360 head choices. What's everyone running?
Here is a 5.2 Magnum; it could be similar to yours at least from the torque peak to the power peak. For arguments sake, lets just say it is and use this graph, as is.
Notice the at least 15 hp difference from 2600 to 2800. You can't touch that with a simple cam change and especially not with a whiplash.
Currently when you floor it with 3.55s and that 2600TC, you are unleashing say 288 ftlbs crank; I get
288 x2.45 x3.55 =2500 ftlbs into the rear axles, at zero mph. This should bust the tires loose no problem. If it doesn't, it's because of a lack of cylinder pressure, or unusual tires.
Lets look at the numbers with a 2800 and 3.91s. I get
293 x2.45 x3.91=2810 That is 310 more ftlbs, or 12.4%. 10.1% is from the 3.91s alone.
310 ftlbs at 2800rpm represents 165 rear axle hp.
You cannot touch this with the Whiplash; with no other changes, probably not with any cam.
If you install that Whiplash; In all likelyhood, you are gonna loose a few ftlbs at 2600. You'll get it back by say 3300, and probably more besides, but if your tires are locked to the road, you are gonna have to drive thru the soft zone.
Lets say the soft is from, stall to 3000, and loosing 12# at 2600 to 8#at 3000, to zero at 3300. I mean I'm just guessing.
Lets translate that to hp; 12@2600 is 6hp, 8@3000 is 5hp, 4@3150 is 2.4 Lets see where this occurs in terms of roadspeed.
With 3.55s, 2800rpm is about;
18mph in first, 34 in second, 54 in direct . That's about where you are gonna feel the hole plus and minus 200rpm.
Look at 2800 on the graph; 5 hp at 2800 is 5/155=3.2% and 6/140 is 4.3%. To get an understanding of that; a change from 3.55s to 3.23s is 9.1%.. In other words, when you install that Whiplash, with a 2600TC,IMO, I estimate it's gonna feel like you lost 3.2 to 4.3% gearage, or from 3.55s to ~3.36s, in the soft zone.
Here's the point;
you gotta decide where you need/want the power most,
then gear the car to try and put it there,
then build the engine to put the power where you called for it.
If you build the engine first,to some arbitrary hp number, then you are stuck trying to adapt it to your needs.
For a streeter; IMO, Having power at 5500 is rarely the solution.
And for a streeter, you will very rarely be able to go thru the powerpeak twice,in the Zero to 60 speed contest. And the first time, with street tires and suspension, she'll be spinning.
To hit 60@5200 with an 80inch roll-out (25.5" tires) requires 4.10s for 60=4710@zero slip to 5180 @10%, and you will need a 268adv/[email protected] type cam. For a weekend bomber, I suppose you could run 4.10s.
But if you put a DC-268 hydro ([email protected]) in a 8/1 318LA, you end up with a bottom end that, to me, is embarrassingly soft. In an 8/1 360, it gets better, but still, I would never do it again; I just ain't that broke.
If you have to run an 8/1 SBM, then your first soldier, against the soft would be a fast-rate,tight-lash,short period, solid-lifter cam,(forget about lift, let it be what it will be.), and a close second, would be a clutch/5-speed ....... or a high-stall.
Or; some guys have run variable duration lifters, to very good effect, but IMO, at this power level, a new set of hi-compression pistons is a better solution. Still, you can think about it.
Here are, in no particular order, some common targets;
1) frying tires, not just chirping, I want major smoke.
2) power at 30 to 35 mph, to play in traffic
3) passing-gear power on the freeway
4) fuel economy.
5) stealth.
6) drifting
7) quiet cruising
8) power from 30 to 40 mph, cuz I know this place.....
9) power thru the traps
10) everybody's favorite, I want it to sound like a "funny-car"
11) add your target here
Most small blocks can achieve two closely related targets sometimes three, after that, yur getting into special builds. And of course some paired targets are just really expensive,while others are impossible.
Happy HotRodding
Ok wait, now we're into 360s, I musta takin' a wrong turn,lol.
