pacesetter header, individual throttles, estimated outputs ?

[MATT 'BACK' VASS]

any thoughts ?

[MATT 'BACK' VASS]

First question is why was this post deleted when I'm one of the sponsors on this website ,and you guys sponsor our twin drift cars.

It would be on a stock block KA24DE also.

[corn322]

with just headers and ITB's? probably not too much, I'm guessing 5-10 wheel horsepower.

[deviousKA]

You may want to look into the greddy s14 model ka24de header. Equal length 4-1, stainless. The primaries are shorter than the pacesetter but have larger diameter. I have one on my ka2.1l with modified collector.

Probably have some pictures of it somewhere if your interested in taking a look, im not sure if greddy still makes it.

As far as estimated power output, you could expect +15-20hp with proper sized and structured itb setup, and a header. The engine must be very fine tuned in order obtain decent numbers.

Id suggest you build a new longblock NA specific, at least eventually.

[PandaS14]

Matt,

It's Scooter from ziptied. hit me up on aim if you want to talk (PandaAkS14). I'll have my dyno within the next couple weeks hopefully. So then you can get some real numbers, not guestimates.

cheers

[MATT 'BACK' VASS]

and it cracks like a sonofabitch.

a friend has had S14 headers, two of them. they both cracked like a sonofabitch.

pacesetter actually makes some decent stuff. (old Z car guys know it works well also. and scca guys seem to like them. )

if the primaries are shorter and larger its more for much more top end power.

i will try the pacesetter first and see how it does.

well, all the otehr bolt ons would be on it also.

build a KA? nah. if anything shave the head .020" - .030" and put a thinner head gasket on it.

[InsanityInc]

with just headers and ITB's? probably not too much, I'm guessing 5-10 wheel horsepower.

Wrong.



Notice how the dyno graph doesn't even go past 6krpm? That's because the power drops off so badly, it's pointless to keep going. The torque peak is at a measly 4600, with a redline of 7000. The first thought is obviously that the cams are at fault. Afterall, conventional wisdom is that to get high-end power, you change the cams. So, I present a cammed KA dyno:



Well, they gained some power, to be sure (though, not as much as it would seem, the second dyno is a totally different engine with other mods). But that's not what I'm looking at. Notice that while it did breathe better at the high end, the power and torque still die a realtive death in about the same place, and the torque goes to hell a full 2.5krpm before redline. Since cams aren't the problem, the only other logical culprit for a high-RPM breathing restriction is the intake manifold. And just by looking at the thing, there is obviously a problem. The runners are 21 inches long, to help low-end torque. However, they sacrifice high-rpm power, which is what we're trying to achieve. Also, if you have an S13, you have secondary butterfly valves, which certainly don't help at high rpms, either.

The idea with creating high-end power is simply to maintain your torque at higher RPM levels, since horsepower = rpm*torque/5252. By simply letting your engine breathe the same at a higher RPM, you gain power, and in this case, quite a bit of power. Currently, the power peak of a stock 240 is about 130whp@5500rpm. The torque at that point is about 125ftlbs. The torque peaks at about 145 ftlbs, but at a lower RPM. Lets say we just moved the torque peak to 5500 rpm, and assumed it dropped to 0 after that. Our new peak power at 5500 rpm would be 151whp. A 21 horsepower gain, just from moving the torque we already produce. And that's a conservative estimate, considering the torque isn't going to instantly drop to 0 after 5500. By having a short runner manifold able to maintain the torque at say 135ftlbs at say 6500rpm, you'll have a peak power of 167whp, and that's assuming we're down 10ftlbs from stock at that point (pretty reasonable estimate with stock cams, i'd guess). A header will improve the torque somewhat as well, so expect even better gains. I'd guess that just a header and ITBs should get you easily into the range of 170whp.

[deviousKA]

Yeah the collector likes to crack on the greddy, you have to modify it.

Pacesetter is decent stuff, give it a shot. There is a handful of 200+hp ka's running them, most sohc.

Shaving the head and/or running thinner gasket isnt going to bump the ratio much within reason. The shorter distance between camshafts and crank (well in this case, the cam chain idler gear) will retard your cam timing. You can recoup your settings with adjustable gears, but you will always have unnecessary chain slack on the bottom chain.

Throw some single cam pistons in it, simple enough.

[InsanityInc]

Yeah the collector likes to crack on the greddy, you have to modify it.

Pacesetter is decent stuff, give it a shot. There is a handful of 200+hp ka's running them, most sohc.

