Important KA Tuning Thread

[WDRacing]

The ugly fact is this, the RB20 through the RB26 will perform in stock trim fantasticly under load and high levels of boost. 400WHP is not even approaching the limits of the internals. This is always assuming the motor is tuned properly mind you.

I've seen 100's of SR20's push well into the 300's for everyday use.

The KA is suffering from a manufacturing defect. I'm almost positive this is a leading cause of the most recent failures. There are KA's around that are in the 300's, but most that crest that point have built the internals. The fact that the KA has a stud girdle stock, piston oil squirters stock, a great cam on bucket head design and enough low end torque to not notice turbo lag means it is a fantastic motor. But somthing is making the factory rods break under load.

I'm saying oil or lube related. No one with any experience in said failures has examined any of the recent failures. I've locked a main bearing before myself, it sucks and causes exactly what we have seen here in the past few weeks. I've also ruined cam journals do to lack of oil pressure in the head, also sucks. Lube and lube temp are crucial things when ever a power adder is used. It's also the most over looked. The underhood temps alone go up at a minmum 200F. That heats the intake air, the intake manifold not to mention the entire motor itself with or without a better radiator.

The biggest problem we have right now is all the bench racing and bench troubleshooting thats going on. I don't wanna here that so and so has a KAT thats run at said whp for 2 years...perhaps his oil pump is running at a greater volume, or that person has a better cooling system.

Point is, everyone's setup is so different you can't comment on what power any of the internals will be good for. Cause they will be different for every motor.

The SR and RB were designed around boost and heat from the get go. The KA was not.

Simply adding fuel and retarding timing will get you a fun car to drive until it explodes. Anyone looking to push past 10 psi needs to address all avenues of the tuning process.

FuelTimingLube and scavengeCooling

With these addressed, you simply eliminate the odds for failure until you actually reach the metal fatigue points themselves. All of this bickering about the KA being a bad motor or the tuner being a retard is pointless. There are very few experienced tuners amoung our current list of members, myself not being one of them for the record. Lord knows I break things at an almost constant rate. So all the speculation just needs to stop.

If we can get the basics addressed for everyone to understand, we'll have a much more happy atmosphere in here. Not filled with threads about destruction, but filled with mebers breaking into the 11's or winning said drift event because they chose to stick with the KA and not go for the swap. It is my belief that we've gotten away from the basics of tuning and it's killing us. So I'm starting this thread to address the most missed and usually the easiest portion of tuning.

Hopefully this will reach atleast a few open minded members who can learn from our mistakes and build a better, faster car for the future.

If you have any trade secrets for tuning, please post away. Have any idea's for cooling, post away. Got a better way to do basicly anything that is usually overlooked....you got, post away. I'll be keeping this thread under a close watch. So it stays on topic and needless posts will simply be deleted.

PS, rather then giving up on a almost 2 year project. I'm sticking it out. I've bled far to much into this car to let her go. So I'm not switching back to domestic...I'm going to be KAT for quite sometime

Peace, I'm OutWD

[klattr1]

something for the NOOBS,

so what was the cause of alot of early boosted KA setups? lack of retarding the timing or being aware of it.

the USDM 240sx (KA motor) is a naturally aspirated motor. i know you know this but dont take the timing maps for granted which are tuned accordingly to a NA setup, being advanced (26-28 deg. in WOT if everything is right). so dont expect your motor to survive even at 7-12 psi ranges with just bigger injectors and a SAFC to trim fuel cuz the aggressive timing might just eventually tear your motor alive eventually.

if you want to survive at a lower level, then leave the tuning up to someone professional (JWT ecu, Enthalpy ECU, knowledgeable tuner on the dyno with AEM EMS, etc).

dont copy what alot of SR guys do by just tuning for bigger injectors with SAFC. the SR timing maps are more retarded compared to the KA so the margin of error is less on SR with that setup.

do things right, research, spend a lil money if you have it, dont cut corners, dont assume anything, diagnose, verify, and then you can really enjoy a turbo KA setup alot longer with less worries or complaints.