Here is a 5.2 Magnum; it could be similar to yours at least from the torque peak to the power peak. For arguments sake, lets just say it is and use this graph, as is.
Notice the at least 15 hp difference from 2600 to 2800. You can't touch that with a simple cam change and especially not with a whiplash.
Currently when you floor it with 3.55s and that 2600TC, you are unleashing say 288 ftlbs crank; I get
288 x2.45 x3.55 =2500 ftlbs into the rear axles, at zero mph. This should bust the tires loose no problem. If it doesn't, it's because of a lack of cylinder pressure, or unusual tires.
Lets look at the numbers with a 2800 and 3.91s. I get
293 x2.45 x3.91=2810 That is 310 more ftlbs, or 12.4%. 10.1% is from the 3.91s alone.
310 ftlbs at 2800rpm represents 165 rear axle hp.
You cannot touch this with the Whiplash; with no other changes, probably not with any cam.
If you install that Whiplash; In all likelyhood, you are gonna loose a few ftlbs at 2600. You'll get it back by say 3300, and probably more besides, but if your tires are locked to the road, you are gonna have to drive thru the soft zone.
Lets say the soft is from, stall to 3000, and loosing 12# at 2600 to 8#at 3000, to zero at 3300. I mean I'm just guessing.
Lets translate that to hp; 12@2600 is 6hp, 8@3000 is 5hp, 4@3150 is 2.4 Lets see where this occurs in terms of roadspeed.
With 3.55s, 2800rpm is about;
18mph in first, 34 in second, 54 in direct . That's about where you are gonna feel the hole plus and minus 200rpm.
Look at 2800 on the graph; 5 hp at 2800 is 5/155=3.2% and 6/140 is 4.3%. To get an understanding of that; a change from 3.55s to 3.23s is 9.1%.. In other words, when you install that Whiplash, with a 2600TC,IMO, I estimate it's gonna feel like you lost 3.2 to 4.3% gearage, or from 3.55s to ~3.36s, in the soft zone.
Here's the point;
you gotta decide where you need/want the power most,
then gear the car to try and put it there,
then build the engine to put the power where you called for it.
If you build the engine first,to some arbitrary hp number, then you are stuck trying to adapt it to your needs.
For a streeter; IMO, Having power at 5500 is rarely the solution.
And for a streeter, you will very rarely be able to go thru the powerpeak twice,in the Zero to 60 speed contest. And the first time, with street tires and suspension, she'll be spinning.
To hit 60@5200 with an 80inch roll-out (25.5" tires) requires 4.10s for 60=4710@zero slip to 5180 @10%, and you will need a 268adv/[email protected] type cam. For a weekend bomber, I suppose you could run 4.10s.
But if you put a DC-268 hydro ([email protected]) in a 8/1 318LA, you end up with a bottom end that, to me, is embarrassingly soft. In an 8/1 360, it gets better, but still, I would never do it again; I just ain't that broke.
If you have to run an 8/1 SBM, then your first soldier, against the soft would be a fast-rate,tight-lash,short period, solid-lifter cam,(forget about lift, let it be what it will be.), and a close second, would be a clutch/5-speed ....... or a high-stall.
Or; some guys have run variable duration lifters, to very good effect, but IMO, at this power level, a new set of hi-compression pistons is a better solution. Still, you can think about it.
Here are, in no particular order, some common targets;
1) frying tires, not just chirping, I want major smoke.
2) power at 30 to 35 mph, to play in traffic
3) passing-gear power on the freeway
4) fuel economy.
5) stealth.
6) drifting
7) quiet cruising
8) power from 30 to 40 mph, cuz I know this place.....
9) power thru the traps
10) everybody's favorite, I want it to sound like a "funny-car"
11) add your target here
Most small blocks can achieve two closely related targets sometimes three, after that, yur getting into special builds. And of course some paired targets are just really expensive,while others are impossible.
Happy HotRodding
Ok wait, now we're into 360s, I musta takin' a wrong turn,lol.
