Advance ignition timing?

[Randomrage]

Running a Zex wet kit, stepped up to the 75 shot, and got a bit of detonation, so Im guessing its time to advance the ignition timing. So. How do I do it?

Also, is there anything else I need to check while Im at it, since I plan on sticking with the 75 for a while?

 

[DSMJim]

Advancing the ignition timing will only increase detonation. You need to retard your timing. Advancing timing makes it happen sooner before TDC which means theh piston is still traveling on the up stroke when ignition happens. The sooner the more pressure on the piston as it travels up towards the downward power stroke. You need to retard the timinig so it happens closer to TDC which helps reduce ignition timing.

Unfortunately I dont think you can reduce you base timing. What plugs are you running are you running one step colder then stock? Also what grade octance are you using? Finally how do you know your detonating?

 

[Randomrage]

I knew it was one of those two

I cant reduce my base timing? Why not? Im using the Zex Hyperperformance nitrous/turbo plugs, and running 93 octane gas. As far as how I know Im detonating, I can only say the car doesnt sound right on the spray with a 75 shot. Im going to check the plugs tomorrow and see what I can see.

 

[DSMJim]

I'm not entirelly familiar with the 420a engine however they run a coil pack not a distributor (which is how you normally do it) so the computer has control over the ignition timing. To change it you need to have some type of manual control which I don't think your car has. My car does not even have that control unless I switch to a 1G cam angle sensor and wire up some other bs.

You need to let me know what the sound is like. The car will get louder and sound like it's woring harder. If your having detonation it will sound like somebody hitting a ballpene hammer on the sides of your engine walls, sort of a high pitch tink tink tink sound. Most of the time you can never hear it and by the time you do your computer has pulled timing back so far already that you wont hear it.

Pull your plugs out and have a look at them to start and see what color they are. For nitrous the should pretty well be black or dark brown. If you are having detonation they will be white or look like they have little drill marks all over them. Take a run with the spray, let off the gas then shut the car off and coast over to the side of the road and pull out a plug to examine it right away. Looking at them after you drive for a minute takes away any evidence of what my be going on.

 

[Randomrage]

When I spray it with the 75, it sounds like a loud lifter ticking noise, (louder than lifter tick, but I can only hear it with the windows down, and even then, its faint) but its not quite the metal on metal sound youre describing. If I read your post correctly, it sounds like my 420a will retard the timing automatically if it senses knock? Does that mean I dont have to do anything to run the 75 shot (besides diagnose that noise)?

The plugs are very black, and about to be replaced. On the straps hanging over the center, there is a bit of white, but thats it. I did have oil on the #1 plug's threads, but I think I fixed it. Im going to refill the bottle, and try again, then check the new plugs.

 

[tsi20gawd]

very bad!!!!! stop spraying!!!.
if you can hear the ping that is VERY BAD!
lower the shot or run higher octane fuel.

 

[Randomrage]

very bad!!!!! stop spraying!!!.
if you can hear the ping that is VERY BAD!
lower the shot or run higher octane fuel.

Higher than 93? Think Ill just put the 65 jets back in, thanks.

 

[DSMJim]

When I spray it with the 75, it sounds like a loud lifter ticking noise, (louder than lifter tick, but I can only hear it with the windows down, and even then, its faint) but its not quite the metal on metal sound youre describing. If I read your post correctly, it sounds like my 420a will retard the timing automatically if it senses knock? Does that mean I dont have to do anything to run the 75 shot (besides diagnose that noise)?

The plugs are very black, and about to be replaced. On the straps hanging over the center, there is a bit of white, but thats it. I did have oil on the #1 plug's threads, but I think I fixed it. Im going to refill the bottle, and try again, then check the new plugs.

Get copper plugs one range colder then stock, never use platinum. Those Zex plugs are not that great IMO I have tried them before on other cars with mixed results, mostly bad.

If your computer sees a lot of knock it will pull timing but sometimes not enough to stop the motor from being blown up. ZEX is very consertivate with their HP numbers so 75hp shot will put maybe 50hp to the wheels which is fine. You should not really be getting any knock with a 75hp shot. If the plugs are black after a run then thats ok, it's rich. The Air/Fuel for nitrous is around 11.5:1 vs. normally aspirated at 13.5:1.

Detonation will not sound like lifter kick (that I have ever heard anyways) are you only getting that sound when you spray the nitrous? The solenoids click when they open. When you spray does the power feel strong and pull ok or does something not feel right?

 

[Randomrage]

Get copper plugs one range colder then stock, never use platinum. Those Zex plugs are not that great IMO I have tried them before on other cars with mixed results, mostly bad.

NGK BP-something somethings right? Will they affect the power or driveability off the bottle?

If your computer sees a lot of knock it will pull timing but sometimes not enough to stop the motor from being blown up. ZEX is very consertivate with their HP numbers so 75hp shot will put maybe 50hp to the wheels which is fine.

I didnt know this, thanks for the info.

