170 RWHP? Need some opinions before I blow this money

[onosqv]

What mods were done to that car to get those #'s above? your car or another car?

[InsanityInc]

Your right, displacement doens't matter, STROKE DOES. A engine that has a longer stroke needs longer duration due to the piston still coming down and being able to pull in air unlike a shorter stroke engine. Also depeneding on rod to stroke ratio you have a longer or shorter dwell time of the pistons at TDC and BDC which affects what is needed in terms of duration. So how about you go do a little of that stuff hmm what is it called, ohh yea "RESEARCH"

Eh, you're the one who needs to do some reasearch.

A longer stroke engine has no special requirements as compared to a shorter stroke engine. You're confused. Rod to stroke ratio is what matters. An engine with a 200mm stroke and a 1.8:1 R:S will have the exact same piston motion as an engine with a 20mm stroke and a 1.8:1 R:S. And if I had to guess, I'd guess the R:S ratio between the CA16 and the KA24 are quite similar. Nissan seems to use about 1.7:1 on most of their passenger car engines from that era.

Also, regardless of what your R:S is, the same basic concepts still hold true. A later intake close will improve top end and reduce bottom end. More overlap will help the midrange.

[Bigvinnie]

Eh, you're the one who needs to do some reasearch.

A longer stroke engine has no special requirements as compared to a shorter stroke engine. You're confused. Rod to stroke ratio is what matters. An engine with a 200mm stroke and a 1.8:1 R:S will have the exact same piston motion as an engine with a 20mm stroke and a 1.8:1 R:S. And if I had to guess, I'd guess the R:S ratio between the CA16 and the KA24 are quite similar. Nissan seems to use about 1.7:1 on most of their passenger car engines from that era.

Also, regardless of what your R:S is, the same basic concepts still hold true. A later intake close will improve top end and reduce bottom end. More overlap will help the midrange.

It's good to know that there are smart people in this forum......

Your right, displacement doens't matter, STROKE DOES.

OK so now you just made an a$$ of yourself like an OXIMORON. BORE X STROKE= displacement.

A engine that has a longer stroke needs longer duration due to the piston still coming down and being able to pull in air unlike a shorter stroke engine.

Where did you graduate from? Defenitely not from any type of engineering school. 360degress is still 360degress no matter how big or small the crank is. Rod length is only determined by the diameter of the crank. No matter what the engine and it's timing is bound by RPM (Revolutions Per Minute), that will never change. The constant variable that make lift and duration change are fuel dumping of what is pulse width of injection. At 270cc injection the KA is bound to certain measurements that make up it's lift and duration. Too much lift or duration can contribute to too lean of a mixture there fore not making the engine streetable for smog emissions on the stock injection. Too much duration can also cause a non streetable car and a screwed idle. If you havent noticed there are 3 reasons why the KA lacks major power after 5900RPM. First the crank is half weighted and deals with harmonic stresses that kill power as RPM's increase. Secondly the cams are anemic that the KA no longer can breath and make power to it's injection meaning we already all know that the duration is too short ( but then again you don't see PDM or JWT increasing the duration too much either do ya buddy). If the duration becomes to long to make what you want as power in the higher rpm range the KA will lose it's smooth streetable idle.Third problem is that upward momentum and weight of rods and pistons is just to much for the valve train as RPM's increase closer to redline.

Also depeneding on rod to stroke ratio you have a longer or shorter dwell time of the pistons at TDC and BDC which affects what is needed in terms of duration. So how about you go do a little of that stuff hmm what is it called, ohh yea "RESEARCH"

Geee well if anything the KA should use a shorter duration after what you just said. Since the upward piston momentum of the KA travels at about 5000FT per minute. It's all linear in rotation you speak of dwell time as if time literally stops for a piston and the crank, that isn't how it works, a crank is ALWAYS spinning then when the degree in the crank and distrubutor are met then the cylinder reaches detonation.....Again simple laws apply such as ignition timing to position of the crank.....Insanity hit it dead on the button with the ratio's in comparison....

The CA and KA having same interchangable valve train parts has no relavancy what so ever to being able to use simliar cam specs. Hey they might both use simliar cam specs but that is based on a whole lotta other variables then similiar components or even stroke.

Well a bucket hydraulic assembly atleast for nissan is all the same and is bound to a certain lift and duration that no matter what cannot be exceeded, of course without major modification... You missed what I was implying. But whatever, this arguement is stupid and CA cam specs are usable.........

P.S I hate it when some Fu^K head that knows jack shiat about the KA and CA is going to tell me I am wrong. I am backed up with years of info and have been in the forums for quite a while.


