Gearing ?

[abodyjoe]

Cause the car will be primarily a daily driver and fuel economy is also important plus stock converter is what i got and really have no ET goal even though high 12's would be nice.

Can have the best of both worlds with a converter built to your combo. The custom one would be a lot more efficient then a stock one. Would help at the track and probably return better mpg

 

[roccodart440]

Correction, You can go down to the dealership & buy a brand new vehicle ENGINEERED TO RUN 4.10's W/ 1 or 2 OD's, NOT a 40 or 50yr. old prop shaft just cut down
to size. I drive these cars every day & if You think they are vibration free, You ain't drove enough of 'em. They also hang all kinds of heavy-*** metal & rubber dampers
all over the drivetrain & exhaust, not to mention the use of CV's, elastomer couplers & damper rings on the prop-shaft. Frankly, I don't give a s**t about a little hum,
or if it seems "OK to Me" on the highway @80MPH, I'm talking about the prop shaft possibly failing as I said"getting top happy". That means taking up to or near it's
terminal velocity, which for any A-body w/oats is going to be an easy 140 if it isn't geared for the strip w/o OD. While the eng. can take it there w/the right final drive
ratio, it doesn't know or care what combo/method You used to get it there, or if the prop shaft is spinning 5500, or 6900!! You'd better know & be sure the one You're using is up to it, that is all I'm saying.

Cut down prop shaft? You mean driveshaft? My driveshaft was made from scratch and balanced. My car in 3rd gear will go 117. I usually cruise at 62ish in OD. 78 tops..

 

[273]

Can have the best of both worlds with a converter built to your combo. The custom one would be a lot more efficient then a stock one. Would help at the track and probably return better mpg

Thats something I'll have to look into then.

 

[abodyjoe]

I think a good converter is one of the most over looked parts of a combo. Too much I see guy dump a ton of time and money into their driveline only to put a cheap shitty converter in. A converter can make or break a combo.

 

[roccodart440]

I thing a goodconverter is one of the most over looked parts of a combo. Too much I see guy dump a ton of time and money into their driveline only to put a cheap shitty converter in. A converter can make or break a combo.

x2

even a relatively stock engine can almost always benefit from a quality converter.

 

[D-50394]

x2

even a relatively stock engine can almost always benefit from a quality converter.

I agree with the above post. I used to run a 360/380 hp crate motor in my D50. It is technically a stock 2000 model 360 with a M1 intake and a .501/.513 cam. It ran 7.40's with a 9 1/2 convertor and ran 7.20's with a 8 in. PTC convertor and on the street you could hardly tell it was a race convertor. I think a good convertor is one of the best things to invest in.

 

[Killer6]

Cut down prop shaft? You mean driveshaft? My driveshaft was made from scratch and balanced. My car in 3rd gear will go 117. I usually cruise at 62ish in OD. 78 tops..

Propeller shaft = driveshaft
Made from scratch & balanced, precisely what I'm suggesting, & by someone who knows what is appropriate for the intended use & maximum stress/RPM.
Your choice of cruise MPH isn't every ones, and your choice to not top end Your car in OD is as well. We are discussing 273's car, not Yours.

 

[Killer6]

Thats something I'll have to look into then.

This why I asked, the various stages of this project will likely not all want the exact same torque converter, but You will have to find the best compromise that will be
perfect for the final stage. The reason racers can use 2 gears is wholly the torque converter, it will put the eng. square at it's torque hit on the line, & bounce between
that and the peak HP all the way down the 1/4. As posted above(& asked by Myself for a reason), getting the most efficient converter that puts You there is what makes
it work, esp. in this instance.

 

[AJ/FormS]

