Ajax wrote:
There are too many holes to fill with water (since I got the extra hole for the IACV. Xcessive has it on their site now, though- 3.4Litres. Yeah, its a bit big for NA, and at some point, I may have a custom plenum made using the same bolt holes and what-not. Then maybe do some back to back testing to figure out the better size.

It isn't massively big though according to A. Graham Bell the plenum should be measured by displacement times .8~1.5. According to your plenum volume It's 2.4litersX1.4167=3.4 volume liters. Although the higher the ratio of plenum volume the compression should be raised as well. It could overall be excessive manifolds overall design as I don't see a taper or bottle end, and towards the back of the plenum it should be 1.5t imes the diameter of the last runner. If not cylinder 1 gets fed less air than the 3 cylinders to the rear, this couold lead to a 3~5% drop in power in cylinder 1, and 5~7% increase in cylinder 4. This is what could actually disrupt your idle unless you can fine tune per cylinder, injector pulse width. Or it could be what I said earlier that the MAF is to big.
Modified by Bigvinnie at 7:08 AM 8/11/2009

There is a very slight taper to the rear, unnoticeable in pictures. Also, my engine is 2.6L so its a 1.3 ratio.

we now seriously need HD youtube videos of in car running, out of car running, engine bay running, highway pulls with cluster visible, etc... cmon :P CMOOON

Ajax wrote:There is a very slight taper to the rear, unnoticeable in pictures. Also, my engine is 2.6L so its a 1.3 ratio.

Forgot that you increased displacement, my bad.What is the taper to the runner diameter?

The taper is pretty much negligent- its hardly noticeable. I only noticed because I set it on a flat surface while painting and saw a slight angle.Working on video and pics- sister's camera so I'm at her mercy.One thing thats very positive is the sound. Even with OBX header and old 5Zigen exhaust, the thing sounds really throaty- nice and loud.

Hi, i am Chase. i know quite a bit about the car, the idle issue IS an intermittent electrical issue from the IACV. It can wiggle itself into a bad spot and start to cause problems. I have about three ideas to try and fix the problem.

Otherwise, after its come up to temperature (IACV without the air regulator doesnt do that much good cold) it idles like a champ.

You cant buy a new iacv and plug it into your s13, and expect it to be plug and play, anyone have any experience with this? At a minimum the connectors need to be changed.

a_ahmed, yes the KA TB has a stop on it that can be used to set idle. Why is this different than the old fashioned set-ups? the computer is still dishing out fuel and timing like it has all its electrical equipment intact. This causes idle to fall on its face when it comes down from revs.

You can find all kinds of info on here about my three different intake manifolds plenums that i messed around with. Its definitely possible to run the KA without all the extra intake BS, but it makes driving the car easier (constantly heel-toe braking to keep revs up when stopping).

I printed out some dynos for dave today, so hopefully he can post them up, but the car has more in it. It needs exhaust, bad. Somehow a catalytic converter found its way back onto this exhaust, and a 2.5in + and off the shelf header isnt gonna make the top end power that this motor craves. So, stay tuned to see what we come up with.

What exhaust are you thinking would be best?

Still working on the 510 BTW, It has brakes and steering now. Oil Pan, header and exhaust next (hence the question)

Chase and I have discussed a few ideas about exhaust- custome header is a must. A side exhaust might be fun- something to keep a hot-rod-ish look, or get a BRM 3" to have it look semi-stock.I decided the style of my car should be called "neo-90s-muscle-compact" not that that makes any real sense.

Enough talk, I want videos LOL.

Oh yeah I fixed my issue, I unplugged the TPS and car was idling at 2000rpm (eeh?) lowered the rpm by screw to 700 and maaaaaaaaaaaaan was it stable.

I checked the timing and it was 10btdc (!?!? wth), I advanced to 26btdc and voila... car is niiiice. Can't believe I went racing with the car at 10btdc lol... shows how I was kicking a** even with a power handicap hehe.

Anyways with all that done, i plugged tps back in and car runs still great, but the idle is a bit flactuaty.... so im gona reckon uhm the tps is not so good and needs a replacement? Didn't get time to check voltage (suppose to be what 0.45-0.5v?)... but being plugged in and not plugged in would kinda explain this i suppose?

Ajax, did AMS set you up with a FCW crank + stroker?

The Brian Crower Stroker uses a FCW crank plus all the other rotating assembly bits- rods, pistons to fit your needs- bore and desired compression, bolts and pins, and rings. Its a complete kit.I wonder if BC would consider producing a straight FCW crank for stock displacement.

