Not yet, but soon. I have the 5.3l, holley system, and car. I was going 6spd, but my wife wants an auto. Go figure.

I had a really nice 88 Camaro that was manual and hated it in the city. I think I would’ve like it more if there weren’t so many stop signs and lights.

 

[pontiacgp]

Well, this is assuming the previous owners never replaced the lubricant, then yes. Do you think this could cause the overheating?

If it was old oil it would cost you hp and fuel mileage but it would not cause the engine to overheat. I don't understand why anyone would buy a used car decades old and not change all the fluids because you did say....

I I’m a stickler for efficiency and mpg.

When you say the engine was overheating what temperature did it get up to?