broken motor

[turbonissan]

93 ka-t with stock head and stock block head gasket blew out at 10.16 psi replaced it and installed arp head studs started running it and hit 10.2 psi and the piston ring blew out all work done at a shop in Huston. all i want to know is what has anybody seen a stock ka-t run psi wise

list of mods garrett gt25 turbo 370 sr injectors 255 fuel pumphks fmicturbonetics manifoldcustom down pipe nismo fuel pressure regulator JWT ecu cobra maf koyo radroyal purple fluids front to back running 93 octane

[nzmoman]

zerothread/223269

also look at Reguild or Not???

these two threads and a little searchin will help.

This is a much better way to ask your question! ( i saw it on the 240sx and silvia forum)

[turbonissan]

what are u running in your 240's

[S13FX]

what are u running in your 240's

Come on you should know this. The amount of PSI differ in HP rating depending on the turbo size. I for sure know I ran really close to 300rwhp mark with my Precision GT32 on my SOHC. But then again I had a bad *** tune.

But Im guessing with that setup and the turbo you have, you were at maybe 250rwhp depending on your tune.

[nzmoman]

what are u running in your 240's

I ran SRs in all of mine, but I have been considering the KA-T, for my next one. Ive had 3 Sr cars, but I want to go for KA-t this time.

the 250ish HP mark may be only 9 or 10 PSI for you, not sure, im new to KA-T also. but your turbo will boost more. Your week link is not the boost output of the turbo its the bottom end. Keep watching this thread. someone will chime in and correct me on this if Im wrong..

Come on you should know this. The amount of PSI differ in HP rating depending on the turbo size. I for sure know I ran really close to 300rwhp mark with my Precision GT32 on my SOHC. But then again I had a bad *** tune.

But Im guessing with that setup and the turbo you have, you were at maybe 250rwhp depending on your tune.

S13FX can you comment on the stock bottom end and turbo pressure combination, how will those two work together?

[nzmoman]

what kiind of clutch are you running?

[S13FX]

S13FX can you comment on the stock bottom end and turbo pressure combination, how will those two work together?

I'm not quite sure I understand what you mean?

And as for my clutch I had a Spec3+ with the Spec Steel flywheel, but my car just recently got totaled by some jerk on the high way.

[nissanfanatic]

On the dyno, I have made:256whp at 7psi326whp at 12psi353whp at 14psi357whp at 15psi419whp at 20psi

Stock internals.

Psi wise, I have ran as much boost at this turbo will make. Peaked at 31psi, ran 25psi for a while, but it wouldn't hold 25psi due to maxxing. Usually just run 20psi.

Your first indication of a problem should have been the blown headgasket at 10psi. What heat range plugs are you running?

[turbonissan]

i am running act 6 puc

[nissanfanatic]

who cares what clutch he is running? His engine is broke..

[nzmoman]

the engine is not broke...he is trying to keep it from breaking again. the clutch matters because he is trying to make good numbers. if he is running a stock clutch he aint goin very far.

I'm not quite sure I understand what you mean?

And as for my clutch I had a Spec3+ with the Spec Steel flywheel, but my car just recently got totaled by some jerk on the high way.

I was asking if you knew any quick tips for understanding how the stock bottom end will react with that turbo. I am asking this with the understanding that a lot of KA guys say the t-2 flange is not the best choice, and you were the only one on here when I posted that and you definately know more than me about boosted KA's. How should the KA owner with a stock bottom go about chosing a good turbo for maximum HP?

[nissanfanatic]

His engine is broke.

Quote »head gasket blew out at 10.16 psi replaced it and installed arp head studs started running it and hit 10.2 psi and the piston ring blew out all work done at a shop in Huston.[/quote]And I've heard of stock clutches holding up to ~250ft/lbs of torque..

Start with a T3/T04E 50trim or a GT3071R. Most people can't keep their engines together using past 60% of these turbo's output, so it will be a good starting point because you can make from stock output to 420whp on either of them, maybe a little more on the 3071R.

To the OP, how did you verify that your base timing is set correctly? And again, what heat range plugs are you running?

[WDRacing]

How should the KA owner with a stock bottom go about chosing a good turbo for maximum HP?

You need to read a compressor map. If you can't do that, then you ask or see what everyone else is running.

