What is a 9 second car
- Thread starter billyo
- Start date
As @TCJBOLDIE says, any car that will do the quarter mile run in under 10 seconds.
It is quite a big goal to set. Power requirements are massive and building something that can handle that much power and get this onto the road is a real challenge.
For a 1200kg car you are looking at 738bhp to beat a 10 second run and achieve a 9 second car.
If you have a heavier car say 2000kgs you would need 1230bhp.
Most guys aim to build a 10 second car which is a little easier and you still have a car you can use on the road as a daily driver.
Traction is a big issue, the car would need to be RWD or AWD at these power levels, you would need sticky tyres and the front of the car will likely lift up thanks to all that torque going to the rear wheels so you'll need to address this and make the chassis stronger.
Then you get into stopping the car, with all that speed you'll need a pretty hefty brake setup to bring the car to a stop and lots of guys use parachutes to peel off the speed more quickly.
It is quite a big goal to set. Power requirements are massive and building something that can handle that much power and get this onto the road is a real challenge.
For a 1200kg car you are looking at 738bhp to beat a 10 second run and achieve a 9 second car.
If you have a heavier car say 2000kgs you would need 1230bhp.
Most guys aim to build a 10 second car which is a little easier and you still have a car you can use on the road as a daily driver.
Traction is a big issue, the car would need to be RWD or AWD at these power levels, you would need sticky tyres and the front of the car will likely lift up thanks to all that torque going to the rear wheels so you'll need to address this and make the chassis stronger.
Then you get into stopping the car, with all that speed you'll need a pretty hefty brake setup to bring the car to a stop and lots of guys use parachutes to peel off the speed more quickly.
That's right 324bhp is all you need for a 600kg car, but try and find a 600kg car. The engine will weight a large portion of that, but if you think Caterhams, robin hoods etc you won't be far wrong.
So I am guessing Steve's aka Old Gits 'Worlds fastest Lotus Elan" is going to qualify to be a 10 second car
I just have to live long enough to see it happen.
I think he's done so much weight saving it's in negative territory now and positively floats down the track!
JohnHubinger
Full member
Is it real to make my 240SX a 9-second car?
Time and money can take any car into the 9's or lower so IMO it comes down to the question do you really want or need one?
So a 240sx weighs around 1224kg So it would need a shade over 1050bhp to beat 9 seconds or 750bhp to get under 10 seconds.
with a large turbo and nitrous this is possible but very expensive to do.
with a large turbo and nitrous this is possible but very expensive to do.
- Points
- 407
- Car
- 2002 Clio 172
Adding power and cutting weight is usually the answer here, there is a lot of excess weight in most factory cars. Swapping a bonnet for a carbon fibre one will save quite a bit, remove the rear seats and spare wheel as well and you'll only have to add 500bhp or so.
Fabia17
Torque Junkie
I used to build drag race cars in Australia back in the 1970s Christ, so long ago. Cars back then were heavy and engines were huge cast iron lumps in general. I built with a mate a 10.6 second HQ Holden sedan. It was a beast and street legal. We used to race back and forth across Adelaide.
I digress in fond memories, excuse me.
We had to adapt a Ford nine inch LSD back axle and diff to chanel the power to the wheels, The axle had tramp bars which (sort of) prevented the axle from tramping when the power went on.
After several sheared half shafts we had a pair machine flat right upto the bearing spigot, half shafts usually have a stepped area several inches long. This step was acting as a shear point. So now instead of shearing the shafts would wind up slightly, just enough to prevent the shear.
We had to modify the propshaft in a similar way to and fit safety loops.
Moving towards to the gearbox, this was an upgraded Tri matic with heavy duty bands and a manic shift kit, connected to the shifter.... More of that story shortly.
A 3000rpm tourqe convertor which was tiny, about 9 or 10 inches across, this allowed you to floor the gas with the brakes locked on, and hold the engine at 3000 rpm, as soon as you released the brakes, bang! You were launched.
Onto the motor
This started life as a four bolt main bearing 327 chevy motor.
It was stripped.
Bored to an inch of its life and fitted with forged pistons, weighed and balanced.
A steel crank was obtained, Machined, nitrided, and balanced.
The rods were replaced with I beam section rods, which were fettled, mirror polished, shot piened, then weighed and balanced.
The engined was blueprinted.
All bolts were racing spec.
The timing chain was replaced by a specialist gear drive unit.
The cam was full drag spec, with roller tappets and roller rockers back then this was super trick gear.
On top was an Edlebrock Hi-Rise manifold connected to heavily worked heads, with port polish and gas flow, all chambers were cc'd. Super race valve springs etc and the crowning glory, twin Holly Mechanical secondary centre shooters.