You should not really be getting any knock with a 75hp shot. If the plugs are black after a run then thats ok, it's rich. The Air/Fuel for nitrous is around 11.5:1 vs. normally aspirated at 13.5:1.

Detonation will not sound like lifter kick (that I have ever heard anyways) are you only getting that sound when you spray the nitrous? The solenoids click when they open. When you spray does the power feel strong and pull ok or does something not feel right?

Are the solenoids supposed to click once open, then click once close, or do they click repeatedly while spraying? And it pulls fine. I hit WOT, the nos comes on, and theres a steady pull to red-line. No jumps, shudders, or hesitation. As far as I can tell, everything is ok, but this noise that I can barely hear. I hope I can keep those 75 jets in there, or better yet, go for a 85!

Edit: These plugs, right? http://www.dsmtuners.com/parts/product_info.php?manufacturers_id=13&products_id=504 Gap 'em to .028?

So, I dont need to worry about the timing?

 

[Colossus]

BPR7ES I believe is the correct number.


Advancing timing is recommended to reduce spark knock.

Lower it to a 50, see if the sound is there. If it isn't, and is still present with the 75, I'd say you're haven some loud knock. If the car stutters, it's your plugs.

I run a 75 without a problem. Perhaps I'm just lucky?

 

[Randomrage]

BPR7ES I believe is the correct number.

Yep, thanks.

Advancing timing is recommended to reduce spark knock.

What? DSMJim said retarding.

Lower it to a 50, see if the sound is there. If it isn't, and is still present with the 75, I'd say you're haven some loud knock. If the car stutters, it's your plugs.

No sounds at 55 or 65. No stuttering at any of em.

I run a 75 without a problem. Perhaps I'm just lucky?

Nobody else has a problem running a 75.

 

[DSMJim]

Advancing timing is recommended to reduce spark knock.

What? DSMJim said retarding.

It is retarding the timing he has it backwards. A lot of people get this backwards because they thing advancing the tming makes it later (hense advance) but it makes it earlier before TDC. Your spark plug fires on the compresson stroke before top dead center, not afterwards on the power stroke. This is why timing advanced too far blows up motors is because the spark plug fires the mixture while the piston is still rising and the mixture is blowing up creating cylinder pressure and the piston is still on the way up fighting against it. It's the two pressures working against each other that melt holes in pistons. If it fired after top dead center (ATDC) there would be little to no power in your engine because the piston is already on the way back down at the same time the mixture is expanding creating pressure against the piston. By that time it's too late.

http://auto.howstuffworks.com/engine4.htm

See where the little triangle is in stroke #2? Advancing the timing makes it earlier meaning your advancing it in that particular cycle, retartind the timing makes it later in the cycle or closer to TDC. If you watch whats happening there you can see why advancing it too far would create a disaster in your motor.

Nobody else has a problem running a 75.

If there was a problem running the shot then you would feel some hesitation or surging etc and your plugs would not be black. Detonation creates a peppering effect on the plugs like somebody drilled little dimples all over the ground strap. If you have black plugs with no evidence of that then you don't have detonation. The solenoids click once to open and close, however I am not sure with ZEX. Remember that they use this brain to keep the air fuel in check so if your hearing clicking it could be the brain doing it's thing. Nitrous solenoids have a very strong mechanical click sound because of the pressure the solenoid has to hold back and be able to control so the magnet inside is very large so it makes a loud sound. Detonation does not sound like lifter tick its more of a high pitches ping sound, which is why it's oftin refered to as pinging. It sounds as I described, ballpene hammer on metal.

If your not having problems at 55-65 then stick there untill you diagnose your problem. What I would suggest you do is call ZEX and tell them your hearing a mechanical clicking noise while your spraying the car. DO NOT TELL THEM YOU THINK IT"S DETONATION. If you start to diagnose your problem yourself over the phone to them and you think it's detonation they will instantly tell you that is what it is and to remove the kit etc etc as a precaution to keep your motor from blowing up and to keep their name. You will get no help from them after that.

 

[big green]

Mechanical clicking? Are you sure your not hearing your selanoids activating? I know mine on my NX kit were pretty loud when I tested them., before I actually used the kit

 

[Randomrage]

Mechanical clicking? Are you sure your not hearing your selanoids activating? I know mine on my NX kit were pretty loud when I tested them., before I actually used the kit

I think thats what it was. It got pretty warm yesterday, and I went for a ride, after the car had been cooking in the hot sun for a half a day, and the bottle was nice and warm. First time Ive gotten good PSI out of the damn bottle since I didnt run it much all winter, and just got it refilled recently. Anyway, when the 75 shot hit, the psssssst noise drowned out whatever it was I was hearing before. Also, if I turn the key all the way to the start position, without cranking the car, and floor the gas pedal, I get the same fast clicky noise. So its the solenoids. For some reason, I was under the impression that it just clicks once when open, then again to close. Oh well, at least its fine! And damn is that a helluva shot when its warm! Next stop, bottle heater!!!

 

[Colossus]

haha....whoops....yes, reducing.