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Old 09-25-2012, 08:20 PM
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needing some advice

names chris new to site.last year bought a 78 nova i've been building into a drag car for bracket racing.just a shade tree mechanic that knows my way around a rig but by no means is a expert.car was cheap and had motor and tranny just needed finished.motor is a 40 over 350 270 comp cam,1.6 roller rockers,stock 601 305 heads with mild porting,street dominator intake,holley 750 vacuum secondart carb and hei dist. with 65000 super coil.th350 tranny with shift kit 3500+stall,4.11 gears with posi trac and 28 by 9 in slicks.no power steering and electric water pump and fans.fought car all season best pass 8.62 in 1/8 mile at 79.4 mph with 1.81 60ft.guys i race with running 4 to 5 tenths fast than me but my mph is the same or 3 to 4 mph faster.they have similiar set up.
i know my car pulls harder at the far end.feel the car should run 8.20s easy any ideas

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Old 09-25-2012, 10:26 PM
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if i made some changes to motor set up where would be a good place to start.i'm on a tight budget on the car don 't have a lot of extra money for it.would just like to get car running alittle better.my father in law had a similiar set up 60 over 350 with a 280 comp but i have better intake and carb and he only had 1.5 roller tips and ran 9.0's to 9.20's in a full size 80's truck weighing 4000+.my car is gutted and weighs 2780 empty.
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Old 09-25-2012, 10:42 PM
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cars hooking?what is the stall speed? how are the traction bars set up?
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Old 09-26-2012, 08:47 AM
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if you only plan on running 1/8mi then i would say that you need to invest in a shorter set of gears, say 4.88:1. you wont want to go on the highway with it. Your trap speed wont change to much but i'd be willing to bet that you will pick up around 0.50 in the 1/8.

next i would get rid of the 305 heads. the only reason the original builder put them on there is becuase they were cheap and would raise the compression ratio a good bit. i would look through classifids and ebay for a used set of 64cc combustion chamber aftermarket heads, as long as they have a good hard deck you can easily have them milled .030" which will take about 4-5cc's out giving you the compression you have now. with a .030" mill everything still lines up fine, but most times you can't go much over that without having to go into angle milling and having the intake milled. if you go this route i would suggest looking into getting a cam with more duration as well, as the cam you are running now was not meant for the higher compression that you are running with the 305 heads.
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Old 09-26-2012, 08:55 AM
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the car already has 4.11 gears my87z, and 1/2 a second is really optimistic for any gear change?
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Old 09-26-2012, 09:08 AM
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Quote:
Originally Posted by vinniekq2 View Post
the car already has 4.11 gears my87z, and 1/2 a second is really optimistic for any gear change?
which is a very tall gear for 1/8mi, 4.11's are a mild gear for 1/4mi cars. i run 4.56's in my 1/4mi car and still have about 500rpm to go when i hit the traps at about 6200 and 122-124mph.

idealy you want to be running through the traps in your final gear at just about your top rpm. right now he is running through the traps with 4.11's, 28" tall tires, and at 79-80mph at 3900rpm. this is way to low, there is still a whole lot to be had out of that engine that is not being used on the top end of the track. idealy about a 5.39:1 gear would put him through the traps at around 85mph and at 5500rpm with the 28" tall tires.

1/8mi is a different beast than 1/4mi
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Old 09-26-2012, 09:20 AM
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Quote:
Originally Posted by vinniekq2 View Post
the car already has 4.11 gears my87z, and 1/2 a second is really optimistic for any gear change?
0.50 may be a little optimistic for the 1/8mi but think about this: my original set up on my camaro was a mild 355, the car originally had 2.72:1 rear gears and ran around 14.00 in the 1/4mi and 9.00's in the 1/8th, once i switched to a posi carrier and 3.73:1 gears i started running 13.30's in the 1/4 and 8.40's in the 1/8th. that's about 0.100 shorter in the gear ratio but also got me 0.6 tenths in the 1/8th. my trap mph didn't change but by maybe 3-5mph and that was in the 1/4
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Old 09-26-2012, 09:26 PM
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the car hooks good with a good burnout and traction bars are all but touching just where their suppose to be i've been told by everyone that has looked at them.im stalling the car at around 2 grand can't really go higher because back brakes need some work and the car starts to push.planning to fix them during off season but only have two races left so making do till seasons done with them.i'm crossing the finish line a 5400 5600 rpm so i dont think gears need to be lowered and im in third by the 330 mark.i ran 26in slicks first few races and my et has stayed within a couple of hundreds.lower gear would take the car out of the power range woundn't it? i know the heads aren't idea planning to go aluminum if money is there this winter.same with cam planning to go with a 280 solid lift also. i have run against similar set ups and always seem to be 2 to 3 tenths slower but 3 to 4 mph faster then them.not looking to be king of the class but running points next year and just want to be in the middle of the pack.fastest cars running 7.20s slowest 9.0s hoping for low 8s and the maybe spraying it if a want to run 7.50 index next year to.
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Old 09-26-2012, 09:39 PM
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recent picked up a set of 882 heads would it be better to use them. also change distributer tonight and car wont hardly run and sounds very rough.i pulled the old one and dropped the new one in should be right but acts like its a tooth off this sound possible?shouldn't i be able to simple adjust this out because tried to and it didn't help it.called it a night because blood pressure was starting to rise and ahammer was laying close and starting to look real good
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Old 09-26-2012, 09:43 PM
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check the firing order,sometimes they get crossed when re installing the wires.fix the brakes,a good converter is very important. maybe a trans brake?
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Old 09-27-2012, 08:56 AM
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Quote:
Originally Posted by chris78 View Post
the car hooks good with a good burnout and traction bars are all but touching just where their suppose to be i've been told by everyone that has looked at them.im stalling the car at around 2 grand can't really go higher because back brakes need some work and the car starts to push.planning to fix them during off season but only have two races left so making do till seasons done with them.i'm crossing the finish line a 5400 5600 rpm so i dont think gears need to be lowered and im in third by the 330 mark.i ran 26in slicks first few races and my et has stayed within a couple of hundreds.lower gear would take the car out of the power range woundn't it? i know the heads aren't idea planning to go aluminum if money is there this winter.same with cam planning to go with a 280 solid lift also. i have run against similar set ups and always seem to be 2 to 3 tenths slower but 3 to 4 mph faster then them.not looking to be king of the class but running points next year and just want to be in the middle of the pack.fastest cars running 7.20s slowest 9.0s hoping for low 8s and the maybe spraying it if a want to run 7.50 index next year to.


