For a streeter, gearing is your friend, you don't really need monster power.
If hiway travel is in your plans then you gotta consider the rpm at cruise speed.
And that leads to either;
1) small engine AND overdrive; or
2) bigger more torquey engine and less gear, or
3) some combination of these with a hi-stall and a lock-up TC
There are several ways to get the starting torque you need to fry tires. With street tires, your target is about 2700 ftlbs into the rear axles.
If you are using a 727 and need to stick with 3.23s for 65=2500 rpm with 28s, Then:
your starter gear is 3.23 x2.45 x ~1.8(at zero mph) in the TC=14.24. So your engine needs to be delivering 2700/14.24=190 measly ftlbs.
However, as soon as the car begins to move or the tires start spinning, the 1.8multiplier in the TC begins to diminish towards say 1.2. That leaves you with a starter of 3.23 x2.45 x1.2= 9.50, so your engine, to sustain the spin might need; 2700/9.5=284 ftlbs.
As the car speeds up, it requires more and more torque to keep the tires spinning, so a point will come, that the engine cannot keep up, and the tires stop spinning. At what rpm this happens depends on the ability of your engine to produce the power.
So if you put a monster cam in that engine, the peak torque might not come until say 4500 rpm or higher. 4500 rpm with 3.23s, a TF, and 28s might be 40 mph, depending on the TC used, so you might run outta power with a small engine, before you get there. So in this case, the big cam will hurt your ability to fry tires.
So is the solution a bigger engine or a smaller cam.?
Well with 3.23s and 28" tires, the 318 is not gonna be happy with a 260@.050 cam.
So then with a 318, the solution is both less cam and more pressure.
In a 3800 pounds or so Modoba, normally aspirated, pulling 3.23s, I can't imagine anything less than a very high compression 360 with a modest cam, filling the target. Mine easily spins the 295/50-15, 27.5" tires to well past the speed-limit anywhere here in Manitoba.
With 63cc closed chamber heads, you can fairly easily build that 360 to in the range of 10.7 to 11/1 Scr; AND with the right cam, you can parlay the pressure to in the range of 175 to 190 psi with a typical street cam. This high pressure will require alloy heads and a tight-Q, if you want to run pumpgas. Which then is easy peasy. The more pressure you have, the less stall you will need with those 3.23s.
Now, as to the cam; every cam has a place in the rpm band where it will make peak power. The bigger the cam, the higher rpm. Stuck with 3.23s and 28s; 65=2520 in lock-up, 3650 in second, 6170 in Low. so what cam will you pick?
Do you pick a cam for 6170 in Low? Then your 250@.050cam is about right. But it will suck gas bad cruising at 65=2500. Or
Do you pick a cam for 65=3650 in Second gear? Aye there's the rub.
So at this point you might be thinking that 3.23s are not gonna work for you and you might be right....... unless you just want to fry tires and do not care how quick she is in the zero to 60mph contest. In which case the 250@.050 cam is totally the wrong cam.
So lets back up the bus.
Lets get rid of the 3.23s. and regear to get the rpm up in Second gear. YellowRose likes 4.56s and says they are the best.
Ok so with 4.56s and 28s 65= 3560 in third,5160 in Second and 8710 in First. Well lookit-that, 5160 in second. This allows a powerpeak at about 4900, which typically requires a cam of about 224@.050, which, geared right, will sip gas. So then, we will need an overdrive, to get the cruise rpm down.
Ok, the Mopar overdrive has a ratio of .69 and comes with a lock-up, so it will turn the 4.56s into 3.15s and with the lock-up, 65=2450, problem solved. And the 224@.050 cam will be very happy at 2450.
So now, we have some of the equation selected; namely the cam, the rear gear, the max pressure, and the overdrive. We only have three things left; the CID, the heads, and the stall.
Lets make it easy, and say the heads are OOTB. That leaves the stall and cid.
At 185 psi, and with 4.56s, even a 318 can do this, but to continue the spin into second gear, IDK. By now, the engine is well past stall so she would need to be a powerhouse in second gear. In second the road gear is 4.56 x1.45 x1.2in the TC so the multiplier is 7.93 and Ima thinking the target will be 3700 ftlbs to continue spinning so; 3700/7.93=441 ftlbs. That will be a real stretch for a 318 with OOTB alloy heads and a rather modest 224@.050 cam.
But easy peasy for a 360. So now, all we have left is the stall. Well with 4.56s in a streeter, that makes the stall to be just about anything you got laying around.
Ok so where are we?
360, alloy heads and very high pressure, small 224cam, Chrysler overdrive automatic, and 4.56s. Cool.
Now, I myself have run a 360/223@.050 combo with a 4+1 stick in a 3650 Barracuda, me in it, but with 3.55s
I am happy to report that it would spin 295s to well past 65 mph, and would initiate a spin at up to and including 50 mph or occasionally more, with just a simple footstomp in 1.92 second gear. For me, the multiplier is 3.55 x1.92x1.0=6.82. To do that with an automatic in 1.45 second gear with the TC at 1.2, you would need; 6.82/(1.45 x1.2)= 3.91s. And with those, 65=2100 for cruising, right where the 224 cam likes to be.
