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4.3 Transmission: The design of the transmission is free, save for the following:

<snip>

• Four-wheel drive is permitted on cars originally produced in that configuration, however they must remain in “floorpan” construction and retain the original engine block and cylinder head/s for that particular vehicle model.

<snip>

4.4 Engines:

(iii) To establish total engine capacity.

• A multiplying factor of 1.7 applies to forced induction engines.

• A multiplying factor of 1.75 applies to rotary engines.

(iv) The maximum engine capacities are:

  • Naturally-aspirated reciprocating 6000cc
  • Naturally-aspirated rotary engine 3428cc

  • Forced-induction reciprocating 3529cc
  • Forced-induction rotary engine 2016cc

So...

RB26 has a "capacity" of 2568cc x 1.7 = 4365cc?

RB30 has a "capacity" of 2998cc x 1.7 = 5096cc???

Do the two clauses mean that we are unable to run RB30s in 3D logbooked cars?!? :P

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there is no requirement in 3D Sport Sedans to retain original block.

RB30 with forced induction can be used:

the limit on the total engine capacity for Sport Sedans is 6000cc. There is a 1.7 multipling factor applied to forced induction engines. So the maximum capacity engine that can be used with forced induction is 6000cc/1.7=3529cc.

All CAMS rules are a PITA to interpret until you get the hang of them.

My mistake - I didn't read the entire set of rules. I just based it on the fact that Sport Sedans has always been "engines are free", and I had a skim over the engines section and it was still the same... I see they snuck that engine rule for 'floorpan vehicles' into the Transmission section of their rules. way to make life difficult CAMS!

Thanks for the clarification guys :)

Doesn't the OS Giken kit retain the use of an N1 block? ;) That would satisfy the rules...

yep, it's a high deck/spacer kit with liners and stroker crank. and it uses the original block. so technically you should be able to use it. when they list the size limits for turbo engines that is before the 1.7 multiplier is applied. so you can go up to 3.5l.

also of course 2.8 strokers are no problem and there are plenty of those around. and I think the race pace 2.9 uses an RB26 block.

LOL, yep, so would the monster engine that Racepace screw together.

LOL, i wonder if the wording is loose enough with retaining origina block that you can just put the bare block on the middle of the car and run a 6L Chev with a diff in the sump just in front of it :)

way to post while I was posting. now I look dopey!

and yes run the RB26 block in the boot. just like group A rules where if a car was factory fitted with an AFM you must retain one and have it plumbed into the intake tract. says nothing about it being the primary load sensor, so you screw it to the inner guard, hook up a tiny 5mm vacuum line to it and use a map sensor to run the engine like you wanted too. all legal. ;)

but seriously, I think in this case you'll be restricted to actually using a 26 block for the engine. but that's no problem. you can get plenty of power and plenty of response out of a 26 block based motor. just get a nice close ratio box, and a nice rev limit and away you go.

yeah the rules will not allow an rb30 in a 4wd. there are a lot of freedoms when they say "standard block" covered in 4.4 part 4 but I don't think they are relevent to rb26 unless you want to make your own block.

However, you can still:

sleeve the block

space the head up

shoehorn an rb30 crank in the 26 block

go way oversize on pistons.

so there are plenty of ways to get to 3 or maybe even 3.1 litre.

but in any case why bother when you can get sufficient power out of rb26. 450awkw should be enough for most cars and more is possible if you want to spend enough.

re the rules - this is just the usual CAMS being stuck 20 years behind the times and protecting the "old" way of building race cars. Production cars are full of 4wds but they are banned in every other category because they go too fast. good irony for racing.

so 4wd are stuck with much higher minimum weights and original block. together this means gtr is about the only car with a genuine outright chance and even then it would be a long shot. CAMS are doing everything they can to keep 6l chev dinosaurs instead of 3.4l rbs.

not sure that they got the balance right even so, the BSM GTR was a genuine 4th in the NSW champs. still about 2 sec off the front runners but a very good start for such an under-developed car

Im with Duncan you dont need a big stroker or bucket loads of grunt.

You need massive corner speed to be at the pointy end, after watching far to many in car laps and recorded races lattely the quickest cars are carrying far more corner speed than the others but the outright acceleration was nothing that a 400Kw GTR could not acheive.

Unfortunatly to get a GTR cornering like a space framed calibra is a massive massive ask. Even if you have bulk grunt and limitless torque your not going to catch the chev in a straight line because he exited with 30Km/h more speed than you did.

:)

in all seriousness....you would only ever get pinged for running an rb30 if you took it full circuit racing. for 99% of cars a sports sedan log book with an rb30 will sneak through fine - there is nothing a scruitineer would pick up on unless they are looking for it (they focus on safety not eligibility). This is exactly the same as improved prod GTRs...there are a few out there but you can be confident they don't run the required 32mm restrictors. There are 3 production GTRs I know of too and none of them run standard boost except when doing NSW champs racing.

our sports sedan is currently 2.6l but I was expecting to chuck rb30 in there next. if cams aren't happy they can shove it an I will do track days and AASA. the only thing I'll miss out on is CAMS NSW race series in 3D but I don't have 200k a year to be competitive there anyway

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