I'm sorry but this is not mathmatically possible with 1:1 final tans gear, 4.11:1 rearend gears, either 26 or 28" tall tires. You wont be in thrid gear at 79-80mph running 5400-5600rpm. In order for this to be possible you would have to be running either 5.32:1 rear gears or running a 20" tall tire.

take a look here:
RICHMOND Street Performance Calculator

Think about this for a second; I run a TH350 just like you with the 1:1 3rd gear, with 4.56:1 rear gears, and a 29" tall tire. I shift my car at 6600rpm. I have to shift a little before the 660ft mark (1/8mi) into second gear and my 1/8m speed stays right at about 92mph.


Now as for the 882 heads, they are smog era heads with very large combustion chambers. they will lower your compression around 1.5+ points. a general rule of thumb is that for every full point of compression you go up you gain around 7-10% power. this would mean that say you are making 350hp, you would loose around 40-50hp just by switching to the 882 heads. even though they were 350 heads they were only designed to produce 160-180hp from the factory, where as those 305 heads were designed to produce 150-160hp from the factory with 45 less cubic inches. so there really is no flow improvment with those 882 heads.

As far as the distributor goes, like Vinnie said i would check the wires, then even though it's a new distributor i would still check to make sure it's getting fire to each post. it's possible that you put it in a tooth of but as you said you should be able to get it to run at least a little better by advancing or retarding it.
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Old 09-27-2012, 09:00 AM
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Take a look at these videos, I really like these guys, it's a shame they only made but so many videos:

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Old 09-27-2012, 04:01 PM
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got it running believe it is a tooth off have to pull it and try it again.i see what you are saying using the calculator but it doesnt add up to ehat the car is doing.i know i have 4.11s put them in the car myself and know what the motor is whineding.i shift from first at about the 60ft mark from second slightly before the 330 a bring my shift light on as i cross the 660 which is set at 5400.maybe i have miss post something or not getting something because this isnt adding up.im more confused now then ever but that isnt hard for me to do
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Old 09-27-2012, 04:11 PM
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Quote:
Originally Posted by chris78 View Post
got it running believe it is a tooth off have to pull it and try it again.i see what you are saying using the calculator but it doesnt add up to ehat the car is doing.i know i have 4.11s put them in the car myself and know what the motor is whineding.i shift from first at about the 60ft mark from second slightly before the 330 a bring my shift light on as i cross the 660 which is set at 5400.maybe i have miss post something or not getting something because this isnt adding up.im more confused now then ever but that isnt hard for me to do


Yeah I dont know what you have going on but like you said something isn't adding up. with 4.11 gears you should easily be able to hit around 120mph before you get to 5400rpm.

use that calculator and check to see what it says you should be running in 1st and 2nd gear when you shift. the th350 has a 1st gear of 2.52:1, a second gear of 1.52:1.

here i did it for you:
RICHMOND Street Performance Calculator

RICHMOND Street Performance Calculator


well i just checked to see if it saved what i put in and it didn't, sorry about that.

just put in the 4.11 for your gears, put 28" for your tires, put 2.52 in the trans gear spot, and then start playing with the MPH to get it to the 5400rpm. It was showing me that you should be hitting about 44mph before you shift into 2nd, and then around 72 before you shift into 3rd.
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Old 09-27-2012, 08:33 PM
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wrong post

Last edited by against all odds; 09-27-2012 at 08:42 PM. Reason: wrong post
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