Shaving the head and/or running thinner gasket isnt going to bump the ratio much within reason. The shorter distance between camshafts and crank (well in this case, the cam chain idler gear) will retard your cam timing. You can recoup your settings with adjustable gears, but you will always have unnecessary chain slack on the bottom chain.

Throw some single cam pistons in it, simple enough.

Something I've been trying to get a straight answer on about the single cam pistons for a while... with stock DOHC timing, will the engine knock with 91 octane (yay california... grumble) if it has the SOHC pistons? From what I hear, they put the compression really high in a DOHC (11.7:1?).

[MATT 'BACK' VASS]

Sorry, ive done this on hondas plenty of times and have not had any problems with them.

the tensioner in the KA can't be that ****ty that it cannot handle some more slack. it's really not that much at all.

as far as the cam timing goes, yeah adjustable cam gears will fix that. not a big deal.

the more i do this the more i think i'll start with an s14 ka intake manifold to make it happen.

[deviousKA]

How much additional compression ratio do you think you will get? In total you wont be able to go any more than .030", maximum decked head and thinner gasket combined. You can drop maybe 6-7cc total, probably less. In my opinion thats a poor "workaround" that has many negative side effects.

Just for reference, heres a chart displaying necessary volume changes to obtain different compression ratios.

All calculations considering 34mm compression height/distance (piston). 0 volume is pure flat top, roughly 14cc difference in volume when compared to oem ka24de piston. Late model sohc ka24e piston (8.6:1) is 2cc dish, early model (9.1:1) is 2cc dome. These would yeild approx. 11.1/11.8CR in ka24de, respectively.

InsanityInc, you can run 11.1:1 with 91 octane. You may be able to run at stock timing advance, you might not. A lot of factors come into play, but you wont be so far out of the ballpark that it cant be tuned to run well. Get a decent efi tuning platform setup in your car, you will find out what it likes.

[j-z]

hey matt, im currently working on an itb setup for my s14. i used the stock manifold, gsxr itbs, and a 'custom', made by yours truly, aluminum plenum. reason for the plenum is because i want to run the maf for now atleast. it should be done tomorrow. i cant wait! ill let you know how it turns out. if you would like to check it out sometime, id be more than happy to show it off.

[Julian]

InsanityInc, wrong. Insofar as you blame the stock factory intake manifold for choking your high-end on a stock motor, you are incorrect. I have dynoed my KA as stock internally (I had to put a new exhaust on it to fit it into my 510), you can see the graph here:



(full size here: http://www.jetlink.net/~okayfi...l.jpg)

Plenty of top end, nice and flat for the last 1000 rpm as well.

After building an ITB setup and running it for ~6 months, I can confidently say it offers no real benefit on a stock KA. Hayabusa ITBs, velocity stacks, 2 liter plenum, 2.75" intake pipe, S14 MAF...it's all about the airflow with this setup, yet there was no real increase in top end and a very noticable decrease in low/mid range.

You'll be needing cams, then.

[deviousKA]

Hey Julian, welcome to nico ka forums, you have an interesting setup.

Are you running this stock block ka24de with the itb, with the oem ecu? If so id say those numbers are pretty much respectable. You cant expect the factory ecu with a factory maf sensor to provide the optimal fueling for best power with itb. Im just assuming a few things here.

Do you have a wideband or a/f graph of your engine?

S14 cams?

[BigLeeRoy EngineBuilda]

S14 MAF...it's all about the airflow with this setup, .

you cant be gettin too much airflow with the s14 maf.

[corn322]

isn't that the same speach you gave 5 months ago when your friend was going to make intake mani's for the ka?

whatever happened to him?

[InsanityInc]

isn't that the same speach you gave 5 months ago when your friend was going to make intake mani's for the ka?

whatever happened to him?

Uh, seriously. How many times do I have to say it? He was just some guy, not my friend. And as far as I can tell, he completely flaked out. I'm now in the process of making my own.

[InsanityInc]

InsanityInc, wrong. Insofar as you blame the stock factory intake manifold for choking your high-end on a stock motor, you are incorrect. I have dynoed my KA as stock internally (I had to put a new exhaust on it to fit it into my 510), you can see the graph here:



(full size here: http://www.jetlink.net/~okayfi...l.jpg)

Plenty of top end, nice and flat for the last 1000 rpm as well.

After building an ITB setup and running it for ~6 months, I can confidently say it offers no real benefit on a stock KA. Hayabusa ITBs, velocity stacks, 2 liter plenum, 2.75" intake pipe, S14 MAF...it's all about the airflow with this setup, yet there was no real increase in top end and a very noticable decrease in low/mid range.

