How much HP will it take? Haven't found my answer with search
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From: Piscataway, NJ USA
How much HP will it take? Haven't found my answer with search
Looking to spray my setup with a 100hp shot with a fresh racetronix fuel pump kit and just want to know if I'm pushin the envelope too far on the stock short block. I've done a lot of searches but maybe just need to hear some advice to ease my mind or set me straight.
The TNT shots at RWHP shots but many have seemed to find they are a little conservative, so my 100hp shot may infact give me 125hp. I currently put out 380rwhp & 370 rwtq as it stands so I'm looking to spray the car again (sprayed it when it was stock with the 100hp jets). So I may be anywhere from 480rwhp ->500+rwhp and who knows what Tq. These are sexy numbers to me but is this putting me on the ragged edge?
-Brian
The TNT shots at RWHP shots but many have seemed to find they are a little conservative, so my 100hp shot may infact give me 125hp. I currently put out 380rwhp & 370 rwtq as it stands so I'm looking to spray the car again (sprayed it when it was stock with the 100hp jets). So I may be anywhere from 480rwhp ->500+rwhp and who knows what Tq. These are sexy numbers to me but is this putting me on the ragged edge?
-Brian
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My motor has 209,500 miles on it original miles been running 100 shot nitrous for a while now, if your internal engine parts are stock youd have to find out how much power it can hold. My friends LS1 pushes 443rwhp and 511rwtq with no issues yet on nitrous stock motor, transmission different story, lol. But im running 100 shot, stock motor i was 289 rwhp and with nitrous im at 392 rwhp dyno numbers done in 5th gear. Just timing was retarded, better ignition and dyno tune A/F. So with the Racetronix i wouldnt know but if i can pull around 100 rwhp off a 100 shot it should be fairly easy for you to achieve atleast that with a good tuning for nitrous and ignition uprgrade. If you have a cam and heads that will also help to achieve better numbers on nitrous.
Last edited by karpetcm5; May 15, 2007 at 01:43 AM.
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The Racetronix kit includes a walbro 255 pump and a dedicated wiring harness for the fuel pump....this keeps the voltage steady at the pump.
This allows the fuel system to support ~6-650rwhp
as far as what the motor can handle that will depend on too many variables to have a clear cut answer.
But you can safely spray 1-150 on a stock motor.
I ran a GTP stage 2 head, 236/242 .568/.568 110, stock short block and a 150 shot for 2-3 years before building the 396. Was shifting at 66-6800.
This allows the fuel system to support ~6-650rwhp
as far as what the motor can handle that will depend on too many variables to have a clear cut answer.
But you can safely spray 1-150 on a stock motor.
I ran a GTP stage 2 head, 236/242 .568/.568 110, stock short block and a 150 shot for 2-3 years before building the 396. Was shifting at 66-6800.
Last edited by Ray@NitroDaves; May 15, 2007 at 09:39 AM.
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From: Belmont North Carolina.
Listen to Ray.
Its too broad of a subject to just say..."how much is too much".
I used to spray a sneaky setup on my LT1 with only one solenoid inside the air tube and a 50 hp jet. I didnt have any of the safety stuff and just relied on the one solenoid to work every time. I had a ball for 2 years until the solenoid stuck in the open position!!!
If you buy and install a competed kit and follow all of the manufacturers safety reccomendated guidelines you will have no issues spraying 150 shot on the stock bottom end.
Now, I have a friend... ( don't we all...lol ) that has all of the safety parts in place and efficiently pushes 200 hp shots through his motor. A/F is monitored via a laptop inside the car and he has never had any engine related problems. Wish I could say that for his 4L60E tranny...
Its too broad of a subject to just say..."how much is too much".
I used to spray a sneaky setup on my LT1 with only one solenoid inside the air tube and a 50 hp jet. I didnt have any of the safety stuff and just relied on the one solenoid to work every time. I had a ball for 2 years until the solenoid stuck in the open position!!!
If you buy and install a competed kit and follow all of the manufacturers safety reccomendated guidelines you will have no issues spraying 150 shot on the stock bottom end.
Now, I have a friend... ( don't we all...lol ) that has all of the safety parts in place and efficiently pushes 200 hp shots through his motor. A/F is monitored via a laptop inside the car and he has never had any engine related problems. Wish I could say that for his 4L60E tranny...