[Craving4Boost]

so getting things like a better radiator and a better fan makes a big difference?

[WDRacing]

To piggyback on Klattr's comment. I would recommend a one degree of retard per lb of boost unless you have a ecu tune or a standalone. If you have the MSD BTM and want to retard a .5 degree per lb of boost like I do, then use a knock meter of somekind just like I do. SO you will see any knock before it becomes bad enough to damage your motor.

Timing is far less forgiving then fuel is. Always lean towards the side of caution and safety. You'll be thankful in the end.

Craving4Boost It makes a huge difference. I'll dig up a good quote on heat variance vs hp ratings in motors I have lying around, you'll be surprised.

WD

[Florida240sx]

Reason why I'm being careful on my boost...Tuning is everythign.Especially when goign from NA to turbo.Liek you said the SR maps give you moe room for error.Glad you sticking with it WD

[Import_Ant]

how many people are running oil coolers? I personally think for such a small cost it's a very important thing to have on the car. I really agree w/ you WD on the extra heat that is going to be generated, look at the threads where people are melting their power steering reservoirs. just tossing some heat wrap on the manifold car isn't going to cut it in the long term.

My current plan is to make a solid motor then work from there. I have lucked out in my choice of car in that my motor is set at 8.6:1 compression out of the box stock so I have a little more room for abuse but I'm not taking it for granted. I have upgraded the ignition coil to a Blaster 2 coil, added an oil cooler, removed all of my A/C components, shimmed my hood, and am in the process of heat wrapping everything. I have the luxury of a spare motor which I am in the process of rebuilding but it will have a nice set of pauter rods, forged pistons, and some other minor headwork when installed. even then I dont plan on running much power until I get a decent engine management system (EMS or E-Manage Ultimate)

I think for me it's not pushing the motor to its limits, its about maturing the motor as my knowlege about it matures. Since this is my daily driver I'm in it for the long haul. I thank everyone who has lost a motor for helping us understand the KA's shortcomings, that will happen any time people start pressing a motor to its limits. lets learn from it and get to the next level.

[srdrifter]

I want to throw out an idea that may address the stock rod problem. Yes, I am a newbie to this site but am a very serious tuner who is learning a crap load of info every day. I just posted a thread titled "Engine Makeover...." check it out for back ground of what I'm doing.

Anyways, about the rods - The performance shop that I/m using is not replacing rods and here's why - He strongly beleives the rods can withstand 4-500hp. Now, here's whats interesting, he's going to put my rods in a "beading machine" - it's going to shoot little beads of metal at the rods that will stick to them. He says this will "relax" the rods - why this is good I still am not positive - but he says that at that time he will be able to literally see any discrepencies or possible weak points. After this is done he will be coating them w/ Teflon - I could have sworn it was teflon - or may have been a ceramic coating to strengthen them up.

Just an idea that you may not have heard about. And this is no weak shop, the guy builds big-block boat dragster motors, porche motors, lots of v-tecs sittin around in there etc.... He is no joke so I trust what he says. obviously it won't help w/ cooling but it'll keep those rods out of the sid of your block. (which he had some of thse there too)

[Import_Ant]

I left out a couple of points for the SOHC motor. if you're going to do a rebuild you can use the 280z oil pump as an upgrade. I think the motor designation is an L28.

spark plugs: I think I spent a good 1/2 hour trying to decypher NGK's designations to find a range colder plug for the SOHC motor. the stock v groove plug is a ZFR5E-11. there are no ZFR6E-11's made. you, however can change over to a BKR6E-11 and it works just fine. I've been running those plugs for about 3,000 miles now and am very happy w/ them.for those not aware the first 2 letters explain size/thread pitch, 3rd letter designates if there is a resistor (r= resistor) then the number is the heat range. the larger the number the colder the range. the final -11 designation is the gap. since you'll be re-gapping them anyhow, this number is pretty much irrelevant.

also, there are some simple things that can be done to lower under-hood temps. heat wrapping things is always good, shimming the hood and removing that weather strip helps too. it's the little things, when put together, that add up to help out in a big way.

what you are referring to srdrifter is pretty much the shot-peening process.

