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Blew #5 Piston on the dyno yesturday

Joined
6 April 2002
Messages
1,095
Location
Wrightsville, Pa
I was on the dyno yesturday and on my third run there was a loud bang. I was holding the video camera and got the whole thing on tape. I am waiting for my friend to convert it to mpeg so I can post it on this site. Here is what happened. I am spraying a 150 shot of NOS, the shop that installed the NOS did not change out my platinum plugs when they installed the NOS. I am very lucky that it lasted as long as it did. It blew off the end of the spark plug into a valve or a cylinder and now I only have 40psi of compression from the #5 cylinder, won't know if it is a valve or a piston until it is taken apart. The dyno results from the first run are:
Max Power 361.4HP
Max Torque 339.4
I had it running rich to prevent detonation, however I now know that you should never run platinum plugs with nitrous period...
I am now looking for someone to take apart the engine and install JE forged pistons sleeve the cylinder walls and new rods. I was going to reinforce the engine but was not ready to do it yet. I guess I have no choice now. The shop where I got the car dynoed said $10k. Is this a good price? When I get the video I will post it.
NEVER RUN NOS WITH PLATINUM PLUGS
 
Your NSX comes with Platinum plugs in it. You should use regular autolite plugs, a degree colder plugs. You can get them at any parts store for around $2 each. If you are running NOS with platinum plugs don't drive your car until you replace them!!!
It is going to wind up costing me around $10grand. Expensive mistake. Also you should check your plugs every few months with NOS.
 
How'd you get such a large peak torque value and such a [relatively] low peak HP? Does torque fall off at higher RPMs with your nitrous setup?
 
First let me say how sorry I am to hear about this. that is what EVERYONE fears the most.

what type of fuel were you running?

just how rich were you running? It doesn't seem that you were getting much more than a 100 shot? What was your stock dyno? - without nitrous?

I've run platinum plugs for a very long time.
no problems. Most stock cars use a 5-7 and then go to a 9 for nitrous use. Now this has little to do with the fact that they are platinum (Which MELT easier under a pre-ignition / detonation atmosphere) but first you must be DETONATING before they melt. I think you should look at why they were detonating.

On your Dyno, is there a sudden 10-20 hp drop somewhere in the rev range? (Knock sensors kicking in) mine did this when I used a 150 shot without race gas. (Was in a hurry and just used octane booster - don't ever trust this crap) No damage to the car, just ended up with a couple funky looking plugs.

Oh yeah, 10K for the fix. Yes, that is a bit pricey.


[This message has been edited by nsxlr8 (edited 25 July 2002).]
 
He hit the NOS at 4200rpm
4500rpm 295hp 255torque
4800rpm 361hp 339torque
5800rpm 348 318
6800rpm 360 282
7800rpm 330 223

I will scan the dyno report tomorrow at work as I am off today trying to find someone that can fix the car. Calling around everywhere.
When you use platinum plugs the platinum tips burn off fast thus causing a bigger than normal gap. The spark plug does not fire as good and that is how the detonation occured.

Rob Hunt

[This message has been edited by nsxlover (edited 25 July 2002).]
 
that is what I am saying. "The tips burning off" is caused by EXTREME heat /detonation. Running too lean or whatever reason. Spark plug tips are not suppose to burn off under any normal or high performance condition.

I'm still curious what type of fuel you were running?
 
Thats bad news!!!

Really sorry to hear you blown youre engine.
Just hope something better will come out of it.


I was getting into nitrous more and more, and wanted to go for a install, but everytime i hear horror stories.
I was at a tuningshop today (very, very knowledgable people), who also told me to stay away from nitrous. Not sure now....


Mich 'nitrousdoubt' DutchBlackNsx
 
Originally posted by nsxlr8:
that is what I am saying. "The tips burning off" is caused by EXTREME heat /detonation. Running too lean or whatever reason. Spark plug tips are not suppose to burn off under any normal or high performance condition.

I'm still curious what type of fuel you were running?
Sorry to here it.
nsxlr8 you sound like you have a very solid foundation pertaining to nos.I have been told another thing about the plugs aside from the gapping and heat range.that another concern is the length of the strap on the plug.that you want to use either a longer or shorter strap length.cant remember which way to go short or long.but the reason was that one lenght does not dissipate the heat well and the correct length does.kinda acts like a sink.but I cant remember if a long strap helps to dissipate the heat or the short one does but if you use the wrong one it gets really hot and breaks off and ends up doing damage to the motor as decribed above.is this true?and if so do you want the long or short strap? I would always run 100 octane even with a small shot to prevent detonation,am I wrong in this asumption?
thanks David



[This message has been edited by BadCarma (edited 25 July 2002).]
 
100 Octane?

I never seen it available in any gas stations I saw...

where is it available?
 
I remember you tould me you didnt have a inline or intank upgraded fuel pump. Sounds to me like the car leaned out and melted the piston or broke a ring landing. The stock fuel pump is good up to a 100 shot but other then that what could of happen the #5 injector ran a little lean and the additional fuel was coming thru the fuel jet rather then both. Remember you practicly have to fuel supply's the injectors and the nos system.
 
Here in Southern California, it is relatively easy to buy 100 octane fuel from a pump. I know of three stations within a 10 mile radius of my work... two of them within 5 miles.

Try a web search. As I recall, there's some sites specializing in keeping track of the places selling 100+ at the pump. Cost varies widely from $3.99 to $5.25 just between the three stations I am aware of.
 
Originally posted by BostonNSX:
100 Octane?

I never seen it available in any gas stations I saw...

where is it available?

