How to improve 60ft and 330 times

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How to improve 60ft and 330 times

Post by AMXstocker1 » Wed Jul 19, 2017 9:32 am

I'm looking for ways to improve our 60ft and 330 times according to our mph the car should be a tenth quicker than it is in this video. the car is a 1969 amx 427 inch iron headed amc solid roller .740 .760 lift and 278 and 288 @ .050 edelbrock torker with a 1050 dominator on e85. it has all calvert racing rear suspension, calvert mono leafs, bars and shocks. and runs a 28x10.5 mt pro bracket radial car weighs 3260 with me in it. this run was on a very hot day and we had to take 3 psi out of the tires to get the car to hook (19psi to 16psi) on pass i'm posting video and the time slip for. oh the car has a 727 torqueflight with a 8 inch tci converter that flashes to 5900 and 4.10 gear and this was leaving of the T-brake on 3200rpm chip.

https://www.youtube.com/watch?v=f_R6PA7dbt8
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Re: How to improve 60ft and 330 times

Post by amcenthusiast » Wed Jul 19, 2017 10:51 pm

You might find a few ideas here: http://www.shopeshop.org/contentsDrag.htm

The SS/AMXs have stretched rear wheel openings for taller slicks. Perhaps that could be helpful if you are class racing?
XRV8 Race Parts > for AM's '56-'67 Rambler V8: http://amcramblermarlin.1colony.com/favorite_links.html

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Re: How to improve 60ft and 330 times

Post by AMXstocker1 » Thu Jul 20, 2017 12:29 pm

We are class limited to 28 x 10.5 and thats whats on the car the fender wheels have been clipped similar to an early ss car and the car hooks it just doesn't 60 ft like i think it could be gear the car could probably use a 4.56. i wonder if the suspension is too tight theres a number of things maybe freeing up the front end could help i'm not sure i was always under the impression that little front end movement would be best if the car hooks.

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Re: How to improve 60ft and 330 times

Post by Speedbump » Thu Jul 20, 2017 1:47 pm

What RPM's does it go through the traps at? Don't know your head numbers but that intake seems like a restriction with the cam you have and it seems like the cam would like to leave closer to 4500+ if the car will hook off the brake at that launch RPM. The turn into the intake port on that old manifold is pretty brutal compared to the newer Victor style units. Don't know what's available for AMC though.
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Re: How to improve 60ft and 330 times

Post by AMXstocker1 » Thu Jul 20, 2017 3:04 pm

the heads flow a hair over 300 on the intake at .700 and 250 exhuast the intake is getting changed this week and there aren't any victors available but we have an intake thats a Herman Lewis intake its not new but its much taller with alot more volume hoping it might help it. we also of a indy intake that could be worth a shot. stole the picture of the herman off line if edelbrock made on it was just one they dont produce it.
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Re: How to improve 60ft and 330 times

Post by Speedbump » Thu Jul 20, 2017 5:41 pm

I think that manifold will make a big difference. Be sure to follow up on the differences.
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Re: How to improve 60ft and 330 times

Post by AMXstocker1 » Mon Jul 31, 2017 4:12 pm

got a new manifold on over the weekend took one picture when trying to figure out how high up the carb was going to be when we adapted the 4150, were still waiting on our new carb so this was just an old 4150 that was on hand for testing.
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new intake the carb thats on it is just for fitment.
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Re: How to improve 60ft and 330 times

Post by F-BIRD'88 » Sat Aug 05, 2017 3:23 pm

On your rear tires what is the measured rolling radius ? measured from ground t the axle centerline...( true height of slicks)

That cam in that motor will want to trap at or near 7000-7400 rpm.
I think it needs a 4.56 gear ( 4.30 if the tires true measure shorter than 28")
You are not trapping high enough above the converter stall speed.
The trap rpm should be 1500 to 2000 rpm higher than the flash stall speed is at launch.
The long cam duration should support that. ( the 278 ish duration helps the top end power stay
at the higher rpm to help the car trap at the higher rpm wit the higher gear ratio.
"after power" (The power created above the peak power rpm point)( this is what allows the car to trap at a high rpm/with agressive gearing) You can play with the valve lash to max this too. Less lash adds duration (time to feed and clear the cylinders at higher rpm)

With that new intake manifold I'd try the twin eddy 500's on a 2x4 adapter in a heart beat.
Don't expect to run any better than anybody else if you run the same cookie cutter stuff they run. Let the motor show you what works. Cool car.