[deviousKA]

I have a question for all you KA-T owners that recently have had bottom end failures, have you inspected the crankshaft yet? KA, and nissan cranks in general have a very poor system of blocking the ends of the oil passages within the cranks. The system used is simply ball plugs fastened with some crank material punched over. Not only is this type of plug prone to failure, but if you ever need to have your crankshaft fully cleaned it is a major pita for the machinist to remove and reinstall these plugs and do it well. What I do on all of my nissan crankshafts that are going into any kind of performance application, is remove these plugs completely and have the holes tapped for allen plugs. This is a much better system.

Another thing, oil pumps. When you add external units such as turbo chargers and oil coolers, you are significantly changing the needs the pump has to provide for. Unfortunately, ka24de has very limited oil pump upgrade options (as far as original pump and location is concerned anyways). With an added turbo and or oil cooler, you guys should really be looking into external belt driven oil pumps in combination with the stock pump. These are available from quite a few different manufactures, manufactures that make staged pumps for racing applications. Even a simple single stage (one inlet/one outlet) would be a very wise addition. Jumping up to a multiple staged pump you could then use the multiple scavenge lines to pull from the turbos, coolers, etc.. directly. Systems like these are what i call glorified wet sumps, and work very well.

Sohc can also benefit from a glorified wet sump, although oil pump upgrades (stock location) arent as slim as the dohc.

Oiling system in general is the main problem you guys are having imho. There is a few other things that can be done i failed to mention here.

[paemt6220]

I see there several thoerys here, but does anyone know yet what the oil problem is? I am lucky in a way to not having turbo'd my KA yet, so the more I can learn before I do is great. I'm glad we are on the right track to becoming reliable.

Chad

[4cefed]

Well, I guess you can take this info for what it's worth since it doens't even involve Nissans.

When my Shelby was running, it had some kind of blockage in an oil galley in the head. The rest of the engine seems to be lubed properly, but the head would dry out so bad, the lifters would rattle to the point where the knock sensor kicked in and backed off my timing and spark. For those 2.2s, there was an upgraded oil pump that puts out more volume, and even a replacement pressure spring that bumps up the oil pressure. Otherwise, on a stock engine you are looking at 4 psi. of oil pressure. Even with the upgraded pump, the lifters still dried out.

So, I got one of those remote oil filter kits, and a $50 oil cooler out of Summit that was about 10"x10" Way overkill for 250hp, but I wasn't sure what airflow I was going to get through it where I mounted it. As it turned out I stuck it in from of the radiator and had full flow. Anyway, I also ran mobil 1 15w50 like I use in the racecar.

I had oil temp and pressure guages in the car since it started having the dry-out problem. I really wish I could remember the numbers after I added the cooler and switched oil, but I do remember that even after a good pounding, the pressure never dropped more than a psi or two than the cold start-up pressure. The car didn't have any other problems with the lifters either.

It would stand to reason that if there was higher oil pressure to the rod bearings, that they would survive more hp. I've followed the SR vs KA "debate" for years now, and the rods seem to be the achiles heel every time for the KAs. So I think you guys may be onto something with an upgraded pump and some oil cooling. I hope I'm not just wasting bandwith with this post.

[WDRacing]

Here is a site I use almost weekly when dealing with tuning or almost any engine related question. I almost always find somthing useful towards my goal.

http://www.stealth316.com/1-tech.htm

[WDRacing]

I want to throw out an idea that may address the stock rod problem. Yes, I am a newbie to this site but am a very serious tuner who is learning a crap load of info every day. I just posted a thread titled "Engine Makeover...." check it out for back ground of what I'm doing.

