Boost Control and SP

Okay, I think I've got if figured out ...

Article 14.10.E in the SCCA rulebook (PDF p.95) ... this refers to ST classes ...

Quote :

The engine management system parameters and operation may be modified only via the methods listed below. Any and all modifications must meet or exceed the applicable US DOT emissions standards for the year, make, and model of the car. 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.

This is very cut and dry ... stock boost levels in STU for the Evo. No mechanical OR electronic control is allowed.

Now, lets move to the SP rules ...

15.10 ...

Quote :

Vehicles may only exceed the allowances of 13.10 as specified herein.

For reference, section 13 is the Stock category, not ST. The Stock category does not mention ANY boost control or ECU tuning at all.

15.10.C.4 is the section that defines forced induction modifications for SP cars ...

Quote :

Turbochargers and/or superchargers (“forced induction”) may
not be added, changed, or modified. On vehicles originally
equipped with forced induction:
a) No hardware changes or alterations to turbocharger(s) or
supercharger(s), in size or number, are permitted. Turbochargers
or superchargers may be updated/backdated only
in conjunction with the accompanying complete engine
unit.
b) No changes are allowed to waste gate(s) size, number, or
location. No changes are allowed to variable-geometryturbine
(VGT) hardware.
c) No changes are allowed to supercharger drive system
pulleys. Belt tensioners may be added/changed to reduce
belt slip.
d) No changes are permitted to blow-off/pop-off valves.
e) Compressor bypass valves (CBVs) are considered part of
the air intake system, and may be replaced or updated/
backdated independently of the other components of a
forced induction system.
f) Boost regulation systems, either electronic or mechanical,
and electronic fuel cuts referencing boost pressure may be
altered or modified except as prohibited herein. Boost
pressure changes resulting from authorized changes are
permitted.

The focus area here is sub-section f ...

Quote :

Boost regulation systems, either electronic or mechanical,
and electronic fuel cuts referencing boost pressure may be
altered or modified except as prohibited herein. Boost
pressure changes resulting from authorized changes are
permitted.

The only other mention of boost control up to this point is modification to supercharger pullies.

As far as I understand the rules, you CAN use a boost controller and still be SP legal. It seems to me that people are often referring to the ST rules or perhaps to older SP rules when stating the boost can only be altered with the ECU in SP classes. I wish I had a copy of the SP rules from a couple of years back to reference and track down this confusion ...

Discussion is welcome!

Thanks Joey.

np.

ahh soo much to read... i'll read up on it later. hehe

booooooring...


lol

I'm reading that the same way you are, Matt.

So, the supersharger guys can't up the boost, but Turbos are getting the good end of the deal here.

It's because you have to physically change part of the mechanism itself to increase boost.

No, turbos still get the crappy end of the deal because of lag. SCs are much more effective for Auto-X.

it depends on the superchargers. Not all superchargers act the same way (most of us think supercharger, down low torque and immediate power, but not always).

Which chargers don't give immediate low-end power? I can only think of the Mercedes clutched chargers, but I'm pretty sure that they always engage at WOT.