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Author Topic:   what gear to run??
JOHN NIP
Member
posted August 11, 2003 08:11 AM
i buddy of mine had a 355 on 3/8 mile track and was running in top 5. now he has a new motor about 525hp its not even in the top 10 car revs up to quick and never hooks up spins all the way down the straight away running a 3 speed 411 gears 3/8 high banked track very slick. a guy at the track said he needed to change gearing in the rearend what should he change it to. he runs it in 2nd gear. Man also said he had a heavy foot lol but even when he lets of and gives it about half thottle it spins . any suggestions will be greatly app.

Thanks alot.

iowa_dirt_track_girl
Member
posted August 11, 2003 10:34 AM
what kind of tranny does he run is it a brit brinn stock?? what
if it is a stock tranny with a 189 sec gear with a 411 rear end that would put him around a 710 or so way to deep you need to run a final gear and at a 3/8 track with that many horse i would run a 529 or 543 depending on your camshaft what you need to turn to make the horsepower


Raz_900
Member
posted August 11, 2003 10:55 AM
Put 5.43's in the rear and run top gear.



towmandan
Member
posted August 11, 2003 01:09 PM
What size tires are you people running to run that high a gear on a 3/8s track Ive ran 82 to 84 in. tires with a 6.50 on a 3/8s turn about 7800.......Towman


JOHN NIP
Member
posted August 11, 2003 01:39 PM
1.89 second gear it doesn't have a third its been lighten it turn about 7200 would like to turn about 6800. 555 solid lift cam lunati. he runs 275/60/15 dot tires that all they will let you on 8in basset rims. any gear suggestions to make this thing take off??

Thanks for thr replys.

rico 08
Member
posted August 11, 2003 04:39 PM
That figures to be a 7.76 gear!Is he sure that it's a 1.89?I ran a 6.07 gear with 87 roll on a big 3/8 mile turning 6200,with a 7.76 it probably would have turned way over 8000.


racer17j
Member
posted August 11, 2003 07:06 PM
what is the roll oif the tire 275/60/15 doesn't tell us a whole lot


iowa_dirt_track_girl
Member
posted August 11, 2003 10:35 PM
you need to figure out what the gear is in the tranny
If he runs a lighten three speed then you must must run in third because ion all the three speeds that i have seen they take first out lighten sec and that makes you run it in final gear (final gear being third in a lighten three speed
you are way better horsepower wise to run a final gear look for a 543 567 to run and see what happens to it try to borrow a gear tyo see what happens
Plus if you do run a final gear do yourself a favor a run a balanced good driveshaft


JOHN NIP
Member
posted August 12, 2003 07:37 AM
its a chevy 3 speed with no 3rd he runs it in 2nd gear with 411 in the rear. Not sure of the gear ratio in second i thought it was 1.89 but not sure the car wraps up very fast as soon as you hit the pedal. with old motor the car was fast top 5 finisher now with big motor its slow. the trans came out of a chevy truck 3rd was took out when he got it.


JOHN NIP
Member
posted August 12, 2003 07:45 AM
HOW DO YOU MEASURE THE ROLL?(82,84,87)DONT MEAN TO BOTHER YOU ALL JUST TRING TO HELP A MAN OUT.

THANKS FOR YOUR TIME AND REPLYS

Raz_900
Member
posted August 12, 2003 09:21 AM
quote:
Originally posted by JOHN NIP:
HOW DO YOU MEASURE THE ROLL?(82,84,87)DONT MEAN TO BOTHER YOU ALL JUST TRING TO HELP A MAN OUT.

THANKS FOR YOUR TIME AND REPLYS


Inflate the tires to operating pressure and measure the circumference in the middle of the tread. I use a thin (1/4") tape measure and mark the tread with a chalk to make sure I start and end at the same spot. Make sure you don't slip off center or it will change the measurement.

A 275/60 should be around 88" - 89". I have 255/60's that are 85" or so and 265/60's that are 86 1/2" - 87".

Ohh.. and assuming it really is a 1.89 tranny, try a 3.23 or 3.43 rear gear. That will put the final in the low-mid 6.0 range. I run a 5.14 with a 'glide in high on a big 1/2 mile around 6300 and on a smaller 1/2 mile around 5800-5900.


JOHN NIP
Member
posted August 12, 2003 09:34 AM
THEY ARE 88.5 AND HE SAID THE TRANS CAME OUT OF A CHEVY TRUCK. HE WANTS TO TURN ABOUT 6500-6800


iowa_dirt_track_girl
Member
posted August 12, 2003 11:31 AM
ok lets take the confusion out of the question
Look at the input shaft of the tranny if it does have a 189 sec gear it will have three little marks on the front of the input shaft that then will tells us what we have to work with

------------------
you never know how fast you are going when your in the lead, until you blow the announcers hat off!!!


