nzdatman
thank u
we also thinking of getting out of drag racing and getting into autocross(short curcuit)
any way once again thanks....
minnesh sa

guys
how do i post some photos and videos here
thanks
minnesh

Let's just clear up a couple of points...the Bathurst 1200s were based on production cars, they definately did not just get plucked from the production line and have the hot bits dropped in. In 75 I think the car John Boston has was specially ordered from Datsun Competition(now Nismo) to do the job at Bathurst in 76. Those cars were extremely well engineered and to be honest highly illegal !!Though in their defence many other teams were bending the rules as well. The engines remained the property of Datsun and were very special. The valvetrains were ultra light and the metalurgy used was highly advanced for the time. I have no doubts they were seeing the revs quoted and possibly more. I personally have revved A12s to close to 10,000rpm and the crank hasn't dropped out! The old timers like Bert and Vixen obviously have a bit of knowledge accrued on these cars and slowly the answers to the "how did they do that" ,that we all ask ourselves are getting answered.I have been researching the factory cars for many years and have even talked to the President of Datsun Competition at the time and he was very reluctant to even now divulge details about those cars and he knew them well. As they are still highly regarded in the organisation. I have a 1974 Datsun build manual which details in very fine detail how to build a 1298cc A12 with factory crank etc to produce a reliable 135 hp. That is without the sodium filled valves and titanium rockers the works cars had....as well as special build pushrods, followers etc etc...

I haven't been researching 1200s in competition, but here is what I know about Bathurst and touring car history in Australia.

Bathurst began in 63 when the race was moved there from Phillip Island. Cars were showroom standard Production Cars. And continued that way till 1973. They had to use the original carb and exhaust and suspension and wheels and... well, everything. Try cheating rules like that! So I guess that's not the era of the 130bhp A12 firebreathers. NB: There was a preiod where the ATCC was running Improved Prodcution rules and Bathurst was still run to Production car rules. There were just plucked from the production line - without any hot bits dropped in...

In '73 after the Supercar scare stopped the Production Specials being produced, Bathurst went to Improved Production rules, and the race went to 1000km (previously 500miles). Some people include this as part of the Group C era, but it wasn't. The Improved Production of the time were not like our current IPRA rules. It allowed for wider wheels and stuff. standard carbs had to be retained. and there were restricitions on exhaust size. Very few freedoms were permitted. I can't see anyone sneaking a twin sidedraught powered 1200 through scrutineering under those rules, so i guess that's not the era of these 130bhp fire breathers either.
Its rumoured that 5spd 1200 GX coupes were brought here for competition in this era, and yes that would have been highly illegal. They are also rumoured to have been widebodied cars, but these are all just rumours (ie it has never been verified). But I don't think they were able to quite squeeze 130bhp out of them even with twin SUs! :P

GroupC began in 77/78 (not sure off the top of my head). And the rules changed constantly until Group A took over for 85? (again not entirley sure - might have been 86)... Group C allowed alot of freedoms to the production cars including carb changes, but the original number of barrels had to be retained. And no amount of nostalgia is ever going to convince me they made 100bhp per litre A12's with 2bbls! And even under these far more open rules, they still had to use production box and diffs with production ratios. 11000rpm down Conrod equates to about 280kph by my guestimates here with a 1:1 top gear (wether it was the stock 4spd or illegal 5spd they were rumoured to have) and 3.9 diff.

I think we're all getting a little carried away about the capabilities of these Datsun 1200s people...

So, where did these over 11000rpm on Conrod 130+bhp A12 1200s fit in?

Quote:

You're absolutely right.
We should all sell these relics and buy R32's

HYP014 ran a 14.3@97mph, with open centre diff (4.8s though). Naturally aspirated, full weight street car.

Mat's seen the light!

Come on Sticks!

I have seen your son Mick run a 14.4 with a pretty stout A series you built for/with him at willowbank a few years ago in his blue ute.

How much quicker if you dropped it into a 1000 ute?

Minnesh,
I have a b110 with a good A14 on sidedraughts that was dynoed on a dynapack dyno at 100hp at the back wheels.
With a 3.9/1 H145 lsd and after throwing a standard 4 speed in for the day to give it more jump off the line, along with soft compound Bridgestone R's the best that I could achieve at Ruapuna drag strip was 16.2 @ 83 mph. Now to be fair the car is set up for circuit racing and would simply NOT hook up off the line, still snaking in 2nd gear- I have never experienced a lack of traction in the car like that ( evidently this is now a common complaint with Ruapuna ).
However, whilst I have set a target of high 14's for the car and I will not stop spending until I get it, I have to say that 13.85 seems a hell of a long way off that.
Perhaps to put things into perspective my turbo'd A14, b110 did 13.7 @ 107 mph and I would seriously doubt your motor would have anything like that sort of snot.
However to be fair I do remember a certain ex Shellsport 1200 coupe up in the Nth Island back in the 80's that had a Malcom Webb built A14 that may have got very close to that- it is possible but back then that was a $4500 engine, you could well double that now.
I'd love to see your engine specs if possible.
Cheers
Dave

Something is amiss

A few years ago I ran a B210 down willowbank, 3.9 and 56a, 165/70x13"

It only had 72.5HP at the wheels and yet managed a low 16. hmmm, more mass and 27% less power?




I was running the stock carb so was changing at 6k to stop the vaccuum gauge rising from 0!

Similar MPH would indicate similar power to weight ratio. Maybe I really did have a 100HP downdraught engine

I think people may be confusing HP with iHP.