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Re: How to improve 60ft and 330 times

Post by cpmotors » Sat Aug 05, 2017 11:38 pm

AMXstocker1 wrote:I'm looking for ways to improve our 60ft and 330 times according to our mph the car should be a tenth quicker than it is in this video. the car is a 1969 amx 427 inch iron headed amc solid roller .740 .760 lift and 278 and 288 @ .050 edelbrock torker with a 1050 dominator on e85. it has all calvert racing rear suspension, calvert mono leafs, bars and shocks. and runs a 28x10.5 mt pro bracket radial car weighs 3260 with me in it. this run was on a very hot day and we had to take 3 psi out of the tires to get the car to hook (19psi to 16psi) on pass i'm posting video and the time slip for. oh the car has a 727 torqueflight with a 8 inch tci converter that flashes to 5900 and 4.10 gear and this was leaving of the T-brake on 3200rpm chip.

https://www.youtube.com/watch?v=f_R6PA7dbt8
Yes your 60 is lacking for the weight/engine/converter. How much preload on springs with Cal Tracs? Rancho shocks? how stiff? My bet would be preload and front eyelet position need to be played with. 1.5 60' is par for a 11.50 car in my experience.
Are you running about 6700 rpm currently thru the traps?
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Re: How to improve 60ft and 330 times

Post by AMXstocker1 » Mon Aug 07, 2017 8:36 am

yes traps at 6700, and were making alot of changes at once to try to get this figured out but along with the intake its getting 4.56s. the caltracs are in the bottom hole and have about 1 flat of preload pass touching the spring and rancho's were set on full loose or a 1 on the pass above the car has been 1.48 with them at a 3 and leaving at 3600 on a better surface.

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Re: How to improve 60ft and 330 times

Post by cpmotors » Mon Aug 07, 2017 1:08 pm

AMXstocker1 wrote:yes traps at 6700, and were making alot of changes at once to try to get this figured out but along with the intake its getting 4.56s. the caltracs are in the bottom hole and have about 1 flat of preload pass touching the spring and rancho's were set on full loose or a 1 on the pass above the car has been 1.48 with them at a 3 and leaving at 3600 on a better surface.
Not enough preload in my experience. Put the driver in seat and do 1 full turn on Drivers side and 1.5 turns on Passenger side. Every time I've had a Cal Trac car not '60 was from lack of preload.
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Re: How to improve 60ft and 330 times

Post by AMXstocker1 » Mon Aug 21, 2017 1:03 am

well i got my wish 4.56s did the trick car went 1.43 60ft and 6.62 in the 1/8th changed the caltrac preload a little added 1 flat on the left and 2 on the right but don't have any video from the weekend to see how it worked the probracket radials are a little tricky on marginal services need to figure that out.

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Re: How to improve 60ft and 330 times

Post by Jeff Lee » Fri Nov 10, 2017 11:57 pm

If you improved with that intake, I’m impressed! Indy manifold was about .15 slower than the Torker that replaced it. Too much plenum volume for my application. Went 10.02 wiht the Torker and 4300 Autolite carb.
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Re: How to improve 60ft and 330 times

Post by AMXstocker1 » Sun Dec 03, 2017 9:11 pm

jeff its tough to say we changed gear with the intake from 4.10 to 4.56 and the car went from a best of a 6.80 in the 1/8th to a 6.61 with the gear and intake change. then we put 4.88s in it and tried again and it didn't gain anything so we will stick the 4.56s, unfortunately after that weekend we went to change plugs and check valves and when we turned the motor water shot out of #8 this motor is 13.1 and is oringed with copper head gaskets and extra head bolts, so i dont think it was gasket issue we pulled the heads and couldn't see anything but they are out being pressure checked. so over the winter we decided to make some changes to better suite the class were running and the first change is Hemi Adkins has a set of indy sr heads he's porting for us, and were using another 401 thats standard and to try and go .020 over instead of .040 with 3.80 inch stroke to build a 418 because we can drop a 100lbs for being under 420 cubes and bumping compression to the 14.5 to 15.1 territory. i don't think we will miss the 9 cubes with an extra 40 cfm of head flow and point and half of compression. it should be a different animal next season.

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Re: How to improve 60ft and 330 times

Post by Jeff Lee » Tue Dec 05, 2017 12:55 am

Sounds like a great plan until traction becomes an issue! Are you using any kind of traction control, via spark, timing or whatever? I’ve got a MSD Grid and I’m positive I will need to experiment with timing curves on launch as I’m also running 9” slicks
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