Anyways, about the rods - The performance shop that I/m using is not replacing rods and here's why - He strongly beleives the rods can withstand 4-500hp. Now, here's whats interesting, he's going to put my rods in a "beading machine" - it's going to shoot little beads of metal at the rods that will stick to them. He says this will "relax" the rods - why this is good I still am not positive - but he says that at that time he will be able to literally see any discrepencies or possible weak points. After this is done he will be coating them w/ Teflon - I could have sworn it was teflon - or may have been a ceramic coating to strengthen them up.

Just an idea that you may not have heard about. And this is no weak shop, the guy builds big-block boat dragster motors, porche motors, lots of v-tecs sittin around in there etc.... He is no joke so I trust what he says. obviously it won't help w/ cooling but it'll keep those rods out of the sid of your block. (which he had some of thse there too)

The first process is called shot peening, it's done by the factory before initial installation. Having it redone is not a bad idea, although it's simply releaving further stress thats been inflicted already.

The inspection process is called NDI, or Non destructive Inspection. Also know as magnafluxing. Here's a link to expalin it far better then I can.http://www.circletrack.com/tec....html

Having the bearings coated with anything is an excellent idea. Just measure the clearence with plastigage to insure the proper fitment.

[swwifty]

I just wanted to add my .2 cents. I think one of the best ways to reduce heat in the engine bay is to ceramic coat the turbo, turbo manifold, and the downpipe. I've had first had experience with before and after cermanic coatings on headers, and it makes a huge difference!

Also to note, Mark had a upgraded radiator and even a oil cooler and still toasted a rod. It's something to think about....

[4cefed]

Well, everytime I see one of my friends ceramic coat the manifold or turbo, they end up with cracked manifold or turbo. Same thing with wraping. In exotic engines that are designed for that sort of thing, it works good, but it doens't alway work well in every application.

[MarkEmark]

I just wanted to add my .2 cents. I think one of the best ways to reduce heat in the engine bay is to ceramic coat the turbo, turbo manifold, and the downpipe. I've had first had experience with before and after cermanic coatings on headers, and it makes a huge difference!

Also to note, Mark had a upgraded radiator and even a oil cooler and still toasted a rod. It's something to think about....

Yup, I had a 2.1" all aluminum Koyo radiator, brand new water pump, thermostat, brand new oil pump (I was REALLY close to getting a hi-flow aftermarkete oil pump), fairly large front mount oil cooler...my water temps never went past 178 degrees, this entire summer (75% water, 25% anti-freeze, a bottle of redline water wetter). I also have a heat shield for the turbo and the manifold/downpipe are ceramic coated (not a very good coating, but it is ceramic nonetheless).

When the engine blew I had only been out on a 10 minute ride and only hit boost once before then. Water temp was 178, ambient air was fairly hot and humid.

The engine was by no means too hot.

But it is uncanny how the #3 rod was destroyed in all the cases of rod-failure...I haven't had a chance to tear the engine down or inspect anything yet...a friend just towed it back this evening. Not sure if I'll even have time to tear into it before I leave for school...pulling the engine/transmission is a pretty involved process!

Another point of interest is that all of the engines throwing rods have happened at high boost levels. No one has thrown a rod at low boost levels (say, 8-11 psi). If the reason the rods were failing were due to an oil lubrication problem, wouldn't they also fail at the same rate at 8-11 psi as well?

But thumbs up for the thread!

[SSS]

Is anyone able to do a photo comparison of SR20DET/RB20/25/26DET rods vs. the stock KA rods and measure the dimensions of each?

[S14tat]

well that is a good point markemark, if its oil starvation wouldn't it be the same reguardless of what boost it is? and since markemark has a T3 super 60, at 3500 rpm he should be making his peak tq no? but anyways, its good to hear that your saying for good wdracing.