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From: Piscataway, NJ USA
Thanks for the replies guys. I have all the safety goodies (FPSS, Window switch, nitrous filter, tr6 plugs, etc etc) so I'm ready to spray it. It sounds like I should be ok with the 100 and I guess if I punk out I'll swap to the 75hp jets and just be happy with that. Sounds like fun!
-Brian
-Brian
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From: Buffalo, New York
You have the pragmatic answer already, I will provide the vague philosphical answer for your confusion and contemplation 
Most of the parts in an IC engine are very understressed. Witness to that is the obsevation that they almost never break, they wear out. When is the last time you saw a broken component in a relatively stock motor? Unless it was a defective part, maybe never? Consequently, when you increase the loads they usually wear out quicker - not break. As you start to apply more and more stress, you can start to see fatigue failures. The older the part is (the more cycles it has already gone through) and the less there was safety margin in the first place, the sooner failure will occur.
Now, if you apply extreme stress to a part, you can experience sudden, catastrophic failure. But this is rare. The exception in the typical motor is the pistons. This is because of two operational facts. Increased power from nitrous occurs as a result of increased cylinder pressure (as opposed to more rpm). This directly increases stress. But nitrous also increases heat delivered to the piston crown. Even normal piston crown temps approach the point at which the alloy loses a lot of strength. Add a couple of hundred degrees combined with increased pressure and the pistons do become prone to rapid failure, especially in the ring land area.
This leads to ideas to minimize the chance of failure with nitrous use. Besides limiting the amount of nitrous, the following are helpful. First, do not bring the nitrous in at low rpm. Even relatively small amounts of nitrous can drastically increase BMEP and peak cylinder pressure at low rpm. Obviously, avoid detonation by running the best fuel you can, as detonation causes severe local piston heating as well as pressure spikes. Along the same lines, timing retard helps decrease peak cylinder pressure and also inhibits detonation. And do not spray for more than a few seconds at a time to minimize heat transfer to the piston crown. Along the same line, do not "hot lap" a nitrous car. Wait at least a few minutes between uses of the nitrous. In terms of tuning, you should borrow a trick from the blower guys and go to an over-rich mixture to cool things off, though this will cost a few hp. Also as with a blower, use a cold plug. A good ignition is also need to get the most out of the nitrous without misfiring and this has the added benefit of allowing a cold plug without fouling. Plugs that are too hot cause detonation, with the consequences described above.
Used properly, a 150hp shot should not cause catastrophic failure absent a defective component. It will cause increased wear, especially on bearings and rings. If you break the "rules" as defined above, catastrophic failure (most likely of the piston crown) may occur quickly. If the motor is built for it, huge amounts of nitrous can be used but the same general principles apply. The trick setup to run really big nitrous shots is oil cooling jets for the undersides of the piston crowns. This illustrates what I have tried to get across about the piston being the weak link. The guys who use nitrous in hill climb cars would be the ones who know the most about this. At the upper levels of drag racing, they don't have major longevity concerns about the motor as it used for such a short perios and rebuilds are so frequent. The hill climbers spend minutes at WOT on a run. Ditto the Bonneville guys. Street and street strip use of a power adder can also be tougher on parts than high level drag racing due to the usage factors involved.
Rich
Most of the parts in an IC engine are very understressed. Witness to that is the obsevation that they almost never break, they wear out. When is the last time you saw a broken component in a relatively stock motor? Unless it was a defective part, maybe never? Consequently, when you increase the loads they usually wear out quicker - not break. As you start to apply more and more stress, you can start to see fatigue failures. The older the part is (the more cycles it has already gone through) and the less there was safety margin in the first place, the sooner failure will occur.
Now, if you apply extreme stress to a part, you can experience sudden, catastrophic failure. But this is rare. The exception in the typical motor is the pistons. This is because of two operational facts. Increased power from nitrous occurs as a result of increased cylinder pressure (as opposed to more rpm). This directly increases stress. But nitrous also increases heat delivered to the piston crown. Even normal piston crown temps approach the point at which the alloy loses a lot of strength. Add a couple of hundred degrees combined with increased pressure and the pistons do become prone to rapid failure, especially in the ring land area.
