Omarius Maximus

You should maybe think about using alcohol injection as a way to substitute for high octane gas. I was able to add 8 degrees of timing on my base map without know, with alky. (not on a ka, but the same principles apply)

RedtopTech

"It's really just how you manipulate the voltage that the ecu reads, there isn't really to much difference between the N60 and N62 accept peak HP choking point. Without any tuning of the SAFC a 2in and 5 out makes 153WHP with all the bolt on's I stated 9WHP was made with just fine tuning the SAFC."

The mass air flow is determined by the amount of amperage drawn from the ECU in order to maintain a pre-determined temperature across the hotwire. This expected ECU input is calbrated into the MAFS by a few variables such as internal circuitry (resistance), composition of the hotwire and most dramaticaly (contrary to your statement) by the cross section of the housing.

"For every compression point higher the engine is, it will make an AVG of about 10 more wheel HP. In this process though there are other factors that the engine now fights such as increased EGT, knock and ping, so now the Octane requirement to make that AVG 10WHP goes up as well so no matter what, that higher compression costs more at the pump."

This is not an accurate statement for compression affects the volumetric efficiency which equated with total displacemant (disregard scavenging and pulse tuning for now) determines the potential power. Therefore change in compression changes the potential power based on a percentage and not an "AVG 10 whp." If the 155 hp, 2.4 liter KA makes 165 horsepower with one more point of compression that shows that the change in volumetric efficiency of 15.5%
A relative 310 horsepwer 4.8 liter engine should than make an extra twenty horsepower as opposed to your 10hp/1pt comp.
This hypothetical example's sole intend is to show the relativity of volumetric efficiency to power potential and NOT intended to give an absolute.

Lastly you mentioned numerous times in this thread that your rise in compression would cause a rise in "exhaust gas temp". The rise in compression produces higher "combustion temperature" which is of course a product of a more efficient burn (POWER). Exhaust gas temperature will rise with an increase in combustion temp however will peak at around 1350-1450 degrees F with (on the edge) tuning. Detonation will cause a DRAMATIC spike in combustion pressure and therefore temperature (as apposed to the pressure being applied to the piston over a longer duration of it's power stroke).
RELATIONSHIP BETWEEN A/F RATIO AND EGT: depending on a few variable's, the most efficient A/F ratio (highest power) will also produce the peak EGT. Start going richer and the EGT will start to decrease but only to a point. A rich enough condition to cause a missfire will send unburnt fuel into the exhaust where it can burn and cause a rise in EGT(falsely). Start going leaner and the EGT will also drop since there is now less fuel to burn and therefore less heat (power) being produced....But again EGT will only drop with a higher ratio untill detonation occurs which will cause it to spike dramaticaly.
Ignition timing has the most influence over EGT is often misunderstood.
An advancement in timing will cause a drop in EGT (untill the point of detonation) since the combustion occurs sooner (in degrees) in the power stroke and therefore has transfered more heat to the engine before the exhaust valve opens and EGT can be read. Therefore retarding the timing will raise EGT since more heat is left in the exhaust gas. This wastes much of the potential energy since less heat and pressure are being used to drive the piston and can cause a dramatic increase in EGT if the fuel is still burning as the exhaust valve opens.
As described above the correlation between valve timing and EGT is also an important factor. An earlier opening of the exhaust valve would have the same affect on EGT as retarded ignition timing.

A rise in compression will always cause a rise in volumetric efficiency because the more you can squeeze the mixture before ignition, the more energy that same amount of fuel is enabled to release.
If a change to an engine increases VE then the focus on ignition timing should be to find its (new optimal point). if a reduction in ignition timing is required it simply means that the combustion process is occuring quicker and therefore later ignition provides more pressure to drive the piston down instead of wasting the pressure flattening the bearings, or worse.
The cost of a fuel that can be squeezed tighter without pre-igniting is the only shortcoming of raised compression, not a required retarding of the ignition. It's a balancing act.

This Thread is full of good information and you obviously have an advanced level of understanding however i felt the need to clarify some things that i feel could be misconstrued.