Modified by Bigvinnie at 3:53 PM 2/13/2006

[ivanqz]

Dam, I am gonna bookmark this thread, good info!

[Bigvinnie]

What mods were done to that car to get those #'s above? your car or another car?

That isn't my car that is Scotts car. I found it in yahoo geocities.Here is his web site. Only thing that sucks is that Jim Wolfe doesn't offer this tune anymore. I'm suggesting that you get a bikirom or a standalone of some sort so that you can make those numbers on the dyno yourself....Heres the link with an impressive 1/4mile time and cheap mods.http://www.geocities.com/wssnider/240sxDYNO.html

[ivanqz]

Hey Bigvinnie, After reading your posts, I am starting to think that there is something wrong witth my 240 because It really just stops pulling after 5000 rpm. It is 92 bone stock with 103k miles. I do show 178 compresson on all cylindres. Is this normal for a bone stock KA? What mods do you have done to yours? Dynoed yet? I am going to get a base dyno run in a week or so. $70 for 3 runs. I'll post them as soon as I get them. Thanks
Modified by ivanqz at 4:20 PM 2/13/2006

[Bigvinnie]

Hey Bigvinnie, After reading your posts, I am starting to think that there is something wrong witth my 240 because It really just stops pulling after 5000 rpm. It is 92 bone stock with 103k miles. I do show 178 compresson on all cylindres. Is this normal for a bone stock KA? What mods do you have done to yours? Dynoed yet? I am going to get a base dyno run in a week or so. $70 for 3 runs. I'll post them as soon as I get them. Thanks

Try a launch diagnostic it will tell you if some of your equipment isn't functioning correctly. I can never answer those questions without driving the car or checking the engine, I just don't know.

Mods done to mine..... Aluminum flyweel, stage2 6 puck clutch sprung, aluminum pulley, DC sports header, catco high flow, Pacesetter cat back exhaust 2.5", AEM intake, removal of SCV's, coolant bypass, a cheap one time tune and safc (for a lean HP mixture). Adding an electric fan after I move this month. I'm pulling pretty hard and keeping up with SR20dets that are on stock boost with no modifications, the throttle responce is amazing.I'm also learning how to use bikirom when I get some spare time I'm going to sauder the daughter board to the ecu.....Not going to dyno until the internal modifications are complete, new block with a 10.5:1 compression.

[Graphfixz]

BigV has a good writeup on club240 on making power with a KA N/A for cheap. Will be alittle more cause the CAMS he wrote it for at the time are like gone. So expensive cams are all that exist now. But cheaper then your price tag you got there.

where is this tutorial? I can't seem to find it.

[ivanqz]

I'll try the self diagnose, I am pretty sure it is also runnig rich, maybe temp sensor. Also, you should try, an electric water pump. On FWD SR20's the water pump was poorly designed causing this thing called cavitation after 5k rpm, basically alot of bubles and more effort to turm the water pump. Resulting in overheating after long periods of hard driving. Most people just switch to under drive pullies and solved the overheating problem. Some People switch to an electric waterpump and seen 5 hp gains on moded engines.Just a thought. Thanks again for the info!
Modified by ivanqz at 5:45 PM 2/13/2006

[Bigvinnie]

where is this tutorial? I can't seem to find it.

It's not really a tutorial, just away to show a method of making power, since most people say that the KA can't yeild upto 200HP at the fly wheel with few mods. Yeah it's all good I used that same dyno to represnt that good power can still be made with the KA.

http://www.club240.com/forums/...30440

[Graphfixz]

It's not really a tutorial, just away to show a method of making power, since most people say that the KA can't yeild upto 200HP at the fly wheel with few mods. Yeah it's all good I used that same dyno to represnt that good power can still be made with the KA.

http://www.club240.com/forums/...30440

thanks!!

[H.D.HUMPERDINK]

There is a post with the dyno graph on nico somewhere or you can look here:http://forum.aempower.com/bbs/viewtopic ... ight=240sx

[SonyPete]

OK so now you just made an a$$ of yourself like an OXIMORON. BORE X STROKE= displacement.

REally that what displacement means *smacks head* I SIMPLY stating that stroke had more of an effect and bore was very negligble

And my statment aboutQuote »A engine that has a longer stroke needs longer duration due to the piston still coming down and being able to pull in air unlike a shorter stroke engine. [/quote]I was just setting up my statment about dwell time. No **** the crank will always be moving and in 360 degrees pattern. That is all information that is assumed in a convo like ours. Thats like stating hey pistons go up and down, man ohh man.

