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SCCA Solo question: Street Touring and ECUs...

Old 11-17-15, 09:52 PM
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SCCA Solo question: Street Touring and ECUs...

Hoping that someone can help me with a question related to ECU and other computers within the Street Touring class.

When I review the rules (section 14.10.F), it's unclear to me what is allowable. I know the Power FC is very popular system, but is that within the rules for this class? It's an ECU replacement, which I don't believe is legal.

If not, what engine management systems are within the rules? Piggybacks are legal, as well as ECU mods. Any advise is appreciated on good alternatives if the Power FC is not allowed.

Many thanks...
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Old 11-17-15, 11:29 PM
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lol, you could drive a motec through those rules...

1. reprogrammed ecu via software, ie a chip. the Rtek is the easy thing here, although the Japanese did chipped ecu's too.
1b. reprogrammed ecu via hardware. i think they mean if the OEM chip isn't flashable, you can install a flashable chip, like in the case of the Rx7's. what it actually means is that you can shove the ecu of your choice in the stock case and call it good.
2. this is an interesting one, you can plug something between the stock ecu and the car. the HKS Fcon is such a thing, the Japanese have the F Con V pro, and it basically lets you do anything you want. you could in theory get an Fcon harness and use a different ecu on it as well.
3. installing things between the sensors and the ecu. this is like the SAFC, goes between the AFM/MAP sensor and the ecu.
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Old 11-18-15, 12:04 AM
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The rule:
F. The engine management system parameters and operation of internal
combustion engines may be modified only via the methods listed below.
These allowances also apply to forced induction cars, except that
no changes to standard boost levels, intercoolers, or boost controls are
permitted. Boost changes indirectly resulting from allowed modifications
are permissible but directly altering or modifying the boost or
turbo controls, either mechanically or electronically, is strictly prohibited.
Traction control parameters may not be altered. Any OE OBD2 or
newer communications port functionality must remain. The Check Engine
Light (CEL) or Malfunction Indicator Light (MIL) may be disabled
via software. Alternate software maps which violate these restrictions
may not be present during competition, regardless of activation. Only
OE sensors may be used for engine management.
1. Reprogrammed ECU/PCM (via hardware and/or software) may be
used in the standard housing.
2. Supplementary (“Piggyback”) ECU may be used subject to the following
restrictions:
a. Connects between the standard ECU/PCM and its wiring harness
only.
b. Must be plug-compatible with the standard ECU/PCM (no splices).
3. Electronic components may be installed in-line between an engine’s
sensors and ECU/PCM. These components may alter the signal coming
from the sensor in order to affect the ECU/PCM operation of engine
management system. Example: Fuel controllers that modify the
signal coming from an airflow sensor.
4. Fuel pressure regulators may be replaced in lieu of electronic alterations
to the fuel system. It is not permitted to electronically modify
the fuel system AND replace a fuel pressure regulator.
5. Ignition timing may be set at any point on factory adjustable distributor
ignition systems.
6. VTEC controllers and other devices may be used which alter the timing
of factory standard electronic variable valve timing systems.
the rule is pretty loose.... power FC is definitely within the rules.

I've seen people go as far as replacing the stock ECU and putting a megasquirt standalone w/ wideband controller in the stock ECU case...
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Old 11-18-15, 12:43 PM
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Is this for the FD or general question?

I ask because I don't see how FD is allowed in any ST class?

All the NOC specify "non-sports-car-based; 4 seat minimum"
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Old 11-18-15, 12:53 PM
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If we were allowed to run FD in Street Touring-

but directly altering or modifying the boost or
turbo controls, either mechanically or electronically, is strictly prohibited.


From the rules quoted above.

On an FD the Power FC connects to the turbo control solenoids and would therefore not be legal.

It would appear to be legal to run a ROM tuned stock ECU that did not alter the stock boost control maps at all, but did remove overboost fuel cut (part of fuel system, not boost control system).

This would allow you to run with the other modifications available in Street Touring with driveability issues from wonky boost, but at least no overboost fuel cut.