BigVinnie

It's all good man preach the knowledge.

__________________
http://i27.photobucket.com/albums/c1...ften12-2-1.jpg

2fast240

Very nice numbers man. You should look into the Brian Crower stage 2's. I am running them with just exhaust and intake. Stock ecu, and maf and made 167HP. You should get to your goal of 195 quite easily.

__________________
RESPECT MAH AUTHORITAH!!!!!

BigVinnie

It was a problem that couldn't be corrected, no matter how much adjustment was made to the safc.
It could be that there aren't enough NE point's allowed for the safc 2 that could of caused the problem with the spike.
I did notice that the more NE points that were squeezed together in a shorter RPM range the better the the A/Fr's could be controlled without the ecu making to much correction. I could assume that the spike has to do with a combination of errors from ignition timing, and A/Fr's.

As for the statement of ITB's. I've personally found it easier to tune plenum manifolds rather than ITB short stacks with the 2.4liter KA. I believe it has more to do with air temperature, and also runner length.
Now in order to improve higher rev on a KA first off the runner length needs to be much, much longer than it is if you just chop off half of the stock OEM manifold and use ITB'S at the ends, I've dis agreed with this method of ITB use since the whole ITB thing became big with KA's. I think the entire OEM manifold (upper and lower) offer about as much runner length as needed. The length of the runner is important for intake velocity and helps with air to fuel atomization since the injector bosses are located at the ports of the manifold rather than what direct injection offers.
As for BMW using ITB's and using them efficiently I would say that has more to do with runner length and engine displacement. When it deals with Nissan OEM's that I have delt with though you don't see to much use of ITB's, accept probably on a RB26dett. Reason for being it cheaper on manufacturing to offer one TB with coolant line placement to prevent freezing, this also offers easy use of tuning since plenum intake manifolds heat up cold air, also for for smog since you need a relative operating temperature. Although Nissan has usually gone the route of SCV's which if you want to think that it is somewhat ITB.

Now to make a correction before I eat my own words is that most of Nissan OEMs go the route of plenum manifolds rather than ITB design, probably for simplicity and smog.



Actually I've been considering PDM racings cams. A little expensive for cams, but I like the duration/lift that are for the intake and exhaust... I think the exhaust cam will help with scavaging (especially when I upgrade injectors) and the differences between the intake and exhaust cam will make tuning much easier when it comes to making some ignition timing changes.



Different A/Fr's and ignition timing. The OBD2 KA engines also use the 232/232 cams, not 240/248. Then your also dealing with ecu corrections, OBD2 ecu's tend to make a lot of corrections, unlike OBD1 ecu's.

__________________
http://i27.photobucket.com/albums/c1...ften12-2-1.jpg

BigVinnie

Actually I lowered the amount of ethanol that is found in pump gas.
One of the reasons why my dyno showed 162WHP was because I lowered the percentage of ethanol by mixing in a half gallon of toulene, and a half gallon of xylene, to 4 gallons of 91octane (AKI) that is mixed with 10% ethanol already. Adding the toulene/xylene mixture increases the Kilojoule burn rate (or for people that don't understand, a higher BTU output). I decreased the ethanol to about 7% rather than 10%. Less ethanol is better.

A 91octane ethanol produces overall less power than 91octane petrol, look at the Kilojoules between the 2. You can use 2 fuels rated at the same octane, but petrol octane will always produce more Kj than ethanol.
With ethanol you will want to increase injector pulse width to compensate for the power to what a petrol engine does already.

__________________
http://i27.photobucket.com/albums/c1...ften12-2-1.jpg

mystery_elmo

Wat is this crap?!! a geo metro? no wait..... i think geo metros are a whole lot better then this!!

xs240

^Heh this guy was banned.

So what's going on with this?

I feel like getting some spare headers and port and polishing like you did. Most impressive.

BigVinnie

I'm actually in the process of upgrading my fuel system. It seems that raising the K value (VIA SAFC) settings and MAF put my injector duty cycle into a high 98% which is bad. Injectors typically burn up after high 80%+ duty cycle. I've burned up injectors 2 and 4.

