Classes Revised for 2007

Questions, comments, and discussions concerning COMSCC rules.

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DanDarcy
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Post by DanDarcy » Thu Dec 07, 2006 3:55 pm

Don this is more fun than working-- it's almost like instant messanging

wow ! we're even up to page 8
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Seven

Post by Seven » Thu Dec 07, 2006 4:13 pm

rajito wrote:
Ignition Advance Map

The ignition advance map holds the timing values that may be added on top of the base map should the ECU decide to do so. The values are set so that base plus correction map values total the timing that should be used with the highest octane fuel that the engine will encounter. The ECU will never advance timing beyond the base plus correction lookups.

At low engine loads, the ignition advance map contains no advance - this is the flat 'valley' of the map. No matter what the quality of fuel, the ECU will never advance the timing above the value in the base map. This is because the engine will not produce further power by advancing the timing - MBT (minimum best timing) has been reached. Advancing the timing further increases the chance of knock and also increases vehicles emissions of hydrocarbons and NOx.

MBT is the lowest value of ignition advance that produces maximum power.

At high engine loads, the advance map contains much larger values. This shows that the timing possible varies greatly with the octane of fuel being used. Under boost, it may not be possible to reach MBT. In other words, the more timing advance that can be run, the higher the engine power output produced - MBT cannot be reached before the engine begins to knock before the plateau is reached. This is where the active ignition timing excels - it allows the ECU to run the highest timing possible without engine knock. This results in high power output, good fuel consumption and low exhaust gas temperatures. At these high loads, emissions aren't relevant for passing government emissions testing procedures, since the cars are always tested at relatively light loads - a handy loophole for turbo cars.
It talks about how the ECU says, "Yo! Octane!" and advances the timing without running into knock.

Raj
Wow that's pretty amazing. Those engines are so stout that tuners choose to advance timing to such a degree that they rely upon the presence of knock (and thus the knock sensor) to retard timing on a dynamic basis just enough to be safe. That's quite a testament to those motors. Obviously the use of knock sensors is nothing new, however, their use (to the best of my knowledge) traditionally has been to provide a level of protection against some form of system "failure" rather than as a dynamic tuning tool.

Raj, is your ECU tuned as well? If not, I assume that stock timing maps are conservative enough that the engine never experiences knock on 93 octane. Or does it?

Seven

Re: Thread

Post by Seven » Thu Dec 07, 2006 4:14 pm

Don P wrote:Do you guys work? :lol:
Yeah, being a Consultant definately has some perks!

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Post by zip4zat » Thu Dec 07, 2006 4:39 pm

Seven wrote:
rajito wrote:
Ignition Advance Map

The ignition advance map holds the timing values that may be added on top of the base map should the ECU decide to do so. The values are set so that base plus correction map values total the timing that should be used with the highest octane fuel that the engine will encounter. The ECU will never advance timing beyond the base plus correction lookups.

At low engine loads, the ignition advance map contains no advance - this is the flat 'valley' of the map. No matter what the quality of fuel, the ECU will never advance the timing above the value in the base map. This is because the engine will not produce further power by advancing the timing - MBT (minimum best timing) has been reached. Advancing the timing further increases the chance of knock and also increases vehicles emissions of hydrocarbons and NOx.

MBT is the lowest value of ignition advance that produces maximum power.

At high engine loads, the advance map contains much larger values. This shows that the timing possible varies greatly with the octane of fuel being used. Under boost, it may not be possible to reach MBT. In other words, the more timing advance that can be run, the higher the engine power output produced - MBT cannot be reached before the engine begins to knock before the plateau is reached. This is where the active ignition timing excels - it allows the ECU to run the highest timing possible without engine knock. This results in high power output, good fuel consumption and low exhaust gas temperatures. At these high loads, emissions aren't relevant for passing government emissions testing procedures, since the cars are always tested at relatively light loads - a handy loophole for turbo cars.
It talks about how the ECU says, "Yo! Octane!" and advances the timing without running into knock.

Raj
Wow that's pretty amazing. Those engines are so stout that tuners choose to advance timing to such a degree that they rely upon the presence of knock (and thus the knock sensor) to retard timing on a dynamic basis just enough to be safe. That's quite a testament to those motors. Obviously the use of knock sensors is nothing new, however, their use (to the best of my knowledge) traditionally has been to provide a level of protection against some form of system "failure" rather than as a dynamic tuning tool.

