What is your opinions on the best 1/4 mile gear. I know it depends on tire size, rpm and 1/4 mile speed, but the majority of people are preaching 4.56 but they don't realize how to come up with the gear they need they just think lower is better.
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What is your opinions on the best 1/4 mile gear. I know it depends on tire size, rpm and 1/4 mile speed, but the majority of people are preaching 4.56 but they don't realize how to come up with the gear they need they just think lower is better.
There is no magic good for all ratio. If youre still in your power curve on your engine,you are still accelerating,go past it and you are slowing down.
if i couldn't have but one gear, i'd go with the 4:10 gear. for the adv. st. car. **)
halftanked is correct. There is no one gear ratio for all cars, but I've always geared so the car was almost or at the maximum rpms of the powerband right at the lights. You want the car to still be pulling rather than running out of steam.
With our 351 Cleveland, we geared 4:88's with a 29 inch tire. With my altered, I had 5;14's, with a 30 inch tire. You have to run the car and see what it is doing at the finish line.
Don
As an example a 71 nova with 700hp, 6500rpm chip, 350 trans, 4.11 gear and 28 inch tire. At the quarter he is at 6500 rpm. People (that don't know) say he needs some 4.56 gears, but that would slow him from 132mph (or so) to around 119 mph. But i don't think it will be any faster would it?
if hes got 700 HP and running around 120 mph, he needs more than another gear. :cool:Quote:
Originally posted by chevydrivin
As an example a 71 nova with 700hp, 6500rpm chip, 350 trans, 4.11 gear and 28 inch tire. At the quarter he is at 6500 rpm. People (that don't know) say he needs some 4.56 gears, but that would slow him from 132mph (or so) to around 119 mph. But i don't think it will be any faster would it?
What do you mean????????Quote:
Originally posted by lt1s10
if hes got 700 HP and running around 120 mph, he needs more than another gear. :cool:
120 mph is not very fast for that much HP.
Mike, you're a day late and a dollar short buddy.....he's running 132 mph now and if he changed to a shorter gear while running the same rpm, he'd slow down to 119.
In order to go quicker/faster with a stiffer gear, he'd have to change the engine rpm's through the lights.
Horse Power has nothing to do with speed! In this situation.Quote:
Originally posted by lt1s10
120 mph is not very fast for that much HP.
Well.....uh......yeah it does. Take the same car to the track with a 200 hp motor and see how fast it goes.Quote:
Originally posted by chevydrivin
Horse Power has nothing to do with speed!
Sorry tech as i was editing my mess you replied. My edit was in this situation meaning same HP.Quote:
Originally posted by techinspector1
Well.....uh......yeah it does. Take the same car to the track with a 200 hp motor and see how fast it goes.
how many 700 hp cars, that run in the 7 sec. 1/4 mile with a speed of 120 mph. so i'll stick by my statement. "if hes got 700 HP and running around 120 mph, he needs more than another gear."
MPH doesn't win a drag race, ET does. I try to gear mine so that its about 200 RPM over the peak torque and horsepower numbers. If the peaks are beginning to descend at 6300 RPM, no reason to run it to 7,000.Quote:
Originally posted by chevydrivin
As an example a 71 nova with 700hp, 6500rpm chip, 350 trans, 4.11 gear and 28 inch tire. At the quarter he is at 6500 rpm. People (that don't know) say he needs some 4.56 gears, but that would slow him from 132mph (or so) to around 119 mph. But i don't think it will be any faster would it?
If your going to stick by your statment then help me out, what do you think the car needs. As I asked earlier "what do you mean"Quote:
Originally posted by lt1s10
how many 700 hp cars, that run in the 7 sec. 1/4 mile with a speed of 120 mph. so i'll stick by my statement. "if hes got 700 HP and running around 120 mph, he needs more than another gear."
I was kinda making a joke, unless I'm over looking something, you are right about the gears, but the hp and the speed don't match. 350- 400 hp will go 120 mph in the 1/4 mile, @6000 rpm's with a 4:10 gear, so all I was saying is if I had 700 hp and only running 120 mph id be probably looking a new driver. here is a few cal., see if they help. i dont believe the example you gave could ever happen. the idea is getting the right gear for the rpm range of you cam. you get the max. hp out of your motor the mph will fall in place.
"As an example a 71 nova with 700hp, 6500rpm chip, 350 trans, 4.11 gear and 28 inch tire. At the quarter he is at 6500 rpm. People (that don't know) say he needs some 4.56 gears, but that would slow him from 132mph (or so) to around 119 mph. But i don't think it will be any faster would it?"
http://home.tampabay.rr.com/1bking/c....htm#calc_disp
http://www.richmondgear.com/101032.html
im always a day late and a dollar short, but if that 700 hp motor isn't running but 119 mph in the 1/4 mile, im gonna out run it. :HMMM: :LOL:Quote:
Originally posted by techinspector1
Mike, you're a day late and a dollar short buddy.....he's running 132 mph now and if he changed to a shorter gear while running the same rpm, he'd slow down to 119.
