LOL !!!! I love it, the first thing I see is .... "KA knocking", and "Im having problems with my KA"

dont u just love the 2.4 liter torque monsters.

Anyways. Im thinking of building an NA KA and I was thinking to myself. Is it even worth it.

So, if anyone can help and post up their highest HP numbers with their naturally asperated KA's and what mods you have done that would be chill...

Im thinking something like-11.5/1 compression (if anyone makes it)-forged rods-lightened crank-lightened flywheel-header-ITBs-Cams of some sort-Rebuild the drivetrain to withstand really high revs- a good tuning

Im hopin that with all that garbage it could maby put it at the low 200whp mark.... Or am i just dreaming?

Thanks

I think the general consensus is that 200 whp is the goal, but we've not seen any results at that mark yet (they could exist, but no one here has proven it).I personally will be happy if I can hit the 180 mark, but I won't be able to get it dynoed for a bit longer.The cost to get up that high becomes a bit pricey and I think people tend to shy away from really pushing that mark. Lord knows my build was way more expensive than it was worth, but that was mostly because I picked a mechanic who really let me down (I don't have the equipment, space, etc, and didn't know the same people then as I do now to do a build myself)I hope that doesn't deter you from doing whatever you want to do, but you asked the question, I gave you my honest response.

http://www.race-cars.com/carsa...s.htm

i think thats about as powerful as they get. but then again thts an Rebello SOHC in an S14 SCCA car...

but it has five hours left on a spare! and its still a current record holder.

You can buy a 210chp head package, that should be good for about 180 wheel horse. now i thought it was someone else who makes it, but right now only Gude comes to mind. i believe it has the whole shebang for the head including cams and an ECU.

i've still never seen a 200whp KA, it sounds expensive. i'm still curious as to see how much i can get out of my latest build, but anything less than 180wheel and i'll be confused.

i wrote all this crap, and you probably have a SOHC, so its useless to you. my new advice is copy everything on that sites spec sheet for 280whp.

You guys are nuts, i personaly have a mag with a 300 HP KA24 that revs out to 10k. Just do some search's on google or ask im sure you'll find a few NA KA's.

Not a dual cam.

Trust me, this site has been in operation for TEN YEARS. If there was a 200+ hp NA KA, we'd know about it.

All claims thus far to the contrary have been PROVEN to be BS.

so you're saying that only the SOHC KA's make good NA power?...i have a DE and plan on intake, headers, testpipe, exhaust, underdrive pulley, electric fan, i have a port and polished head, 264 streetstrip cams, so what kind of power should i expect?...i would think that would put it around 200 right??

niemczykj wrote:so you're saying that only the SOHC KA's make good NA power?...i have a DE and plan on intake, headers, testpipe, exhaust, underdrive pulley, electric fan, i have a port and polished head, 264 streetstrip cams, so what kind of power should i expect?...i would think that would put it around 200 right??

I seriously doubt that you'll see 200hp at the crank. This is just a wild guesstimate based on what other people have dynoed, but I'd say you might be able to crack 170 to the wheels if you're lucky. Most likely you'd need to bump up compression too.

I don't think a race-built single cam KA would be a) very streetable or b) able to last long enough between rebuilds to be practical. Maybe some carbed KA racing engines or ITB setups are out there, but I doubt they're being daily driven.

^ Correct.

Even throwing $10K in mods at a NA DOHC, no one's cracked the 200hp mark.

Boost is much easier (and in this case, cheaper).

The SOHC race motors, as Mojo said, are NOT streetable.

Its probably possible to make 240+hp on an n/a DE, its just all about know-how, money, time, and dedication. Because you are asking that means you probably dont have the knowledge required to do so, but that doesnt mean you cant learn. Start buying books and picking the brains of anyone who might know more than you!I dont think that anything more than 8000 rpms is really even necessary, everyone always talks about the extremely high revving engines but if you talk to the people that work on most n/a racecars you'll see that most dont rev much more than stock. Its all about runner length and size, cams and cam timing, and building intake and exhaust manifolds that all work together. The DE may need some port modification, but i dont know, i havent had a chance to really study a KA head.

We are currently making 235+whp from a renesis 13b with stock ports, stock intake mani, and a stock tb. Its very useable power and people say its impossible to make any more than stock power from an rx8. Stock dyno #s peaked at 167whp.

