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Post by spud on Sept 27, 2023 4:31:17 GMT -8
Thats pretty good. 2.64 , 1.75 and 1.33 is more like it. The 2nd is kinda tall… It would be awesome if you could get the 2.88 low like the 79-81 trans… but then the 1.75 second is a big jump. If it was like burger king i think a 2.88, 1.96,1.33 would be nice. But its gonna be better than the crash box.
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Post by n2ojoe on Sept 27, 2023 5:09:04 GMT -8
I really like the 1-2 drop personally. I have 2.72-1.60 drop in my pro shifted T10, and it works well other than the harsh hit to the driveline/tire spin when pulling 2nd gear. This will be more smooth going from 2.64-1.75, and smooth is fast. It shouldn't be nearly as violent. Another reason I believe that Brian Higgins knows what he's talking about, is he claims the GM ratio T10 will be 1.5 tenths quicker than any AMC factory ratios That is exactly what I have seen first hand with my Liberty T10.
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Post by spud on Sept 27, 2023 5:38:36 GMT -8
The 2.72 to 1.60 situation was pretty ridiculous. I agree 1.75 is better. Your new trans will have better gear spacing. If the taller 2.64 low hurts at all you can always tune with an axle ratio increase. All in all your moving forward in multiple ways with the new (synchronized) t10. Its gonna be a lot more fun and smooth with the more sensible ratio spacing. No ifs ands or buts about that. As far as the 2.23 low trans, not sure why amc went that direction, but it was never gonna work on a dragstrip or the street. A 3 speed would have worked better.
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Post by PHAT69AMX on Sept 27, 2023 15:02:20 GMT -8
So do you shift always at the same peak rpm, or shift at different peak rpm so it always falls-back to the same peak-torque rpm?
example: 108 MPH 1/4 mile trap speed, 12,xx secs AMC T10 P, 2.43 - 1.76 - 1.47 - 1.00 3.73 gears, 25" effective tire diameter
Always dropping-back to same max-torque engine rpm: SHIFT RPM 5,430 Top of 1st , 4,052 Btm of 2nd 4,925 Top of 2nd , 4,052 Btm of 3rd 5,986 Top of 3rd , 4,052 Btm of 4th 5,430 4th 108 MPH
Always shifting at same Peak engine rpm: SHIFT RPM 5,986 Top of 1st , 4,254 Btm of 2nd 5,986 Top of 2nd , 4,925 Btm of 3rd 5,986 Top of 3rd , 4,052 Btm of 4th 5,430 4th 108 MPH
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Post by n2ojoe on Sept 27, 2023 15:14:49 GMT -8
Interesting numbers there. I always shift at 5,000 rpm (peak hp is at 4900), and go through the traps at 5400-5500 ish, at least according to the questionable factory tachometer in the 70.
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Post by PHAT69AMX on Sept 27, 2023 17:41:10 GMT -8
AMC T10 with 1977 GM GEAR SET 2.64 - 1.75 - 1.33 - 1.00 3.54 GEARS, 26" EFFECTIVE TIRE DIA
Always dropping-back to same 3,308 max-torque engine rpm: SHIFT RPM 5,131 Top of 1st , 3,308 Btm of 2nd 4,221 Top of 2nd , 3,308 Btm of 3rd 4,432 Top of 3rd , 3,308 Btm of 4th 4,887 4th at 107 MPH
Always shifting at same Peak 5,131 engine rpm: SHIFT RPM 5,131 Top of 1st , 3,308 Btm of 2nd 5,131 Top of 2nd , 3,829 Btm of 3rd 5,131 Top of 3rd , 3,829 Btm of 4th 4,887 4th at 107 MPH
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Post by n2ojoe on Oct 23, 2023 4:23:47 GMT -8
I had a busy weekend in the garage. All the gears came back from Liberty's last week with new pro shift rings on 1st and 2nd and a new 1-2 pro shift slider. I had 3rd and 4th converted to face plated rings and slider. They said that face plating 1st and 2nd in a T10 was very difficult due to space limitations to the case and reverse idler gear. And with my aftermarket 2.72 1st gear which is twice as wide as stock, there was zero chance of converting. So, I spent Saturday reassembling the transmission. I also had an extra set of factory torque links I've been wanting to install on the Javelin, so I sand blasted them and pressed in new poly bushings. The frame rails are double thick where the frame brackets mount and appeared plenty beefy. I welded a 3/4" nut to the back of the frame brackets, and hole sawed a hole large enough so that nut could drop through, and welded the brackets into place. I actually plotted the suspension points on the Bickel chassis program and mounted the frame brackets where they'd help provide a bit shorter instant center, and more "hit" to the tires. I put the transmission in Sunday, and swapped out the race clutch for an aluminum flywheel with a Centerforce clutch so I can sort the other issues on the car without the variable of unknown clutch slippage (I have no data logger yet). The car drives much better, and the face plated gears are amazing. They just click into gear with no grinding or drama. The plan is to test at the F.A.S.T. race this Friday at US131, weather permitting. 20231015_104501 by Joe Pinsoneault, on Flickr 20231015_104526 by Joe Pinsoneault, on Flickr 20231021_131323 by Joe Pinsoneault, on Flickr 20231022_111732 by Joe Pinsoneault, on Flickr
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Post by amxdreamer on Oct 23, 2023 20:25:29 GMT -8
It seems a shame to hide such nice looking parts!