So I'm moving forward with higher lift cams from PDM which are on the way.
Installing a circuit sports HV fuel pump 255, sr20det 370cc injectors, and adjustable FPR.

I've also realized that allowing the KA engine to make peak power in the 6500 RPM range and keeping the engine in a state of high rev at 7000RPM for a few minutes causes the engine to over heat from oil starvation caused from the stock oil pump, so I am looking to upgrade to a TOGA HV oil pump.

__________________
http://i27.photobucket.com/albums/c1...ften12-2-1.jpg

UNISA JECS

Nice, snap some pics of your TOGA HV oil pump if you can when you get one.

__________________
PARTS 4 SALE !!

• Z32 E-Brake/Parking Brake Heatshield Assemblys!!!

Rep/Feedbacks

BigVinnie

Will do boss. Should be in about 2 weeks from now.

Looking to get it from one of my friends in Japan for about $180, IPP here in the states sells it for almost $260, and thats not including the shipping cost.

__________________
http://i27.photobucket.com/albums/c1...ften12-2-1.jpg

Zen S14

No underdrive pulleys? That should help free up 1-2 hp.

BigVinnie

If anything an ATI dampener.
My engine already makes peak power higher in the RPM range more than it should.
An underdrive pulley would just destroy my enigne.
I have an aluminum underdrive crank pulley sitting in my garage and I will probably never use it.

__________________
http://i27.photobucket.com/albums/c1...ften12-2-1.jpg

viperbite

sorry to bump, but i found this on google.

great information already. im in the process of doing the same mods youve done to your s14 upper plenum. along with the lower plenum modifications.

it sounds like your safc is holding you back though,

consider an aem system?

i can also personally vouch for the brian crower cams on a naturally aspirated motor. when i installed them it opened the engine up from 5000rpm till redline. never had it dyno'd but it felt like a 5 to 10 hp increase.

looking forward to more updates

BigVinnie

SAFC is definitely holding me back. I'm on my last few months of using it. It's not that accurate, and A/Fr's are all over the place.
I checked into the AEM EMS it looks like it has awesome potential, and has a great resolution.
Unfortunately i will be cheaping out on chip headers, and a willem rom burner. It just seems more economical and the bigger bang for the buck. Although down side will be lack of resolution which the AEM has.

As far as cams, I'm sticking with PDM. Those cams are pretty much a 30% increase in lobe and duration from the stock OBD1 KA24de cams. It has a nice high end range.

__________________
http://i27.photobucket.com/albums/c1...ften12-2-1.jpg

96NismoZ

So, to bring this thread back to life... I actually came accross this looking up N60 MAF sensor info. Great read by the way. I have an intake, header, exhaust, and SAFCii w/N60. I was just going to use the setting you posted earlier, but wanted to ask first: is it safe to daily drive with these settings?

BigVinnie

I stated earlier that the excessive use of injector pulse width/duty cycle had caused my injectors to burn up. It is recommended to install sr20det injectors, and calibrate for those injectors. I don't have new settings for the sr20det injectors yet and am planning on possibly doing a NISTUNE, or daughter board chip upgrade VS the SAFC2.
270cc injectors don't handle to well at 6500RPM peak hporse power and an A/Fr of 12.6:1.
If the peak power was at 6000RPM peak Horse power with an A/Fr of 12.6:1 the injectors would be a tad more stable but would still exceed duty cycle a bit, I don't know the exact figures unless I was using ecu talk with a smaller maf such as the G70.

__________________
http://i27.photobucket.com/albums/c1...ften12-2-1.jpg

96NismoZ

Wow, so we are max'n out out stock injectors NA? Yikes! I heard a rumor that you could run N60 mafs with 370 injectors without tuning at all. Remember, I said rumor. What's your take on that? I haven't looked into it at all, you seem to know a lot though.

BigVinnie

I don't think you read or comprehended anything this thread had to offer. If you did the answer would be in front of your face.

__________________
http://i27.photobucket.com/albums/c1...ften12-2-1.jpg

steve shadows

The SAFC is what is causing the giant dip in your torque curve, as well as afrs not being flat.