You'll be needing cams, then.

Did you dyno it afterwards? Also, I fail to see how a dyno of obviously stock output disproves me. Your peak power is still at 5600 or thereabouts, and your peak torque is still at 4400 and drops off badly afterwards. The dyno doesn't even continue past 6300rpm, and you can see it's headed right downhill before it would. How is it "nice and flat for the last 1000rpm" if your graph doesn't even show the last 1000rpm, and it obvious that it's going to be in steep decline for them? I'm seriously not seeing how that dyno is a disproof of anything. Maybe you're being fooled by the fact that your graph is substantially more stretched out than the one I posted, so the vertical movement doesn't seem extreme, but take a look at the numbers.

[corn322]

Uh, seriously. How many times do I have to say it? He was just some guy, not my friend. And as far as I can tell, he completely flaked out. I'm now in the process of making my own.

say it... one more time.

[deviousKA]

Lets kick the hostility down a notch people, dam

[Julian]

They dyno sheet is based on my stock long block KA, stock ECU, no fuel correction.

My impressions of the ITB setup are with that same block and ECU, but with fuel correction. I bought and built this electronic kit:

http://autospeed.drive.com.au/....html

which allows for 128 points of adjustment. I installed the Zeitronix WBO2 to datalog the fuel curve after the ITB installation. I found I actually had to lean out the top end, from 4700 on up the ECU was making it 12.1:1. I leaned it out to 13.1:1. In addition, the Zeitronix allows one user input and I graphed the MAF output, which reached a peak of 4.8v at 6500.

With all that done, there's not much benefit of the ITB installation. Throttle response is sharper, mileage hasn't really declined, but all in all there is no real, seat-of-the-pants benefit to installing ITBs on a stock motor.

Which was my point - the stock intake isn't restrictive on the stock setup. You'd at least need cams to show up any restriction. No, I have not dynoed the ITB setup. This is mainly because there are no dynos in my county, the dyno sheet I have from the stock setup is from a shop 120+ miles from me, and I just haven't made the trip again.

[Julian]

you cant be gettin too much airflow with the s14 maf.

The S14 MAF is feeding four 46mm throttle plates, yet it not maxing out. It isn't the restriction and could flow a little more air if necessary. How much more airflow would you expect?

[Julian]

I'd guess that just a header and ITBs should get you easily into the range of 170whp.

As I said, I don't have a dyno sheet to back up the lack of power improvement, there is no way I have 30whp from the ITBs. If there's 10hp on top now, I'd be very surprised. But that is with a serious cut to torque in the low/mid-range.

I realize your math is theoretically correct, however I've driven both the stock intake and the ITB setup and there is no improvement in HP or top-end lunge.

[InsanityInc]

Which was my point - the stock intake isn't restrictive on the stock setup. You'd at least need cams to show up any restriction. No, I have not dynoed the ITB setup. This is mainly because there are no dynos in my county, the dyno sheet I have from the stock setup is from a shop 120+ miles from me, and I just haven't made the trip again.

That's why I posted a dyno of a cammed KA. Radical cams make almost no difference in the location of the power and torque peak, and result in a paltry gain. Did you not read the second half of my original post? It goes over that. 21 inch runners are too long for an engine that can rev to 7000, because at speeds that high, the cylinder will have too much restriction, as the plenum is too far away. Look at the intake manifolds on engines that rev high (ITR, s2000, etc). They all have very short runners. This is for a reason. Take the SR20DE and SR20VE for example. Obviously the VE is designed to rev higher. Thus, the intake manifold runners are shorter. It does make a massive difference in high-RPM breathing.

Also, DeviousKA, would you happen to have any dynos of your car, or some other KA that's either carbed or has ITBs? I can't find one for the life of me.

[InsanityInc]

I realize your math is theoretically correct, however I've driven both the stock intake and the ITB setup and there is no improvement in HP or top-end lunge.

You won't get a top-end lunge... you didn't install variable valve timing on your engine or anything. The powerband just won't die off. If you rev a stock KA all the way to 7000, you can feel it getting slower as you rev higher and higher. You shouldn't get the same sensation with ITBs (and theoretically, you'll get the opposite sensation to some effect). But it isn't going to suddenly give you a kick in the *** at 6000 or something.

At the very least, run a 1/4 mile with your car, assuming there's a strip closer to you than a dyno.