Raj, is your ECU tuned as well? If not, I assume that stock timing maps are conservative enough that the engine never experiences knock on 93 octane. Or does it?
This is OEM from Subaru, tuners can take advantage of the inherent programming already on the ECU. On top of this, the AVCS (Active Valve Control System) in the valve train in the newer models yields increasing flexibility to the ECU to increase power output before knock sets in.

Long story short, you dont have to tune the cars to take advantage of higher octane fuel. You can strech the limits of these parameters more over OEM. I think there are more parameters that tuners can play with on these cars to gain more power without touching boost. Hence the ability of the T2 cars to gain more hp on stock boost, than bumping boost alone.

Back to the subject, I think those involved in proposing the re-classification have done their homework on objective evidence. This is not to say that there may or may not be other metrics that can bear weight on these rankings. In doing such work you HAVE to rely on data available to make decisions, not anecdotal data from results in the past years; there are just too many variables involved.

And btw, for those that fear another cheater, I am also on completely stock EM and drivetrain.
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Post by rajito » Thu Dec 07, 2006 5:20 pm

Seven wrote:Raj, is your ECU tuned as well? If not, I assume that stock timing maps are conservative enough that the engine never experiences knock on 93 octane. Or does it?
Nope, no tuning here. I was running OEM exhaust until I dinged it and broke something inside it at NHIS.

I've not experienced any pinging/knocking. Actually, I've not heard pinging ever, so I doubt I'll even recognize it until the motor blows up :)

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Post by DanDarcy » Thu Dec 07, 2006 5:37 pm

Is there some way I can put one of "dem dare ecmmms in my Stang?"

Seriously now , I was running behind a Subie at Line Rock (not a WRX or STi not sure exactly what it was ) and when the driver let off the gas, flames would shoot out both exhaust pipes. Is this common with stock boost ? The car was in ST1 and it had a pipe on either side of the car.
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Post by Tsurara » Thu Dec 07, 2006 5:39 pm

Seven wrote: The ignition advance map holds the timing values that may be added on top of the base map should the ECU decide to do so.
If only rotaries could take advantage of knock, am I right :) ?
DanDarcy wrote: Seriously now , I was running behind a Subie at Line Rock (not a WRX or STi not sure exactly what it was ) and when the driver let off the gas, flames would shoot out both exhaust pipes. Is this common with stock boost ? The car was in ST1 and it had a pipe on either side of the car.
I can't speak for the STi crew, but the Evo runs pig rich from the factory, which I assume, is a safety measure. On my last Evo with an upgraded exhaust and no catalytic converter, I would shoot flames everywhere on the stock ECU with stock boost. I loved the huge "BANG" that would let out down the NHIS straight.

Ah man, I miss modding my car!
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Post by DanDarcy » Thu Dec 07, 2006 5:46 pm

Hey Charles nice to hear from a new person.

In ST1 you have to run cats if they came with the stock car when new. Will the Evo "flame" through the cats ?

I love the flames-- is there a way to get my car to thow flames too ?
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Seven

Post by Seven » Thu Dec 07, 2006 6:30 pm

DanDarcy wrote:Is there some way I can put one of "dem dare ecmmms in my Stang?"

Seriously now , I was running behind a Subie at Line Rock (not a WRX or STi not sure exactly what it was ) and when the driver let off the gas, flames would shoot out both exhaust pipes. Is this common with stock boost ? The car was in ST1 and it had a pipe on either side of the car.
The flames are really a function of the removal of the cat(s).

Seven

Post by Seven » Thu Dec 07, 2006 6:33 pm

Tsurara wrote:
Seven wrote: The ignition advance map holds the timing values that may be added on top of the base map should the ECU decide to do so.
If only rotaries could take advantage of knock, am I right :) ?
I am SOOO jealous... 1 knock in a rotary and you're buying yourself a rebuild. That's why I feel badly for those behind me on the track. I run so extremely rich I burn my own eyes!

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Post by Tsurara » Thu Dec 07, 2006 6:35 pm

DanDarcy wrote:Hey Charles nice to hear from a new person.