I mean think about it, there is a GrandAm team making 330hp from n/a honda 2.0liter through a basically stock intake mani. I mean their motor is built but its 330hp at the wheels!!! Its all about R&D. It just helps to have tons of people and large companies with large budgets doing most of it for you.

What sucks is that in the racing world $10,000 is absolutely nothing. That wont pay for the time that most teams put into tunning their $5000+ motecs.

There is someone working on an intake manifold for NA KA's, so maybe we'll see some interesting results from that. Not sure how far off they are on actually producing one at this point.

Well, the problem is you (probably) arent going to break 200hp with any one thing. You need an intake manifold, header and exhaust, and cams. The problem is most people dont realize how important it is that the lengths of the exhaust runners compliment the length of the intake runners. And then if cam lift and timing isnt right on top of that then you still wont see any gains. AND all of THAT would be assuming you can tune the fuel and spark to whatever may be necessary.

All of that would most likely have to be figured for a specific compression ratio too. So pretty much if you change any one thing then you have to do it all. And pretty much everything can be figured on paper but it still only gets you in the ballpark, it just takes trial and error after that.

The same thing applies to all builds, n/a, turbo, or otherwise. Some ways of making power are just more foregiving to poorly designed parts. (IE: Forced Induction)

I am that some one. I forgot to check with greg first before we posted for complete racing, so the thread got deleted.

we're working on a pair of manifolds for turbo and n/a. i am aware that an intake manifold is built for a specific RPM, rather than induction method. However, the difference between the manifolds is the power output potential.

the N/A manifold is a compromise between response and power production, while the turbo manifold is being built for power exceding 700chp. but who cares until we get some out. shoudl have pictures in a few weeks max, we're waiting on some more materials.

to break 200hp in a KA with just intake manifold, cams, header and exhaust would take quite the custom effort. you're absolutely right, the exhaust primary and secondaries should be tuned to the intake manifold plenum and runners, as well as the intake ram. Some one find me a top end power producing header, it doesnt exist yet, everything is built for mid range gains, thats why it works so well with the stock intake manifold.

However, its unfair to say that you "wont see any gains." It's easy to build an intake manifold or header that will make you lose power though, we're still totally in agreement.

compression ratio is actually uninvolved in any intake manifold or exhaust manifold equations that i've seen. its basically length, diameter, reflective value, and effective cam duration.

the KA head definately can using some porting/cleaning up. there are some good head packages for sale that include cams, clover leaf welding, porting, tb, and ecu, and thats in a 210chp head package

so i'm still only reiterating what you're saying. Especially if you change any one thing, you need other things to compliment it, especially tuning. the only reason why we're haivng a hell of a time even making 200hp is because companies dont make parts that work together well. Non one makes an N/A de manifold, no one makes a high rpm DE header, few companies make cams that would even work with these if you could buy them.

and i dont know why you wouldnt think more revs would help you make more power. hp = tq/5252. So, add more revs (very expensive on the KA, think fully counterweighted crank) and make all these exotic top end power adders, throw in a dry sump, and hundreds of other tricks, and you can make ridiculous N/A horsepower figures.

i just dont have over 10 grand to do it

Im not saying that higher revs wont help power output, but its probably not worth the cost and reliability issues you would face. Long strokes mean high piston speeds, not to mention the many other problems. You just said you probably dont have the budget to address most of them anyway, so again we agree

The compression ratio will affect the runner length to some degree, it just may not be enough to matter. More heat and pressure changes the speed of the exhaust pulses both in the exhaust manifold and on their way back through the combustion chamber.

well, you're in luck.

we're gonna dyno test the n/a manifold on my 11.2:1 compression car. we're also going to dyno test it on a stock 240, jsut to see what baseline gains are. we're all eager to see the results.

I'm trying to imply we have to explore higher revs to compete with higher reving low output motors. You could build for as much mid range as you can, but there is always a ceiling of VE.