AJ has trouble hooking cuz he has totally a street suspension, set up to hammer into turns on city streets, and do powerslides. His 60ft is 2.2 or more,lol. The front did not transfer any weight to the rear on the start line, and the rear does not rise. That is about the worst case, all-messed-up-set-up, for dragracing.There was no engine tuning, no chassis tuning, no tire tuning,no shift loops, no nothing. He showed up, got a successful run,ate hamburgers, bought a T, watched the show, and went home. He only went to the track to be able to truthfully answer the question;"how fast is it?" that people kept bugging him about.The answer was [email protected] with a 2.2 60ft. He left on the first yellow and did not redlight,lol.
But I tell you what, You wanna get some exercise around town? just try and keep up; I don't slow down for speed bumps either,So wear a mouthguard. Don't try and pass cuz I use the whole lane.When I lift,engine compression slows me down pretty quick, so don't be looking for brake lites; there won't be any.You won't need headlights cuz my taillights will shine up the way for you. If you get too far behind, I'll put on the 4-ways for ya. If we get to the hiway, I gotta warn ya, I'm geared for 180mph.Second-over is good to about 110.If you get lucky(sometimes I may make a mistake)and if perchance you do pull alongside me, well, then I'll just hit the afterburners;then you will be toast for sure.
He said with a wink and a smile.

 

[AJ/FormS]

I reread the thread, and specifically, I reread post #1.
I think you have some good ideas.

But I 'll counter your good ideas with one of my one.
First is this; I think you said your P/W as 10.0.
This translates to about 107 in the qtr.
I think that early-Barracuda is several hundred pounds lighter than the next generation. I think it quite a bit lighter than a 70Swinger 340, which mine scaled at 3330 me in it@ 130 back in 71,lol;, so that's a net of 3200 on the Dart. I'm guessing yours will come in under 3000 plus your weight with gear, rounds to 3200 maximum..
So that means no problem building the teener to hit the target 320hp.
So lets say the target P/W of 10/1 is done.
But you wanted to hit it with up to 100hp N20, for a total of 420hp. Now, that then makes a P/W of 7.6 and the new mph to go with that is 118. This is no longer a 2 gear project.
So lets back up the bus.
The optimum gear for 118 depends on your engines power peak. I'm gonna guess that with a 220ish cam, you're gonna have a hard time making 320hp.(BTW, I'm not keen on that Voodoo). But let's say you do get the combo up to 320 no matter what. Lets say the cam you finally install makes peak power at 5600.
But lets back up some more.
You have an A999 with the ratios of 2.74-1.54-1.00, and splits of 56.2% and 64.9%. These numbers are pretty wide. You are not gonna cover that with a 110*cam. Ima thinking the 1-2 shift needs more than 114, while the 2-3 might be ok with 114*. Using a cam with this wide an LSA, means the absolute power number will be down some, while the average will be up. But to make the most with that tranny, a 110 will cost you.
Ok back to the 5600peak. I'm betting this is gonna be a 232* or bigger cam.And if you get a fast rate, that will be about a 274. This is streetable in a 367,lol. In a teener, maybe it's getting up there, so I understand your Rhoads idea. (but if you are serious about those, I would run a bigger cam and make it worth the expense). So Lets say that 5600 is doable, and the ported heads stretch the top end out to 6300.
This is where it all falls apart.
Shifting at 6300 drops the Rs into second at 3540. With a 5600rpm power peak, the torque peak comes in around 4200. You see whats happening here, right. The little teener is gonna have to claw it's way outta that hole to get back to where the power is. Not only is she way below the power-peak, but she is also quite far below the torque-peak. That tranny is costing you roughly 190 rpm on the 1-2 shift, as compared to a 904. With the tighter A904 gear spacing the drop from the same 6300, would be to 3730. With the shorter powerband requirement, of the A904, you could also reduce the LSA and pick up some peak power, giving up some, where it's not needed. BUT, lets carry on with the A999. On the 2-3 shift, the Rs will drop from 6300 to 4345. This makes the powerband requirement now only 1955. And the 114* cam is now costing you mph.
Recap
The 114* and the A999 is a bad combo, for dragracing.

But lets continue.
So we want to hit 118, having pulled every bit of power out of the teener before the power plummets. So, lets say with your ported heads, the power extends 500 past the peak of 5600, so 6100. A little math says you need 3.73s with 5% slip and 25.5 tire. Wow, that's not so bad. These will get you 3200@65mph with 0 slip. The starter gear will be 12 /( 25/2x2.74x3.73)=9.81, hey that's pretty good too.
Now let's see what it does NA. Same 320 hp/A999.Same 107 target with the 10/1 P/W, now with 3.73s . I get 5532 with 5% slip in direct.Hey it could be worse!
So that's one plan using your 320hp engine and the A999