The constant variable that make lift and duration change are fuel dumping of what is pulse width of injection.

Wrong pulse width is based on engine specs such as cam and intake setup not hte other way around. Injector pulse width are figured out pretty much towrds the end of the engine creation.

At 270cc injection the KA is bound to certain measurements that make up it's lift and duration. Too much lift or duration can contribute to too lean of a mixture there fore not making the engine streetable for smog emissions on the stock injection. Too much duration can also cause a non streetable car and a screwed idle. If you havent noticed there are 3 reasons why the KA lacks major power after 5900RPM. First the crank is half weighted and deals with harmonic stresses that kill power as RPM's increase. Secondly the cams are anemic that the KA no longer can breath and make power to it's injection meaning we already all know that the duration is too short ( but then again you don't see PDM or JWT increasing the duration too much either do ya buddy). If the duration becomes to long to make what you want as power in the higher rpm range the KA will lose it's smooth streetable idle.Third problem is that upward momentum and weight of rods and pistons is just to much for the valve train as RPM's increase closer to redline.

All that you posted is very basic knowledge and does nothing to disprove my prior statements, don't even know why you posted all of it. Hmm maybe just so people reading it would see you spewing out common knowledge that is TRUE that it makes you look like all your previous points were factual also.

And you hate how people come in making statements about not knowing what the heck there talking about. Please spare me the words cause I hate Mr. Know it alls like your self that like to jump down peoples throats when ever they think their knowledge is all mighty. and are never wrong. SO how about yuou re-evalute your thinking before branding someone a noob when it comes to anything engine related.

So thank YOU for showing all the young ones how NOT to act in a public place such as this.

[Bigvinnie]

And you hate how people come in making statements about not knowing what the heck there talking about. Please spare me the words cause I hate Mr. Know it alls like your self that like to jump down peoples throats when ever they think their knowledge is all mighty. So thank YOU for showing all the young ones how NOT to act in a public place such as this.

Good if you don't like it then leave. Nissan has followed the same stroker dynamic and geometry, it really hasn't changed up until the SR, so all you need to do is apply what valve train went to what engine and use those specs( like L is to Z as is to CAE as is to KAE, as CADE is to KADE), (I just spoon feed you as well as 300 other people with that info). If you knew your damn history on Nissan and 4 bangers you would of known what was compatible with what. Fact is I'm right and you are wrong so appoligize like any civilized adult. You started the arguement like a child without knowing what the frick you were talking about...Nissan history 101 b*tch.......

It's guy's like you that think you know what the f%ck your talking about that actually makes the learning process counterproductive when you argue something with zero validation......


Modified by Bigvinnie at 8:39 PM 2/13/2006

[SonyPete]

Quote »Fact is I'm right and you are wrong so appoligize like any civilized adult. You started the arguement like a child without knowing what the frick you were talking about...Nissan history 101 b*tch.......[/quote]LOL like I stated before Mr. Shove it down everyone throat. I never started any of this negative conatone that you started and have set this thread as. And for the papers you have yet to disprove ANYTHING I have posted.

Yea the engines might respond to simliar cam specs but not because they share simliar valve train parts.

[Bigvinnie]

LOL like I stated before Mr. Shove it down everyone throat. I never started any of this negative conatone that you started and have set this thread as. And for the papers you have yet to disprove ANYTHING I have posted.

Yea the engines might respond to simliar cam specs but not because they share simliar valve train parts.

You suck at life... Stop posting.....

[BadMojo]

It would suck if this thread got locked. Lots of good info in this thread and the forum in general. I think the NA KA forum is a hidden gem and really deserves more traffic.

Can't we just keep it civil so the mods don't start locking stuff in here? I've learned quite a bit from reading these forums but stuff like this is really counterproductive.

[ivanqz]

^^^ Same here , I wish I could change the title of this thread...

[Bigvinnie]

Anyways back on topic.... So lets break down the R:S ratios.CA16DE 1.75:1 rod/stroke ratioCA18E/CA18de 1.59:1 rod/stroke ratioZ24/KA24e/KA24de 1.71:1 rod/stroke ratioL16 1.80:1 rod/stroke ratioL18/z18ET 1.62:1 rod/stroke ratioL20b/Z20e/Z20s/KA20de 1.76:9 rod/stroke ratioZ22e/Z22s 1.59:1 rod/stroke ratioFJ20E/FJ20ET 1.75:1 rod/stroke ratioFJ24 1.59:1 rod/stroke ratio