The sump capacity had to be increased by 50% and a high pressure, high volume pump fitted with a huge oil cooler. The radiator had to be replaced with a much larger one and a transmission cooler which was oil to water and air cooled.
It was a lot of work, months and months. The engine dyno showed 1280hp at the flywheel, it was frigtening.
The first few runs were OK. We managed mid to low 11s over the following weeks we stripped out unnecessary interior etc, but left enough for it to be legal-ish, and we tweeked the jetting and fuel and eventually managed the 10 second bracket.
This was an amazing feat back then, if I remember correctly we threw about 10 or 11 thousand Australian dollars at it, in those days, about 6 or seven thousand pounds, almost a years wages....
Alas, it would not last. My mate was out Street racing one evening, and we had ordered a ratchet shifter for the gear selector, but it had not arrived.
Down by Oaklands Park was a rail crossing with a ramp off and on, oddly just recently been removed, he hit it at speed and the jolt threw the gearbox into reverse which tore the gearbox off the back of the engine, shearing every single bolt, and twisted up the propshaft.
We recovered the car back to the garage and removed the engine and gearbox. we removed all the sheared bolts and offered the box back upto the engine and it no longer fitted.
All the bolt holes were out of alignment, the reverse tourqe generated by the box being thrown into reverse had stretched the flange on the back of the engine block so nothing lined up.
That was the demise of our 10 seconds car. All for the impatience of waiting for the ratchet shifter to arrive....
It was not the only car destroyed in the need for power, speed and time....
I digress in fond memories, excuse me.
We had to adapt a Ford nine inch LSD back axle and diff to chanel the power to the wheels, The axle had tramp bars which (sort of) prevented the axle from tramping when the power went on.
After several sheared half shafts we had a pair machine flat right upto the bearing spigot, half shafts usually have a stepped area several inches long. This step was acting as a shear point. So now instead of shearing the shafts would wind up slightly, just enough to prevent the shear.
We had to modify the propshaft in a similar way to and fit safety loops.
Moving towards to the gearbox, this was an upgraded Tri matic with heavy duty bands and a manic shift kit, connected to the shifter.... More of that story shortly.
A 3000rpm tourqe convertor which was tiny, about 9 or 10 inches across, this allowed you to floor the gas with the brakes locked on, and hold the engine at 3000 rpm, as soon as you released the brakes, bang! You were launched.
Onto the motor
This started life as a four bolt main bearing 327 chevy motor.
It was stripped.
Bored to an inch of its life and fitted with forged pistons, weighed and balanced.
A steel crank was obtained, Machined, nitrided, and balanced.
The rods were replaced with I beam section rods, which were fettled, mirror polished, shot piened, then weighed and balanced.
The engined was blueprinted.
All bolts were racing spec.
The timing chain was replaced by a specialist gear drive unit.
The cam was full drag spec, with roller tappets and roller rockers back then this was super trick gear.
On top was an Edlebrock Hi-Rise manifold connected to heavily worked heads, with port polish and gas flow, all chambers were cc'd. Super race valve springs etc and the crowning glory, twin Holly Mechanical secondary centre shooters.
The sump capacity had to be increased by 50% and a high pressure, high volume pump fitted with a huge oil cooler. The radiator had to be replaced with a much larger one and a transmission cooler which was oil to water and air cooled.
It was a lot of work, months and months. The engine dyno showed 1280hp at the flywheel, it was frigtening.
The first few runs were OK. We managed mid to low 11s over the following weeks we stripped out unnecessary interior etc, but left enough for it to be legal-ish, and we tweeked the jetting and fuel and eventually managed the 10 second bracket.
This was an amazing feat back then, if I remember correctly we threw about 10 or 11 thousand Australian dollars at it, in those days, about 6 or seven thousand pounds, almost a years wages....
Alas, it would not last. My mate was out Street racing one evening, and we had ordered a ratchet shifter for the gear selector, but it had not arrived.
Down by Oaklands Park was a rail crossing with a ramp off and on, oddly just recently been removed, he hit it at speed and the jolt threw the gearbox into reverse which tore the gearbox off the back of the engine, shearing every single bolt, and twisted up the propshaft.
We recovered the car back to the garage and removed the engine and gearbox. we removed all the sheared bolts and offered the box back upto the engine and it no longer fitted.
All the bolt holes were out of alignment, the reverse tourqe generated by the box being thrown into reverse had stretched the flange on the back of the engine block so nothing lined up.
That was the demise of our 10 seconds car. All for the impatience of waiting for the ratchet shifter to arrive....
It was not the only car destroyed in the need for power, speed and time....
Last edited:
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