I dont know what the revs are on that Rebello KA i posted, but since it claims 280whp, im sure they are significant.

look at the specs " * Engine Builder: Dave Auerbach * Manufacturer: Nissan * Type: KA24 * Displacement: 2.4 liter * Induction: Twin Mikuni 44 side draft * Heads: Nissan 12 valve * Block: Nissan * Main Caps: Nissan Comp * Crankshaft: Nissan Comp * Connecting Rods: Carillo * Pistons: J&E * Camshaft: Rebello * Valves: Nissan Comp * Valve Train: Nissan Comp * Clutch: Tilton 2 disk 5 1/2 * Pressure Plate: Tilton 5 1/2 * Flywheel: Tilton 5 1/2 * Exhaust: 4-2-1 * Total Time: 1.2 hrs * Races: 1 "

this motor is obviously built for high rpm use, which is necessary for its claimed 340hp output. obviously this is for a race car, but it gives you a bit of an idea of what you need to go through to build huge N/A numbers out of these.

Especially because this is a carb'd SOHC.

well, whats your definition of midrange? And what kind of rpms are you going to be turning safely? I am talking about staying away from 10,000 rpms like someone mentioned earlier in the thread. I would think something like 8,000 rpm or MAYBE at the very most 9000 rpm would be more than high enough.

EFI and ITBs woudl make the same peak power with a better powerband. Side drafts are cool and everything but they are not by any means the best option.

i believe that motor and some of the Rebello built DEs turn 10,000rpm.

i wouldnt want to spin anymore than 8k on any street KA, and that would still require a serious bottom end build. Im not sure you would even have to worry about the top end other than valve springs. still, im not going to be doing anything liek this. too much money.

they clearly have a serious ignition system on this car, why do you think they consistently choose carbs for this high rpm application? mainly because its easy to tune for WOT and part throttle, easier to maintain, and has some sort of greater power potential that major engine builders use this. i wish i knew more.

i think efi and ITBs arent used due to the level of tuning required possibly?

so basically going NA with a KA is a waste of time. You could make more power throwing on a T25 and running 5psi then you would doing ALL that work.

Cool thing about NA is all that bottom end power ur missing out on with the turbo.

The whole reason i was asking cause it would be cool to build a 510 with a KA thats making like 170ish. It would be a very fun car.

you could make 170whp probably without spending too much. But yes, for the same money you could make more power with a turbo and low boost. With a t25 you arent going to be missing out on any low end power. I think i would go with the t28 though, it will still spool plenty fast.

Keep in mind, people have been shooting for 200 chp on the DOHC KA since 1990. Still hasn't happened.

The head on the DOHC is actually pretty well-designed, very few people make major changes to it - flow bench testing confirms it to be pretty close to an optimal design.

Also, the little things add up - I added a crank scraper and windage tray to mine, coated the internals, and balanced the rotating assembly for more RPMS.

Remember, you can also add displacement. The KA will take a .040 overbore easily, and 0.60 is close to the outer limit.

I would never ever say building a KA for N/A is a waste of time, its just over cost and under developed.

Greg, are you serious about 200chp on DEs? because that would come out to around 175 wheel horsepower. And i know there are definately some 175whp KA's running around. It wouldnt take all that much work to put those kind of figures down.

i just assume you mean 200whp? correct me if im wrong.

For a typical streetable N/A engine it is hard to achieve OVER 200WHP. There would need to be alot of timing advancement as well as retarding the cams to a point to were a streetable idle isn't likely for stop and go traffic.

I believe a few years back there was an N/A KA that made relatively 198WHP to the wheels but it was costly with almost every bolt on, an SAFC and a set of expensive Jim Wolfe technology cams( I believe this was back in 1998)..KA parts are now becoming cheaper such as Brian Crower cams which are about $300 (cheaper than JWT cams were in the 90's), SAFC's have dropped in price, and so have bolt on's due to the surplus of chinese and taiwanese importing.The majority of the problem isn't in the parts, it's in the guy's that spend the additional money to have a shop install all the bolt on's and cams, plus dyno time for the SAFC. All that for bolt on's will run into a range costing about $3500, after labor and parts.For the select few in the forums that are lucky there is the expression time equals money so some chose to give up early anyways....Now if an N/A ka was making 200WHP and was still streetable I would be a very happy guy myself. Especially since newer production engines being honda's K20A's,K24A's, H22's make about 200 CRANK HP, and little to NO torque.

