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View Full Version : Max Boost on stock KA internals


nissandrifter
01-07-2003, 07:09 PM
I read somewhere the KA24DE could only be run up to 7psi safely if using the stock internals, but this one guy says he is running 10psi with no problems. Right now I'm deciding between SR and KA, and I don't plan on upgrading internals for a while because Im gonna use the car as a daily driver, so what do you think max boost is on stock internals?

240racer
01-07-2003, 07:25 PM
you can run 10psi without problems if you don't detonate. Detonation is the key, if it happens no matter what boost you are running you will have problems. BTW, it doesn't do the SR or good pistons a lot of good either. The pistons are the only real weak part of the engine, it is the only thing you need to upgrade for a while. I would just plan on running about 7 or so for a while and get comfortable with everything, that is going to cost a fair amount anyway, I wouldn't jump in with 10.
Make sure you have larger injectors and a good fuel pump, the walbro 190 can be used with the stock pressure regulator (according to my calcs, anybody know otherwise?) if you plan on going with more then 700cc/min inj in the future then get the 255. The 190 will make a lot of power.

Potatoskins02
01-07-2003, 07:29 PM
I've seen one running about 12 psi.... although his piping wasn't all that great so i think it would drop to about 10psi or something like that. he did have however upgraded injectors and fuel pump which 240racer mentioned to be a must have upgrade.

DarkRaptor42
01-08-2003, 10:52 AM
The KA can and will hold up to 17-18 psi. I have seen Dynos of one that ran that. Cant remember the guys name but if you do a search they are on here somewhere. Like they said though the key is not to detonate. Im setting mine up to run 12 then rebuild it sometime but thats enough for now. 12psi on a KA is a hell of alot faster than 12 on an SR. Keep that in mind when making your decision.

240Stilo
01-08-2003, 12:38 PM
Wasn't there a thread recently about someone who had boosted 17psi on a T3/T4 and detonated because there wasn't enough fuel going in? I would look for it and post but.....eh....i'm lazy right now.:p

Foxcolt
01-08-2003, 01:59 PM
Originally posted by DarkRaptor42
The KA can and will hold up to 17-18 psi. I have seen Dynos of one that ran that. Cant remember the guys name but if you do a search they are on here somewhere. Like they said though the key is not to detonate. Im setting mine up to run 12 then rebuild it sometime but thats enough for now. 12psi on a KA is a hell of alot faster than 12 on an SR. Keep that in mind when making your decision.

Aish:rolleyes:

And I assume you think that the more PSI you have the more power you make right?

Mark & Irena
01-08-2003, 02:23 PM
You can do 10-11 with high-octane gas. I'd also use octane booster.

uiuc240
01-08-2003, 02:26 PM
So true, Jed. These dudes just don't get it, man. PSI is not all there is to making power. Once again, my T25 at 12psi will only flow...ummm...prolly about 300 CFM. I have no idea...no maps. Point is, if a T3/T4 is built with big enough wheels, it could put out DOUBLE that amount of air at 12 psi. CFM is clearly more important than PSI. But they are interrelated due to temp/compression/etc. But given equal PSI, more CFM will make more power. And almost EVERYONE with a KA turbo uses a T3/T4, while most SRs are using T25s or T28s...much less flow.

So for that reason, you're right DarkRaptor. But if you put the same T25 on a KA that I have on my SR...expect similar results from both engines. In fact, the T25 would be a very poor match on the KA, but I'm just illustrating a point. You're comparing apples to oranges. PSI to PSI is rarely ever the same. Only way to compare something like that is if you and i both had SRs with very similar mods, except i had 12 psi and you had 7. That would be comparable (as in, able-to-be-compared). But not a 12 psi T3/T4 KA and a 12 psi T25 SR. Get it?

Eric

240Stilo
01-08-2003, 04:23 PM
Any idea how much CFM was being made from the T3/T4 that Jeff240sx (i think thats who it was) was using before his KA detonated?

Kreator
01-08-2003, 05:45 PM
lol Eric, you should've just posted the link :rolleyes: But fine i'll do it :D

BAAAAAAAAAAAAAAAAAH (http://www.zilvia.net/f/showthread.php?s=&threadid=19582)

misnomer
01-09-2003, 12:39 AM
Hey, Jeff240sx, wanna field this one?

Sorry man, but who knows the max boost on KA internals better?

Foxcolt
01-09-2003, 08:13 AM
It's not really about max boost. It's more about max power compared to the system your using. I suspect your talking about your average t3/t4 jwt ECU KA setup.

You CAN run crazy boost/power levels on any stock internal motor....with the right tuning. Most people who blow their motor don't blow it because they were running to much boost (in a sense) they blew it because they detonated due to too much power and a lack of fuel to handle it.

That said if you really want to find out how much boost your perticular setup can handle then your gonna have to hook your car up to a dyno with an a/f meter. Try the run at different boost levels and check out what the meter reads. That way you will have a good idea of the capacity of your fuel system.

I don't know what power level KA internals can handle safely. But I'm sure someone can chime in. I just wanted to make you aware of what exactly you were asking.

DarkRaptor42
01-09-2003, 11:15 AM
And I assume you think that the more PSI you have the more power you make right? [/B][/QUOTE]

I never said that. The guys dyno charts were on here not to far back and he had a t3, not a t3/t4. I know its not the PSI that makes the power but the CFM. And as I tried to say, you can run pretty high boost assuming like you also said, have the proper tunning. I run a T3 at the moment and have no problems with it, but I know if I went to a t3/t4 Id need to adjust to it. Also jeffs car blew up because he made a huge detonation in it when his acctuator line popped off. He didnt hit the "Max Boost" rather he had too much air and not enough fuel. In my opinion however, the KA is a very strong engine that can handel some pretty high boost as long as you are smart about it and know what you are doing.