JOHN NIP
Member
posted August 12, 2003 11:57 AM
IS THERE ANY WAY OF NOWING WITH OUT TAKING THE TRANS OUT?? ITS A THREE SPEED OUT OF A 70'S CHEVY TRUCK.


towmandan
Member
posted August 12, 2003 04:14 PM
I cant see the problem you didnt say anything about duration but your 555 lift cam should turn 7000 or better...I always like to turn mine 7200 to 7800 get your car hooking up and you can spank them boys in the turns and coming off thats where all your passing takes place and with your gear you should be right in your power range in the turns if it were me I would play with other things than gears right now...But as usuall thats just my opinion......Towman


iowa_dirt_track_girl
Member
posted August 12, 2003 08:47 PM
sorry john i really know of no other way of knowing what you have for a tranny if you dont take it out that is the only way that i know of because of the different trannys put in trucks and etc... you really have no other way of knowing

------------------
you never know how fast you are going when your in the lead, until you blow the announcers hat off!!!


JOHN NIP
Member
posted August 13, 2003 06:59 AM
towman what do you suggest we do to get the car to hook up with the small motor it did great now we cant get it to stop spinning.this is in a 84 monte with afco spring and blistein shocks all the way around adjusters in the front and weight jacks in the back. car weighs 3200# i think he has to much motor but i know there are others out there that have way more.


racer17j
Member
posted August 13, 2003 04:36 PM
what are the weihgt %'s probably not enough tail weight


dtd_93
Member
posted August 13, 2003 04:40 PM
too much motor... never... but it maybe too much for the old set up on that car..


JOHN NIP
Member
posted August 14, 2003 07:00 AM
49% rear


JOHN NIP
Member
posted August 15, 2003 06:59 AM
should he drop to a 373 or go lower. Do you think he should put iton scales and adjust the weigh jack in the back to get more %?


Dixon
Member
posted August 16, 2003 04:04 PM
I run on a 3/8 mile high banked track that is usually very hooked up. Most people in my class (modified street) run between a 6.20-6.33 rear gear in 3rd. I was running a 5.43, but couldn't get the motor to turn over 5,500 rpm. They were all running away from me out of the corners.

I'd take a close look at the set up. A buddy of mine was running super-late model with an engine that made around 600 HP. He was turning 12.50's by handling very well, but the motor just couldn't keep up with everyone else. Now he's got a monster that dynoed over 750 HP, but he can't get under 13 flat. When you make a big change in HP, you've got to make some big set up changes as well.

racer17j
Member
posted August 16, 2003 04:14 PM
get those %'s right thats what the weight jacks are for i can't run them and i have better rear % then that


towmandan
Member
posted August 17, 2003 08:34 AM
All Im saying is spend a wknd. getting more rear% before you go buying gears because your very close on gear and something to remember their are a lot of classes of cars that run enough motor to buzz the tires when they want to... with your little motor you may have been able to stand on the throttle comming off the corners without any problems....but now welcome to the world of horsepower and light feet....what Im trying to say is you spent alot of money to get a motor and now your wanting to get gears to kill part of it...Do somemore chassis work....just my opinion....Towman


rico 08
Member
posted August 17, 2003 08:44 AM
He's probably got a 1.50 second tranny,that would put the final at 6.16.


towmandan
Member
posted August 17, 2003 08:49 AM
The most important thing you can do is get that tranny out of there and see what youve got we can give you all the opinions in the world now but we can fix you with the right information and we need to know your final gear ratio....and to get that youve got to ID the tranny......Towman


Speedway65
Member
posted August 18, 2003 03:35 PM
Weight jackers just move weight around.The only way to change rear or left side weight is to physically add more weight!


MEANGENE83
Member
posted August 18, 2003 06:01 PM
you can ID the tranny without taking it out. Jack the car up put it in the gear in question, mark the driveshaft, have a buddy spin the motor (by hand) and count the # of times the balancer turns, and have him stop when the driveshaft turns 10 revolutions. Take the number of crank revolutions and divide by 10. For example, if it takes 18.4 revolutions of the crank to turn the driveshaft 10 times then you have a 1.84 ratio.


prarielabs
Member
posted August 18, 2003 07:35 PM
I may be overstating the obvious, but how do you take third gear out of a three speed tranny when third is one to one. There is no "gear" for third, it is direct drive. Just thought I'd point that out.


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