I get it at the spur gas station located on hercules ave clearwater fl.it is pricey though huh smoore.its like 4.50 a gallon but if you spray its a heck of alot better then octane booster or if you are supercharged.I received replys on this topic from x-factor that running the high octane is a waste of money on a n/a motor BUT (me not xfactor talking) not if you have replaced your stock ecu with a stand alone fuel management box like aems.
it sees boost no tricking the ecu
it has multible built in templates to build maps for adjusting to:
i/h/e performance
it allows you to set your ecu (aem) to dial in octane rating for best performance
set up your a/f ratio for whatevr boost level you run
set up your nitrous for amount sprayed, built in nos control like a progresive nos controller as not to go from cruise to nose bleed and control detonation
interfaces with a laptop realtime.
SO you could take the car to a good tuner and have them dyno it with the stock ecu then tune the new aem unit for all the above,create (this is what i love)multible maps
one for everyday driving your timing is not retarded and car runs perfect but suddenly you see a need for speed.pop the laptop out punch a hotkey macro that changes your map to nitrous mode retards timing adjusts a/f and away you go.same scenerio for boost.after your done hotkey back to normal driving.this will do away with the problems of driving a car that is set up to spray a large shot..as you drive normal far more then on the nos you dont have to cruise around town in a car optimized to run the big shot of nos.retarded timing while not spraying for instance.yes you can have it all for a mere 1200 bucks and having a tuner set up the initial maps.I would not try to tune it out of the box myself.I have tested the software that comes with the unit.they were kind enough to provide me with the full blown copy.with that all said thier are instances when you can benefit from high octane if you have the firmware software to make it work.and considering what we pay for our bolt ons 1200 is a bargain even for an n/a car and a must for those running nos or sc.I know I will get some flak from my tuning methodology.but as you see over and over again there are alot of conflicting viewpoints on nos wet or dry. boost which unit is better.and as for the ecu the concensus is dont mess with it.I disagree.but its my ride and well if I break it with my tuning I will fix it.sorry for the long post but thought I should explain the advantage of custom tuning not just for s/c.this methodology I believe would be awesome for those wanting to run nitrous and a turbo or s/c regardless of what most advocate.xfactor did indicate to me they thought the aem unit was overkill for anyone running less then a 150 shot.I need the unit to(attempt pushing 450 to the rear wheels and do it safely for under 5000
1200 for the ecu replacement unit
1000 for pro tuning of the unit
1000 bucks for the best nos kit
1000 for a very small laptop
uncertain as yet about going copper head gasket.decking,sleeving and custom pistons.here the price goes up.but I think 425 to the rears with stock internals could be achieved with this unit and progresive nitrous to save the motor from sudden shock.
fyi with the sos dvd pod jacked into the laptop video output you would get live sensor updates warnings realtime and you could run a mouse out from wherever the laptop is and change maps with mouse clicks(macros setup like single left click street,right click nos double left click nos and s/c or turbo
this is not science fiction..let the flames begin
wink.gif
hopefully not in my engine bay!
best regards david
AND no this is not concocted from watching the dreadfull F&F movie.just lots of late nights toying around..hey thats what engineers do
 
From my MANY runs and experimenting with Nitrous on the NSX, I've learned alot. A 100hp shot runs just fine on 93 octane. (One year almost two bottles used a week - every week. NO PROBLEMS. To test this before I upped the Horsepower (Pill size)I went to Houston Raceway Park and tested them (Did 3 runs back to back with nitrous, pulled ALL the spark plugs. - The STOCK PLATINUM PLUGS - Nothing, they looked great, didn't hear any pinging or feel any sort of timing being backed out because of the knock sensors. - 100shot I proceeded to bump up the nitrous and fuel pills to a 125hp shot. I ran three runs the runs felt solid. I pulled all the spark plugs (Oh yeah, I had a magnifying glass to aid in the spark plug inspection) and I did see what could be a few flakes of metal (detonation.) I believe that the 125 shot is the limit for pump gas. I ran a 150 shot. First run felt like it had a few hiccups (Timing being backed out by knock sensors - i.e. short horspower drop) during the run. I pulled the plugs and there were definate signs of detonation on the plugs. That is why when I go to the track (Houston Raceway Park 1/4 mile) and I plan on using nitrous, I then, and ONLY then use a 150 shot - Racing fuel is available at a pump there. ANY OTHER TIME. I am running a 100-125 shot. I do NOT put in larger FUEL PILLS to keep the engine from detonating. Richening up the fuel will just bring the horsepower level DOWN to a 125-100hp shot anyway. So JUST USE a 100 shot and be sure you're not screwing up your engine. - unless of course you use race fuel with your 150 shot. 100 octane or higher. (Un-leaded type of course)

I have a two stage nitrous kit, but I've done a "few" other things to keep the car running! NGK-R plugs that run a 9 heat range (Very cold plug) I back off the timing a few degrees (Only when I plan on using a shot larger than 150) , and I have a larger in tank fuel pump. AND I use race fuel of 104 or higher. These things help ensure it all stays together.

Don't be afraid of nitrous. Just don't go above a 100 shot unless you're absolutely sure you know what you are doing. Don't go switching out the pills from what the manufacturer suggest or go pushing your stock fuel psi higher. those charts for pill size are BASED on the stock psi. They know what they are doing. follow the directions. I've done the leg work. 100shot works great. I've bounced off the rev limiter on nitrous, accidentally left the tcs on while using nitrous and all sorts of mistakes and the engine just kinda laughs at it.- 100hp shot. 125hp or more is a different story. Who you get to install it is the other half of the worries. Someone who's done this once or twice is preferred!


[This message has been edited by nsxlr8 (edited 26 July 2002).]
 
bostonnsx, the only place i know of around here to get it is up near new england dragway in epping, NH. a few of the stations have 100 and 104 octane unleaded cam 2 race fuel. im sure there are others though. it's very expensive and doesn't do a thing for you without some really serious modifications to your vehicle.
 
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