The BEST turbo for a KA24DE is a T3/TO4E in 50 trim. .63AR hotside with a stg 3 wheel. A good tune and this turbo will get you about 420WHP at only 20 psi. The turbo still has another 5 psi left before it becomes a total heat pump.

The bottom end has nothing to do with the choice of turbo. However, if you buy a small turbo, say a T25, then you're asking for melted pistons no real power because the exhaust housing is so restrictive the combustion chamer can't even scavenge all the fumes out.

Anyone who says a T2 flanged turbo is worth the hassle of installing is simply telling you a lie. I don't even like the T3 super 60.

WD

[GEO]

t3/t4 57trim .48ar with a stage 5 wheel ftw!

[S13FX]

Precision GT32 63 compressor .48 ar hotside is the mother fwakin ****

[WDRacing]

The .48 AR is for people who don't want room to grow. You'll never catch me buying injectors I'm going to max out or a turbo I'll max out with my first setup.

.63 FTMFW

[turbonissan]

so you are saying i need to upgrade my pistons and rods

[S0lid_Snake]

^it would appear that way. iirc the pistons fail first, but you may as well do pistons and conrods while the engine is torn down

[WDRacing]

If you're popping pistons at 10 psi you have other serious issues besides the internals.

You need to see what the matter with the tune you're using. No way you should be blowing stuff up at 10 psi....

[Florida240sx]

Ever had it on dyno/wideband?? I'm thinking the sr injectors could be the problem....

[Florida240sx]

Had them tested and cleaned?

[turbonissan]

no never had them cleaned and never on a dyno or wideband how would stopped up injectors blow out rings?????

[nissanfanatic]

^it would appear that way. iirc the pistons fail first, but you may as well do pistons and conrods while the engine is torn down

Sounds like a bad idea to me. If you can't make at least 350whp on a stock block, you will probably have issues on a built block.

[WDRacing]

no never had them cleaned and never on a dyno or wideband how would stopped up injectors blow out rings?????

How did you tune the car if you haven't had it on a dyno or used a wideband???

Thats your problem right there.

[nissanfanatic]

He's running a JWT ECU, it really doesn't need to be tuned as long as TPS and timing are set correctly..

But then again, he probably saw some thread saying JWT ECU and just bought it. Probably is tuned for 550s or something..

[Edub1]

He said JWT tune. I'm begining to wonder if a good share of blown motors aren't due to those small stage I wheels. I noticed that my super 60 hit a wall around 5000 RPMs. It just felt like the motor couldn't breath and there was considerable boost creep.

It just seems like it's a bad idea to create that much backpressure and force the motor to overcome it. Even the best WG won't vent off pressure before it opens.

I don't know if I'm right but I have this vision in my mind of the stage III being able to maintain boost by maintaining lower pressure but higher exhaust gas velocity through the wheel rather than by builing backpressure.

[shockload]

i would still run the car on a dyno and watch afrs regardless of the tune before you go getting on it. with the result you just had its likely you would end up breaking a built engine too if you dont sort out your issues. blowing a ka on 10 psi had to of been an 18:1 afr at least. ka's arent weak something is wrong in your setup. figure it out, destroying engines is no good.sounds like a stock ecu and an afc hack would be your best bet as far as tuning with that small turbo.

[nissanfanatic]

He said JWT tune. I'm begining to wonder if a good share of blown motors aren't due to those small stage I wheels. I noticed that my super 60 hit a wall around 5000 RPMs. It just felt like the motor couldn't breath and there was considerable boost creep.

It just seems like it's a bad idea to create that much backpressure and force the motor to overcome it. Even the best WG won't vent off pressure before it opens.

I don't know if I'm right but I have this vision in my mind of the stage III being able to maintain boost by maintaining lower pressure but higher exhaust gas velocity through the wheel rather than by builing backpressure.

It is bad. During valve overlap, if pressure is too much higher on the exhaust side, then flow is going to want to go backwards through the engine.. That can cause all sorts of problems related to fuel burning before it even enters the combustion chamber.. Small turbos are just gay all around.

But don't get too confused, as long as pressure inside the combustion chamber is two times higher than exhaust manifold pressure, flow is not affected. I recommend maximizing turbine housing size to the highest acceptable level of the user.

[WDRacing]

Oh yeah, I guess so.

Ok, so there's obviously a problem with the AFR/Timing.