I have another plan. I hope a better one.
First my thinking;
I think a 320 hp teener is pretty pipey, with a 274 cam.I've never had Rhoads cuz I have more engine, but they ain't cheap.My idea is to make the engine fit your 2plus 1 idea.I think it's a good one. If you build the engine for torque, it will be way more fun around town and pull harder during an Autocross event, which are run mostly in one gear.Then you can juice it up and run whatever mph you want until it blows up. So how would we do that?
Well lets pick a gear first.
Since you would like to keep the 25s, lets go with 2.94s. This gets you 65@2550 w/zero slip.
So then lets take some power out of that teener.How much. Well lets say we target 6000@the top of second, with those 2.94s,and she is well past her prime.This makes 96mph with 5% slip. in a 3200 pound car, this is a P/W of about 13.8, so we need just 232 hp. That is the minimum to go 96mph.
Now back up a sec. The reason we only went 96 is cause we ran out of rpm.And part of that was the 1.54 second gear. The A904 second would get you 101.5mph, which requires a P/W then, of 11.6, or 276hp. Now let that digest. It took 276 less 232 =44 hp to go from 96 to 101.5!
The stock teener was advertised at 230hp. You slap a 4bbl and headers on it and that can jump to 250 pretty easy. Add a little compression, and just a bowl clean up and you are at 275 and more pretty easy. and no big cam. That stock 240/114 cam, is not gonna pull to 6000 tho.
So lets compromise. We'll put just a little cam into it and sub in 2.76s, and target 100mph. This will require a p/w of 12.3, and that is 260hp. Easy-peasy.
And it will require 5900 rpm with 5% slip,to hit 101.5.
Ok,now we are getting somewhere. We need 260 hp and 5900 thru the traps.
Now since this is a streeter, and you are gonna supercharge it,the engine will not necessarily have to be pulling that hard at 5900, it just has to go there.
So,lets pick a cam that doesn't require the Rhoads,nor a rollercam. Lets go with a 260Advertised/216ish@050 This is a great torque cam and you can tune it for great fuel-economy.
So this cam will peak around 5000 in a teener.And it will torque peak at about 3750.With the right valve springs it will hit 5900 easily.
So to recap
We have at least 260 hp(probably closer to 275 or even better) that peaks around 5000, and pulls to at least 5900. It goes 100mph in the qtr at the top of second, with 2.76s. It cruises at 65=2368 with zero slip.The starter gear is 12/(25/2x2.76x2.74)=6.72. The extra torque of the smaller 260cam will get you off the line quicker than the 274cam. The stock TC will be just fine, allbeit I would go with at least a 2400, on account of that steep starter gear.2800 would be better.
Now here's the good part;Peak torque at 3750 is 36 mph in first gear. Think about that. Think about cruising along at 35 mph,in Drive, just loafing along at 1300rpm, and then the urge hits. You slam the pedal down, the tranny kicks down two gears,the secondaries open,and Shazzam!, the teener is frying the tires! Now imagine autocrossing,and having peak torque or near-peak torque,available almost all the time.
But let's go racing! Ima thinking that teener is gonna be making more than 260hp with that 260 cam. I think it will be an easy 275. And you will want to max out those 2.76s now. So lets go back to the powerpeak at 5000. If you clean up the heads, they will still be strong at 5600. So lets max her out a 5600. I get 146 mph. Well that is about 800hp, so I guess we can't max her out after all. Ok that just means we have enough gear to go there, even if we can't actually go there,lol.
Ok then, we know the SBM will easily go to 450 hp so this would be 450less 275= a 175 shot. You were planning a 100, so lets compromise and now go with a 150shot. This will get us about 425 hp and a P/W of 7.53. And that should go about 118mph and that would be about 4500.Well at 4500 she may not be cranking out 425 hp yet on the 150 shot. If you wanna go 118 you might need a lil more. Or maybe 118 is fast enough.
I tell you what; I would be scared to go 118 on those skinny rollers,lol.
So that's my idea. Give up a little motor for a funner time.
Also, special note, if you build this right, it will burn skunk-pee,day in and day out.With iron heads, this is a Dcr of between 8/1 and 8.5/1, plus tight-Q.You will save thousands of dollars over the next ten years,the life of the engine.
Also, you can build more hp,but invariably that will raise your power peak, and increase the need for a bigger TC. It will burn more gas just cruising around.
Also with a power peak around 5000, you can keep the teener heads. I wouldn't even bother fitting big valves. With 2.76s first gear is good to over 50 mph So you won't be needing them for city driving. I can see them being beneficial as the speed goes up; say over 75mph (4500 in second); and also for autocrossing. But 2.02s would be overkill I think.
Anyhow, I tried to marry your excellent thinking, with some of my ideas and experiences. See how it fits.