This leads to ideas to minimize the chance of failure with nitrous use. Besides limiting the amount of nitrous, the following are helpful. First, do not bring the nitrous in at low rpm. Even relatively small amounts of nitrous can drastically increase BMEP and peak cylinder pressure at low rpm. Obviously, avoid detonation by running the best fuel you can, as detonation causes severe local piston heating as well as pressure spikes. Along the same lines, timing retard helps decrease peak cylinder pressure and also inhibits detonation. And do not spray for more than a few seconds at a time to minimize heat transfer to the piston crown. Along the same line, do not "hot lap" a nitrous car. Wait at least a few minutes between uses of the nitrous. In terms of tuning, you should borrow a trick from the blower guys and go to an over-rich mixture to cool things off, though this will cost a few hp. Also as with a blower, use a cold plug. A good ignition is also need to get the most out of the nitrous without misfiring and this has the added benefit of allowing a cold plug without fouling. Plugs that are too hot cause detonation, with the consequences described above.
Used properly, a 150hp shot should not cause catastrophic failure absent a defective component. It will cause increased wear, especially on bearings and rings. If you break the "rules" as defined above, catastrophic failure (most likely of the piston crown) may occur quickly. If the motor is built for it, huge amounts of nitrous can be used but the same general principles apply. The trick setup to run really big nitrous shots is oil cooling jets for the undersides of the piston crowns. This illustrates what I have tried to get across about the piston being the weak link. The guys who use nitrous in hill climb cars would be the ones who know the most about this. At the upper levels of drag racing, they don't have major longevity concerns about the motor as it used for such a short perios and rebuilds are so frequent. The hill climbers spend minutes at WOT on a run. Ditto the Bonneville guys. Street and street strip use of a power adder can also be tougher on parts than high level drag racing due to the usage factors involved.
Rich
Last edited by rskrause; May 18, 2007 at 07:46 AM.
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Rich,
I fully follow everything you just mentioned and I am pretty sure I have all the safety precautions in place to reduce the chances of a catastrophic failure. The nitrous in this car will be used here and there, so it will not be an everyday thing nor probably an every weekend thing. I run TR6 plugs, window switch set for 3k-6k, fpss, and WOT switch so I think I am covered there. The motor burns no oil between changes and I am a fanatic about keeping up with regular maintenance. Aside from a few sensors going bad and a rear intake manifold leak thats been taken care of...the car has been very reliable and a strong runner from the first day my dad picked it up to now.
I guess I was simply hoping someone would say...yea the stock shortblock is good for 500rwhp for a decent amount of miles.
Thanks for the input.
-brian
I fully follow everything you just mentioned and I am pretty sure I have all the safety precautions in place to reduce the chances of a catastrophic failure. The nitrous in this car will be used here and there, so it will not be an everyday thing nor probably an every weekend thing. I run TR6 plugs, window switch set for 3k-6k, fpss, and WOT switch so I think I am covered there. The motor burns no oil between changes and I am a fanatic about keeping up with regular maintenance. Aside from a few sensors going bad and a rear intake manifold leak thats been taken care of...the car has been very reliable and a strong runner from the first day my dad picked it up to now.
I guess I was simply hoping someone would say...yea the stock shortblock is good for 500rwhp for a decent amount of miles.
Thanks for the input.
-brian
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Posts: 616
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jOn: more than welcome to come sit around and watch me blow it up at HSW on the 4th when they install the racetronix pump I have sitting in my garage at the moment . However no go on the 200 shot since my TNT kit only goes to 150 
Come be the camera man since my hand gets too shaky when my cars on the dyno anyway. My buddy had to hold the camera on the dyno day.
I am going to leave my 100 jets in and hope it runs the way it should. I'll bring the 75's just in case.
-brian
. However no go on the 200 shot since my TNT kit only goes to 150 Come be the camera man since my hand gets too shaky when my cars on the dyno anyway. My buddy had to hold the camera on the dyno day. I am going to leave my 100 jets in and hope it runs the way it should. I'll bring the 75's just in case.
-brian
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Joined: Jul 2004
Posts: 557
From: Central Jersey
jOn: more than welcome to come sit around and watch me blow it up at HSW on the 4th when they install the racetronix pump I have sitting in my garage at the moment . However no go on the 200 shot since my TNT kit only goes to 150 Come be the camera man since my hand gets too shaky when my cars on the dyno anyway. My buddy had to hold the camera on the dyno day.
I am going to leave my 100 jets in and hope it runs the way it should. I'll bring the 75's just in case.
-brian
. However no go on the 200 shot since my TNT kit only goes to 150 Come be the camera man since my hand gets too shaky when my cars on the dyno anyway. My buddy had to hold the camera on the dyno day. I am going to leave my 100 jets in and hope it runs the way it should. I'll bring the 75's just in case.
-brian
it goes up to 150...
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