[S13FX]

I won't really know much from first hand tuning a SOHC, cause my project won't start untill early OCT. But I have reserach and read many threads on here from which I have learnd a lot and gotten some ideas. Here it is I was planning on cryo freezing my Rods, Pistons, and some other accesories. Any one ever hear of that? Seposably it's seposeto raise the durability of the application by 110%, cause it brings all the molecuels much closer to each other after the 72 hour process is done. Also I thought when you heat wrap anyhting that produces large amounts of heat is a bad idea cause it traps the heat inside the application, for instance like the turbo and and all the heat inside the heat wrap weakens it? One of my buddie is a fire fighter and they use this heat absorbing tapae stuff he said might be a lot better to use. Cause it dosen't trap the heat what it dose is it kinda works like heat sink and then cools the application down. Granted the tape stuff dosen't look pretty heh but if it works who cares what it looks like. That's it for now.

[fiznat]

As far as the "professional inspection of failed motors" question, I am headed to the machine shop tomorrow morning, 10AM. This guy is VERY, VERY experienced in engine work and I treat his word as gold. I will return with the results.

As far as thinking this is an oiling problem, I am very skeptical. My bearings (the ones that didnt get chomped up after they popped out) are very, very clean. They have a slight amount of hazing as WD and others mentioned, but absolutely nothing close to what could be considered oil starvation leading to bearing failure. I dont see where the oil conclusion is coming from here.

Glad you decided to stick with the KA, Brian. I've been back and forth myself, and I think we're both making the right decisions.

[WDRacing]

I don't want this to turn into a rod discussion fella's...I do think we should start a new rod thread though since the last one is cluttered with crap.

Just for reference though, when I say oil problem, it doesn't have to be temp or a pressure problem, the oil jackets near the #3 could be smaller, there could be a small orifice that gets clogged easier...almost anything could be the cause.

The cool thing about my KA is it will still be faster then Fiz's...lol. Had to throw in a poke Foster.

[neoamd]

My thought would be the fact that the KA makes so much TQ down low. Its having to put a constant force of XXX FT lbs on the rods at a very low operating speed (RPM). We all know the higher the RPMs climp the more you can push through the motor. OR the moe it will take.

Think about it, it you sprayed a 50 shot down low in your RPM band (Say 2500 up) One of the time you did it something would break. Surf the LS1/Mustang boards.. people break **** all the time by having to much TQ down low. Maybe I'm wrong but I come fromthe worl of RX-7's where all we know is 8,500rpms for decent power.

I figure once some decent cams come out that shift the powerband up about 1000rpms we all will have less trouble. People say 350rwhp is the peak of the stock block.. I say anything over 330rwtq is going over the limits.

No doubt the stock rods are strong but deail with XXX amout of tq every day downlow (5th gear pulls on the interstate etc) will soften the rods and then one day boom like Fiznat. A small turbo pushing out a ton of boost will cause more stress on an engine than a big turbo pushing less boost will.

In our care maybe bigger is better to keep safe level of TQ downlow. It not like we need 300ftlbs of TQ by 3,000rpm.. We arent a Dually!

Josh

[Jookmasta]

well if oil is the problem, i guess my simple minded question to those who did have their engines commit suicide is what brand oil were you running and what weight? probably wont matter much but it would be interesting to know

[fiznat]

I used nothing but Castrol 10w-30. I was planning to switch to synthetic within the next 500 miles or so (once I ran out of the castrol), but I never got there..

[Colorado_S14]

Was rod bearings we all those with the built motors running? One of the techs at a local race team that competes in the Speedvision GT series (3R Racing) reccomended against Clevite bearings when I build my motor.

[duncan351]

So what Rod bearings did he recommend then?

[fiznat]

I just got back from the machine shop. Talked with the guy there and looked over the wreckage with him. The conclusions are as follows for my block:

1. This was NOT a oil starvation/heat/bearing failure of any kind. The bearings, as the machinist pointed out, still retain factory markings on them that are, and I quote, "less than 2/10ths of 1/1000 of an inch deep." Any failure, or even moderate wear on the bearings would clean these markings straight off, and yet they are still clearly visible as they should be.

