do tell the battles on the s12 board of the KA vs sr battles 
a"nd in fact I’ve been waving your flag on the S12 site in our raging SR20DET vs KA24ET wars there. "
just to add fuel to the SR vs KAT battle… to sum it up (i can show you mathmatically as well )
basically its as simple as this…
The RPM advantage that the SR has does not outweigh the DISPLACEMENT advantage that the KA has.
thats why the KA is a superior platform for performance…
let the battle begin…
just for fun here is my conclustion from a battle we had on NEO
“THE 700RPM ADVANTAGE THE SR HAS OVER THE KA, DOES NOT OUTWEIGH THE 400CC ADVANTAGE THE KA HAS OVER THE SR”
Note: I did the split at the same time you re-posted ADAM, but i’m going to keep this one.
hmm … let me see what I can link to here.
But most of it was the same … except a few more technical advantages.
Like the iron block, (I was told the SR is an alloy)
Availability ($200 for a KA24E)
Crank girdle
longer stroke, more torque
More displacement = more air
Better intake design
A few guys on the site went ahead and did the SR20DET swap and ended up not being much faster than they were with the CA18ET … just a lot poorer.
And considering 300+ whp is very possible out of the SOHC CA18ET … the argument for swapping an SR20DET in its place was getting pretty weak.
But then again, we also have an Australian member into the 10s on a stock block FJ20ET … over 500whp. And that’s for real, not a “internet myth” the magazine article about his car (fastest in his class in Australia) is bed time reading for most S12 owners. Too bad we never got the RSX here.
Too bad they’re harder to find than un-riced CRX.
its all in the math…once you see that its a simple choice …IMO
SR 118ci engine 7200rpm, 4valves/cyl design
KAT 142ci engine 6500rpm, 4valves/cyl design
SR=118ci x 7200RPM x 0.5 x 80%VE/1728=196.6 base CFM
KAT=142ci x 6500RPM x0.5 x 80%VE/1728= 213.7 base CFM
just so you know… the 0.5 is due to the engine being a 4 stroke…the 80% volumetric efficiency is guessed…but being that BOTH of these engines are 4 valves per cyl they will be very close…
so what does this tell us? basically that in a NA form the larger displacement engine flows more air than the smaller displacement higher reving engine…
what we can’t see is that the larger displacement engine will have more power and torque under the curve, have more reliability due to its lower operating RPM range…and its ability to power a larger turbo due to a higher base flow rate.
so right off the bat in an unmodified flow form the KA will outflow the SR by about 8%…that means 8% more air to burn gasoline…
you can play with the numbers to see at what level the SR starts to win out over the KA, and vice versa…same goes if you boost the engines…
pick a boost level… eg 15psi…find out what pressure ratio that is…
15+14.7/14.7=2.02 PR (pressure ratio)
then take that 2.02 and times that by the base CFM
in the case of the SR its 397.13 CFM
in the case of the KA its 431.67 CFM
as a APPROXIMATION it takes about 1.5-1.6 CFM of air to generate 1hp (actually to allow the gas to combust) at this simple level we are not taking into account density varables…nor need we since we are just discussing 2 motors under the same conditions
SR=approx 264hp
KAT=approx 287hp
anyway it gives you an idea of the RELATIONSHIP between the 2 engines…and thats what we are really after…
Let’s not forget the SR20 was mentioned in F&F … that’s worth like 1,000 points right?
actually dave is the only one doing the right swap out of all of us…
the 5.0…ohh yeah baby…
IF it does not effect the handling too much…
Adam you’re such a sh!t disturber I though that this topic was banned…
You forgot to mention that in your quest for power you have destroyed how many engines? How many dollars has that cost in machining alone? If you cunted labour?
I applaude you for your persistance and your car is fast as fu(k but it’s been unreliable as hell too.
Sure my SR coupe is almost stock, except for a nice FMIC and 3" exhaust. I estimate I’m running ~200rwph. I’ve run a couple of track days, run and won a road rally series, and it’s been my every day driver for over a year ~26,000km of trouble free motoring on 91-94 octane gas.