So now, Ima reducing your 4.56s to 3.91s, and I'd up the stall to say 2600 or a bit more, and you should still use a lock-up if you can get it in a 2600Plus TC. If not then just use whatever the A500/A518 comes with.
All that's left is to get your 360 up to 185 psi; easy peasy.
Will a 224-cammed 185 psi 360 boil your tires to 65 mph with 3.91s. Well, considering that with 3.91s, and a 1.45 Second gear, with 28s, that 65=5100 with 15% slip, that is right on the powerpeak of that 223@.050 cam, I'd say if it doesn't, you got some pretty sticky street tires, cuz mine did it with no help from a TC and with a gear ratio of 3.55 x1.92= 6.82 compared to yours at 3.91 x1.45 x1.15=6.52; should be doable. With an A500, your ratios are 2.74-1.54-1.00 so top of Second is 3.91 x1.54 x1.15=6.92, Shazzam!
Ok gotta go, it's supper time!
EDITED May 12th
OK but if hiway travel is not in your plans, then we can forget the overdrive and concentrate just on getting Second gear right, cuz most of your street fun will be in second gear.
So with a 3-speed auto, and no lock-up. your starter torque target is still 2700, and the 3700 in second is still the target, But without the OD you have to decide what gears you are willing to put up with around town. Say you are good with 2800 at 50 mph and will run the 26.7" tires as before, then, your rear gear can be as high as 4.30s, for 50=2700 at zero-slip say 2837@5% slip Close enough. So that is the max.
Now how will that work out?
Lessee
32 mph in second would be 2510 @ zero-slip, say about 2900 at WOT. That won't be enough torque. 2700 (the torque target)/(1.45 x4.3 x 1.2in the TC)= 360ftlbs at the crank required. That's a lotta torque for an SBM to try and make at 2900. So then you got two choices; more stall or
lets try a downshift into first;
I get 32= 4240@ zero slip, perhaps 4900 on the tach. Ok so that now has plenty of power to spin the tires in First gear, but the Rs will hit the rev-limiter in a second, pretty darn quick; so then on the shift at say 5500, the Rs will drop to 3250*/say 4000 on the tach and now you might find 400 ftlbs/crank which translates to 2750 into the axles, but by this speed you might be needing 3700 to keep them spinning, so, yur gonna need a 360/5.9 at the least Yeah I think that is doable. So to recap, for impressive frying of tires, a 5.9 with a regular TF and 4.30s will do it. Even initiating a spin at up to say 45 mph in second gear.
Stall?
Well; that 5.9 will fall together with small-chamber alloy heads at over 10.5 Scr, Which you can parlay into mega-pressure with the right cam. So..... with 4.30s and mega-pressure, and the rpm generally well over 3000, Who cares about the stall!, lol.
Are the 4.30s required?
No I don't think so. I think you could do with less. But it won't be as impressive or as much fun, or as controllable.
For a streeter I really like my 1.92 Second gear x3.55= 6.82 ratio. My manual-trans-367 can pull that from 2000 to 4000 real nice which is from 23 to 46 mph, spinning the tires effortlessly in that zone. In order for your auto to make that, you would need 6.82/(1.45 x1.2TC)=3.91s Remember the 4.30s I chose for the city cruise rpm of 50=2837@5% slip; and for no other reason.
With 3.91s, 50mph is now 2580@5%; good deal.
But, with 3.91s, 32 mph in first gear is now 4624@15%slip which IMO is a lil high, but your torque could be up to 400, which will get you
400 x2.45 x3.91 x1.2TC =4600 ftlbs in First gear or
In second gear, 32=2565@15% slip. Torque might be around 330/350 so say
340 x1.45 x3.91 x1.15TC=2220 and you might not get the tires spinning from a foot stomp with a sub 2200 stall The number I'm looking for is around 2700 so you need ;
2700/(3.91 x1.45 x1.15TC)=414 ftlbs so then your stall with a 5.9M will have to be up around 3500 to get that.
So IMO, 3.91s/3500TC are about the minimum gear/TC if you want to initiate a spin in second gear. Well you know unless you install skinny tires,lol. But that trick will not impress anybody, and especially not you, when you keep doing 360s in traffic..........
So having settled that, we are back to needing a 5.9M with a minimum of 3.91s now, with a standard 2.45 low TF, and a stall of around 3500.
Hang on a sec; with 50=2600 now, I'm not real excited to run a 3500stall.
Guys say that modern TCs are better than the used to be, so maybe that will be alright.............. but I think I would run a 2800 and just increase the speed at the 2-1 downshift. I think that would work out just fine, especially if you are able to keep the cylinder pressure up.
