ShortChevy

iTrader: (21)

My car is dead on 2000rpm at 70, my buddies 98 Z with 3.23s turns right around 2400rpm I don't remember the exact number sense its not my car.

ShortChevy

iTrader: (21)

Yea dude we are all banding together to lie to you and make you think your getting bad mpg. Do a search it is not uncommon at all for a ls1 to get 30mpg and lt1's are right up there as well. But if you think I have the time to go through the trouble of scanning fuel repeipt's and such to prove to some guy houndred's of miles away that my car does indeed get 30mpg your wrong.

djsanchez2

iTrader: (14)

I got 31mpg on my way out to yosemite from LA, and 30mpg on my way to Vegas. Normally i get around 20-24 average because i get a bit of traffic/city driving. The stop and go **** REALLY cuts into the gas mileage. If it's all open stretchs and no traffic it will do high 20's- low 30 all day long.

Scoggin Dickey

iTrader: (34)

2000 rpm at 70 = 3.23s
2400 rpm at 70 = 3.73s

2.73s turn 1750 rpm or so at 70

Feel free to play with the calculator at http://www.f-body.org/gears/ all you have to do is select the year/tranny at the top on the left and it will fill in all the fields for you with the accurate f-body information.

If you would like you can get the rpo codes off of your door and see what you car came stock with, but there is no guarantee it hasn't been changed, your friends obviously has because he has 3.73s. Another option would be to pm me your VIN and I can look it up to see what options your car came with stock if you like, including gear ratio. I don't mind at all.

BTLD_LS1

iTrader: (1)

its all about gearing. My dad has a 95 LT1 with all boltons and a 2.73 rear end, gets about 29-31 MPG on highway trips. at 75 it turns like 1750 RPM or something retarded.

Im getting about 22 out of my LT1 with 90% city and 10% highway driving.

How can you complain when you have all that fun sitting under your right foot?

mike1500

iTrader: (3)

On chevys its called Active fuel management, Im pretty sure by putting a set of switches on spark and fuel injectors for 2/8 or 4/8 cylindars you could achieve the same effect when flipping a switch at optimal speeds to shut off fuel delivery to x amount of cylinders and spark. Somone made an incorrect statement above, DOD fuel management etc.. w/e doesnt stop the piston from turning.. can you imagine a crank shaft or cam shaft with some sort of bearing system in it? lol

Im not sure if thats how the cars comef rom the factory but i bet it would work.

Brad Hutchcraft

iTrader: (8)

Take your seats out??? man... this is getting retarded.

ShortChevy

iTrader: (21)

I know my car has 2.73s, I've checked the code and I have all the paperwork from when the car was ordered. I'm telling you dude it turns 2000rpm at 70, I can take a picture with my phone. I know my buddies z28 has 3.23s and it turns 2400. Your calculator is wrong or doesn't account for a slushbox. Both cars have 245/50/16's

dragonrage

So your tach is way off or someone changed your gears then.

Scoggin Dickey

iTrader: (34)

The only reason I am arguing with you is because some newb is going to come into this thread and get incorrect information based on your posts and it sucks when people get misinformed and make a bad decision in modding based on that information. I am not saying that you don't turn 2000 @ 70, I'm saying that you have 3.23s if you turn 2000 @ 70 and your friend has 3.73s if he turns 2400. Someone changed the gears in your car along the way if you have the 2.73 RPO code
You are saying that I am wrong, the guy who just posted was wrong, and every gear calculator on the internet is wrong? Simply do a search on this site, or google more gear calculators considering there are at least 100 on the internet for you to use. The information is out there (all over google AND this site) if you'll just give it a chance

BTLD_LS1

iTrader: (1)

Im not saying you are worng by any stretch, but if all these calculators are correct, can you explin to me this:

on the screen shot I have posted below, my trap speed was 121, yes I realize the speed listed is 117, that is because I have not changed the gearing in the tune yet. The RPM is clearly 6400, the rear end is a 3.42, and yes i am 100% sure it is 3.42 becuase I just had the cover off and inspected it and everything and it is 3.42. The tires are BFG DR's 275 45 17, your calculator states at 121 MPH I should be turning 1200 RPM less, so where is my 1200 RPM?



then at cruise in OD - should be 1900 RPM @ 63, but turning 2500

Scoggin Dickey

iTrader: (34)

Wierd, there was no screenshot in the thread but when I clicked to quote I can see it in the reply window.

You have a stalled auto, your RPMs have NOTHING to do with a locked stock stall at a set cruising speed and SHOULD NOT match up to any calculator. You have a totally unrelated setup. Your lost speed vs RPM is in your converter

You're talking a WHOLE different ball game than a guy cruising at highway speed with a locked stall. His could vary LITTLE in rpm based on tire brand at a set speed of 70mph, no offense but your example is in no way related. His gear ratio is VERY predictable at 70mph cruising speed.

Camaroholic

iTrader: (1)

Yep, you can easily have 1000+ RPM of slip from an unlocked torque converter. Some scan tools will even log Slip RPM (I know my OBD1 TTS Datamaster does as a transmission parameter).

Gear calculators only work for M6 cars or locked autos (and preferably in a relatively steady state). Gear calculator based WOT shift points are rarely close to being accurate, but at steady cruise they'll do OK.

Lickeyman

iTrader: (1)

You have to get special lifters/block/computer. Want DOD easy? Swap in a fwd v-8 somehow or get one out of a truck.

Could it be done? probably.

Is it worth it right now? probably not. Money spent would be way way more then money saved.