In car video from Suzuki S1600 Finland 2005

[tortfeaser]

Its never been clear why the KC and KE Laser Sport were recognised for PRC. Why were they? Same question for the Corolla FXGT. AFAIK they weren't sold here. What's the diff between those and any other car not sold domestically.

1020kg weight from http://www.drive.com.au/buy/market_v...X3&year=&body=

I think the way you get a car recognised is to build it, then beg ARCom for a few years. Renault Clio Sport V6 anyone?

[TX3 Rally]

Originally Posted by tortfeaser

I think the way you get a car recognised is to build it, then beg ARCom for a few years.

We didn't beg for a few years, we simply did our research, spoke to the relevant people to find out what it was that they would require in a submission, spoke to someone else who had also done a successful submission (Lee Peterson for the Mirage Cyborg), and then wrote the submission and submitted it.

[Mark]

Jeezus Christ! You've got to put up the dyno curve for this! I'll show you mine if you show me yours....

Have you changed the valve size over the stock?

Mark

[tortfeaser]

So the question remains - what rationale was given for allowing a non-Australian delivered car to compete in PRC?

As for 230Hp at 12,800RPM using the standard crank, rods, unmodified head and stock valve sizes, standard method timing gear...

...as Darryl Kerrigan would say, 'tell him he's dreaming'.

[TX3 Rally]

Originally Posted by Mark

Have you changed the valve size over the stock?

We've done everything the pre'86 rules allow.

We are doing some more work on the dyno today to try some different cams to see what change it has on power and torque (particularly where the peak power and torque points are, and how much if any it looses). If these cams are still successful then the engine guys reckon we will drop the redline by between 2000 to 2500, which will be nice.

[TX3 Rally]

Originally Posted by tortfeaser

As for 230Hp at 12,800RPM using the standard crank, rods, unmodified head and stock valve sizes, standard method timing gear...

...as Darryl Kerrigan would say, 'tell him he's dreaming'.

Suggest you go back and read your CAMS manual again re. pre '86 freedoms for engines Particularly Page 11-44 of the 2006 manual - just reading the top half of the left hand column will do.

So hence Carillo Rods, oversize valves, modified crank, lightened flywheel, ported head, Motec, quad 45mm throttle bodies, etc etc.

[Mark]

The problem is, Kent, is that you're talking big horsepower out of 1600cc.

There's a bit of knowledge from a few people on the forum regarding 4AGE's for example-another 1600cc as you know- engine. And it is commonly rated that you can get 240hp out of them at 10,000rpm in Formula Atlantic (open wheeler) trim: huge porting, big - 312 deg.+ cams, awesome exhausts that are physically constrained so much - so I reckon you could spend the $10K on a race engine and fit it to the car. The closest I've seen anyone in rallying do this is Sam Brand, who I think, had 13:1 compression, TRD parts throughout the engine and it was good for an impressive 200hp. I'm sure the Charade's guys - Global/Russ etc - can correct me but I think Rick Bates/Warwick Rooklyn's Charade crunched out around 185hp.

I asked about the valves because it seems to be a limitation on heads that the stock valve size is the big restriction once you start to flow towards the upper end of the engine efficiency. Even a SR20 valve fitted to a 4AGE only flows 244hp - which maximum valve seat angle porting...if everything else doesn't provide a restriction. Hence my question regarding valve size in your case?

Crank shaft speed - what's the stroke and bore. I seem to remember that there is a physical common limit regarding metal strength in crankshafts: yes, F1 cars pull 18,500rpm but with little stroke. Yet a big loping V8 at 7,000 rpm pulls a similar amount of g-force on the crank because the stroke is 2.5 times longer than the F1 engine. I'm just curious as to what your bore and stroke is to make those revs?

It's all possible - I'd just love to see how you've done it. Even if you PM/Email me...I'm not in the same car class, so I'm hardly likely to copy what you've done!

Thanks.