In order to go quicker/faster with a stiffer gear, he'd have to change the engine rpm's through the lights.
"the car" is 350 twin turbo 10psi, 350 trans, 4.11 gear, 6500RPM chip, 28 inch slicks, and about 9.8 @134 1/4. If It had 4.56 gears then 6500 rpm the car would only be 119 mph, with 5.88 gear at 6500 rpm it would only be at 92 mph. 3.50 gear if he could get up to 6500 rpm would be 155 mph. A 10,000HP motor in that setup would be the same MPH.
I understand that, but they are not realists(sp) #'s. there is a ball park that you should be in. the starting place is what ever the cam co. says the rpm range is, and after that you would have to go to the track and try it. if I was doing it id know what the cam called for, then I'd use the cal, I gave you and pick the tire size and the gear ratio I thought I needed and that's what id start with, if you cam is calling for 6000 rpm in the 1/4 and you're with in 3-400 rpm's of that, that's about all you can do. if you're in your cam setting, then it would only hurt you to change it either way.Quote:
Originally posted by chevydrivin
"the car" is 350 twin turbo 10psi, 350 trans, 4.11 gear, 6500RPM chip, 28 inch slicks, and about 9.8 @134 1/4. If It had 4.56 gears then 6500 rpm the car would only be 119 mph, with 5.88 gear at 6500 rpm it would only be at 92 mph. 3.50 gear if he could get up to 6500 rpm would be 155 mph. A 10,000HP motor in that setup would be the same MPH.
What numbers are not realistic?
10,000 hp motor running 92 mph. in the 1/4 mile. i must be missing something. there are certain expectations of that a motor with a certain amount of hp turning a certain rpm's should be able to do in a 1/4 mile. there is a standard that we all go by, and try to beat. if you have a 200 hp motor you will need a dif. gear to get it to 6000 rpm's in a 1/4 mi. than a motor with 700 hp, if you're trying to get the max. out of the motor.
I think we are both missing somthing. You said the numbers I metioned were not realistic numbers and I was wondering what you ment. I am saying that i think his setup is the best he can do, because his cam is for 6500 and that is what he is at at the quarter. I am aware that less power needs more gear, thats not what I was getting at.Quote:
Originally posted by lt1s10
10,000 hp motor running 92 mph. in the 1/4 mile. i must be missing something. there are certain expectations of that a motor with a certain amount of hp turning a certain rpm's should be able to do in a 1/4 mile. there is a standard that we all go by, and try to beat. if you have a 200 hp motor you will need a dif. gear to get it to 6000 rpm's in a 1/4 mi. than a motor with 700 hp, if you're trying to get the max. out of the motor.
if i was looking at the # you gave, id have to say something is wrong with the over all pic. if its a 700 hp motor, in a 3000 lb. car, turning 6000 rpm's and if is not running 150 mph, you got to find out why. changing gears won't fix it. 700 hp, 6000 rpm's and 150 mph, now you got sometyhing to work with. you start messing with the gears now and you can tell where you are gaining or loosing, but if you're turning the rpm's you want then its no need to chande it.
The numbers I gave you are actual numbers. The motor is around 700 hp setup for 6500 RPM. SO the motor and drive shaft turn 6500 RPM. The Pinion turns 6500RPM so the 4.11 gear means the axle turns 1581.5 RPM which means the wheel turns 1581.5 times. A 28 inch tire covers 695,231 ft in a minute divided by 5280 ft/mile equals 132 MPH. No matter what the horsepower is. A 6500 rpm motor/28"tire/4.11gear/will only go 132 mph in the quarter is what I am saying. If the 700 Hp motor should be around 150MPH then he needs to try a higher gear right? around a 3.50 gear maybe, but then will he get to 6500rpm.
Good question. You're correct in one way. If the motor is limited to 6500 RPM, it will never go faster than 132 in the quarter. Lower the gearset to 4.56 AND keep the limiter at 6500 RPM, the car may rush to about 120 and flatten out. However, it's not impossible for the ET to drop when the MPH drops. That's where horsepower comes in.Quote:
. . . around a 3.50 gear maybe, but then will he get to 6500rpm?