I'm curious what you do for loading the rear for setting the torque links?
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Post by n2ojoe on Oct 24, 2023 3:53:32 GMT -8
I've tried the pre load set up with 209, 300, 400 lbs in the trunk, and honestly I don't see any real performance advantage for what I'm doing. I set the drive shaft/pinion angle by shimming the transmission mount on the cross member and with angled shims at the rear axle spring perches, then tighten down the torque links at normal ride height. The links are just to control axle wind up and wheel hop, and they are good at that. The factory leaf springs were soft and wheel hopped violently, even after clamping. The Caltrac split mono leafs cured that for the most part, but still need a little help.
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Post by spud on Oct 24, 2023 4:30:19 GMT -8
I have the same opinion on stock springs. They are very weak and even the best traction aides cannot cover their flimsyness. The six cylinder springs in my ( now 304) car were horrible. The pinion was against the driveshaft tunnel hammering away. With a stock 304. Calvert springs are basic equipment for drag racing any chassis in my opinion. If your skeptical, you havent tried them against stock. I even put a set in my roadkill streeter just because i know i will race it. Once the pinion angle goes up over negative your in trouble.
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Post by amxdreamer on Oct 24, 2023 13:58:16 GMT -8
Thanks Joe, I figured you would have a good legit answer. I've never had wheel hop with my AMX but obviously don't race it very often or do more than the occasional small burnout. The cop car has had it a couple of times...you know during "testing".
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Post by Captain Awesome on Oct 25, 2023 6:31:52 GMT -8
I broke the lower shock mount off the shock before I put the slappers on mine. I saw the "slapper" post on "the other forum" and funny how Clowns are talking about using the cheapest 28" bar. I have the longer 30"? Lakewoods, heavier steel and longer, they come real close to the spring eye.
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Post by spud on Oct 25, 2023 7:11:13 GMT -8
Which is correct. The snubber should hit the eye. My roadkill javelin has all the signs . The upper shock mounts were hammered to shreds. The driveshaft tunnel is hammered and ripped open from the pinion and u joint beating on it. You can see the witness marks on the frame rails where the leaf spring clips were wearing on them because the springs were compressed and wrapped up. The old battered leaf springs were “S” shaped. Someone beat the dogshit out of her. Probably had a decent engine in it at one time , which apparantly was pretty useless with the stock suspension.
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Post by Captain Awesome on Oct 25, 2023 9:30:01 GMT -8
My lower leafs are all wavy and this is just a Turd 304 with a peg leg rear. The factory springs are just garbage.
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Post by spud on Oct 25, 2023 12:15:30 GMT -8
They are great for a production car and a nice ride. They just aint up to the job for drag racing. Which they werent made for. Nothing else in the car was intended for that either. So its pretty normal for 50 year old leaf springs in a 60-70’s era sporty sedan to be whipped by now. I have used various leafs from other cars to tune up the stock main leaf. The main leaf is still there and pretty wimpy, and putting stiffer leafs under it focuses the force on the front end of spring and spring eye, which bends it, potentially can break it, so its not a great modification . Calvert split monoleafs are really a basic standard nessesity in a chassis that is going to race ( and hook). They are inexpensive, light, engineered to fit, work well and are safer than any modded amc main leaf. They have a much heavier duty cross section and spring eye. Yeah they are stiff on the street. Thats just how it goes. I dont think most wannabees give those leaf spring a first thought. But look at the big 3, all the real musclecars had beefed up springs in the rear. As far as i can tell, amc did not have very beefy spring options if any options at all.
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