ah, i see. so what does it use as a substitute as a distributor?Originally posted by ZEROmotorsports@Feb 24 2005, 09:15 AM
you would have to use a piggy back computer of some sort to do that with the tC as it has no distributor.
Well said Lo Bux! Very good post. Yes, the tC uses a coil pack instead of a distributer. Alot of cars are Distributer-less now, at least most imports from my experience. Better way of doing things as far as I'm concerned. But yes, don't mess with timing. Too risky. I'm sure Toyota tested and tuned this motor for the tC and used the best timing to give it the best power. Could you theoretically squeek an extra 3 or 4 ponies out of the car if it had a distributer? Probably, but with gas prices on the rise, why force a car that is perfectly tuned to 87 octane to use more expensive gas for the same amount of power the TRD air filter would give you?Originally posted by lo bux racer@Feb 24 2005, 06:09 PM
Maybe, but your risking the entire engine by advancing the timing. For instance, I set an engine I was tuning to 28 degrees full advance and it ran great, but economy seemed low. I added two degrees and promptly detonated the thing to death on the next WOT run. It crushed the ring lands and cracked the head between the intake and exhaust seats in one cylinder. Expensive lesson.
Timing isn't usually where you look for performance increases, and advancing timing is just the opposite of what you want to do anyway. The more you advance timing, the sooner you reach peak cylinder pressure. There is a "sweet spot" for when that should happen. If it happens too soon, you are just working the engine against itself and putting a very large stress on the crank bearings.
A truly powerful and efficient combustion chamber needs very little advance to work well. Yes, you want to advance to get the pressure peak at the right time, but, you want to modify the piston and combustion chamber to allow the smallest amount of advance to get there.
That is what can happen to a forced Induction motor but it is very unlikely that an NA motor will be damaged from too much timing advance within reason.Originally posted by lo bux racer@Feb 24 2005, 06:09 PM
Maybe, but your risking the entire engine by advancing the timing. For instance, I set an engine I was tuning to 28 degrees full advance and it ran great, but economy seemed low. I added two degrees and promptly detonated the thing to death on the next WOT run. It crushed the ring lands and cracked the head between the intake and exhaust seats in one cylinder. Expensive lesson.
Timing isn't usually where you look for performance increases, and advancing timing is just the opposite of what you want to do anyway. The more you advance timing, the sooner you reach peak cylinder pressure. There is a "sweet spot" for when that should happen. If it happens too soon, you are just working the engine against itself and putting a very large stress on the crank bearings.
A truly powerful and efficient combustion chamber needs very little advance to work well. Yes, you want to advance to get the pressure peak at the right time, but, you want to modify the piston and combustion chamber to allow the smallest amount of advance to get there.
They absolutely will.Originally posted by lo bux racer@Aug 9 2005, 12:04 AM
2JZ's won't even start if the crank and cam signals are out of phase.
This is funny. The engine I described is a Yamaha FJ1100 NA engine running 30 degrees full advance in a 76mm bore. It blew up. I've seen lots of other NA engines do the same. FI just makes it easier with boost overshoot, but the fact remains, any engine will blow up from too much advance.Originally posted by SupraTC@Aug 8 2005, 05:02 PM
That is what can happen to a forced Induction motor but it is very unlikely that an NA motor will be damaged from too much timing advance within reason.
I'd put my money on Lance. He know's more than god. (about engines at least).Originally posted by SupraTC+Aug 11 2005, 03:30 PM-->QUOTE (SupraTC @ Aug 11 2005, 03:30 PM)<!--QuoteBegin-lo bux racerThey absolutely will.@Aug 9 2005, 12:04 AM
2JZ's won't even start if the crank and cam signals are out of phase.
They will throw a check engine light and the ECU will revert to the cam sensor for timing input.
Ever hear of people breaking the little spot weld on the crank timing gear that holds the pickup in place?
Its pretty common, its happened to me and several others.
The car runs just badly. [/b]
So theoretically if I wanted to spend the $5/gallon on Permium resetting the ECU (remove negative on battery?) will cause the vehicle to relearn its timing to 93 fuel? That sounds way too easy... and will it even increase HP?Originally posted by SupraTC+Aug 8 2005, 05:02 PM-->QUOTE (SupraTC @ Aug 8 2005, 05:02 PM)<!--QuoteBegin-lo bux racerThat is what can happen to a forced Induction motor but it is very unlikely that an NA motor will be damaged from too much timing advance within reason.@Feb 24 2005, 06:09 PM
Maybe, but your risking the entire engine by advancing the timing. For instance, I set an engine I was tuning to 28 degrees full advance and it ran great, but economy seemed low. I added two degrees and promptly detonated the thing to death on the next WOT run. It crushed the ring lands and cracked the head between the intake and exhaust seats in one cylinder. Expensive lesson.
Timing isn't usually where you look for performance increases, and advancing timing is just the opposite of what you want to do anyway. The more you advance timing, the sooner you reach peak cylinder pressure. There is a "sweet spot" for when that should happen. If it happens too soon, you are just working the engine against itself and putting a very large stress on the crank bearings.
A truly powerful and efficient combustion chamber needs very little advance to work well. Yes, you want to advance to get the pressure peak at the right time, but, you want to modify the piston and combustion chamber to allow the smallest amount of advance to get there.
The Scion will advance timing as much as possible on its own until the knock sensor starts hearing knock and it will then settle timing just below that #.
If you put higher octane fuel in your car and want better performance be sure to reset your ecu so that it will advance timing up until the knock threshold again.
Moving the CAS is NOT recomended as this sensor measures engine position for not only ignition timing but also injector timing.
Plus if the CAS doesn't coincide perfectly with the cam angle sensor you will get a check engine light immediately. [/b]