Found boost limit on stock bottom and fuel, KA-T

[Jeff240sx]

Ok.  I lied.  I found out where I couldn't boost to.  17psi.  Nobody with a stock block and fuel system try to boost to 17 psi, ever.  My wastegate line kinda came off somehow, and now, I am shopping.  It went really, really fast up until 40 miles per hour, right after the 1-2 shift, when the BOV blew off, and then smoke poured out of my hood.  My PCV valve is blowing smoke, and my car won't start, and I have ZERO compression in all four cylinders.
-Jeff

[ca18guy]

damn, 0 compression in all of them, you really busted up that thing.

[Bbandit]

holy crap.. now you have to sell your car really cheap!!
email or pm me.. i'll buy it for 1000 dollaaaa &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'>
j/k

dude why are you running on 17psi? 0 compression?
you busted up all of the piston rings i guess.. or your headgasket?

[uuninja]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Bbandit @ Dec. 14 2002,8:28)</td></tr><tr><td id="QUOTE">holy crap.. now you have to sell your car really cheap!!
email or pm me.. i'll buy it for 1000 dollaaaa <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'>
j/k

dude why are you running on 17psi? 0 compression?
you busted up all of the piston rings i guess.. or your headgasket?</td></tr></table><span id='postcolor'>
Re-read the part about his wastegate actuator hose comming off. It was not on purpose.


Jeff, sorry to hear about your car. Any plans for repairs or replacements?

-Matt-

[datkwikracer]

wow that sucks, Jeff <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sad.gif" border="0" valign="absmiddle" alt=':('>
(sniffs)
i feel (sniffs again) for you let us know how repairs go

[DarkRaptor42]

wow man that really really sucks.... any reason as to why the acctuator line blew off? I dont even know where to start to tell you how shitty that sounds. Let us know what your gonna do.

[uiuc240]

Oh damn, Jeff. &nbsp;That totally sucks ballz. &nbsp;Well, look at the bright side. &nbsp;Now you can just get a new KA and a 5speed all at once. &nbsp;That should only be like $800 for a decent setup. &nbsp;Hopefully you didn't [email protected] up your turbo or any of that stuff.

Eric

[drift freaq]

dam that sucks Jeff. Oh well, guess your shopping for another KA to strap your setup on. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sad.gif" border="0" valign="absmiddle" alt=':('>

[Foxcolt]

Sorry to hear it. G'luck with the repairs.

If you need any KA parts email me, I'll give em to you for next to nothing to help you out.

Jed

[240Stilo]

What was the highest amount of boost you ran, consistantly, &nbsp;before that happened? It'll be cool to know if it was taking the same boost SR's can take on the everyday basis.

[uiuc240]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (240Stilo @ Dec. 16 2002,3:41)</td></tr><tr><td id="QUOTE">What was the highest amount of boost you ran, consistantly, before that happened? It'll be cool to know if it was taking the same boost SR's can take on the everyday basis.</td></tr></table><span id='postcolor'>
Jeff blew the motor because of lack of fuel. &nbsp;He's not tuned to run 17 psi. &nbsp;His wastegate pressure line came off and he went to "max boost". &nbsp;'Nuff said. &nbsp;That will kill most any car. &nbsp;If I had a T3/T4 on my car and the wastegate line blew off, my SR would go poof too.

KA is a tough motor. &nbsp;SR is a tough motor. &nbsp;Oh, and one more thing PSI means almost nothing. &nbsp;CFM is what's really important. &nbsp;17 psi on my T25 is not nearly as much air as 10 psi on Jeff's T3/T4. &nbsp;Hope that makes sense. &nbsp;He was probably making around 350 hp when he popped.

Eric

[Jeff240sx]

The question I get asked most often "Didn't you see it spike?" &nbsp;And my answer "yup.. right before I heard THUD" &nbsp;
Anyway... my plans are to go nuts on the KA. &nbsp;For about $3,200 I am gonna get some forged pistons and rods. &nbsp;Then rings and gaskets and shit like that. &nbsp;Then bored block, honed cylinders, ported and polished head, port matching on everything, balance my internals and 3-way valve job, with Stainless valves. &nbsp;I think. &nbsp;If anyone has a hookup on JE pistons (8.5:1 CR) or Crower rods, EMAIL me at [email protected]
I'll be back online after my engine build up and can drive home. &nbsp;I'm stuck like 2 hours from my apartment in Tampa.
-Jeff

[whateverjames]

sorry to hear about this. can't wait to hear about the build up of the new motor/5 speed.

[kandyflip445]

Wow, that's sh*ty...good luck getting your build-up done. Hopefully everything will turn out better.