 

[Cudafever]

On the GVOD sit there is a section of Q@A
This one was quite informative even made me go Hmmmmm
Can I run a high stall converter in overdrive with a 3.42 axle?
Here is the link
Gear Vendors under/overdrive, Frequently asked questions.

Here is just a snippet of the article......
"When his converter was made it was set up to stall at 3500 with 400hp. However if you put 600hp to it, it would stall at something like 4500. Conversely if you only put 125hp to it (as when you are just cruising at 75mph not accelerating) then the stall is way down at 2,000 rpm. So his stall with a 3500 converter is not 3500 at cruise because he is not making 400hp"

 

[Killer6]

On the GVOD sit there is a section of Q@A
This one was quite informative even made me go Hmmmmm
Can I run a high stall converter in overdrive with a 3.42 axle?
Here is the link
Gear Vendors under/overdrive, Frequently asked questions.

Here is just a snippet of the article......
"When his converter was made it was set up to stall at 3500 with 400hp. However if you put 600hp to it, it would stall at something like 4500. Conversely if you only put 125hp to it (as when you are just cruising at 75mph not accelerating) then the stall is way down at 2,000 rpm. So his stall with a 3500 converter is not 3500 at cruise because he is not making 400hp"

Precisely, well, it's torque applied actually, but just the same.........A slanty vs a 360 vs a 440 vs a 528 all stall the same converter differently, but so does Your right foot.......
it you'll let it!!!

 

[273]

My plan is falling apart. Back to the drawing board.

Step 1 is the same. Use the parts I got for a 318, pocket port, isky 264 cam with Rhoads lifters and the 2.??:1 gears I got.

Step 2 goals and objectives are totally changed now. Since 2.76 are gonna rev to high on track and highway OD will be a must for step 2 now. So the goals are now still daily driver but I want to do 11.5 et in the quarter mile since that's the fastest before roll bar/cage.

Now I want for step 2 is a 360 magnum, beer barrel with OD and cammed, headers and ported for 375 ish hp. And same as before use nitrous as a filler to get me to desired et.
Depending tire size I'm guessing 3.55 and the right stall will round out the combo.

The chassis will be a compromise of street, autox and drag.

 

[AJ/FormS]

A 360?!
I love those
The 11.5ET target is easy enough with a SS suspension; requiring a P/W of just 8.1. With street suspension, you could lose a half second on the line,tho, and so I would target 11.0, which is a P/W of 6.85.This is about 123mph. 3.55s will get you there at 5700 with 27"tires and 5%slip.
At 3200 pounds, this is 467 hp.
With a 100 shot of nitrous, your engine is an easy build of 367hp.With the way that Nitrous works. you may get away needing a little less NA power.
The 360 will be a much better fit to your stated useage.

