DougFD3S

I'm in the process of rebuilding my FD, which will be receiving an LS1. I'd real like to autocross the car and be in a class in which I can be competitive. The only class I figure that I can compete in with an engine from another make is the Prepared-X class. Would this be the correct class? Also, how well would an LS1 FD do in this class?

DamonB

By SCCA rules you would be in E Modified which is the catch all for all cars with engine swaps from a different make. The winning national level cars are things like fully stripped and race prepped 3 rotor Sprites and Miatas along with other huge engines inside tiny cars with 12" wide tires

DougFD3S

Now I'm confused. What is the difference between the scca prepared-x and modified-e? It looks to me like the rules for prepared-x says that drive train and related components are unrestricted. They also note that chassis components attached my removable fasteners may be modified and replaced without penalty. Does that not allow an engine change?

speedturn

iTrader: (1)

Prepared class must have the type motor that came in the car.

Modified class can have any motor put in.

finky

iTrader: (2)

I am pretty sure that any engine swap will be allowed in the new X Prepared class. Scca.com has the rules all online.

Nihilanthic

Why the hell not just do it based on performance instead of whats in it... V8 FDs should be going up with Vettes, Vipers, 911s and the like, not one off auto-x race cars.

Icemastr

iTrader: (2)

Stock rotary FDs already compete with those cars in SM2 and soon likely ASP.

NeoTuri

iTrader: (2)

Like mine

NeoTuri

iTrader: (2)

That might be fine for your region, but I don't think X Prepared is a nationally recognized class.

And Damon is right, v8 rx-7's go into Modified.

hotfd3s

iTrader: (1)

I agree, too.

NeoTuri

iTrader: (2)

I need to make a correction. X Prepared is a class, but it only allows the rx-7 engine swaps of other rotaries (e.g. Renesis).

Mindspin311

wouldnt he go to SM2?

NeoTuri

iTrader: (2)

2006 Rules


Street Modified
16.1.D.1 - Engine block must be a production unit manufactured and
badged the same as the original standard or optional engine
for that model.

DougFD3S

Hmm. That is disappointing. Thanks for the clarification.

finky

iTrader: (2)

I just emailed an Auto X board member for clarification on this. I still think you can run a V-8 RX-7 in X prepared.

BryanDowns

iTrader: (2)

How is that different from an SM2 engine swap? You cant put a renesis or a 3 rotor into an FD and run SM2?

finky

iTrader: (2)

The rules for F prepared just changed for the 06 season where you could run a Renesis in place of a 12a or 13b in an FB or N/A FC. In B prepared I believe you have to stay with the 13bt.
You can do any porting you like but it has to be a 2 rotor that came with the car or legal ud/bd
SM2 on the other hand you can put ANY Mazda engine into any RX-7 and be legal.

finky

iTrader: (2)

I got the email back from the board member and he said he thinks any engine is legal and it is a National class. If you look in the Nov. Fastrack it has an equation system that has a base weight + _ X cubic inches.

I think AMRX-7 will see this soon and reply. He is now on the Auto X board too if I am correct.

DougFD3S

For reference, this is from the Appendix A of the 2006 SCCA Solo Rules book

Prepared Class X
XP vehicles must conform to the rules in Section 17 except as noted herein. Any
vehicle meeting the requirements of 17.2.A, listed in another Prepared class in
Appendix A, specifically listed in BP, CP, DP, EP, FP or GP that is not required to
run at 17.11.A specified weights, or listed below is eligible for XP. 17.11.A does
not apply. “In-excess” cars are not eligible for XP.

1. BODYWORK AND STRUCTURE
a. Chassis components attached by removable fasteners (e.g. bolton
subframes) may be modified or replaced without penalty.
b. 4WD/AWD systems may be modified or replaced.
c. Hoods (engine covers), front fenders, front & rear fascias, and
side skirts may be added, modified or replaced. Fenders may be
flared as per Street Prepared (15.2.A) or Prepared (17.2.L,
17.2.M). Non-metallic fender liners may be modified, replaced,
or removed. Body panels may be attached with removable fasteners
(e.g. Dzus).
d. Wings may be added, removed, modified, or replaced. Nonstandard
wings may only be attached to the rear deck/hatch area
and may not extend more than six inches beyond the widest part
of the bodywork on either side. The total area of all wings, including
standard parts, when computed as described in Section
12.9, shall not exceed 8 square feet. Wings may not extend more
than 66" above the ground, or above the height of the roofline,
whichever is higher.
e. Steering wheel, pedals, and driver’s seat must be completely to
the left or right of vehicle centerline.
f. Exhaust may exit through the bodywork. Rocker panels may be
modified for exhaust routing.
g. The transmission tunnel/cover may be altered to allow the installation
of an alternate transmission and/or driveshaft. Cars originally
equipped with a removable transmission tunnel/cover may
substitute a tunnel/cover of an alternate material.
h. The shift lever opening in the body of the car may be altered to
allow the installation of alternate shift linkage.

2. WHEELS
Any size wheel may be used. Wheel size does not affect minimum
weight.

3. SHOCK ABSORBERS & SPRINGS
a. Section 17.5.G, which restricts the type of shocks authorized by
17.5.C, does not apply.
b. Active/reactive suspension systems incur a minimum weight
adjustment, including standard parts.