DJpant's I will give you "props" when I see the release of this intake mani, since it could possibly increase flow in the high end of the RPM range which is what the KA definitely needs. Speaking with many engineers that deal with fluid dynamics the stock KA plenum and runners causes the engine to go anemic at very early RPM's relatively 5500RPM. Some have done the math and claim that the stock manifold is a 30HP loss at the crank in higher RPM's exceeding 5500RPM. Maybe with bolt on's, SAFC, Performance cams, and a newely redesigned mani over 200whp can be accomplished with a streetable idle and feel......Right now people look for methods of dropping over weight inertia parts such as crank pulleys, aluminum flywheels and even using electric fans, (instead of belt driven assembly fans) to increase HP in the higher RPM's, but when it comes to an engine that has to over compensate for a crap runner/plenum design the gains on any part are minimal, or just small fractions that were made in the higher RPM range.....The KA head is a well engineered head, and follows much of the same dynamic that the F24, and FJ20e use in there day. Infact I find the KA head to be far more superior than those old school heads just because the KA head uses a pentroof design instead of a hemi design.I say do it DJpant's and prove that there is room in the market place for a well designed performance mani.


Modified by Bigvinnie at 4:29 PM 2/13/2007

I dont wanna say anything about making 200 wheel horsepower. its a scary promise that only a fool would make. I definately need something to control ignition timing. I'm looking into getting an SAFC ASAP. i have one i might be able to use, but it has a burnt out screen....

I may have F'd myself on cams. SOHC pistons in this current rebuild. I'm not sure how much cam timing i can use, and if performance cams are in my future. I should know as soon as i get my bearings in the mail so i can slap her back together.

i'm excited to see this too. its really more scary than exciting. I loved how my prototype felt. I hated my second prototype. So i'm really looking forward to the third design. This is a much better design than the previous two because i have someone who can actually make the shape plenum i never could.

so thanks vinnie, and now you've gotten me thinking some more...

An SAFC isnt nearly enough to really tune an engine. No offense to anyone but this thread just turned stupid. SAFC really???

The new Honda K series engines are making tons of power and way more torque than anyone has even made in hp from the DOHC ka. 230whp and 190wtq can be done with minor bolt ons. Im really not joking when i say that there are teams that are making 320+whp n/a with well over 200lbft from built engines with k-pro ecu's. Bigvinnie here are stock #s:k24a2 (tsx)hp=220@6800rpmtq=166@4500rpm

ka24dehp=155@5600rpmtq=160@4400rpm

Sorry boys, Honda wins, even the H22 in 1992-96 had more.

H22a in the Prelude Sihp=195tq=160Even the doodoo H22a did betterhp=160tq=160

Modified by wankelTII at 6:45 PM 2/13/2007

Modified by wankelTII at 6:47 PM 2/13/2007
Modified by wankelTII at 6:49 PM 2/13/2007

maybe you entirely misunderstood me. I should have put to two thought in a different order.

A safc is plenty to tune for fuel in such a low power N/A application.

But i need a daughterboard at a minimum before i can get the ignition timing to compliment it. luckaly high compression will benefit from the less than optimal ignition timing. it's jsut money i dont have right now.

so, yes we all know that an SAFC isnt nearly enough to tune an engine. But speaking of this thread turning stupid....

random honda stats being posted...

wankelTII wrote:An SAFC isnt nearly enough to really tune an engine. No offense to anyone but this thread just turned stupid. SAFC really???

The new Honda K series engines are making tons of power and way more torque than anyone has even made in hp from the DOHC ka. 230whp and 190wtq can be done with minor bolt ons. Im really not joking when i say that there are teams that are making 320+whp n/a with well over 200lbft from built engines with k-pro ecu's. Bigvinnie here are stock #s:k24a2 (tsx)hp=220@6800rpmtq=166@4500rpm

ka24dehp=155@5600rpmtq=160@4400rpm

Sorry boys, Honda wins, even the H22 in 1992-96 had more.