Oh thats right you got the BC kit i remember from your other thread i think.. heh.

SPIN THAT MOTOR. Its the only way your going to be happy with it. Hope your rotating assembly was balanced, and you really should use an aftermarket dampener(ATI)[Kinda to late at this point if the motors together and balanced]. With the way you have your Ka setup, its going to make unimpressive power(as in significantly less than stock under 3500 rpms for sure) unless you rev it out. Should be able to put down over 200 without much difficulty however if you rev it out. Id shoot for at least a 8500 rev limit IF your rotating assembly is balanced. Otherwise your just effd lol.

BC has offered and has made the FCW cranks with stock rod length. I think the price was around 1500 bucks.

The torque hit 165 at @2500 rpm and didn't let up until about 6500.

seang wrote:The torque hit 165 at @2500 rpm and didn't let up until about 6500.

I kinda want to see a dyno graph PDF of this. That's close to the kind of torque band that the RB25det makes if this is true.

Whats up with a graph AJAX's?

The engine is balanced, and has a clutch-type damper by Fisher Harmonics- ATI didn't have one for KAs at the time of this build start.Sorry for lack of graph update. I've got a paper copy and as soon as I find someone to help me scan this thing at the office (I'm not too saavy with this computer stuff). I'm hoping I can get it done on Monday.Also, I was mistaken about one number- the torque starts to drop around 5500 rpm. It fades slowly down to about 125ft-lbs around 7000 rpm.Right now my rev limit is 7500, and since the power starts to drop off @6400, there's not too much need to spin too much higher.

Thats really depressing to hear that the power starts to drop off so early. Second time this has been confirmed to me about the BC kit.. This example of the BC kit in NA action, it sounds like you actually did your stuff right so i cant see any reasonable excuses. Well, except for the fact your running BC stuff.. I would seriously look into getting your cams degreed. They are almost always off.

Im just going to say it, im sorry Ajax. Why stroke a stroker motor.. ? IDK, i cant wrap my head around that BC kit. Just seems like a complete waste unless your just trying to be different. Now if you went for a FCW crank with stock rod length, then youd be on point in my book, but who cares about that lol.

480sx wrote:Thats really depressing to hear that the power starts to drop off so early. Second time this has been confirmed to me about the BC kit.. This example of the BC kit in NA action, it sounds like you actually did your stuff right so i cant see any reasonable excuses. Well, except for the fact your running BC stuff.. I would seriously look into getting your cams degreed. They are almost always off.

Im just going to say it, im sorry Ajax. Why stroke a stroker motor.. ? IDK, i cant wrap my head around that BC kit. Just seems like a complete waste unless your just trying to be different. Now if you went for a FCW crank with stock rod length, then youd be on point in my book, but who cares about that lol.

I wouldn't bet to much on it just being the bottom end assembly. It could be the intake manifold. I've dug through a couple forums and found that there was another NA build in the 240sx forums high compression 2.4 liter and only made 183WHP with the excessive manifold.I also dug through some threads at KA-t.org that claimed that they actually made less power with the excessive manifold over the stock manifold.I've spoken with brian Crower personally at formula drift about his bottom end assembly. He explained quite well that the reduced rod length, stroked crank, and pin height adjustment reduces friction to the cylinder walls, which would make the bottom end spin to 9000RPM. Should I or anybody believe what Brian Crower said? Probably not.At 9000RPM with a 102mm stroke piston momentum is 6023 FPM.At 9000RPM with a 96mm stroke piston momentum is 5669 FPM.

There also isn't a specific cam in development for the stroker kit. Being that the stroke is increased, cam duration, and actual opening of intake valve (cam placement) have to be adjusted to the new rod stroke ratio.

I don't think Brian Crower R&Ds to much on KA24 parts, as much as his company does with VQ parts. It seems more like what R&D was spent ,the company is trying to make there money back on. The KA24 bottom ends havent sold to well and Brian Crower claimed that he only made 15 sets of that stroker kit.

I think if Ajax advances the intake cam to open sooner 1~2degrees before TDC. Adjust the exhaust cam a tad to retard, theres probably an additional 10~20 more whp.


Modified by Bigvinnie at 10:26 PM 8/15/2009

Cam adjustment is another place to look for more power right now. I'm not sure exactly how AMS set up the cams with the adjustable gears- we may be able to set up some more overlap to help it breathe higher. A custom header and new exhaust are also high on the list, but winter will be largely focused on refreshing my interior and rebuilding my rims.