Mark

[tortfeaser]

Re pre '86 - of course you can. When you can run anything you want model wise the '86 date becomes irrelevant.

What is a Laser Sport? Was it built here? Did Ford sell Lasers in Japan? Or is it a Mazda? BP motor? What CVs? Driveshafts?

It just is not believable.

[Glen]

Originally Posted by TX3 Rally

not yet, currently just a close ratio dogbox, but it could be getting something much better real soon
LSD only I'm afraid

I was just looking through B06/026 (The ARC sporting Regs for 2006), and the requirements for the F16 Cup on page 14 say:
- sequential boxes are not permitted
- only mechanical, non-active differentials are permitted
- Maximum wheel diameter is 15"
- maximum of 12 tyres used in each nominated Super Series Event
- fuel shall be Level 2 control fuel (BP Ultimate)

I'm not sure if you plan on running in the F16 Cup but these restrictions may mean you won't be able to improve upon your dog box. Perhaps running BP Ultimate may also mean you might have to detune the engine a bit.

[fro]

Glen,

The TX3 shouldn't be eligible for F16 anyway... from what Kent's said, it's pre-86 PRC P2, not F16 (which is, by definition, post-86).

[Glen]

Oooops!

Disregard what I said. Fro is on the money!!

[Mark]

Kent, I just don't get it now that I run the numbers. Feel free to correct me at any point.

Take an F1 engine. The facts I took are:
-the bore is 2 - 2.5 times the stroke.
-V10 configuration.
-F1 engine is the ultimate in engine speed blah blah blah
-Therefore, a cylinder has 300cc capacity.
Let's calculate the stroke (x), hence piston speed.
-I ended up with around a 40mm stroke, 100mm bore gets me close.

Chucking it (40mm stroke) into the piston speed calculator: http://www.csgnetwork.com/pistonspeedcalc.html
gives us 4855 feet per minute piston speed.

Interestingly, most engines run around the same pistons speed: my evo 3 at 7,000 rpm in normal form, 88mm stroke produces at 7000 rpm 4041 fpm piston speed.

So, it shows the most cars have around a similar piston speed.

Say you've got a big V8 - 101mm stroke? - revs less to say 6,500 produces 4307 fpm.

Elaboration:
To run undetermined stroke, but at 12,800rpm the numbers you have given us, to reach a similar piston speed to the best of the best - an F1 car - requires a stroke around 58mm in length (4871fpm by the way).

A quick google brings in the normal stroke of around 86mm? for your type of engine. Running the calculator on 86mm stroke with 12800 rpm produces an impressive 7223 fpm - 48% more piston speed than an F1 car. How do you cool that? That is a lot of heat.

My maths and facts could be a bit shaky so feel free to correct me.

Thanks.

Mark

[Mark]

Oh and Suzuki S1600 - bore: 81 stroke: 77.5
Official rev limit: 8,500rpm: 4322fpm
Rumoured revlimit: 9,200rpm: 4678 fpm - very similar to F1...

Mark

[Bede]

Originally Posted by Mark

A quick google brings in the normal stroke of around 86mm? for your type of engine. Running the calculator on 86mm stroke with 12800 rpm produces an impressive 7223 fpm - 48% more piston speed than an F1 car. How do you cool that? That is a lot of heat.

The real problem is the inertial loads caused by the piston on the con rod and crank!! Try slowing down a piston from that speed in ~4cm!!

[fro]

Originally Posted by Bede

The real problem is the inertial loads caused by the piston on the con rod and crank!! Try slowing down a piston from that speed in ~4cm!!

4855 feet per minute = 24.6634 metres per second = 88.7824 kilometres per hour

7223 feet per minute = 36.69284 meters per second = 132.094224 kilometers per hour

Think about accelerating a piston and rod (300g+++) from 0, up to 88km/h, and back to 0 again, in the space of 86mm... then think about the extra momentum that projectile has with an additional 44km/h on board.

The stresses inside an internal combustion engine are amazing. But metals have finite limits...