[boosteds14]

ya that sucks.

i hope the prices were ok.

its the best i can do. sorry about the motor

[d240t2]

Oh, and one more thing PSI means almost nothing. &nbsp;CFM is what's really important. &nbsp;17 psi on my T25 is not nearly as much air as 10 psi on Jeff's T3/T4. &nbsp;Hope that makes sense.

This isn't really as big of a deal as people make it out to be. Volume is fixed by the size of the engine. Pressure we can play with. The only way to change mass at a consistent pressure and consistent volume is to change the temperature. (PV=nRT if ideal)

Temperature goes down with a more efficient turbo, but larger does not necessarily mean more efficient.

The real power increases from a larger turbo at the same pressure level come from the increased VE from the larger turbine.

Dennis

[AceInHole]

what kind of fuel system were you running?? RRFPR?

[Jeff240sx]

Originally posted by AceInHole
what kind of fuel system were you running?? RRFPR?
Ace... it was totally stock. 4.35psi was fine on the stock fuel... but not 17.
Boosted- I dunno yet. I have a shop getting me quotes. I'll get back with you on Monday to let you know what I'm doing.
UIUC- Never thanked you for fielding those questions.
I'm using a damn webtv internet access... I can't see anything and don't get on very often cuz it's SLOW.
Thanks everyone for pity and support.
-Jeff

[nrcooled]

I have got a KA that I will let go mad cheap to help you out. Just give me a holla. FYI spec compression, never modded, w/ 100k out of a '91, 5spd

[AceInHole]

Originally posted by Jeff240sx
Ace... it was totally stock. 4.35psi was fine on the stock fuel... but not 17.

OK... you were getting me worried for a little bit there with my own turbo project. After finals I hope I can get at least the turbine side of things on, even if I'm not actually boosting.

I'd imagine some sort of fuel control might've helped a little bit.... but when it surged on you was it that quick that you couldn't get off the throttle??

[S13Grl]

So you are buying a new motor? Why?? I think it would be just another $500 unneccessarily gone down the drain. Build that KA. Crank should still be good. Honing and boring of cylinders should do it justice. You only know how good the head is, though... Sorry about everything, hope it all comes through okay. Good luck!

[InferiorWang]

Originally posted by uiuc240
KA is a tough motor. &nbsp;SR is a tough motor. &nbsp;Oh, and one more thing PSI means almost nothing. &nbsp;CFM is what's really important. &nbsp;17 psi on my T25 is not nearly as much air as 10 psi on Jeff's T3/T4. &nbsp;Hope that makes sense. &nbsp;He was probably making around 350 hp when he popped.

Eric

What was he doing running 17 psi on a T-25? It's just pushing hot air at that point. There is a reason that the mitsu crowd calls it a T-too small. You really oughtta look into upgrading to a T-28. Flows more air and will give you much cooler air at 17 psi which will lessen the chance of detonation. Sorry to hear about your motor.

And someone above me pointed out the 17psi on a T-25 vs 10 on T3/T4 thing. There is not more are at 10 psi, that is a huge difference there is more oxygen at 17 psi on a t3/t4 at 17 than a T-25 at 17 because of the temperature. PV=nRT
Pressure x Volume = number of moles x R (gas constant) x Temperature. If you want a lengthy description I can give one or dig up a link to one.

[InferiorWang]

and you really shouldn't be running 17 psi on a stock fuel system. You need at least 440cc injectors and a 190lph fuel pump to boost to 17 and that's the bare minimum on injectors. You will want 550's if you ever want to boost higher. You must have been running really fucking lean which will kill your engine.

[drift freaq]

What was he doing running 17 psi on a T-25? It's just pushing hot air at that point. There is a reason that the mitsu crowd calls it a T-too small. You really oughtta look into upgrading to a T-28. Flows more air and will give you much cooler air at 17 psi which will lessen the chance of detonation. Sorry to hear about your motor.

And someone above me pointed out the 17psi on a T-25 vs 10 on T3/T4 thing. There is not more are at 10 psi, that is a huge difference there is more oxygen at 17 psi on a t3/t4 at 17 than a T-25 at 17 because of the temperature. PV=nRT
Pressure x Volume = number of moles x R (gas constant) x Temperature. If you want a lengthy description I can give one or dig up a link to one.

if you read Jeffs post carefully you would have seen that he was A. running a T3/T4
B. keeping his boost at 4.5 because he had a stock fuel system.
C. that it was an accident due to a line failure which caused his boost to spike at 17psi.
Now that over with, before you respond to someones thread read it carefully and get your facts right.