Bigvinnie wrote:I wouldn't bet to much on it just being the bottom end assembly.

Ill completely agree with you there. Im glad you brought that up actually..

The excessive manifold sucks. Strait up, sucks. Especially for N/A. You would make way more power throughout the curve(maybe SLIGHTLY less PEAK power[were talking N/A only here]) with a stock intake manifold. Its been proven on the .Org, and that was with boost. Without it, that intake manifold is power curve and volumetric efficiencies worst nightmare... I mean give me an effing break. You chop off the runners and slap an oversized plenum on it and charge 700 bucks? Hurts my head...

EDIT - I want to further that point. Its not so much simply that the excessive manifold sucks, its that for most cars unless they are purpose built for high RPM operation only, the motors power curve is severely hurt by SRI's. Aka, Short runner intakes. People focus WAY to much on peak power, and no where near enough on the curve.

On a sidenote, its funny too that you bought that excessive manifold hehe..... Your probably using runners that i sold to excessive LMAO! DAMN i wish i had marked them. I sold them 5 sets of runners a year ago heh.

Its a known fact, that for the KA24, there is no better mass produced option than the stock intake manifold. You may look at it like its a piece of crap, but give the engineers at Nissan a little credit? The Ka-T guys usually run stock intake manifolds unless we are pushing 500+ hp, or its a drag car.

Idk i just want to see a controlled test of the BC stroker kit. Stock everything, just the BC kit baseline run VS a stock Ka dyno. Im... damn close to convinced that if BC's stroker kit isnt complete crap that had no R&D, that the stroker kit should be able to put down over 200 HP with no difficulties at all if you can get it to make power at high RPMs. This is going to take high intake port velocities, a well designed header, free flowing exhaust, built head, awesome tune+some 'race' gas[e85 if your lucky], and the balls to spin a 7000 dollar 200 hp motor up to 8-9k. Will obviously take more than that, just a small list.

Ah, also, just to give you maybe a little hope.. There has been a SOHC race Ka that was built with a custom FCW crank spinning to 10,000 rpms that put down 300hp way back in the day. Race motor though, they dont last long. It HAS to be possible to get decent high rpm power out of the Ka with a FCW crank and the right trimmings though.
Modified by 480sx at 2:10 PM 8/17/2009

480sx wrote:On a sidenote, its funny too that you bought that excessive manifold hehe..... Your probably using runners that i sold to excessive LMAO! DAMN i wish i had marked them. I sold them 5 sets of runners a year ago heh. Modified by 480sx at 2:10 PM 8/17/2009

Nope, they had new runners cast- hence my fitment problems documented on page 1...

Honestly, I think I may have shot myself in the foot with the Q45 TB. That throttle is simply huge, which could be killing intake velocity, but I'm not going to begin to pretend I'm an engineer, so I can't say for sure. The nice thing, though is that we're prepped with the N62 MAF and 370cc injectors- I can swap some things in and out and still drive it around/to the dyno. If I want to fab a custom plenum, its a simple matter of making a mounting template to match the runners. If I want to get another plenum with stock TB, that's bolt-on. We'll try some things in the future.Also, they do not cost $700- you can get the basic kit for @$500, with shipping.Also, I'm not too particularly concerned with peak HP. Don't get me wrong, I'd love to see my car break the 200 mark on pump gas, but I'm more interested in seeing big torque over a long stretch of revs.

480sx wrote:

The excessive manifold sucks. Strait up, sucks. Especially for N/A.

There were several problems that I noticed with the excessive manifold. I've kindly tried to infer this to Ajax.

Problem 1.

BigVinnie wrote:It could overall be excessive manifolds overall design as I don't see a taper or bottle end, and towards the back of the plenum it should be 1.5t imes the diameter of the last runner. If not cylinder 1 gets fed less air than the 3 cylinders to the rear, this could lead to a 3~5% drop in power in cylinder 1, and 5~7% increase in cylinder 4. This is what could actually disrupt your idle unless you can fine tune per cylinder, injector pulse width. Or it could be what I said earlier that the MAF is to big.

Problem 2.Runner length was completely killed. Short runners are for high RPM use only. If you have an engine that only revs and makes peak power at 6500RPM and it redlines at 7500. But the efficiency of the manifold only demands that it makes power at 9000RPM. The engine/ecu will never see the grunt nature of the manifold. Problem 3.Both TB and MAF are too large. Natural aspiration thrives on velocity. stagnant Turbulence is the exact opposite of velocity. When diameters become to large to the rated CFM then what is made is lots of stagnant turbulence which disrupts the MAF hotwire. There will also be an overall problem with intake runner velocity because the velocity needed before the plenum isn't there. Without the velocity before the TB warm molecules aren't compressing so it lowers the efficiency of the air charge into the cylinder.

