In car video from Suzuki S1600 Finland 2005

[Bede]

Originally Posted by fro

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...

Mechanical sympathy hey Fro?!

[fro]

Oh, and for comparison:

L18 Datsun crank = 78mm stroke
L20B Datsun crank = 86mm stroke

L18 @ 7500rpm = 3838 feet per minute = 19.5 metres per second = 70.2 kilometres per hour
L18 @ 8000rpm = 4094 feet per minute = 20.8 metres per second = 74.88 kilometres per hour
L18 @ 9000rpm = 4606 feet per minute = 23.4 metres per second = 84.24 kilometres per hour
L20B @ 7500rpm = 4232 feet per minute = 21.5 metres per second = 77.4 kilometres per hour
L20B @ 8000rpm = 4514 feet per minute = 22.9 metres per second = 82.44 kilometres per hour

[Ben Wilson]

Originally Posted by fro

L20B @ 8000rpm = 4514 feet per minute = 22.9 metres per second = 82.44 kilometres per hour

L20B @ whatever Fro revs the car to = ?????

[fro]

Originally Posted by Bede

Mechanical sympathy hey Fro?!

I've got sympathy. I wince all the time when I'm abusing my vehicles.

[fro]

Originally Posted by Ben Wilson

L20B @ whatever Fro revs the car to = ?????

L18 @ 9000rpm = 4606 feet per minute = 23.4 metres per second = 84.24 kilometres per hour

I knew there was a reason I didn't have a 2 litre motor.

L20B @ 9000rpm = 5078 feet per minute = Kaboom...

[Spac]

And remember that the piston speeds Bosshair is estimating, are AVERAGES, not peak speeds... And that the piston is at a standstill at both ends of the stroke, so the peak speeds are significantly higher...


Anyway, the real reason I'm posting:
Tort, the TX3 Sport is allowed because it was F16. Remember, ARCom is/was desperate to get people into FWDs (for some incomprehensible reason), and they fudged their own rules to encourage it.

I find the 20V AE101 far more offensive - at least the Mirages and the Lasers were a factory built car, where the Corolla is a parts bin special...
I wonder if Guys Turbo SW20 proposal could float, now that the Cyborg Mirage and TX3 Sport have been allowed. It would be very hard to refuse to allow the MR2 because it is not Aust delivered, and not homologated, when they've already allowed two similar cars...

[fro]

Originally Posted by Spac

And remember that the piston speeds Bosshair is estimating, are AVERAGES, not peak speeds... And that the piston is at a standstill at both ends of the stroke, so the peak speeds are significantly higher...

Damn... Anyone know of a peak-piston-speed calculator?

[Mark]

Spac started alluding to it.
Surely for every rpm of the crank shaft, you are changing acceleration four times at the piston?
1) Piston heads up from BDC but before halfway ( from zero velocity to max velocity).
2) Piston slowing from halfway to TDC (from max velocity to zero velocity)
3) heading back down from TDC to halfway down
4) halfway to BDC.
Take the F1 engine revs: 18500rpm. Equals 308.3 revs per second.
As described above there are four acceleration (absolute of acceleration and deceleration) periods every revolution of the crank, for a total of 1233 acceleration 'periods' per second.
1 second divided by 1233 means each period is 8.11 x 10 to the power of -4 which I think means 0.0008 seconds.

Acceleration can be defined as a = difference in velocity / time.
The difference in velocity is 88kph into m/s = 24.4m/s
Therefore,
a = 24.4/0.0008
a = 30500 m/s/s !!!!!!!!!!!!!!!
Otherwise expressed less impressively as 3112g

Mark

[fro]

Originally Posted by Mark

Otherwise expressed less impressively as 3112g

I still think that's pretty impressive. If you had a 300gram piston-rod assembly, pulling 3112g, it would have the same force as a weight of 933.6 kilograms.

That impresses me a whole bunch. Any idea how much an F1 piston-rod assembly actually weighs?

[global]

Originally Posted by 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

We have done alot of research into N/a 1600. The answer in the power stakes lies with Honda B16A's. I have just got back from NZ where I saw / drove a cams legal (f16/prc) N/A 1600 with 230 + bhp - yep I want one!!!!

The Charades Rooklyn/ Bates etc had generated (forgive me Neil if I am wrong) around 180 fw/hp. The manifold pressure is the problem to generate more power. A chap in Perth has managed 200hp at the fly with Quads/ ecu etc from the Charade.

Rev limit is 8300 ish (8500+) to much causes troubles.

We have spent reasonable $$$$ to improve our Hp - Motec / Quads / Engine etc and won't speculate to much on power - apart from its adequate.

With extra power you do need ratios, strength and a clutch to suit.

Having helped a formula Pacific team in the late 80's I know what it takes to get 230 hp from a 1600cc and I am very sceptical of anyone claiming around this figure in a privatley run rally car. I don't doubt its possible, I question the logic given the use/ relaiblity and cost. A pacific engine in today's money can be close to 25k!!!!!!!

In p2 anyone with 165 - 200 hp and various weights is going to be competitive. Why build the hand grenade option?

[Ben Wilson]

Originally Posted by Karl Willett

You guys do know you're going to get a Factor rotary speil at this point, don't you?

Bring it on...

[Swill]

Originally Posted by TX3 Rally

we're redlined at 12,800 with the new engine
unfortunately I'm about 20hp short here
we come in at 920kg

Twelve thousand eight hundred? out of 1600cc wet sump? im in the non believer camp, but ill eat my words if you produce the dyno sheet. Maybe a touch peaky for a blind rally on a wet night...

[tortfeaser]

Originally Posted by Spac

Anyway, the real reason I'm posting:
Tort, the TX3 Sport is allowed because it was F16. Remember, ARCom is/was desperate to get people into FWDs (for some incomprehensible reason), and they fudged their own rules to encourage it.

I find the 20V AE101 far more offensive - at least the Mirages and the Lasers were a factory built car, where the Corolla is a parts bin special...
I wonder if Guys Turbo SW20 proposal could float, now that the Cyborg Mirage and TX3 Sport have been allowed. It would be very hard to refuse to allow the MR2 because it is not Aust delivered, and not homologated, when they've already allowed two similar cars...

Oh yeah, I'm on the Corolla thing too - its just rubbish. The F16 argument doesn't wash as (apparently) these are a pre-'86 car not eligible for F16 at ARC level. Unless there's a loophole - have a particular car manufactured after 1 Jan '86 that is of a model type manufactured prior to '86. You get the pre'86 freedoms and get to compete in F16.


Basically, both the 20v AE101/2 and the Laser Sport are about as legit as a twin cam C20XE Camira, just someone's found a way to fool ARCom into a dumb decision.

[tortfeaser]

Originally Posted by YRALLY

Twelve thousand eight hundred? out of 1600cc wet sump? im in the non believer camp, but ill eat my words if you produce the dyno sheet. Maybe a touch peaky for a blind rally on a wet night...

Picsofdynosheetorban

You'd want a pretty good right toe to modulate that Hp and some flash drive shafts and CVs.

[MarkH]

Class me as ignorant, but what engine does a Laser Sport run????