single to dual?

[Ridleyj329]

i currently own a 94 SL1 SOHC. ive seen a lot of posts with people wanting to swap a SOHC for a DOHC or vice versa. i was just curious how the two compare. my lst car was a 92 SC2 DOHC which was recently in an accident and i loved it. :-(

[peppermrj]

The DOHC has about 43 more ponies than your 94 SOHC.

[saturnspeed_12]

depending on where you buy everything, a sohc to dohc swap is the cheapest way to make the most power. the only thing that kind of changes things up is the trans. dohc trans are geared for more acceleration.

but as of the swap goes, pretty much the head, intake(to do your car), exhaust manifold, pcm, timing set+cover, wires, and valve cover would do the job. but to do a swap in your sohc would envolve much more, so its better off to go with like a complete motor/harness/pcm.

[drew300]

Just curious.
My '99 SW1 is rated at 100 hp, the SW2 was rated at 124 hp.
The SW1 torque is 114 ft/lbs at 2400rpm, with the SW2 at 122 ft/lbs at 4600 rpm. A lot of 16 valve engines lost their low end power to get hi end power. Is this true of the DOHC?
I find having the low end grunt pleasant, and it saves a lot of shifting.

[saturnspeed_12]

the dohcs were made for low end torque. its why hondas and most imports get blown off the line, and pretty much entire way. it says peak torque at 4800 rpms, but the torque curve is prett smooth throughout rpm range, and the torque on low end can range from 105-112 from probably 2000-4300 rpms to the wheels. i took these numbers from my dyno run. a stock car would be different since i got some things added, but the curve should be the same.


i circled the torque. not big numbers, but its quick little car. needed a baseline for a project.

[drew300]

Yes, that's a nice flat torque curve, but what about the low bottom end? Below say, 2700, it dives! Was this just where you started the graph, or is it that bad down there?
My racing days are over, and I find it nice to loaf along at 1600 / 1800 in 5th, with enough power to accelerate (but of course not quickly), and take on normal hills. Many years ago i did build an interesting engine, a Toyota 1600, with twin Webbers etc. It would past 8500 rpm, and it would pull 6500rpm in 5th. Interesting sound at 8500.....

[saturnspeed_12]

that drop is where i was holding steady at 2500 rpms and i laid it into the floor, thats why there is a drop. if i had started lower, then you would see a longer curve.

i drive around in 5th gear alot. i drive in town, 35-40mph, in 5th gear and it still pulls really good. the dohc is very good torque wise. also, my torque is slightly down due to my aluminum flywheel, since it doesnt have that extra rotational weight.