maybe you need to reread what I wrote. cause its 100% correcto. crying about having to shift to fifth is for the uneducated.

It is really without knowledge to say your car will improve .1-.2 in the quarter by not having to shift to 5th. So here are some facts for you. At 120mph you are moving at 176ft per second. During a shift you loose acceration but not speed. What this means is instead of being able to accelerate to 177ft per second you stay at 176fps during your shift. So what does that do to your ET? Not much. Not worth crying about. But worth discussing just this once. In a drag race I have noticed how much distance my car looses during a shift. In a really close race where you are door to door it is really easy to tell how much distance your car looses during a shift. For me it is about 2 feet on a good shift and 6 feet on a really bad shift. Perfect example is I was racing a mustang and our cars were really close in performance. Door to door in fact. He couldn't pull on me and I couldn't pull on him. When it came time to shift to 5th I look at his car and see how much distance I loose. Since this is a mustang and his gears are spaced different during my whole shift the mustang is still accelerating. I loose 2ft during my shift to 5th. Are you with me so far? Shifting to 5th costs me 2ft. but at a time when the car is moving 176fps. That means my ET will suffer by having to drive an additional 2 ft at 176fps. or .011 seconds. So in reality your ET will plummet by .01 on a good shift and only .03 on a real granny shift . Is this really worth crying about?

 

Maybe you should account for aerodynamic drag as well as the drag of the tire at that speed.

A shift will decelerate the car...meaning you WILL lose velocity.

If you're going 130mph, you can't tell me that you won't decel if you lift on the throttle.

I could do the math for you if I was really bored with nothing to do, but you WILL lose speed.

 

This whole debate is kind useless because we are discussing how/what is causing the not so good times... so yes it is worth crying about shifting to 5th.

 

its never been to the track under my tune / guidance before.. if he goes back and i adjust the launch rpm / rev limit etc, based on the time slip he gives me each run i can get the car to prob go 128 for him shifting to 5th based on his cars weight maybe.

but if he has a crappy dying clutch that is locking him out then its not even worth attempting at all.

 

you have got to be kidding. how much speed do you think you loose in .3 seconds?
get unlazy and do some math. in the end you will agree people are stupid quoting they will loose a tenth having to shift to 5th. I look at logs on my car last week showing the car still picking up MPH in between shifts. 2-3 and 3-4. Didnt have enough road to check exact numbers shifting to fifth. But I already know the answer anyway. you only loose the time it takes to travel the two feet of lost acceleration. which amounts to about .011 seconds lost ET on my car.

 

Should move this to the drag racing section with all the factual info you guys are spitting out, No wonder everytime i use the search button i cant find crap...

 

Give me the dyno plot of the car, the transmission used, the final drive, frontal area, cD, & the tire size used.

Couple of pointed questions for you Jerry.

How much speed(mph) do YOU think you lose in .3 seconds while going 120mph in an Evo 8/9?

Can you plot vehicle speed versus time for the 1-2, 2-3, 3-4, and 4-5 shift then? If you're going to call me lazy, I'm going to ask for data.

Furthermore overlay each data point on the same scale for velocity AND time... and make the origin of each line be the point at which the shift started. Be nice and make them different colors or line patterns.

This will prove my point of aerodynamic losses at speed. Just because momentum maintains velocity at lower vehicle speeds doesn't mean that the aerodynamic drag doesn't completely eat up your momentum @ 120mph.

For example...open wheel race cars decelerate at a little over 1g just by lifting off the throttle @ 180mph. (paraphrased from RCVD)

Pretty tough to KNOW anythign when you haven't even looked at your data.

Where do you come up with 2 feet? Is this based on that data that you haven't looked at yet? How can you have 2 feet of acceleration? A foot is a measurement of distance. Acceleration is measured in feet per second squared. It's the second derivative of position(distance). I seriously doubt your ability to undertsand the problem let alone your ability to compute the time lost between shifts based on your inability to understand basic physics.

How did you calculate .011 seconds from your "2 feet of lost acceleration"? I'm very curious how you're generating these precise delta's in time. Actually I'm waiting to be entertained by a copious amount of backpedalling and a post comprised of guesses, estimates, and some serious violations of Newton's Laws of Physics.

 

All this applies to is you and your car.

Seeing as your comparing a evo 4 to a evo 8/9 which has different gearing, drag Coefficient, and power levels.

Not to mention shifting to fifth in a MR 6 speed and 5 speed are different because of the gearing.

I however do agree slightly that shifting at the end of the track doesn't affect your ET like it does in the first half of the track. Beyond that I can't say much cause I haven't looked into it so I won't guess.

 

Hi

 

m

Lol stacio

I kno my car and I kno it doesn't like the 4th to 5th shift. Personally before this post went this route I searched to see what people were trapping with an EVO 9 gearset, didn't find a lot of big HP cars doing so. Found a few but most were on smaller turbos.

I'm not as scientifically inclined as for instance RT Ernie, but from driving my own car and trying it myself I kno I don't like it. My powerband is late and the car is heavy. Honestly I dnt care and enjoy the car as is. The EVO 8 4th is worth 7 mph more and I def think its worth it.

I'm not trying to break any records or prove anything. I jus like having a fast car for my own enjoyment. N the occasional bragging rights

 

post number 7 in "shift to fifth" thread gives all the data you need. there is only one graph with a shift to 5th. it looks like the shift took .5 seconds. must have been a sunday drive. (RYU has posted .15 shift times, mine are trans friendly .3 ) but even with that slow shift speed the car looses about .5 mph. dropping from 123 to 122.5 (at end of .5 sec) at worst. I dont have time to spoon feed you. if you think I am wrong please post some proof. everyone who disagrees with me is just wrong as I see it. its very simple math yet no one seems to be doing any. I guess you just have fun telling me I dont know what I am talking about.

Update: I did some calculations in that thread so as not to clutter this one if anyone wants too take a look. post #38
https://www.evolutionm.net/forums/dr...ift-5th-3.html

 

STFU

 

Force = Mass * Acceleration -> F = m*a -> a = F/m ... engine and transmission provide effectively the Positive Acceleration.
a = Change in Velocity / Change in Time = dv / dt
When 'a' goes to the change in velocity (dv) also goes to zero. a = dv/dt -> set a to 0 -> 0 = dv/dt -> 0 = 0 (obviously)
In the case of a car when power (Force) is not applied to the wheels because of a shift in a frictionless world the car would maintain its velocity (speed in your case).
However because of friction and wind resistance your total Force changes to negative, which means negative acceleration which means decreasing speed.

I hope this helps.

~Joel.

 

That exact info was going through my head when I read the post about not losing speed during a 4-5 shift.