Now, this is a really neat build, cuz you can actually optimize the engine for Streetability, and dial in the ET with the Nitrous.
So, Now, you don't actually need the $2000 heads and wicked cam and 4000TC.
Also, now, building the engine for torque,means you don't necessarily need an OD, she will be quite happy to pull those 3.55s to 65mph at a tic over 3000 with those little tires.
Also now, the A833od is back on the table. A torquey 360 will pull those gear splits easily enough.And the 1.67second gear with the the 3.55s will get you 38mph@3000, not ideal for autocrossing with a teener, but doable with a 360. With the A999, 38 would be about 2900 in second.
>So this is actually shaping up to be a 3.73 geared car with the od box. This will get you 6056@123mph in direct, 2336@65 in od, and 3125@38mph in second, AND, an 11.53 starter gear. Yeah this is coming together nicely.
So now, easy on the cam.
The starter gear of 11.53 is plenty of take-off gear. The 2336 cruiser gear will allow up to a 230@050 gear, but the 38mph at 3125 will want a smaller cam, like maybe 215/220@050. The nitrous motor will be alright in this range.
I think, based on my experience with a Hughes HE2430 cam which was 223/230/110, this might be your ideal size in a roller motor. This cam had tons of torque. It would lite up 245s up to 50mph(4200rpm) with a gear ratio of 6.78 x .89tire=6.03 normalized, with just a stomp on the little pedal.That combo went 12.9@106; which is a 10.4 P/W or 351 hp @3650race-weight, close enough,I'd say.
>This was just a basic build,zero deck, with OOTB Eddies, That HE2430, and 1.6 arms for a lift of .549/.571 IIRC.Compression came in at 10.9Scr. I used a 750DP on an AG, TTIs and full length dual 3" exhaust.I shifted that beast at 7000rpm, probably 1000/1200rpm past where it would have liked to be shifted at. I only ever made the one pass. 12s were good enough for me.I was running the 3.55s and a 2.66low box, trapping at the top of third gear.
>Of the three cams my engine has seen, this 2430 was my favorite. The current cam is only 1 size bigger, yet it is a world away from that 2430.

>I gotta remind you tho,that I am now running the 3.09/direct box with a GVOD behind it.And still the 3.55s. This combo is far superior to the od box. It would get you
6300@123 in 3-od, or 5764 in direct. 38mph would be 3400 in second/4300 in first-over. And 65 would be 2376.
The neat thing about the GVOD, is you can set it up to be used as a splitter. This gives you the following ratios; 3.09-2.41-1.91-1.49---1.40-1.09-1.00-.78od GV in red
These can be used in the following ways;
for 1/8 mile I shift 3.09-s2.41-1.91. Splits are all about .78
for the qtr, I shift 3.09-s2.41-1.91-s1.49.Again the splits are all about .78
as a steeter I shift the box;3.09-1.91-1.40-s1.09-.78od.Sometimes I split 1-2 if I'm showing off. First-over gets me 60@6377, a two ratio blast.
To go 123, I would shift 3.09-2.41-1.91-1.40-s1.09,hitting 6350 with 3.91s or
I would shift 3.09-1.91-1.40-1.00 and hit 6060 with 3.73s
So you can see how versatile this combo is.
Because splitting has such tight rpm drops I think I would someday like to try a cam with a tighter LSA; say a 104*, and go back to a fast-rate 268/272cam. Shifting at 6200say, the .78 split drags the Rs down to 4836, for a powerband requirement of just 1364. This would generate some serious average hp.
> the splitter also works very nicely with the od box. The ratios are
3.09-2.41-1.67-1.30-1.00-.78-.57, all 7 useable ratios. You can use any rear gear you want to, to optimize either the trap rpm or the launch.
I went away from this combo with the current 230 cam, cuz it was not happy with the standard splits. I found that I always had to split, and the way the splitter works, I just got tired of it.
The splitter works GREAT under dragracing conditions,shifting like lightning. And it works great, using it the way it was intended to be used.
But HAVING to split it was a pain. At low driveshaft speeds, the shift does not come instantly. So you always have to anticipate the shift on the clutch, cuz when the shift comes, it is BAM! The faster you go, the shorter the lagtime. I almost cursed that 230 cam for being so lazy on the bottom. With 4.30s the driveshaft speed was higher and the lagtime was better. But 4.30s and a 3.09 low is a crazy 13.29 starter gear, and that got to be too much to bear. Either the 230* cam had to go, or the tranny. I chose to ditch the tranny.
The HE2430 pulled that combo pretty nice. I did not have to split gears all the time. It pulled those splits ok.
I gotta say tho that double od is pretty cool. They would turn 3.73s into 2.12s,dropping the direct Rs at 65mph,from 3200(with your tires) to 1822.

 

[273]

A 360?!
I love those

Ya I know
Don't why I didn't go for the 360 right away there's still part of me the wants to build the 273 lol.

 

[AJ/FormS]

I agree with the 273 concept. If I was made of money, I would have a turbocharged one.It would make 400/450 hp and do 30 mpgs, and it would pull the front tires.
And you might hear the cam if you listened really hard, but I doubt it. Well 30 might be a stretch , but I can try.
Ima thinking .8 hp/cid NA,then just stir it in. Oh yeah, hi 20s for sure,lol.