If you invest in a AEM you will be able to tune the AFR out to be perfectly smooth and you will be able to have seamless torque and HP graph.
Either way AFC takes about an hour max to really "tune" and the sweet spots usually vary AFR readings very largely which can get really annoying to a tuner. No more dips and a perfect AFR at 13.5:1 is what will really have this thing screaming - Again for Naturally aspirated motors any experienced EFI Tuner will know that target AFR for power is 13.5:1 -- 13.8:1 AFR even on 91 octane. - I would watch timing advance slightly on california gas only for the reason of the KA's compression ratio however. I would invest in an EXT Temp gauge - this helps even more when tuning a NA car for maximum ouput.

I am sure that with AEM EMS or some other direct way of controlling Timing Mapping, Settings and INJ Mapping alone and even with the same current setup you could see 175-180 WHP on the same dyno with ditching the AFC with my suggested AFR

steve shadows

You are missing out on a decent amount of power by tuning the car SOO RICH and also using such a crappy way to manage your Fuel.

The Nissan ecu effectively acts like it is in LIMP Mode when an AFC is on the car, you can actually watch the computer running in a cell range and retard the timing on the motor as you do runs if you are using a Apexi Multi-Checker to see what the ECU is mapping in (timing wise)

If you invest in an AEM EMS or some other way to directly control the cars injectors and Timing MAP + Find tuner who is experienced and knows what AFR to tune NA for.

12.5:1 is Turbo Car AFR

13.5:1 is NA CAR AFR -tuner should know this if he has EFI experience.

96NismoZ

Thanks for being a dick. Your reply really pointed me in the right direction.

roboticnissan

wow man if you hit 200 plus power on an na built ka im way down to attempt this. i actually love na over boost good luck with all your doings

__________________

S14_Kouki

I some what looked thur this thread you are making good numbers and PDM cams = great I have a set in my SR . Why dont you run itb's with a surge tank?? And if your going just for HP gains, then you need the shortest intake runners as poss but im sure you know this. and last but most important you have to get a standalone good job tho. can you see pics of the engine??

__________________
http://www.fabthis.com

http://www.childhoodproductions.com/dbfab/store.html

BigVinnie

Hold on there Mr. Shadows.
You have to present more clarity than just stating to tune at a 12.5:1 a/fr for turbo, or a 13.5:1 A/fr for NA.

My problem with establishing a specific A/Fr is that it isn't probable for all engines.

Now to finish on that statement greddy claims that for Forced induction it's good to shoot for a 11.8:1 Air to fuel ratio, and for natural aspiration to shoo for close to a 12.6:1. Based that most assume that between 13:1~12:1 is assumed for RPM/load for natural aspiration a 12.6:1 seems pretty fair for peak power at 6500RPM peak power.

Aeromotive claims that best power for naturally aspirated can be achieved between an 12.0:1 to 13.2:1.


Heres the link to my information.
Bristol Dyno technical article - air / fuel ratio
http://www.aeromotiveinc.com/tb.php?id=69



I agree with the whole idea of the AEM EMS, although for natural aspiration to a point there is only going to be so much resolution needed. Once you get into 32X32 resolution and higher then it's just fine tuning for fractions of HP where for forced induction its much more relative for larger gains. I could get away with a basic NISTUNE/PLMS set up, over the AEM ems and get those pretty good to where I want power to be.

The SAFC at the time was just practical to see if the stock ecu could achieve higher numbers than what most people were making between 153~158 WHP (full bolt on JWT tune). the idea was just to break over 158 wheel hP to see if the ECU it self could b capable of this with piggy back tuning. It was just a practical idea at the time, and was mostly as a learning experience. What I have learned is that it's time to move on to something better in fine tuning.
I believe internally the OBD1 KA could clearly make 190~200 to the wheels with a few more bolt on applications, and some serious fine tuning of the MAPS and a good amount of 100 octane.

__________________
http://i27.photobucket.com/albums/c1...ften12-2-1.jpg