Kreator
01-09-2003, 12:47 PM
Ok dude, relax. You shouldnt've been picking on the sr guys in the first place. They get pissed fast we all know that :rolleyes: j/k. Anyways. Everyone understood what you meant, except you said it the wrong way and got itsy bitsy flamij yer way.

On the other hand, all the KAs that run 17-18 psi on the dyno are just doing it on the dyno. Try running it every day and pretty sure you'll detonate very fast. Even boosteds14 who i think got up to almost 30psi runs 6psi daily driving (i think... from what he told me long time ago lol). Daily driving i think you are safe at 10psi and 12 is pushing it.

DarkRaptor42
01-09-2003, 02:07 PM
id agree with that.
I wasnt getting upset though.

uiuc240
01-09-2003, 02:23 PM
Originally posted by Kreator
itsy bitsy flamij yer way.

hahahahah. That was awesome. We need a little flaming smiley. http://www.nevac.nl/flensjes/images/smilies/flame.gif

Eric

PssshhhMr2
01-09-2003, 10:06 PM
Originally posted by Mark & Irena
You can do 10-11 with high-octane gas. I'd also use octane booster.

Don't bother spending money on octane booster from an auto parts store. It raises your octane a maximum of 7 points, meaning your 92 octane goes to a rating of 92.7.

Spearco sells a pretty inexpensive water injection system that will cure a detonation problem, but don't use water injection as a bandaid, make sure the car has an efficient enough intercooler first.

some guy
01-09-2003, 11:14 PM
What about adding toluene (sp?) to the gas, i heard it raises the octane significantly. (never tried it myself) will it hurt the car or the engine in the long run?

DSC
01-09-2003, 11:40 PM
http://www.geocities.com/pichound2000/toluene.html


"Q: Will toluene damage my engine or other parts of my car?

A: A 5 or 10% increase in the aromatic content of gas will most likely be well within the refining specifications of gasoline defined by ASTM D4814, which specify an aromatic content of between 20% and 45%. What this means is that if the 92 octane gas that you started off with had an aromatic content of say 30% and you increased it by 10% to 40% you would still be left with a mix that meets the industry definition of gasoline. So the above question would amount to: "Will gasoline damage my engine or other parts of my car?"

Even in the unlikely event that the 92 octane gas has a aromatic content of 45% the resulting mix would still be within the bounds of gasoline sold in other countries. "

d240t2
01-10-2003, 03:51 PM
The KA will easily handle 10-12psi. I am running 15psi with no problems, but I know I am on the edge.

Larger compressor does not necessarily mean more air at the same pressure. The amount of air is only a function of engine size, pressure and temperature. If the compressor is larger, it tends to be more efficient for higher boost levels, making the temperature lower. That gives you more air. That isn't a huge power adder, however. The reason you get more power from a larger turbo at the same boost is the turbine section, which is more free flowing and therefore increases the VE of the engine.

93 octane pump gas has never detonated on me at 15psi of boost. You would be safe on 10-12psi with 91 octane forever, as long as you don't overboost or have some catastrophic failure which causes you to run lean.

And, IIRC, the guy who ran lean at 17psi and blew his motor didn't have the fuel setup for it.

Dennis

PssshhhMr2
01-10-2003, 05:42 PM
Pressure and flow are directly related - Therefore you can not flow more air at the same pressure.

d240t2
01-10-2003, 08:25 PM
Pressure and flow are directly related - Therefore you can not flow more air at the same pressure.

That doesn't make any sense. Even the simplest gas equation has volume as a function of both pressure and temperature. Flow is just some extensive value (volume, mass, moles, etc.)/time.

Dennis

240racer
01-11-2003, 03:48 AM
Originally posted by d240t2

And, IIRC, the guy who ran lean at 17psi and blew his motor didn't have the fuel setup for it.

Dennis

yes you are correct, he was only planning on running a little over 4 psi and his wastegate line came off, so it overboosted. He was just running stock injectors, fuel pump and MAF.
I don't know how the 9.5:1 comp pistons would like 17psi on less then race gas either, hopefully I'll find out sometime.

Dennis - What MAF and injectors are you running at 15psi?

DarkRaptor42
01-11-2003, 10:26 AM
240racer what boost are you running? and what compressor?

Jeff240sx
01-11-2003, 04:39 PM
Yo. I blew up my car, and need to get rides everywhere. I stay at friend's houses, cuz it close to campus... so sorry I couldn't get in here earlier.
Yea, I didn't have my fuel tuned at all... at my wastegate line blew off, leaving holes in my pistons. The size ranged from a dime sized to a quarter sized hole in the edge.
I am pretty sure T.Y. has ran to 18psi on a fully tuned fuel system, and put down 350+ hp to the wheels.
But yea, as far as the stock pistons, they are allright (hypereutectic (sp?)) but have very thin ring lands, and slight detonation on boost will blow them apart quickly. I went 80 feet before the car was destroyed... and that was after the 1-2 shift (auto tranny...) then a big loud BOV noise, and then smoke comming out, and zero compression.
So... you can go up pretty high on stock pistons, but you'll need extreme management and fuel. I don't remember T.Y.'s AF, but I think it was under 11:1
-Jeff

d240t2
01-11-2003, 05:51 PM
Originally posted by 240racer
Dennis - What MAF and injectors are you running at 15psi?

50lb MSD injectors, UH fuel rail, JWT ECU, Granatelli Cobra MAF, stock FPR.

Dennis

240racer
01-12-2003, 12:42 AM
Originally posted by DarkRaptor42
240racer what boost are you running? and what compressor?

about 8psi with the toyota CT-26 turbo

DarkRaptor42
01-12-2003, 03:12 PM
thats awesome to run a 14.1 with that set up