Now I'm not to sure about this, but I've been told that the N62 is rated for engines up to 600CFM. A 2.6 liter stroker on average is only going to see 366CFM @7500 redline. So there is roughly only 54% of the MAF being used. So that means that air velocity passing the hot wire is only at 54% efficiency or less. The higher this percentage is to diameter opening, velocity is more efficient to the engine as the ecu is calculating theoretical pulse width. You roughly want the MAF within 60% or better, you will notice a huge difference with air/fuel atomization. I've always stuck with an N60 MAF for this reason and it seems to work great.

The N60 and N62 are the same size.I had one of each, but the used N60 I had did not work, therefore we went with the N62.

Ajax wrote:The N60 and N62 are the same size.I had one of each, but the used N60 I had did not work, therefore we went with the N62.

There's a wider range of hot wire voltage on the N62, the range on the N60 is alkmost 1/3 less than that.Some ones going to have to point out the diameter size to me because last a I checked the N62 is slightly larger.

DustinZ NICOCLUB wrote:All 90-96 300zx's turbo and non have the N62 MAF along with the infiniti J30s. The N62 MAF has the capability of flowing 50lbs/min of air with out pegging the output voltage. The N60 is a smaller MAF from a Maxima. If you are trying to make power go with the N62 everytime. You cannot just plug one in though. The output values are completely different and you would have to have some sort of engine management to compensate (not meaning Super-AFC).

Hope that helps,DustinZ

Modified by Bigvinnie at 3:31 PM 8/17/2009

The only difference I could see was the label itself. Otherwise, they were identical. I suppose there could have been a slight difference in the interior diameter, but it did not appear so to me.

Ajax wrote:The only difference I could see was the label itself. Otherwise, they were identical. I suppose there could have been a slight difference in the interior diameter, but it did not appear so to me.

You could be right I haven't touched an N62 in years to know the diameter differences.

It could just be that the hotwire for the N60 is more efficient than the N62 since the voltage range is more limited to a practical CFM/HP rating.
Modified by Bigvinnie at 5:16 PM 8/17/2009

Ajax wrote:The nice thing, though is that we're prepped with the N62 MAF and 370cc injectors- I can swap some things in and out and still drive it around/to the dyno.

Thats the old internet myth. In theory it sounds really good, idk it got started. Every time someone trys it, the car runs pig rich and like crap. If you have a SAFC you can run it like that(although thats 'tuning'), otherwise, doing so is going to damage your motor if you run it like that for any significant amount of time at all.

Im assuming your talking about the n60 maf + 370cc injector with no tuning?

480, what I mean is that its tuned with the MAF and injectors, so I feel comfortable in swapping a different TB, installing new header, fabbing a new manifold; in comparison to this winter when we installed the entire intake manifold, but still needed to install the MAF and injectors- I didn't feel I could safely use the same tune that was programmed to drive it anywhere.Vin, that's what I figured about the difference between the 60 and 62.

GL with your new manifold. You auta just go ITB's dude if your confident in yourself and your talking about fabbing a new manifold. Get an air filter for each one, or an airbox with a CAI/filter and your golden.

That was another option, but it was going to cost too much for everything involved- I'll probably do a full stand-alone computer first and then think about ITBs, but that is way down the road unless I win the lottery.

A few weeks later... (I'll have to re-edit these pictures so you can actually see them when I've got the hour it'll take because photobucket takes so damn long- sorry. I hate computers, and photobucket apparently sucks)

Here's the Dyno from AMS. The purple/red line is what the car pulled when it got to AMS. This was after a rebuild which was supposed to include high compression, over bore, port and polish- basically a few internal mods and a bunch of bolt-ons. That shop hadd given me a dyno hitting 171hp, 167ft-lbs. However, the vent tube from the head had been plumbed directly into the manifold, thereby creating more pressure, thereby cheating the dyno and giving a supercharged effect. That's also probably what caused 2 pistons to eat through their own ringlands and contribute to a poor rebuild that burned a lot of oil (lawsuit pending).The blue/green line is AMS' tune after their rebuild with the stroker, etc.

Now here is the dyno after the installation of N62 MAF, Q45 throttle, Xcessive intake manifold, 370cc injectors, and a retune.


Modified by Ajax at 4:30 PM 8/22/2009