In ST1 you have to run cats if they came with the stock car when new. Will the Evo "flame" through the cats ?

I love the flames-- is there a way to get my car to thow flames too ?
Hi Dan, glad to be here :) The Evo will not shoot flames with the stock cat on. As far as the 'Stang goes, you might want to try this instead:

http://www.axdo.net/

Yeeeee-haw! Jeff, all of us forgive you for the smells and smoke from running rich, it takes some large balls to own a rotary. :)
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Post by eastcoastbumps » Thu Dec 07, 2006 6:39 pm

DanDarcy wrote:Hey Charles nice to hear from a new person.

In ST1 you have to run cats if they came with the stock car when new. Will the Evo "flame" through the cats ?

I love the flames-- is there a way to get my car to thow flames too ?
Dan, you typically need to remove the cats to shoot flames. A turbo helps too, but I'm sure its possible with a Mustang. The car runs rich, the turbo, or headers in your case, get hot then air flow is stopped when the throttle is closed. The unburnt fuel passes into the exhaust and the heat of the turbo (or headers) ignites it and it gets a great big pop and flame as soon as it gets to the oxygen at the end of the tail pipe.

I've also tuned carbs so that they shoot flames. Thats way cooler. :D
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Post by rajito » Thu Dec 07, 2006 7:13 pm

DanDarcy wrote:Seriously now , I was running behind a Subie at Line Rock (not a WRX or STi not sure exactly what it was ) and when the driver let off the gas, flames would shoot out both exhaust pipes.
Probably the Legacy GT.

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Post by DanDarcy » Thu Dec 07, 2006 8:50 pm

I like that "Flame Thrower" kit, I might install one so when one of them Subies comes up behind me I can ------ well you know, than i won't have to worry about point bys. Do you think the "Flame Thrower" is legal in ST1? :oops:

I hope you can get flames while still running your cats, otherwise the car would be illegal in ST classes.

I have no experiance with modifying turbo engines, but
i have built racing motorcycle engines for over 40 years and too much advance can cause a loss of power. Using a gas with too high of octane will also cause a loss of power, the flame front will still be burning when the exhaust valve(s) open,and the charge burns into the exhaust pipe. Also 100 octane low lead airplane fuel has high lead compared to the lead levels that were (are) used in auto fuel and will damage your cats. I had a 1964 Studabaker Lark Conv. with a factory supercharger a long time ago. It was so easy to increase manifold pressure , one little screw. You could not tell the boost was modified but the little 289 would leave the 1970 Mustang Mach1 390 in the dust. I once drove it North skiing up Rt.91 at incredable speeds (won't say how much , don't want a lecture like what happened to Sam). I also sell some speed parts for cars through my business and several of the manufactures state that their "chips " for turbos modify boost. I'm not saying the Ryan, Raj, and others are not running stock boost, but it is too easy for some one to do a "Super Chip" and not realize they have modified boost. As pointed out by Jeff , a small increase in boost can yeild a great increase in horse power. With the NEQ club at WGI this summer there was a stock looking Evo. The fellow said he had modified the ecu and the boost was increased. The car had been dynoed at 440 h.p. and it looked stock. He was from Ohio and does not drive with Com.
I think Raj is right that the STis, Evos etc. should stay in SSU and STGT. Right now there are not enough Z06s to cause much trouble. :)

I would like a chance at winning ST1 next year also, so I can be like Ryan and do two in a row :roll: With the STis moving down this would be impossible.
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Post by turtlevette » Thu Dec 07, 2006 10:15 pm

RyanC wrote:Outside of a separate boost controller (manual or electronic), not appreciably so. If you can cite an example or two outside of a boost controller, please do so, cause I don't know of any, especially for any of the cars that appear to be under a cloud of suspicion.
.
When i had my Buick the trick was to get a 2 dollar 1/8" valve from the corner hardware store. It is used to bleed off signal to the computer to fool it into thinking the boost is lower. The computer will then increase boost depending on how many turns you have opened the valve. A pinhole in the feedback line to the computer would do the same thing and be totally undetectable.

I used to run 18 - 20 pounds of boost on my Grand National and its very safe as you said because the computer will sense detonation and retard timing before the next cylinder fires. My bad ass Buick V6 used to walk souped up big block chevys. Hell yea.

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