S13 ka24de Swirl Control valves

[modulation]

What if anything have most people done that have S13 ka24de's with their swirl/butterfly valves?

I replaced my manifold with a S14 one and having no SCVs kills torque from around 2,000-3,200 rpms, but definitely helps out top-end. Sucks for auto-cross but would be better at the track.

How do the S14 ka24de's not have the same problem since they don't have swirl control valves? Is it the cams that they have which make up for it? Or is it it the fact that the S14 ODB2 ECU has VE tables unlike the S13 ODB1 ecu?

[stewiefied]

I think it's the cam shafts. s13s with the butterflies were the ones with the "hot cams". That's why there wasn't a change in advertised hp from s13 to s14.

[eazye2000]

Balancing act with the addition/subtraction of cams/butterflies.

I read a while back that 248/232 (or the other way) netted an awesome powerband. I'm not sure if this is with or without the butterflies installed.
I would personally try 248/248 and keep the butterflies. (just putting an exhaust cam on your intake side) I did this swap, but already had my SCV's out, and had crazy top end with a sacrifice below 3,500. This is why I would keep the SCV's with this swap to help the bottom end. But that's just me.

Not sure of what you're doing. Do you have to keep 'stock' cams?

[cdlong]

I replaced my manifold with a S14 one and having no SCVs kills torque from around 2,000-3,200 rpms, but definitely helps out top-end. Sucks for auto-cross but would be better at the track.

I was thinking of doing essentially this eventually (SP s14, I can't swap cams, but I can backdate entire engines and swap manifolds.) but that last line has me worried. What about s13 engine/cams, s14 manifold, and cam gears. Would the cam gears bring enough mid range back? Or would I be better off just doing a modified S14 manifold on the stock engine?

[Tower240sx]

I'd backdate the engine just for the exhaust manifold on the s13, leave the SCV's out and run it on the s14 ecu and wiring harness

[r20crazy]

isnt the motor u built in my s13 similar Mike?

I have s14 ka24de head with s13 cams and s13 intake without butterflys. it doesnt idle worth a damn until it warms up, and i get some breakup during that period too. after warmup its great and I have noticed the powerband 'lack' described above. but you get used to it, and I wouldnt go back

[Tower240sx]

yeah but you have s13 ecu thats why i think it runs a little rough cold, hence the suggestion to keep the s14 ecu so you aren't relying on the scv valves that aren't there...

There's no difference except valve cover bolt pattern between the heads overall (save the camshafts)

[AceInHole]

I was thinking of doing essentially this eventually (SP s14, I can't swap cams, but I can backdate entire engines and swap manifolds.) but that last line has me worried. What about s13 engine/cams, s14 manifold, and cam gears. Would the cam gears bring enough mid range back? Or would I be better off just doing a modified S14 manifold on the stock engine?

Intake manifold an exhaust manifold are unrestricted in SP, IIRC. I'd go ITB's and longtube 4-2-1 headers.

[djsilver]

I have an S13 motor with an S14 intake and a JWT ECU and never noticed a loss in the bottom range (?) I run in DSP as well and have other things done but I still have a nice fat torque line from 2,500 RPM. I've run across several 1993 S13's built late in that year that don't have SCV's and don't have the S14 valve cover pattern. I haven't really looked closely at the '94 convertible only S13's but I'm guessing they don't have SCV's either.

[Tower240sx]

my 94 had scv...but atleast one of my earlier s13 had no scv

[cdlong]

Intake manifold an exhaust manifold are unrestricted in SP, IIRC. I'd go ITB's and longtube 4-2-1 headers.

Yep. I don't know about ITB's (though I have thought about it) but there is some sort of manifold upgrade beyond the s14 one in the future. And I've already got a hotshot header so I'm probably not changing that.

I'd backdate the engine just for the exhaust manifold on the s13, leave the SCV's out and run it on the s14 ecu and wiring harness

When I get to that point, I'm doing some sort of computer upgrade. As djsilver, noted, with a tune and possible cam gears, it shouldn't kill the low end too much.

[modulation]

I have a S13 with a +1995 ka24de in it. It had the s13 intake with the scv's. I removed it and put in a intake manifold with no SCVs.

There is definitely a loss of torque at low rpms. I have a S14 setup (valve cover pattern and block are from a +1995 ka24de, and a s14 manifold) so everything is the same minus the ECU and the low end torque sucks.

When I went from SCV's to no SCV's I also had a test pipe installed, and high end was way better, it would actually pull all the way to redline. Since it's my daily though I put a OEM cat back on, but top end is still better without SCV's. Like I said I use it for daily driving though so I do miss the mid-range torque.

[Umai Kakudo]

One other hot tip: The S13 IACV and AAC valves (the idle air control and auxiliary air valves) are an inferior design to the S14. The S13 ones will wear out and always leak air over time.

The re-designed the S14 valve to not wear out and it would be worthwhile to switch to the S14 part if you are having high idle or idle fluctuation issues due to the worn S13 valve.

If I recall the parts are interchangeable except for the connector ends on the solenoids. Options are to re-wire for the new connector or swap solenoids out for the S13 ones.

[eazye2000]

^ You can swap over to the S14 subharness that has all those connectors on it. The big plug at the throttle body is the same.