From racing FD in stock class I can tell you the wonky boost issues are boost creep on the primary turbo (no problem), terrible boost spiking 2ndary turbo transition (overspeeding the 2ndary turbo before coming online) and possible boost creep on the 2ndary turbo (no problem).
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Old 11-18-15, 10:43 PM
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Blue TII, I interpreted the rules just the same was as you. Was hoping I was wrong, but appears not.

BUT-- are you also saying that the FD is not allowed in the "Street" class? Wouldn't it qualify for AS?
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Old 11-19-15, 10:15 AM
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FD is in AS (A Street)

Allowed modifications-

1" larger/smaller diameter wheels of same width and up to 7mm difference offset +/-
Front or Rear swaybar change (includes modified swaybar mount)
Cat back exhaust
Drop in air filter or no air filter (stock box)
Change any expendables (brake pads, plug wires, oils)
Remove spare tire, jack, tools
Any single 12V battery in stock location
Any shock (up to 2way adjustable)
Any bumpstop (no longer than stock)
Harness Bar
Harness
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Old 11-19-15, 10:59 AM
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Originally Posted by pjr View Post
BUT-- are you also saying that the FD is not allowed in the "Street" class? Wouldn't it qualify for AS?
Street and Street Touring are different classes.

Street used to be "stock" class until they got rid of r-comps and changed it to street.



in regards to ST:

I didn't realize the PowerFC could modify boost levels with stock hardware. but it should be pretty easy to just not bypass those wires in the harness and pipe them to the stock ECU.... but I don't really know how the PFC works that well, so I might be wrong. Not that it matters though, I thought we were talking about an NA FC (which is legal for an ST class)
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Old 11-19-15, 11:48 AM
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I didn't realize the PowerFC could modify boost levels with stock hardware. but it should be pretty easy to just not bypass those wires in the harness and pipe them to the stock ECU.... but I don't really know how the PFC works that well, so I might be wrong. Not that it matters though, I thought we were talking about an NA FC (which is legal for an ST class)

You could certainly do what you are saying (use the stock ECU and the Power FC on the side) as this is how the RX-8 is run on a stand alone ECU...

However, this is not legal for Street Touring.

You are allowed whatever piggyback units as you like that intercept and alter the signal from the sensors to the ECU as long as they plug into the stock wiring harness and plug into the stock ECU.

You are allowed any ECU in the stock ECU case that plugs into the stock wiring harness.

No matter what system you employ, it may not allow for any changes from the standard "boost levels" or "boost controls".

On a stock FD ECU boost levels and boost controls are a simple closed loop map that does not reference boost pressure (hence the wonky boost/transition with ANY modifications to intake or exhaust).
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Old 11-19-15, 12:15 PM
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Hey look at that.... I really don't know what I'm talking about

I always thought the powerFC was a piggypack that still used the stock computer. it looks like it's not at all. Sorry
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Old 11-19-15, 02:24 PM
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Well, I just dug into this particular issue a lot because I raced my FD in stock class 1 year and it sucked because of lack of boost control.

So, I was always looking for a solution.

With just a cat back and K&N drop in filter you get over-boost fuel-cut from boosting over 10psi and a crazy 2ndary turbo transition boost spike that makes the car harder to drive.

I have Mazda dealer papers from '97 with the owner trying to fix this (FD raced in stock class since almost new).

So, I race my FD in A Street Prepared where I can do everything I want for a nice driving FD (I don't mind stock port and stock sequentials).

Last edited by BLUE TII; 11-19-15 at 02:29 PM.
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Old 11-19-15, 07:38 PM
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Originally Posted by BLUE TII View Post
FD is in AS (A Street)

Allowed modifications-

1" larger/smaller diameter wheels of same width and up to 7mm difference offset +/-
Front or Rear swaybar change (includes modified swaybar mount)
Cat back exhaust
Drop in air filter or no air filter (stock box)
Change any expendables (brake pads, plug wires, oils)
Remove spare tire, jack, tools
Any single 12V battery in stock location
Any shock (up to 2way adjustable)
Any bumpstop (no longer than stock)
Harness Bar
Harness
So I should focus on A Street... and no Power FC for sure.... unless I decide to go further over the SP. Thanks... really appreciate the feedback and insight!!
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