[InsanityInc]

I just thought of something else. Is your engine an S14 engine? If so, you might not have nearly as good of gains simply because the camshafts are definitely more in line with where the powerband normally is for a stock KA. You should still see a gain up top, but s13s will have more, considering the cams are 240/248 and higher lift than the s14 cams, even though the powerband stock is pretty much the same. The cam profile just doesn't add up with where the power is in an S13, and to a lesser extent, an S14.

[deviousKA]

InsanityInc, I do not have a dyno sheet on my car or any other carb/itb type setup ka's. Im in the same predicament as Julian pretty much, I caught word that chassis dyno went in a couple hundred miles from here and i will be hitting it up soon as i can.

Julian do you have any pictures of your itb setup in the datsun? Id be interested in taking a look.

As far as fueling is concerned, my setup as a reference, I am maxing out 270cc injectors (80% duty) at 4.5-5k rpm without throttle "tip-in" enrichment. In order to obtain decent a/f I am dumping much more fuel than stock at any given point of the map. The injectors are not adequate so i bought a set of 330cc (dont want to get extremely large and lose resolution), i will be installing these and retuning my full rpm range soon. This is on the built sohc with 43mm throttles, open stacks.

Julian, just the mere fact that you are actually having to lean out the top end probably directly reflects your output. I find this very surprising really, but have not had much experience with plenum/maf itb setups.

Are you dissatisfied to a point that you dont want to continue to mod? In my opinion your setup would have underlying potential, just a few simple things holding you back.

[Julian]

Thus, the intake manifold runners are shorter. It does make a massive difference in high-RPM breathing.

Theortically, sure. I'm just telling you there is no difference in reality. I'm not trying to slam you, but you're here saying the stock intake manifold is a restriction. I've run the KA with the stock manifold and then with a ITB setup (amounting to 11" of intake runner length to the back of the valves). There is no real power increase from the ITB/short manifold setup. Top-end is basically the same (to the point of me saying it is basically the same). This is not what you would expect (nor, what you stated), but it IS what it is.

I'm no engineer, but I understand the basic's of manifold design. I've tried a short manifold and ITB setup. There's nothing in it bolted to a stock motor.

[Julian]

The powerband just won't die off. If you rev a stock KA all the way to 7000, you can feel it getting slower as you rev higher and higher. You shouldn't get the same sensation with ITBs (and theoretically, you'll get the opposite sensation to some effect). But it isn't going to suddenly give you a kick in the *** at 6000 or something.

At the very least, run a 1/4 mile with your car, assuming there's a strip closer to you than a dyno.

As an aside, my ECU cuts fuel at 6500, this is what I gather to be the redline on an S14, as I've tried both auto and manual ECUs.

In butt-dyno driving, there's no more on top than there was with the stock intake manifold. Again, there may be a few HP difference, or the curve might not start to drop at 6300, but there's really nothing there to claim the stock intake manifold is a restriction. My stock setup rapped the tach needle pretty convincingly, the dyno sheet shows flat power from 5700-6400. Compared to your stock dyno sheet, my engine is up 25hp at 6000. Maybe something wrong with the engine your stock sheet was based on?

As to the 1/4, I'd very much like to. However, I've relocated my battery and LACR wants an external disconnect that will shut off the car. I'm not going to run all that wiring just to take a 1/4 mile pass.

[Julian]

Julian do you have any pictures of your itb setup in the datsun? Id be interested in taking a look.

I don't have small pics, so I'll just link the photo.

http://www.jetlink.net/~okayfi...0.jpg

Julian, just the mere fact that you are actually having to lean out the top end probably directly reflects your output. I find this very surprising really, but have not had much experience with plenum/maf itb setups.

I was also surprised I had to lean out the mixture. I don't know why this is, but assume the stock fuel maps are safely rich from the factory. I didn't have the WBO2 setup when I was running the stock manifold.

QUOTE=deviousKA]Are you dissatisfied to a point that you dont want to continue to mod? In my opinion your setup would have underlying potential, just a few simple things holding you back.[/QUOTE]

There are no downsides to the ITB setup, it drives around town just like my stock intake setup. It's just that there are no real upsides on a stock motor. In researching the prices of cams I'm looking at $600. With that amount in mind, I could spend another $100 or two and build a nice JY turbo setup that would be much more powerful and less peaky.

I have the stock intake setup on my workbench and I think about installing it again. Before I do, I'm building a second plenum to house the longer Hayabusa curved velocity stacks to see if that affects torque at all. I also plan on trying a smaller set of ITBs (GSXR750/1000 - 42mm throttle plates), though the inlet and outlet sizes are the same as the Busa ITBs.