ok... ive read about starting speeds and cruise speeds but what about top speeds???

[morbid creations]

so.. this is my first post on this forum... im still in the stages of body work on my 69 camaro... but im trying to plan everything way ahead...

i read alot about people worried about the speeds and rpm of the 1st and 6th gear in t56 trannies.. but what i wanna know is what kinda speeds do you guys go in full out 5th and 6th gear??? and if you could include info on rpm, engine, and read end, tire size please...

[JamesJ]

I dont think that anyone goes full tilt in 5th or 6th. Most peoples setup would yeild 200 mph in 6th

[sinned]

Very few people if anybody has enough grunt to pull a T56 in top gear wide open. Most of the T56 cars wind out in 5th which is still an over driven gear and will easily bring the red needle to the end its travel on almost any speedometer. Ultimate top speed is determined by so many factors you could not even begin to determine what that would be in a general discussion. You need to know specific information with regards to exact tire sizes, trans gearing, axle gearing, engine HP at peak, what peak is, vehicle frontal area silhouette, etc…

[morbid creations]

ok first off i guess i was dreaming with a small block t56 combo that would do something like the "big red camaro"... which has a 540ci 800hp... to do 220mph

... ok so ... if you run which seems to be the avarage t56 set up being...
ls6/ls1 engine to t56 tranny... and gears something like 3.90 in the rear... i guess in the 1/4 you would only being shifting into 4th or maybe 5th gear?

... and for cruising 4th and 5th for getting up to speed and throw it into 6th once up to speed for cruising?

[JamesJ]

http://www.5speedtransmissions.com/calculators.html You can find what you want to know here.

[morbid creations]

thanx for the link... its also in my bookmarks...

im just kinda confused on a 400 or 500 hp car with a 6 speed... and since the most hp i have ever been behind the wheel of is 300 hp if i was lucky in my camaro before i took it apart... right now i drive a vw golf with 100hp 170ft lbs... and does about 130mph top speed in 5th gear and it feels like if i had a 6th it would still pull.

heres where the calculator wont help me i think... im not sure what ratios it takes to have the car still pull me to a high speed quickly... and all the local cars i see at the track use 4 speeds and automatics i think.. and are mostly just drag cars...

anyways i just about finished my body jig tonight.. so thinking gear ratios is not my thing tonight.. ill figure it out later... thanks

[sinned]

"Calculators" for top speed don’t work for one reason...none of them have the ability to compensate for the "wind wall" that all vehicles experience once they hit that magic mark around 150MPH. Getting a 300HP car to 150MPH is easy, the right gearing and almost any car can do that. Getting past that mark or anywhere even close to 200MPH requires huge amounts of aero work and massive HP to push past "the wall".

There are dozens of factory vehicles that are geared to do those insane top speeds; very few actually can hit the number though. I think there are only 3 vehicle produced domestically that even do 150MPH.

[morbid creations]

i guess thats why most of the funny cars are shaped like they are...

[morbid creations]

ok so i started reading about automotive aerodynamics, ground effects and downforce... and it sounds like thats getting way to complicated for my project... i think im just gonna go with the stock front and rear spoiler and lower it a little... and besides back to the point of the "big red camaro" i love this car... it does speeds around 220 mph with a stock looking body so it is possible to do in a camaro i guess. it just may not be easy

[ProdigyCustoms]

Let's use the benchmark 200MPH for an example. To run 200MPH will require somewhere north of 800HP for a 3500LB car. Look at Winston Cup cars. It is basically horsepower to weight ratio, although HP to weight to MPH is an inexact science, this is a very good ball park figure. You would need that kind of horsepower and torque to pull 200MPH speeds, assuming you can keep the car on the ground (not fly away) and cut through "the wall" Denny is talking about,

Here are some basic numbers for you.

Assuming a 6500RPM motor with sufficient HP / TQ - weight to pull the high gear, using a 26" tire, and manual transmission with no slippage..................................

With your referenced 3.90 gear and over drive with a .064 5th gear, she will run just tick north of 200MPH, on the dyno

You could also do it with a 2.56 gear and no overdrive and come up just a few MPH shy of 200MPH, on the dyno

Now weather she will do 200MPH driving, that is where all the aerodynamic crap comes in. And that math is probably far beyond anyone's capabilities here.