Fastest 904

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416gene

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Gilbert S.C.
I think one of our readers has ran 9.40s with his low gear trans. Hope to see some improvement with 2.45s and more power!!!! 8) 8)
 
So where is it?

My car uses a 904 it runs 10.60's at 125 and some change with 1.40 60 foots. It weighs 3060 pounds.

BTW there are quite a few Comp cars out there with Marv Ripes A1 3 speed trannies in them. These transmissions are AMC torque command 727 cases adapted to the Chevy bellhousing pattern and Marv's own billet machined internal parts, all 904 based. He does use the stock sun gear shell though. I hear there's over 200 different ratios available too.
 
I have one that is kinda fast. I have a 70 Dart w 416 w Indyheads w 904 has 4.56 rear on 31x10.5w tires. Fastest times so for is 5.94 at 113.78 in 1/8 9.46 at 138.70 in 1/4. Cars has 1.24 to 1.26 60ft on a fairly good track. Trans has stock parts ,But fully rollerized, drums were lighted. I build my on trans but JPT TRANS in Eaton Rapids MI (517) 663-0578 did all machine work and built converter that is a 8" 5500 stall. Was all stock w 2.75 gear set till 2 weeks before mopar nats broke input shaft out of low drum. I replaced stock low drum and aluminum high drum. I just rebuilt and put 2.45 gear set has high and low aluminum drums in it now. To keep from draging bumper again. Hope for some improvements when get heads back and did away with timing chain put a WEBER BELT DRIVE ON.
 
Car weights about 3050 lbs with driver. Car weight changes according to how much driver eats. Stock 904 case had all stock parts in it Did have drums lightened upgraded spring kit in high drum. Fully rollerized.
 
That's impressive Johnny. I've been contemplating building a stroker but then traction will become a problem again and well, you know, one thing leads to another...
 
wow a Webber belt drive, that's Ritter's old partner from the Comp Eliminator days, we should talk about crazy smallblocks, I have a few here
 
Car ran 5.90s at Rockingham. Had lots of wind and dust on track .Will think it can pickup more .Belt drive worked very good But we had a few problems .Johnny did a good job of driving ,He had two .005 lights and some 1.30 short times .He mad 4 rounds!!!
 
Johnny P said:
Is there nobody else run a 904 ? I know we can't be the only ones out there? Are we?
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i do but my car still havent seen a real dragstrip.. will post times as soon as everything decides to work properly and do it when our local track is open..
it always work perfekt.. i gues timeslips will be 12.something but i will post when i know. you guys are not the only ones using 904 transmisions with some power :wink:
 
I am wanting to run the 904 in my 76 Dart behind a 360 I am building. I am looking to go low 12's or high 11"s with around a 4:56 gear and a twenty-six inch tire. I am trying to figure out the converter situation. Will be using the B & M flexplate. What should I choose in the 3k to 3500 range
 
I have run 8.60's with a 904 with 2.45 1st gear in my 91 Dodge Datona with a 383 small block with W7 heads. Car 60 foots 1.20. Trans has a billet input shaft with brake from A-1. Going to A-1 Proflite as I need the lower first gear of 2.13.
I did put a glide in the car as everyone told me it would work better, but at the shift it causes too much RPM drop. My W8 motor likes RPM.
 
Mine is a JW Transmissions 904 with a 2.71 low. Debating on trying a 2.45. Nothing fancy!
Not that fast overall at mid-11's, 114mph. But it's also 3,530lbs+ with lots of restrictive rules! Been 1.49 60'. I know of several similar, lighter combos that are quite a bit faster!
 
416gene said:
Car ran 5.90s at Rockingham. Had lots of wind and dust on track .Will think it can pickup more .Belt drive worked very good But we had a few problems .Johnny did a good job of driving ,He had two .005 lights and some 1.30 short times .He mad 4 rounds!!!
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You said the belt drive worked good but you had problems?? was it problems with the belt drive? or something else?
 
Locomotion; I suggest not trying the 2.45 first gear at that weight. You will definitely slow down. I did that when I was running 10's and it slowed down a tenth.
 
Thanks Joe. That's basically what I've always heard also, the more weight in a car, the more it would respond to more low gear. But another factor is torque. We are limited by cam lift, valve sizes, no porting/polishing, all which limit rpm potential. So we have to rely a lot on torque. One "theory" is that a low gear may rev through the torque curve too quickly to provide optimum accelleration. I've heard lots of stories, debates and inconclusive comparisons. But each combo is different.

It's just a theory which I don't know when I'd get around to trying. It's a never-ending learning process that alters optimum results every time you change anything. (i.e.: cam, intake, spacers, etc.) I currently have my best running combo since I started!
 
Belt drive worked great ,The problem was water pump bolt broke in the block . We hope the 904 can handle a w8 stroker for next year, we will keep the belt drive
 
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