[Jeff240sx]

S13grl. I'm not dropping in an old motor. I am building my motor up with forged internals, balanced, ported and polished head, 3 angle valve job, port matching everything, bored cylinders and plate honing it. The slap everything together with ARP bolts and it should be good. If anyone dissagrees or has suggestions while I'm spending money, let me know.
Thanks DriftFreaq for reiterating what I have typed. I DO NOT RUN, AND DIDN'T INTEND TO RUN 17 PSI.
Ace - I don't think that fuel management would have helped anything. It was a boost-check. I was dicking with my wastegate cuz my damn revhard manifold spits out bolts, which frys gaskets, and makes me not boost at all. I had like 3 people in there, and one shut the hood. I figured he would realize that the barb fitting on the wastegate needed to have the vaccum line that was laying next to it hooked up. We went out, and it ran at 4 psi, then jumped to 17. I let off, the automatic shifted, and the BOV vented into the atmosphere, which I don't think helped my lean situation, and then pistons started blowing apart.
Ehh... what can you do though?
-Jeff

[InferiorWang]

Originally posted by drift freaq
C. that it was an accident due to a line failure which caused his boost to spike at 17psi.

I understood the reason for failure. I was stating other facts pertaining to the amount of boost that I mistakenly thought he was running.

[Apparition]

Good luck with your new project. At least your new motor will be sweet. :D Always unfortunate when misfortune twists your arm into spending money when you didn't want to right away. But on the bright side, the engine is gonna be solid.

[C-Kwik]

Originally posted by Jeff240sx
Ok. &nbsp;I lied. &nbsp;I found out where I couldn't boost to. &nbsp;17psi. &nbsp;Nobody with a stock block and fuel system try to boost to 17 psi, ever. &nbsp;My wastegate line kinda came off somehow, and now, I am shopping. &nbsp;It went really, really fast up until 40 miles per hour, right after the 1-2 shift, when the BOV blew off, and then smoke poured out of my hood. &nbsp;My PCV valve is blowing smoke, and my car won't start, and I have ZERO compression in all four cylinders.
-Jeff

This is quite misleading. Based on the other facts, it seems detonation was your enemy in this case. With a stock fuel system and 17 psi, you probably had some very extreme detonation. Chances are, you would have heard it starting at about 6-7 psi. Anyone with a turbo should try to keep a sharp ear for detonation and back off the moment you hear it. Even forged parts probably would have taken a crap with that much detonation.

In any case, I would not say what the limit of the stock internals are until someone starts to break things without detonation being the culprit.

[Apparition]

Isn't a "boost spike" basically uncontrollable, and since its a spike, that'd be to maximum boost with NO control?

If what I'm saying is correct, I don't think he had time to hear any ping except the possibily of a piston flying through his hood. ;)

[C-Kwik]

Originally posted by Apparition
Isn't a "boost spike" basically uncontrollable, and since its a spike, that'd be to maximum boost with NO control?

If what I'm saying is correct, I don't think he had time to hear any ping except the possibily of a piston flying through his hood. ;)

Depends on what causes the spike. In this case, it was the signal line coming off. But to build up to 17 psi from 4.5 psi, there is plenty of time to notice a difference. A heavy foot and maybe even a loud stereo can drown the sound. So extra attention should be used. Not that I blame him. You start feeling that extra power and you don't necessarily question it. Typically, with wastegate failures that cause boost spikes, it only spikes a few psi at most.

[uuninja]

Originally posted by C-Kwik
Depends on what causes the spike. In this case, it was the signal line coming off. But to build up to 17 psi from 4.5 psi, there is plenty of time to notice a difference.

Yes and no, with a manually actuated waste gate (simple pressure line from the turbo) the waste gate begins to partially open very early. The effect of this is the turbo takes longer to spool. Disconnect the waste gate actuator line the waste gate stays shut and boost builds much faster. The line probably "popped off" under load, which means that boost would surge drastically as soon as the waste gate closed.

[uiuc240]

Originally posted by InferiorWang
What was he doing running 17 psi on a T-25? It's just pushing hot air at that point. There is a reason that the mitsu crowd calls it a T-too small. You really oughtta look into upgrading to a T-28. Flows more air and will give you much cooler air at 17 psi which will lessen the chance of detonation. Sorry to hear about your motor.

And someone above me pointed out the 17psi on a T-25 vs 10 on T3/T4 thing. There is not more are at 10 psi, that is a huge difference there is more oxygen at 17 psi on a t3/t4 at 17 than a T-25 at 17 because of the temperature. PV=nRT
Pressure x Volume = number of moles x R (gas constant) x Temperature. If you want a lengthy description I can give one or dig up a link to one.

First off, I'm NOT running 17 psi on a T25...I was using that as an example. And yes, you're right that a larger turbo is more efficient at higher pressure levels, and therefore pushes less hot air. This is just a more precise and technical way of saying what I was saying. If you take a T25 that squeezes out, what, 350 cfm at 14 psi, and replace it with a T3/T4 that pushes 550 cfm at 14 psi...there's going to be a substantial difference in power. That's all I was trying to say. You're right on with the thermodynamics, bro.

Eric