Boost limits on the KA

[TwinTurbo]

Im looking to do some work to a KA and was wandering what the limmit is to the factory bottom end. I read somewhere that the all the majior components are forged so i would imagine it would be good for 12-15psi safely. Let me know if im in the ballpark. Im new to Nissan but not to FI so hit me up with the facts. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''>

[daywalker]

which ka?
anyways the ka24de is good for like 7-9 with the blue top 300zx injectors and depending on the turbo.rods are good till like 400hp and the crank from what i heard is good for 700hp or more.
it all depends what u use for a rebuild or if u lighten stuff.
i ran 17 psi w a t4 and 50lb an hour injectors w the 4 bar fuel press @ idle program running the cobra maf meter from jim wolf and no problems just gobs of power all the way till 8k rpm.
just upgraded to 70 lbs an hour injectors didnt test the car yet, but w race gas 20-23 psi should not be a problem

[dsjunkie]

wait a minute....what do you got?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'> &nbsp;super crank?!?!?!?! &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=''> look i'm not trying to be mr jerk here but your numbers just dont sound right....i mean the pistons ok i guess i'll give you that, i heard that they're good to APPROXIMATLY 330hp but the crank good to 700<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>? &nbsp;i've heard it's more like good to APPROXIMATLY 450hp....i know i said approximatly because i'm not exactly too sure if these numbers are correct but they came from a fairly reliable source so i go by them....basically i take them as truth, not as the word of God though.....somebody help me here...are my numbers wrong or am i more in the ballpark here?

[S13Grl]

WTF?!?!?!

Stock head will NOT handle more than 10psis AT THE MAX!!!!

Crank will be in danger after 450 hp.



Please don't post stupid info, guys. No offense to anyone...

[DuffMan]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (S13Grl @ Mar. 15 2002,01:38)</td></tr><tr><td id="QUOTE">WTF?!?!?!

Stock head will NOT handle more than 10psis AT THE MAX!!!!

Crank will be in danger after 450 hp.



Please don't post stupid info, guys. No offense to anyone...</td></tr></table><span id='postcolor'>
Huh? Do you mean stock pistons? Stock pistons yes, they wont take much more than that, at least not for a while.

[daywalker]

the reason y i said that about the crank its because i know a couple of guys that run like 25 psi w secondary injectors in the ic pipes, and huge turbos.
they told me their output is close to over 600 @ the rear.
thats y i said "from what i heard of".
i put down a little over 400 @ the rear w unorthodox racing pulley on. guess what my crank is still fine.

[HippoSleek]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (daywalker @ Mar. 14 2002,08:28)</td></tr><tr><td id="QUOTE">the reason y i said that about the crank its because i know a couple of guys that run like 25 psi w secondary injectors in the ic pipes, and huge turbos.
they told me their output is close to over 600 @ the rear.
thats y i said "from what i heard of".
i put down a little over 400 @ the rear w unorthodox racing pulley on. guess what my crank is still fine.</td></tr></table><span id='postcolor'>
WHO?

I know there is one person upwards of 400 whp on stock internals (Deleted Member/ D21 Hardbody Beater/ TY) (w/ lots of work in it) and one person that was boosting and spraying with a totally rebuilt motor (Duy). &nbsp;Name some names or the BS flag will be flying quick!

For the original poster: a search will reveal info on both of these set ups... to most people recognize TY as the highest hp stock internal car and Duy's old car as the fastest 240 in the US.

[AceInHole]

Duy's car's "totally rebuilt motor" was pistons and rods. &nbsp;Stock crank, stock head, stock cams, you get the point.

Ty's car with "lots of work in it" is the prototype FMax Stage II kit (the newer kits might actually be a bit "better"), Apexi GT exhaust, a single '91 cam with one stock cam for less lag (forgot which was where... pretty sure the exhaust side was the '91), and ignition (HKS twin spark or something??). &nbsp;That's pretty much all he has done to it. &nbsp;AFAIK, he hasn't done dyno tuning or anything, just upped the boost, slapped it on a dyno, saw what he got and kept it there. &nbsp;From what I've seen, almost all of the work Ty has put into his car is to stiffen it up with ladder bars, cross bars, etc.

So:
S13Grl is really wrong: the stock head handles over 600hp
Dsjunkie is also wrong: the stock crank also handles over 600hp. &nbsp;
Duy's car is the base example. &nbsp;The Nasport and Sunbelt KA's also use the stock crank with some preparation to rev to 7500+. &nbsp;The only thing bad about it is that it's only half counterweighted, which doesn't necessarily apply to strength.

[S13Grl]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (AceInHole @ Mar. 15 2002,09:47)</td></tr><tr><td id="QUOTE">So:
S13Grl is really wrong: the stock head handles over 600hp
Dsjunkie is also wrong: the stock crank also handles over 600hp. </td></tr></table><span id='postcolor'>
Ross,

Are you seriously trying to tell me that stock KA pistons will survive up to 600 horses?

[97S14]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (S13Grl @ Mar. 14 2002,11:38)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (AceInHole @ Mar. 15 2002,09:47)</td></tr><tr><td id="QUOTE">So:
S13Grl is really wrong: the stock head handles over 600hp
Dsjunkie is also wrong: the stock crank also handles over 600hp. </td></tr></table><span id='postcolor'>
Ross,

Are you seriously trying to tell me that stock KA pistons will survive up to 600 horses?</td></tr></table><span id='postcolor'>
</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Duy's car's "totally rebuilt motor" was pistons and rods. Stock crank, stock head, stock cams, you get the point.</td></tr></table><span id='postcolor'>

S13Grl: He stated that the pistons and rods were replaced, and the head can handle over 600hp. &nbsp;He didn't state that the stock pistons can handle over 600hp.