4. BRAKES
a. Brakes, including calipers, caliper mounts, disks, drums, lines,
backing plates, pedals, boosters, master cylinders, handles, ABS
systems, proportioning valves, etc. are unrestricted.
b. Active automatic anti-lock braking systems incur a minimum
weight adjustment, including standard parts.

5. SUSPENSION CONTROL
Any front and rear suspension system type (MacPherson/Chapman
strut, double A-arm, live axle, etc.) may be used.

6. ELECTRICAL SYSTEM
Any ignition system is permitted. The number of spark plugs may
be changed.

7. ENGINE & DRIVE TRAIN
a. Drive train and related systems (induction, ignition, fuel, electrical,
cooling, oiling, etc.) and components (mounts, clutch, flywheel,
etc.) are unrestricted except as noted.
b. The engine block and cylinder head must not cross the location
of the original firewall separating the original engine compartment
from the original passenger compartment.
c. The engine orientation must not be changed (i.e., transverse
stays transverse, longitudinal stays longitudinal).
d. Any traction or stability control systems are permitted, but incur
a minimum weight adjustment, including standard parts.
e. Intercoolers must fit completely within the bodywork.
f. Air may be ducted to the induction system. Openings in the
bodywork to allow air to be ducted are allowed provided they
serve no other purpose.

8. OTHER
Vehicles exceeding these rules and prepared to the GCR/GTCS or
GCR/PCS are not eligible for this class.

9. SAFETY
a. All throttle linkages shall be equipped with more than one system
of positive throttle closure.
b. All non-stock fuel line(s) passing through the passenger compartment
shall be made of metal, or of metal braided hose with
AN Series threaded couplings; or entirely covered and protected
with a metal cover. Fuel pump(s), filter(s), pressure regulator(s),
and cool can(s) may not be located in the passenger compartment.
c. Dry sump tanks must be mounted within the bodywork. If a dry
sump tank is mounted in the driver/passenger compartment, it
shall be isolated from the driver by means of a metal bulkhead
or additional container that retains any spillage or leakage. Oil
filters and accumulators must be securely mounted within the
bodywork.
d. Oil coolers must be mounted completely within or under the
bodywork, but not in the driver/passenger compartment. Radiators
must not be located in the driver/passenger compartment.
Expansion or header tank(s) must be mounted in the engine
compartment.

10. MINIMUM WEIGHT
a. Engine Classifications
1. Four-stroke cycle and two-stroke cycle, naturally aspirated,
internal combustion engines will be classified on the basis of
actual piston displacement.
2. Turbocharged or supercharged versions of the above engines
will be classified on a basis of 1.4 times actual piston displacement.
3. Rotary Engines (Wankel): These units will be classified on the
basis of a piston displacement equivalent to twice the volume
determined by the difference between the maximum and
minimum capacity of the working chamber, times the number
of rotors.
b. Minimum Weight Calculations
All listed weights are without driver. Displacement is rounded
to the nearest
whole liter
RWD: 1200 lbs + 200 lbs/liter
FWD: 1200 lbs + 150 lbs/liter
AWD: 1200 lbs + 250 lbs/liter
- Cars with engine located behind driver: +20 lbs/liter
- Cars equipped with traction/stability control: +50 lbs/liter
- Cars equipped with active/reactive suspension: +100 lbs
- Cars equipped with ABS: +50 lbs.

Nihilanthic

According to this, a RWD LS1 car would have a min wbeight of 2400 lbs, w/o forced induction, abs, tcs, etc.

That would be a good class for LS1 rx-7s for sure, though I dunno if my 2.3T project would fly so well. 1800 min weight... dunno if I could get a FC nearly that light w/ a drivetrain.

I find it funny theres no stipulations about hp or hp/weight ratio, just minimum weight. But, I guess I could put on TCS and ABS and still be over min weight

Curiously, according to that formula, a 13BT would have a min weight of 2K lbs, and a 20BT would be 2400 min. NA 13b and NA 20b are 1800 and 2000 lbs respectively.

This could be a fun class

AMRX7

Sorry, I haven't really looked at the XP ruleset. In any case, for an official answer, write a letter to seb@scca.com.

From reading the rules posted here, it would seem a V8 is OK to run provided you run at the correct weight. It certainly would be illegal in SM2.

-Andy

NeoTuri

iTrader: (2)

Ok, I think I found something:

According to XP, the rules default to Prepared and does not authorize a modification unless specifically defined.


2006 Rule 17.10.J.1

Block
1. The block may be rebored no more than 1.2mm (.0472 in)
over standard. U.S. produced six-cylinder and eight-cylinder
engines may be rebored no more than .060 inches over standard.
Alternate blocks which are of the same material and
nominal dimensions as standard are allowed.

I don't think that includes rotary to v8 swaps.

NeoTuri

iTrader: (2)

SM only allows swaps of motors which come factory for the vehicle.

Icemastr

iTrader: (2)

SM allows any motors from that manufacturer not just the standard for that model. 3 Rotor in an FD is SM2 legal or else Erik Strelnieks wouldnt be doing it.

NeoTuri

iTrader: (2)

Alright, I see. I misinterpreted the rule when I had originally posted it. Make-only not model-only.