2. Cyl #4 has a huge crack along the inside of the bore, and is dented in at one point. The machinist said that he has seen this happen before on chevy V8 blocks, where a manfacturing defect called a "cast shift" in the block material causes an uneven distribution of metal along the cyl walls. He said that sometimes cyl walls, by defect, can be much thinner than they are supposed to be-- and that sometimes while boring blocks he has gone straight through to the water jacket simply because the walls were made too thin at the factory. If this is the case, the #4 cyl could have had a wall collapse slightly, and hyrdolocking could have caused the failure. At 20 pounds of boost, it would take a VERY small amount of fluid in the cyl to cause hydrolocking. He said he has seen this happen a few times before, but it is not common *at all* with japanese blocks. He offered to have my block sonically checked to determine if there was any of this "core shift," I'll have results for you when I get them.

3. Most likely, though, the conclusion is that I experienced a simple mechanical failure of the rods. They bent and snapped, then took out a whole lot with them. The machine shop guy said that mine was "the worst damage he has ever seen" in a block like this. He showed me remains in his shop of some V8s that had snapped in half, other rods that had broken or pistons shattered, but nothing like the complete destruction that my block experienced.

To add weight to this guy's claims, the evaluation (and work on this block) was done at Carlquist Competetion Engines in Oakville, CT. Bill, the owner and guy who I have been working with, has over 20 years of experience working with all types of race and high performance engines. This guy knows what he is talking about, and like I said before, I trust his word on engines more than anyone else I know.

So there you guys go, a professional evaluation of my failure. Watcha think?

[Mustangs_Suck]

So it pretty much sounds like if you want to push past a basic T25 or so set up you'll have to completely rebuild the KA motor; rods included - to have a safe set up. Not to mention all the proper cooling,fuel and tuning supportive mods as well.

Yes you may get lucky or whatever and have no problems - but better to be safe than sorry when it comes to your car.

Good job on getting it inspected Fiz - hope you can all come to a conclusion on how to make more reliable KA-T's

[deezlins]

As I said in the rod discussion thread, one of my friends has gone through 6 ka's (NA) and its been the #3 rod bearing on all of them.

Some tuning tips:

Remeber that the SAFC will inadvertantly alter timing, it makes the car think its in a different load cell than it actually is and that means it will use the timing from that cell as well (which could be a bad thing).

Getting your car custom dyno tuned from a competant tuner (there are alot less of these than you probably think) with a standalone is the best way to go. The best dynos to use for this are Dyno Dynamics and Dynapack. They both can hold load very well and make tuning precisely for each cell possible. Dynojets are pretty much worthless as far as tuning goes. They have come out with load dynos now, but I hear they arent up to par. Mustang dynos are better than the Dynojets, but not as good as the Dyno Dynamics and Dynapack and don't hold load as accurately and precisely. Dont skimp out on tuning and management, you spend all this money on your car and all these performance parts, tuning and management is the most important part, do not skimp there. As far as adjusting timing, theres different ways to do that depending on available equipment. The engine will tell you what timing it wants by watching readings like tractive effort on the dyno.For A/F ratio, it depends on what load and rpm you're at, and what your car needs as far as heat management, and how important fuel mileage is. Contrary to some popular belief, leaning out your a/f ratio doest really increase power. Your engine usually has a "window" of what a/f ratio it likes. Go too far above or below this and the engine will probably not run well or be dangerous, but inside that window adjusting the a/f ratio really wont affect power noticeably at all, its pretty much just safety. On higher hp cars the window is usually smaller. For example say youre running a 13:1 a/f ratio, then you adjust it to 11:1,the difference in power won't even be noticeable, maybe like a few hp difference. I think the leaner=more power idea got started with the SAFC's and piggybacks like that that when you adjust the fuel, it also adjusts the load area the ecu see's and adjusts timing as well, affecting power.

Maybe sometime I can go into more detail about things when I have more time.

[turtl631]

I wish Ivan would chime in here, seeing as his work with stock block and also forged piston/stock rod setups are a lot of what caused people to claim that the rods could hold over 400 whp and that the pistons could do over 350 whp. Perhaps he's doing something that other people aren't, tuning better, etc. I don't know really, it just seems like a logical place to look for some answers.