twin exhaust cam set up?

[DjPantsSpecR]

upon closer inspection, and the fact that those cams are still on ebay for about nine more hours here...

the cams are sitting in the S13 position, granted this means almost nothing, but orange is on the exhaust side and green on the intake side. However, for as dumb as the auctioneer seems, especially with his final two comments, its hard to tell if he did that on purpose or if he is just really dumb.

without seeing the sprockets, there really is no way of tellin what kind of cams those are, other than they look like butt. Once again this means nothing, because an S14 motor i bought also has cams that look like butt like that too, so thats not an indicator of age either...

anyone ever wonder if 94 s13s (all convertable automatics) that had 232/232 cams, what the color on those would be? would they be colored according to S14 232's or would they be orange exhasut and green intake just like the S13 it is?

[Bigvinnie]

Why has no one done a 248/240 set up in the s14 KA's. I know that 248/248 is to drastic for only top end. Most people claim that the 248/232 is the best for the s14. But who is to say that a 248/240 set up may be better for mid range and top end........But really why doesnt some one just switch the s13 ka cams intake onto the exhaust side, while the exhaust side onto the intake side of the s14 KA. Does it make sence.......

[1991S13]

It has been done, just no one has talked about it in this thread. It sounds to me like DJPantsSpecR has experimented with pretty much every setup you could, so he can probably tell you how it feels.

[DjPantsSpecR]

i remember one cat who said "248/232 felt mushy in the low end" and he said that 248/240 feels just right to him. I think 248/232 feels pretty damn good in the low end. I don't know how he got any more midrange or torque out of adding duration with the exhaust cam, but who knows.

s14s inheriently have larger MAFs and more aggressive ecu tuning while S13s lack these. So its hard to say where your weak points are and exactly which cams are going to give you what you want.

i have the feeling i'm going to be trying 248/240 very soon here just to see whats the dealio, and hopefully, to answer your question

[guyaverage]

Meow, folks..... that cat was me. It wasnt 248/240, it was 240/232 for the low and mid range. I never tried 248/240. The 248/232 was smooth, and it did have good mid range, but it felt like I lost low end, which is what I like more than the high end, so I put in the 240/232 and instantly liked it so I kept it. This is on a 93 vert automatic.

I would be curious to see what 248/240 feels like or to hear anyone elses results though. Sounds like a high-mid to high end setup to me, which is why I didnt bother trying it. 240/240 might be interesting enough to try, if I had another 240 cam laying around....

(If anyone cares, I had the car smogged with the stock 240/248 cams then smogged with the 240/232. With the 240/232 cams the HC (hydrocarbon) emissions dropped almost 50%, from 22.2 parts per million to 12.2 parts per million. CO, NOx, and CO2 all stayed almost exactly the same.)

[Bigvinnie]

s14s inheriently have larger MAFs and more aggressive ecu tuning while S13s lack these. So its hard to say where your weak points are and exactly which cams are going to give you what you want.

It doesn't have alot to do with the MAF. It has more to do with the fact that the S13 KA's have secondary butterfly's in the manifold decreasing flow and diameter size. Removing the Butterfly's is about a 6HP gain. found it much easier to use the 95-98 intake mani......I found that with an SAFC and the removal of the secondary butterfly's you ca get a little more juice out of the s13KA's than the s14KA's.....

[DjPantsSpecR]

wow, talk about your mis quoting on my behalf, thanks for clearing that up for me, and just cuz i screwed up i will try 248/240 and report back as soon as possible, however i'm hopeing the results are predictable. Maybe, just maybe, 248/240 is better in the top end then even 248/248.

i also want to note that all of my tests are on S13s and s14 should be able to outflow the s13 at least a little

and hopefully within this week i will have my automatic running, and i can give you my impressions of 240/240

[DjPantsSpecR]

good point about the swirl control valve. Its hard to believe that each butteryfly when its wide open is taking up that much space, but when i think about it i can see your point.

You can even hear the restriction its making, when at WOT when you hit 3500 you start to hear a high pitched whine, and then it increases to a maximum volume. This is where everyone thinks my car has a turbo...

However, the butteryfly valves make the car very peppy at 1/4 to 1/2 throttle, especially with 248/232

i think you've convinced me to use my 96 intake on my 5spd, but leave the butteryflys on the automatic

[Bigvinnie]

good point about the swirl control valve. Its hard to believe that each butteryfly when its wide open is taking up that much space, but when i think about it i can see your point.

If you think about it, those secondary butterfly's kill the KA's high end performance for the s13KADE's.

You can even hear the restriction its making, when at WOT when you hit 3500 you start to hear a high pitched whine, and then it increases to a maximum volume. This is where everyone thinks my car has a turbo...

I realized that too, my friend had an s14. I took him on lowend power on the streets. But when his s14 was on the freeway, his car defenitely gained on me pretty quick. We both had our cars bone stock about a year ago.

However, the butteryfly valves make the car very peppy at 1/4 to 1/2 throttle, especially with 248/232.