This is the true advantage of the SR, it’s designed as a turbo motor, in stock, or even close to stock form it’s extremely reliable. Now watch me go lean and burn a piston on the way home
-Martin.
can you repeat that please… the last two words especailly… haha
adam, if you were a bit younger and sexier i’d switch teams for sure…
i’m no hardcore math-dude, but those numbers are wicked…
me thinks i should use them as reference when anyone bashes the KA… not that i realy car, but the ignorance it takes to dimiss it as a truck motor…
i have made reference and linked to your vehicle many times, in defense of the Ka along with Phil’s and Ken’s.
good thing i took pics at shannonville last year
If you cunted labour?
hey hey…i am not a pimp here
no whole motors yet…just one head due to an engine fire…and one blown head gasket due to no engine management…plus some melted stuff…it was ol anyway so its probably better i melted it.
you remember that i shot-gunned the first ride at shanny-ville this year
Quit picking on my honest spelling mistakes :oops:
-Martin.
does it really matter which one is really “better”?
let people do whatever they want. if they have the money, and want to go a certain way, then that’s their decision…
i know this whole thread is just food for thought, but still. i think the KA is a damn good engine, and i’ve considered turbo-ing one off and on. (then again, i switch engine plans more then a sugared up hummingbird)…but i’ve been an SR fan since '97 and it’s still what i keep going back to time after time. not because i want to look “JDM 7y73 y0”, but just because it’s a good engine, i know more about it then the KA. doesn’t mean the KA isn’t good in it’s own respect.
certainly isn’t a truck engine, that’s for sure. (although Marc’s sounded like one for a while… 
)
I’m not a hardcore car guy, but from all that I’ve read, the KA just isn’t a
‘great’ turbo motor. It’s got the displacement, but its internals are weak.
So if you want to turbo the KA you can, but you will have to spend more
money into rebuilding the bottom end. You can still buy a kit or something
and safely run 5psi on the KA and it will come to a stock SR, but if you
want more power, you wil have to spend more on upgrading it.
I just want cheap power, and the SR seems to be best bet. The SR is also
becoming so mainstream that parts are also getting easier to obtain. I
can honestly say that I can easily get my (long term) goal of 300rwhp with
the SR, then I can with the KA.
If the KA was so great, everyone would be turboing it. :roll:
SR can take more boost than the KA stock, but for the price of an SR you
can build the internals of the KA.
They are both engines with good potential. IMO the SR is better for drifting
because of its RPM range and smooth reving qualities. Thats what I am
building my car for, so in my case the SR suit better.
Oh yeah, the SR is JDM tyte, cant forget that.
Hmmm, SR20DET vs. KA24ET…interesting. What happens if the lowly CA18DET is thrown into the mix? Let’s see…
The stock rev limiter on the CA is set at around 7200-7500, however, assuming that the engine is just broken in (very little wear), the engine is more than willing to go to 8500rpm with no modifications. So using 8500rpm, I come up with this:
CA 110ci engine 8500rpm, 4 valves/cyl design
CA= 110ci x 8500rpm x 0.5x 80%VE/1728=216.4 base cfm
216.4x2.02=437.2cfm
CA=292hp
I do realize that since I did use a different rev limit than stock, the above calculations aren’t really valid in relation to ADAM’s calculations. With the rev limit set at 7200rpm,the numbers would be a little lower than the SR.
However, who is going to keep any of these engines stock? I don’t know alot about the KA24E/DE, but I will now try to compare the SR and CA with 1mm overbore and upgraded valve springs.
CA (1mm overbore) 84mm=1853cc=113.1ci
SR (1mm overbore) 87mm=2045cc=124.8ci
CA with upgraded valve springs=9000rpm rev limit
SR with upgraded valve springs=8000rpm rev limit
CA=113.1ci x 9000x0.5x80%VE/1728=235.6 base cfm
SR=124.8ci x 8000x0.5x80%VE/1728= 231.1 base cfm
Now, using the 2.02 pressure ratio,
CA=475.9 CFM
SR=466.8CFM
Approx Power:
CA=317hp
SR=311hp
yeah but isn’t this comparission based on the highest rev while still gaining power (redline) not the limit, and since when does the SR need to be modded to reach 8000rpm? I thought the stock cut off was that if not higher.
Sorry. I was trying to make the CA look good. I guess it really isn’t. Bow down to the KA24!!!
I thought the rocker arms started popping off at around 8000?
Anyways, sorry for screwing up the thread. 