You might wanna add something about engine maintence that should be performed on a turbocharged car, that wouldn't normally be needed on a N/A car. Things like, checking intake piping, vaccuum lines, and other things that can make the boost do weird things. Like in my mazdas case shoot past 25 psi >:\
Well, I didn't want to create a "maintenance" thread on every possible situation of something going wrong with boost, just a better understanding of what happens with the rotating assembly when you are running a turbocharged setup. I'd like to keep this thread limited to the issues outlined in the first post as much as possible, ie: issues with tuning and timing moreover than when things go wrong spontaneously. Thanks for the input. Hope it's informative to those who take the time to read and comprehend it.
Ok, I've seen this asked more times than I can remember and there are a few possible reasons that can cause this. I will outline everything I can to help you guys run a safer setup and avoid these problems. Some of the things outlined here are going to be minimally debatlable but I am going to back everything up with real world reasoning as best as I can.
1) Overheating the engine.
If you bring the engine temperature to far over the operating temperature, you're asking for problems. You heat it up due to a coolant loss and get air into the water jackets is a number one cause for overheating the engine. How do you avoid this? Keep a close eye on your coolant and watch your temp gauge like a hawk. Do those two things on a regular basis and you can most likely avoid this problem.
2) Detonation/Pre-ignition.
a) Detonation: When you're running to lean of an air/fuel mixture, you can blow things up. Head gasket is usually the first to go. You can run lean for a number of reasons. Not to bash on sf's fuel kit but anytime you're tripling the stock fuel pressure rating on a stock injector, you're asking for trouble. You'll be good at 80 psi of fuel pressure or so, but as you begin to overload the injectors with too much pressure, they begin to spray less consistantly and can short your mixture, robbing the engine of fuel needed to burn properly. Alot of people claim to be running very rich, which may be true at a lower boost level, but once you begin to move into 7-10 psi of boost, you can lean out due to this. The best bet is to properly match injectors to the setup you want to run.
b) Pre-Ignition: You can also detonate from not retarding the timing. I've seen the word "tuning" used quite loosely around the fi section of the site but I want to try and clear up it's meaning a little bit. Tuning is anything you do to your vehicle to improve performance. In this case, I'm speaking of tuning the ignition, in other words, at what point the plugs fire to burn the a/f mixture. If you ignite the plugs too early with a boosted setup, you're not putting the force on the pistons at the correct time. The way the ecu times the spark in the engine is optimal for the amount of a/f mixture at any given rpm prior to the piston reaching top dead center. When you are boosting, you are creating a more powerful a/f mixture which will burn quicker. When you do this, the force on the top of the piston is going to come much sooner than it would without the added air and fuel. So you need to compensate for this to prevent pressure on the rod or piston prematurely.
Think of it this way; when the piston reaches tdc, the rod should be at a 90 degree angle with the crank. If you exert pressure on the piston at this point, it's going to be absorbed by the rotating assembly, ie; crank, pistons, rods and block instead of causing the crank to rotate. This will cause the head to want to separate from the block due to the vibration caused and this is not what you want to do, you want the pressure to hit at some point after the piston reaches tdc to continue everything running in motion smoothly. This is how people crack ring lands, break pistons, blow head gaskets and break rods. If you set off your mixture too early you can even cause the rod to want to rotate backwards which will snap rods.
So you may be wondering what you can do to safely run boost without this problem. Well, you can use any type of tool that will allow you to adjust your ignition timing and retard the timing to come a few degrees later until you reach the optimal ignition timing.
So to summarize, any of these things can and will blow out a head gasket. If you do the things suggested in this post, you can avoid a lot of unnecessary damage to your motor. Another thing to always realize is that your stock internals will only handle so much boost. If you want to run more than 10 psi safely, it is a good idea to run good forged pistons and rods. Another commonly known and tested fact of Honda motors is that the sleeves tend to float at or around 15 psi, so anything above or beyond that would be a good idea to think of reinforcing the stock sleeves with aftermarket ones.
As always, comments welcome, I’ll answer any questions I can as thoroughly as possible and I’m always open to friendly and intelligent debate.
Well, I didn't want to create a "maintenance" thread on every possible situation of something going wrong with boost, just a better understanding of what happens with the rotating assembly when you are running a turbocharged setup. I'd like to keep this thread limited to the issues outlined in the first post as much as possible, ie: issues with tuning and timing moreover than when things go wrong spontaneously. Thanks for the input. Hope it's informative to those who take the time to read and comprehend it.
I just suggest that cause some people might not realize that after boost some lines, such as intake lines are now filled with pressurizied air instead of a vaccuum and could pop off when running big boost.
I just suggest that cause some people might not realize that after boost some lines, such as intake lines are now filled with pressurizied air instead of a vaccuum and could pop off when running big boost.
Some people blow pipes off like there is no tomorrow. Others, never have a C/P blow off. I personally belive design is a big factor, size coupler and band used & hair spray is the key.
I use the one from auto zone for 16bucks for 2 about an inch wide and about a mil thick, the alluminum rings looks pretty durable, i've been using it after I had a blow charge pipe about a month ago and never had a blow charge pipe since... but if you're low budget use 2-3 "o" clamps per side that would take care of it...
Quote:
Originally Posted by 4drcivic2k1
adel wiggins clamps all the way. Never blow a charge pipe.
Last edited by pnoyster2k1cvic : 09-24-2004 at 04:02 PM.
damn, thats gotta suck. But good information...it helps to have this on hand when deciding if someone wants to turbo, and what to do/not do after their turbo is strapped in. My cars in the process of getting "tuned" right now...so next week i should be on the road again with a stronger motor