[S13Grl]

I never said that the cams weren't good after 10psis. I was talking about pistons, rings and rods and the bearings.

[97S14]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (S13Grl @ Mar. 14 2002,12:01)</td></tr><tr><td id="QUOTE">I never said that the cams weren't good after 10psis. I was talking about pistons, rings and rods and the bearings.</td></tr></table><span id='postcolor'>
The pistons, rings and rods and the bearings are in the block, below the head. &nbsp;The head consists of the valvetrain/cams, intake/exhaust chambers and so on.

[AceInHole]

lol.... i was about to say that. &nbsp;yeah... make sure your talking about the right head... like, you can go to the head.. or get ****....

[DuffMan]

You said stock head. Duy has a stock head. I've never thought that pistons were considered part of the head.

So are you talking about the pistons or the head, s13grl?

[AceInHole]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (DuffMan @ Mar. 13 2002,3:07)</td></tr><tr><td id="QUOTE">You said stock head. Duy has a stock head. I've never thought that pistons were considered part of the head.

So are you talking about the pistons or the head, s13grl?</td></tr></table><span id='postcolor'>
she's talking about the bottom end... stuff BELOW the head.

[S13Grl]

I'm sorry, I should have phrased myself correctly. The stock crank can handle up to 450hp, guaranteed. Cams, valves, springs, and whatnot can handle the same if not even more. The pistons & rings, rods & bearings cannot. Sorry for the misunderstanding.

[AceInHole]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (S13Grl @ Mar. 13 2002,3:25)</td></tr><tr><td id="QUOTE">I'm sorry, I should have phrased myself correctly. The stock crank can handle up to 450hp, guaranteed. Cams, valves, springs, and whatnot can handle the same if not even more. The pistons & rings, rods & bearings cannot. Sorry for the misunderstanding.</td></tr></table><span id='postcolor'>
Still a misunderstanding: just like the crank: the rods are forged. &nbsp;They'll hold for a pretty decent HP (and you know my definition of decent.... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=''> ) &nbsp;Also... the crank bearings should be fine... so long your oil isn't messed with.

[importcargarage]

Most engine builders will tell you that "IF" you race prep the stock rods they are good to 400-450hp. That means stress relieve, magniflux...... Anything over that and Sunbelt, Top End.. Malvern will all say go to aftermarket rods.

There are a few tricks the engine builders are using on the bearings to aid in better oil flow, they are adding a second and or a third groove to aid in oil retention around the bearing. Both Chris May and I were victums of stock bearing replacements and had failures.

The KA crank will hold a lot of power but everything else needs to be right too! I set my top hp bar at 400 and see little need to go higher for a daily driver. I have 5K miles on my Stage III engine and it is performing flawlessly.

[daywalker]

I have one name for u guys . Kenji Sumino @ greddy .
He was the first ka tbo w a rebuilt motor. He was on the cover of turbo magazine like 4 or 5 yrs ago. At that time he put down 396 to the ground running the 4 bar fuel press prog from jwt. Later on he put the secondary injectors in the ic pipes controlled via rebic 3 sim. After that he got his nos setup from jwt w the piggy back ecu to controll it. He needed nos to spool up his t-67(might be t-66) turbo.
He dynoed it and from what i remember it was either close to 700 whp or above.
So he went drag racing put on nitto drag radials warmed them up put some of that neo sticky crap on his tires too and launched. Guess what?? He found the weak link on the 240. The input shaft in the tranny went bye bye. He sold his car to his buddy mike @ greddy and the car is still running strong he only had to replace the distributor cuz the gear cracked on it.
Oh he ran like 27 psi on race gas.

[AceInHole]

Apparently Duy's car ate trannies for breakfast too.... I'd have to wonder if it'd be worth it to swap to an SR bellhousing and bolt an SR tranny to the KA.....

[daywalker]

i dont drag race so im not worried. i usaually race on the highway.
thank god my tires are not too sticky and just spin through 3 gears <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''>

[daywalker]

oh by the way the head has no limits on how much power it can take.Just how much power u can make and how high you can rev.
the head gasket is the thing that lmits hp.
BCE did my head and i usually shift @ 7,600 rpm.
JWT just got some new cams out w less overlap. They say 20 hp or more @ the top end.
I got mine just not installed yet, ive been lazy.
ill let u guys know ill dyno them before and after.

[BlackS14]

I thought the Sr and Ka trannies were one in the same..or was it the bell-ousings....oh well

Most of your "fully built" Ka motors you'll see consist of just some higher in strenght rods and lower comp. pistons. Exceptions are of course Chris Mays car and some others who have fully prepped race motors from Sunbelt, but other than those few. most of your rebuilding is done in the block...pistons and rods.

I've seen upwards of up to 27 psi and above on some Kas who only had the above upgrades as mentioned above. Jay(PSI240SX) runs 20psi daily on his built KA.......nice!!!!

When I do my "rebuild", that's all I'm doing to mine besides for the other precautionary stuff....leakdown test, ect.

...then again, all I want is a good 300 to the wheels andI'll be happy

Bill

Well it sounds like from the jist of things a well tuned system can do up to 15psi no prob. Im looking to break that fastest 240 in the US record eventualy. Oh yea what is it?!?! Ive worked on manny crazzy fast and high $ motors and i think i want an all out race car. It seem like the Ka24De will work for me. Its a little heavy but ive had bad luck with alluminum blocks and high boost levels being the slightest bit reliable. If you ready to throw up the B.S flag just wait and see. Ill do it! gimme a year, maby 2 but ill do it. After all i managed to build an 11sec daily driver for myself out of an 89 dodge daytona.

[mbmbmb23]

This guy snapped his driveshaft on his car.......SR I think tho.


http://www.back-yard-productions.com/HUGH.htm