Minimizing the ET in a car with this configuration takes a combination of things, and horsepower does matter. You need to minimize ET, then take the top speed that goes with it. If you want to go 150 and keep the rev limiter - and you have the horsepower (which seems to be the case) you do need a higher gear. However, you may have to "fiddle" with other stuff also. For example, if it's an automatic car, you can work with the converter to provide a little more slip to avoid bogging. If it's a four-speed car, you can go to work with the lowest gear and the spacing between the gears or go to a five-speed.
You've just painted a good picture of why many people go with a higher revving motor.
.
Matt,Quote:
how does your wheel turn the same speed as the rear end, should be a lower number, tires are the final ratio, they won't spin at the same RPM as the axles, that is why they can effect a cars performance,
You better re-think that one. The tires are bolted to the axles (lug nuts, remember?). If the tires don't rotate at the same speed (RPM) as the axles, you just broke something.
The diameter of the tire does affect the acceleration and top speed, but only because a small tire travels less distance per rotation than a larger one.
yeah, that makes sense:)Quote:
Originally posted by Henry Rifle
Matt,
You better re-think that one. The tires are bolted to the axles (lug nuts, remember?). If the tires don't rotate at the same speed (RPM) as the axles, you just broke something.
The diameter of the tire does affect the acceleration and top speed, but only because a small tire travels less distance per rotation than a larger one.
Unless you got dimm spinnin rims. LOLQuote:
Originally posted by Matt167
yeah, that makes sense:)
or a broken axle:LOL:Quote:
Originally posted by chevydrivin
Unless you got dimm spinnin rims. LOL
lol i watched that happen the other day. A 1990ish model camaro was doing his burn out before he staged and his driver's side axle came out from under the car.
To make a long story short, they had to get a jack to lift the car off the tire so they could slide the axle back in, needless to say, that car didn't race that day. :LOL:
that usually happens because people are too cheap to buy c-clip eliminators
Why would anybody put a 6500 top ranged cam into a turbo-charged motor pushing 10 lbs. of boost, and 700 hp??
I smell poo....
Well, it wouldnt be ideal, but on paper it sort of makes sense:S. a turbo is only able to make decent boost around 3000rpm+. Match that with a small block turning 7000RPM, and you have a peak powerband near 6500. However, with only 10lbs of boost tops, you would probably have more backpressure from the turbo than you would gain from the 10psi with a radical cam, so it does strike redundant. Or am I the only one who thinks this way?:confused:
First figure out what the original gearing is or the gears that are in it now. You can do that by geting on a flat serface and putting a peice of bright tape on the drive shaft then rolling the car backwords and counting how many times the drive shaft rotates per one full tire rotation. After you figure out what gears are in it run it and see what RPM you finish through that Traps. second in no mater what application the higher the numbers of gears the more tourqe is going to get to the wheels Ex: 3:73 is going to deliver more tourqe to the rear wheels than a 3:08 will. becouse the rear wheels will make 3.73 retations for every one time the engine completes a power stroke. where as a 3:08 gear will be 3.08 rotations for ev.... weel you get it anyway it all depends on the application your using. i ran a 3.08 with a 400hp 350 and a 3 sp trans and swiched to a 3.73 gear and it made all the difference in the world. after all if your going to drive it on the street you cant go to wild with the gearing
:LOL: Exactly right ,except backwards.:)Quote:
Originally posted by CIzA5IHIOvIzId3
. second in no mater what application the higher the numbers of gears the more tourqe is going to get to the wheels Ex: 3:73 is going to deliver more tourqe to the rear wheels than a 3:08 will. becouse the rear wheels will make 3.73 retations for every one time the engine completes a power stroke. where as a 3:08 gear will be 3.08 rotations for ev.... weel you get it anyway
Update on the gear setup in this car. Had some miscomunication, my buddy had 3.55 gears and 4.11 gears. I just found out the gears in the car are actually 3.55, so somthing is wrong somewhere. With his tire size and a 3.55 he should have been around 150 MPH but he was only at 132. So that tells me somthing is slipping. Either the torque converter or transmission, how do you tell which one is slipping?
Not sure i ran 3.23 in my car stock ten 4.11 well then to 3.55 thought about highway driving then thought well im never on the highway 4.11 with a sbc chevy th350 trans 3,500 rpm at 60mph . In the 1/4 mile its sick
I'd start with 4:56's depending on tires diameter and go as much as 5;14's
It is a mild small block v-8 or not? When u don't have much torque gears
really help. ET not mph gets u there first.
Ron**)
Google "quater mile time estimator" or something like that and you will find a few pages that allow you to "experiment" with tire and gear combos to see which works best for your car. They use weight and HP to calculate everything and from what I have heard they are pretty accurate. One I was on actually gave you an ideal gear ratio based on HP and tire size.
CHAZ