H22a in the Prelude Sihp=195tq=160Even the doodoo H22a did betterhp=160tq=160

Modified by wankelTII at 6:45 PM 2/13/2007

Modified by wankelTII at 6:47 PM 2/13/2007

Modified by wankelTII at 6:49 PM 2/13/2007

SAFC and VAFC's are used for tuning I have enough knowledge that I actually help tune my friends Honda H22 (SI PRELUDE). Just with a VAFC, my friend Rollyn was able to make an additional 5HP at the wheels, that would be adjusted to about 8 additional HP at the crank. In the middle of the power band there was an 11HP spike gained allowing the engine to run much smoother, SAFC's and VAFC's do work.....Unlike most people in the forums I don't talk out my A$$ and as you can see H22's don't make close as much torque as a KA24de. Thats the bottom line.You can wright any stock numbers you want on paper, I want graphs at the wheels...LOLMy boy Rollyn's H22 prelude, bolt on's and VAFC...The first dyno run was before the VAFC the second was after the VAFC was tuned. It's all the same technology accept VAFC's also have Vtech controller installed. This VAFC was tuned to run slightly leaner than stock to make the additional numbers, just as a SAFC does, and KA's run a bit on the rich side so there is plenty of room to tune to stoich, so that ignition timing for stock is more evenly matched...

BTW we run head up at infinion raceway for me having such a short power band....LOL

Now here Scott's infamous dyno with just header, cat back, pulley, and a JWT ecu tune. compare for your self the KA engine makes more power across the board with a shorter power band and a larger degradation loss to the rear wheels...That's also not including simple facts that honda uses electric fans, while our KA24de's are strapped with a belt driven fan that consumes losses in HP as well. By far the KA24de engine makes more power at the crank...

The only one relating to anything stupid in this thread is you Mr.WankelTII.......


Modified by Bigvinnie at 8:47 PM 2/13/2007

My auto shop teacher spent 100K on his sohc S14 which has about 300 rwhp. I had a pic of it but I lost it.

Vinnie, GREAT info.

DJ, there's a local here in town doing ROM tunes on the S-chassis ECU's - You guys should get together.

Save the SAFC for the kids, you're gonna need timing adjustment if you're chasing the 200hp mark.

Again, I think a fat overbore is an overlooked possibility on these engines, combined with increasing the CR.

Throw in some alcohol / methanol injection and you might be on the right reack.

Any chance i can get his e mail?

AZhitman wrote:Vinnie, GREAT info.

Save the SAFC for the kids, you're gonna need timing adjustment if you're chasing the 200hp mark.

Again, I think a fat overbore is an overlooked possibility on these engines, combined with increasing the CR.

Your right SAFC's are kiddie toy's. I just had to prove that they make power thats all. It is crude tuning and the hours that are spent on the dyno can be ridiculous, widebands speed up the process, but still too many hours are spent on the dyno.If anything I would rather tune BikiRom, but it is still in it's infancy stages and does have small flaws that are getting worked out.I found out that using iridium plugs, I can advance the crap out of the timing through the distrubutor, right now it is at about 32BTDC, thats a 12 degree advancement from stock (20BTDC) and no detonation. AGAIN crude tuning and NOT recommended for the faint at heart and it does raise the EGT my coolant temp gauge is up 2/3 the gauge instead of 1/2 of the gauge. There is slightly more knock noticed on the SAFC as well, SAFC's are GREAT monitoring devices.

The only reason I don't agree with an overbore is because the KA engine is almost bored to it's MAX, the fullest bore would still be under 2.5litre's, without increasing stroke to the crank.I've been trying to explain to people that the best route to go would be to clover leaf weld the head to maximize compression while still using stock pistons, and a extremely high lift performance cams (up to about a 13.1:1CR and PERFORMANCE cams with high lifts and duration's is what is really needed to use the full CFM of the KA head). I always recommend the the crank scraper by ishihara/johnson for the bottom end.... Scrapers work wonders for the bottom end, great alternative since there is no fully counter weighed crank available. Just my 2 cent's.

i'm surprised more people havent cut up two KA cranks, and welded it back together slightly destroked. I've been looking all over to try adn find someone who has done it, but i cant find anything.

jsut so you know what im saying, each crank has four counterweights. and then there are four sections without counterweights. So cut up two cranks, and use only the counterweighted portions.

Physically it looks like it would work, its jsut the precision involved as well as the need for a knife edge and serious balance afterwards. Not to mention the clearancing you probably have to do to the block. BUt as long as you are welding the journals back in, you can destroke to whatever.

it would cost at least over 2 grand to get this done at a shop, so it definately isnt worth the investment. But i know someone has to be screwing around with this somewhere...

i'm sure the reason no one has done this is because its probably WAY easier to modify an L20B crank to fit. As long as this thread is gonna get extremely off topic..... anyone know?