Thats probably from the vacuum and swirl that is created by the butterfly's, it probably helps atomize fuel to air better giving it better low end responce. Probably makes it a leaner mixture at lower RPM too.

i think you've convinced me to use my 96 intake on my 5spd, but leave the butteryflys on the automatic

For shure, with an Aluminum fly wheel, no butterfly's, and a aluminum crank pulley the s13KAde can make some pretty wicked mid~high end HP without any other mods required or ecu tuning............. Well maybe accept for something cheap and affordable like an SAFC. .......... For my situation atleast.
Modified by Bigvinnie at 11:01 PM 8/22/2005

[InsanityInc]

good point about the swirl control valve. Its hard to believe that each butteryfly when its wide open is taking up that much space, but when i think about it i can see your point.

You can even hear the restriction its making, when at WOT when you hit 3500 you start to hear a high pitched whine, and then it increases to a maximum volume. This is where everyone thinks my car has a turbo...

However, the butteryfly valves make the car very peppy at 1/4 to 1/2 throttle, especially with 248/232

i think you've convinced me to use my 96 intake on my 5spd, but leave the butteryflys on the automatic

The strange part about the secondary butterflies is that they don't open all the way. They actually block off a pretty large portion of the intake port when open.

[Bigvinnie]

The strange part about the secondary butterflies is that they don't open all the way. They actually block off a pretty large portion of the intake port when open.

I think it consumes about 1/3 of the intake port diameters when fully open. Probably why Nissan made the s13KADE cams more aggresive than the s14KADE's

[Bigvinnie]

Just imagine.... The PDM cams in the s13KADE with no butterfly's......Sounds NIFTY......

[DjPantsSpecR]

so are you saying when the butteryflys are wide open they aren't open are far as they go?

i looked at my intake manifold on the car i was working on today and when you open the valve by hand its actually about 1/6 of the runners inner area

i'd be heated if the butterflys never went wideopen. And incase anyone was excited to see how 248/240 was, i didnt have anytime becasue i ran into a bunch of problems putting my other car backtogether today

and for anyone putting an S14 KA in their S13:the damn S13 AC compressor wont bolt up to the S14 AC bracket. and i hope S14 alternators work on S13s because the large ground wire has to be modified to fit

[Bigvinnie]

so are you saying when the butteryflys are wide open they aren't open are far as they go?

i looked at my intake manifold on the car i was working on today and when you open the valve by hand its actually about 1/6 of the runners inner area

I don't think the swirl valve allows it to open as much as you can by using your finger to push it open more even on wide Open Throttle

[DjPantsSpecR]

i would say that i would bust out the vacuum pump and see if it goes wide open, but i bolted it on to the car already. and it was such a big pain im not going to do anything about it.

i can't help but feel, somewhere this thread lost its way... i don't think its been about 248/248 for a long time

[Bigvinnie]

i can't help but feel, somewhere this thread lost its way... i don't think its been about 248/248 for a long time

Well to get back on topic. I was told by several tuners you can retard the 248 exhaust 2 degress from stock timing to shift power in to the mid range......I wonder if that is true......

[DjPantsSpecR]

i've read this too, but its really hard to believe that only 2 degrees will help that much, but maybe it is believeable because 248/248 makes power where the KA never even sees.

unless you have one of those 11,000 rpm racing trucks... but you probably have a lot more duration than 248...

[ArticDragon192]

I know, revival of the dead thread, but is for clarification, it's 2 degrees on the timing correct?

[Bigvinnie]

I believe it is 2 degress for the exhaust (retarded). Cant remember if the Intake cam is to be advanced 1 degree . 1 degree advancement on the distributor. Not shure if the info is correct, I wouldn't attempt to try it without alot of time on your hands............

[DjPantsSpecR]

2 degrees too far advanced for a 248 on the intake side. if the 248 is on the exhaust side its exactly how it should be.

i wouldn't advance the distributor at all, i've tried it and was dissatisfied. If you are using 248/248 you're making mostly top end power anyway, so it would be in your best interest to throw a little retard on the distributor to help add on to that area

is that even what you were asking?

[ArticDragon192]

Yes it was. I just aquired a set of S13 cams and was gonna run the dual exhaust cam set up in my s13 KA. So retard the timing about 2 degrees on the distributor to help the midrange, correct?

[DjPantsSpecR]

i gotta apologize, i don't know what the hell i was thinking. I realize now that i told you just the opposite of what i meant to.

well that all really depends. If you run a decent octane and are using dual exhaust cams then i would advance the distributor a few degrees to help give it a little more top end, after all that is where you are trying to make power

you can certainly try to retard it a few degrees. just warm it up then drive it around, or do a quick 0 to 60. Then pull over and advance it a few degrees and do the same thing. just find where you want it to be, there is no right or wrong, and completely contradictory to what i just said, shooting for the most top end may not be exactly what you are looking for...

base timing may even be what you want if you're looking for midrange from 248/248. you'll find that when you hit redline that those cams just got cooking.

either way, what i'm trying to say is all these power gains are so minimal from dist timing, thats why i think you should just try it out, then try something else out. it couldn't be easier to loosen two bolts...

i had a long weekend, and i just screwed that up before. so to reiterate, retard = bad, base or advance = good but base should give you more midrange than advanced. But i think you should try em both