Pretty much all these older engines share many similarities with the rod stroke ratio. Although this isn't always and necessarilly true the engine with the larger ratio usually has the larger duration cam. Although you can't always insist that it is generally valid. There is also differences in fuel dumping and emissions that took place through the majority of these engines over the past 30years with some engines with the smaller ratios, actually having better consistency in making power with lift and durations. The CA18de although using a much higher rev could also use much longer duration cams than the KA, such as ones made from HKS. If infact you can get specs from any of these engines that used better use of lift and duration I don't see why you wouldn't want to use them. It basically simplify's time used on R&D, and can save you hundreds when compared to a $700 JWT cam. Especially since regrinding at the most will cost you $110. All you need is one of these old cams that you can find just about anywhere on craigs list or the classifieds so that you have a template of the actual cam to regrind it onto your own cams....

So lets recap. Match specific cams to valve train used. Why? Because the particular lobe and duration only works for the shim and lash of that particular valve train.So for the KA24DE there is the KA20de cams, CA16,CA18. FJ20E used a different kind of bucket style hydraulics that used dfferent shimming than the DE series of valve trains so I'm not to shure that it would work.The list for SOHCs used small differences in the valve train that could effect the lash slightly weither it was either arocker arm assembly or a lifter assembly, but cam specs were all pretty close to being relatively the same. KAE's have the advantage of usign a solid lifter assembly with lash adjustment witch is a defenite plus....

I learned this trick building 510's, it's amazing the tricks you learn from old wise men that love nissans. Technically somepeople would be mad that I just handed out this info....

For an example: At this site you can get CA18de cams made by Tomei for under $250 (individually), Then you can get the KA cam reground at a machine shop for $110. Then you can sell the CA cams on craigs list to some guy that owns a CA18de or T. Everyone wins accept JWT....http://www.sumopower.co.uk/tomeicam.htm


Modified by Bigvinnie at 6:23 PM 2/14/2006

[n_bogie]

kinda off topic but was just wondring on a stock sohc settup how much you think i could deck the block? or plane the heads. i havent got any books yet on the ka they comeing soon just wondered if anyone had any ideas seeing how my head will be getting done soon

[new_to_drift]

wont a 3" exhaust be too big? ive heard that the most you would want to go on a NA motor is 2.75.If you go too big you wont get enough back pressure which would in turn make you lose horsepower.Correct me if im wrong please.But ive just heard that 3 is too big.

[TrueSlide]

wont a 3" exhaust be too big? ive heard that the most you would want to go on a NA motor is 2.75.If you go too big you wont get enough back pressure which would in turn make you lose horsepower.Correct me if im wrong please.But ive just heard that 3 is too big.

why would 3 inch be too big for NA? V8s run 3inch and bigger and lots of them are na. We also are NOT dealing with a 1.8 honda motor, the KA is alittle bigger.

Exhaust size is all about what you want for your car. Its all about exhaust velocity. Smooth = Faster. The smoother the exhaust the flow, the better the velocities and power comes with it. That is what kills peoples theory on backpressure. Back pressure interupts the smooth flow of exhaust, which in turn causes a decrease in power. Gas velocity is what makes the exhaust better. The best exhaust will have the highest velocity with the lowest amount of restriction(backpressure).

Choosing the exhaust size is all about powerband and engine size.

A smaller pipe will produce faster velocities at low rpms but create backpressure at high rpms

A bigger pipe will produce low velocities at low rpms and high velocities at higher rpms.

If you have a low rpm powerband. A smaller exhaust would be more benefical because you tuning for the maximun velocity in your respected powerrange.

If you have a high rpm powerband. A bigger exhaust would be more benefical because you tuning for the maximun velocity in your respected powerrange.

The reason ppl get confused about "backpressure". They put a huge exhaust on their car loose "backpressure" and lose power. So they are like "damn with the 'backpressure' there I had power, backpressure = power" But in reality the pipe is too big for their powerband and does not produce enough gas velocity.

The least backpressure you can get while mainting the highest velocity will produce the best results.

[180fan]

It would suck if this thread got locked. Lots of good info in this thread and the forum in general. I think the NA KA forum is a hidden gem and really deserves more traffic.

Can't we just keep it civil so the mods don't start locking stuff in here? I've learned quite a bit from reading these forums but stuff like this is really counterproductive.

Well said!

[InsanityInc]

You always want 0 backpressure, as was already said, and gas velocity is what you want due to the overlap period and the venturi effect. 3" is fine for an NA KA, and definitely produces the most peak HP. A well designed header with large primaries (the only ones for KA have tiny primaries, hardly bigger than stock if at all) will accentuate the high end gains.