I have a 94 ls auto stock internals 50 wet shot and my motor keeps blowing at 90 mph when nos is on. the 1st time i put 2 holes in 1 of my exhaust valves and the 2nd time it looks like i melted the top of my piston. my fuel pressure is at 41 psi, cam gears are set 5d retarded exhaust and 3d advanced intake. just would like to know so it wont happen again after i buld my motor.

 

because you are running nitrous on a stock internal engine...why are you even spraying?

 

i can run my nitrous all day long when i'm not on the interstate and it won't blow but on the highway it blows. also i was told that a 50 shot was ok on stock internals.?.?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1INTEGRA &raquo;</TD></TR><TR><TD CLASS="quote">I have a 94 ls auto stock internals 50 wet shot and my motor keeps blowing at 90 mph when nos is on. the 1st time i put 2 holes in 1 of my exhaust valves and the 2nd time it looks like i melted the top of my piston. my fuel pressure is at 41 psi, cam gears are set 5d retarded exhaust and 3d advanced intake. just would like to know so it wont happen again after i buld my motor.</TD></TR></TABLE>
you are a retard

 

look im not looking for flaming just trying to get information so it won't happen again. i know i should have built my motor first but i didn't and now i am working on it. if you can't give me useful information don't reply

 

sorry I did not meant to come off like that, it was the first thing that came to my mind..
but maybe you are running too much timing and not enough fuel, your blowing the motor with only 50 shots? thats not normal. too much timing, bad fuel, not enough fuel. or you may be spraying at too high rpms

 

yea my rpms are at about 6k but why would that cause my motor to blow

 

your rev limit is at 6800rpms in a automatic correct. your motor is not build so you are pushing it to the limits

 

so with a built motor bigger injectors and fuel pump i should be able to hold 6k rpms all day if i want to while spraying

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1INTEGRA &raquo;</TD></TR><TR><TD CLASS="quote">so with a built motor bigger injectors and fuel pump i should be able to hold 6k rpms all day if i want to while spraying</TD></TR></TABLE>

yes that would help a lot, timing also played a role you need to make sure you have good timing, I use to spray back in the days, stock d16z6 120 shots. and I blew the motor after trying to spray right before my redline.

but as every one is probably gonna tell you, why not build the motor for turbo, even a simple jackson racing supercharger, to keep it simple, instead of using nitrous, the prices adds up for bottle fills and blown motors, cheaper to boost it.

 

Ah nitrous is INSTANTANEOUS power! Also you are not supposed to spray more than say 10-15 seconds at a time, most kits state 15 second bursts. If you are burning vakves, melting them then it is getting too hot, have you tried changing out your Fuel jet to run richer? Have you even had it on a dyno and checked your plugs for proper A/F? Very important to read your plugs with nitrous it will tell you alot

I had nitrous on my 91 Integra and never had a problem UNTIL one day on teh hiighway I kept racing a Firebird WOT up to 135mph and my Fuel controller was set to lean out due to the big cams loping so bad, I had a nitrous setting which my dumbass didnt change back to. DOH! KABOOM! Sooo hot ground strap and porcelain melted valve and piston went chomp on them, ran like a lawnmower after that

 

yea this happens like two or three seconds after i hit the button but only at 85-90 mph anything slower 0-50, 40-70 etc i don't have this problem and the plugs look fine. but at 85-90 the plug is broke off and my engine runs like a "lawn mower"

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1INTEGRA &raquo;</TD></TR><TR><TD CLASS="quote">yea this happens like two or three seconds after i hit the button but only at 85-90 mph anything slower 0-50, 40-70 etc i don't have this problem and the plugs look fine. but at 85-90 the plug is broke off and my engine runs like a "lawn mower" </TD></TR></TABLE>


You have the most load at that speed, you are probably in 4th gear already EVEN though it should still be in 3rd in an Auto I would think.

 

no i go into 4th at 110

 

Obviously you are going lean and detonating. Why only at redline? Your fuel pressure is dropping because flow is increasing, and then you are not getting enough fuel. You can either up the fuel pressure with a better pump or add bigger fuel jets.

 

Dry or wet kit?

 

wet

 

so if i get a bigger fuel pump will i have to up my fuel pressure even for daily driving or will the bigger pump hold at 41 psi where i have my regulator set

 

Did you get a wideband and tune your AFR? how do you control your timing? did you tune your timing?

 

There's a lot more load on your engine at these speeds. The engine gets a lot hotter, and works a lot harder as it has to overcome way more drag and resistance. This is why people are afraid of 5th gear pulls on turbo cars

 

50 shot isnt **** for an ls motor

I ran 65 dry on a d16 for 2 years no problem

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rudebwoy &raquo;</TD></TR><TR><TD CLASS="quote"> or you may be spraying at too high rpms</TD></TR></TABLE>

nitrous is safer higher in the rpms

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elpiar &raquo;</TD></TR><TR><TD CLASS="quote">Did you get a wideband and tune your AFR? how do you control your timing? did you tune your timing?</TD></TR></TABLE>

what is a wideband and my ignition timing is set at stock

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1INTEGRA &raquo;</TD></TR><TR><TD CLASS="quote">what is a wideband and my ignition timing is set at stock</TD></TR></TABLE>

found your problem^^^ but i will tell you that your problem lighs in the EGT, to hot and your burning valves and melting pistons. because it is your exaust valve that tells me 2 things:

1- your timing is 2 retarted ( but that is not the case since your timing is said to be at stock)

2 -or your AF ratio in the upper rpm band and highload situation is leaning out an just melting everything.

get a wideband and sit on a dyno and tune your fuel jet to supply you with the correct fuel as not to lean out. or just chip your ECU and tune it correctly.


oh------ wideband - newer type of o2 sensor that is extremely more accurate than the one in your car. combine tha with a meter and you will have precise readings of your air fuel ratio.

 

Yeah man these guys are 100% right.
It's your fuel leaning out to much under load.
Whats happening is. your air fuel ratio isn't tuned rich enough to keep the engine cool with the nitrous.It's getting so hot inside the combustion chamber that your plugs or maybe some carbon ontop of the piston is getting cherry red and preigniting the left over fuel mixture in the combustion chamber.and blowing your engine.The classic examples of preignition are holes being blown in the top of your piston"like you said it was doing before" And broken spark plugs.

Check this link out http://www.hastingsmfg.com/Ser...n.htm