TCCoA Forums banner

Status
Not open for further replies.
21 - 40 of 62 Posts

·
Registered
Joined
·
188 Posts
sounds like fun!

I'll be doing this also but I know for a fact that at 110 my car is doing 3000 rpm's and my drive terrain is all factory for right know.
 

·
Registered
Joined
·
1,431 Posts
This has always been a tough theory...

to teach....How do I explain? At a given power and torque
setting your car will go through thin air faster than
thick air...that's why pilots like to fly at higher altitudes,
less fuel consumption, less drag, more speed. It takes a sharply increasing power curve to move a car through the air
as speed and drag increase. At a given gound speed it takes
less power to move a car through the thinner air at 10,000'
than it does to achieve the same ground speed at sea level as
the vehicle is encountering less drag. Remember, pressure
and\or drag increases very rapidly as speed increases...
yes, if you were to remove the drag/friction/pressure factors from
this scenario then you would come much closer to your theoretical
140mph....but out on the street you can't escape from the
drag pressures created as you start approaching velocities above
say, 70mph.

Hope this helps,
 

·
Registered
Joined
·
1,565 Posts
im not arguing the drag, i get that concept, its not hard to grasp. what im arguing is that there is no drivetrain slippage caused by the drag.

picture a bike, your feet are the motor. with your arguement, saying that drag will not only increase the amount of effort to reach a speed, it will also cause driveline parts to slip and decrease final speed, your saying that if i am pedalling at a speed of 60 revolutions per minute and with gearing traveling a final speed of 20 mph, that if i double my pedalling speed to 120 revolutions per minute, i will not be travelling 40 mph. your saying that the drag from the increased speed will somehow cause my driveline to lose speed even if i can maintain the desired pedalling speed.

the drag will make it harder for me to reach the desired 120 revolutions per minute, but if i can still reach that pedalling speed, i will be travelling that final speed of 40 mph.

again, i ask you which part of the driveline is failing or slipping, resulting in the final speed loss?


your arguement is more related to the amount of power needed to reach the desired speed. with the increased drag, you might need exponentially more power to double the speed, but if you can accomplish that, and get to that speed...well... there you are
 

·
Registered
Joined
·
6,223 Posts
well comming up us41 after going to the track, i was following a 99gt and he said he was at about 138-140 when i was going past him. now i dunno how fast i was going.
 

·
Registered
Joined
·
1,431 Posts
With respect to slippage....

or lack thereof your thinking is correct.

My problem is I find it difficult to picture one
of our 'Birds being able to be brought up to 140mph
with approximately what...? 215 rwhp, I don't know the
torque figure, in overdrive at 4000rpm - it sure wasn't
in third. I'm not questioning Blackbird's numbers, but
with the facts as presented - the picture doesn't add up,
at least in my mind. Some test runs by others should
prove to be helpful.

Well, I just saw Vic's post... it's beginig to look as
if my estimate was/is wrong.

Vic - were you driving your '96 'Bird?
 

·
Registered
Joined
·
1,565 Posts
well ive pegged my speedo several times, it took quite a while to come down. judging by the engine speed, i calculated i was doing approx. 140. i guess theres no real proof that i was indeed traveling that fast if you can dispute that there was slippage at that speed.

btw, mager, did you get my pm?
 

·
Registered
Joined
·
6,223 Posts
major, yea i was in my car, i had it to the floor for quite awhile before i was passing him, i wish i could remember the rpm's but its been a while and i dont remember.

it was kinda funny the look on his face when i passed him.
 

·
Registered
Joined
·
1,431 Posts
LOL... I wish you'd Top Gunned him and...

taken a Polaroid as you passed......:D :D :D

Well, I'm beging to realize - I think I'm flat wrong.

I guess our 'Birds are aerodynamically even more efficient
than I thought they were - otherwise I wouldn't be hearing
all these high speeds!
 

·
Premium Member
Joined
·
4,161 Posts
My 2 cents worth.

I've had my car up to a bit over 120 when I first got my chip. That was back with the stock 3.27 gear. Now with the 3.73, I start getting major driveline vibes at around 105-110 so I don' t push it til I can afford a new drive shaft.

On another note, at this past World Ford Challenge 5, I rode with Tony Serno in his 95 SC Auto. Granted, he's got quite a bit done to his car and is making way more power than most 4.6's. We commenced a high-speed run that had us still accellerating at 145. Needless to say we outran EVERYBODY in the group and it took a while for them to all catch up. I can't verify that his speedo is 100% correct, but there were other members in the group in the triple digits and they said we flat out left them.

Anyway, that's my colour for the story.

On the RPM/Speed/Power discussion, once you get past a certain point, it takes nearly double the power or more just to gain a single MPH or two. Ask the guys who run Bonneville. It has nothing to do with the RPM you're running, but whether you have the power to get to the RPM you desire with your gearing.
 

·
Registered
Joined
·
940 Posts
I can't wait till I get a custom chip, I top off the speed at least 4 or 5 times a week (that's 105mph or somtin),
 

·
Premium Member
Joined
·
4,161 Posts
KewlBird, that sig pic is atrocious. WAAAAY too gawdy. Please come up with something less obnoxious.
 

·
Premium Member
Joined
·
4,161 Posts
BlackTbird96 said:
Glad someone said that. I was just staring at it for the last 5 min.
This coming from a guy with a three-color, 15+ line signature.

I see I'm going to have to issue an edict limiting sigs..... :D
 

·
Registered
Joined
·
940 Posts
Sir William said:
KewlBird, that sig pic is atrocious. WAAAAY too gawdy. Please come up with something less obnoxious.
Sorry, it's my old one, once I get some pictures of my freshly painted hood I'll make something (And yes I finally have it painted)
 

·
Registered
Joined
·
1,739 Posts
Hey it took me along time to make it look like that. I know I got a little crazy but I like it. I will be shortening it up soon. I will just have my website link soon.


Wheres your sig bill? I think you need a 15line one too.
 

·
Premium Member
Joined
·
4,161 Posts
BlackTbird96 said:
Wheres your sig bill? I think you need a 15line one too.
Mine's right at the bottom of my posts. Mine is under the new 10 line limit and doesn't contain any images. Simple enough.
 

·
5w30 Guzzler
Joined
·
1,462 Posts
uh oh

uh oh. trying to comprehend an automatic transmission. (i apologize ahead of time if this is wrong. someone please kindly correct me if MY GUESS is wrong). i think what this comes down to is the torque converter. the TC lets your rpm's jump when you hit the throttle hard and accelerate. but if you let off the throttle (if the TC isnt locked up), the rpm's are able to drop significantly even if your wheels stay spinning at the same speed. is it right that the TC in our car locks up in OD? if so, then there is a direct relationship from the engine to the wheels (meaning there will be no change in relationship). so yes, [email protected] makes sense if 70mph [email protected] if the friction is too great and the TC is locked up, then the rpm's simply wont climb any higher. they wont rev higher and your speed stay the same, there just simply isnt enough power to make the wheels spin faster. sorry again if i'm wrong.
 
21 - 40 of 62 Posts
Status
Not open for further replies.
Top