38 replies to this topic

[Ice]

Would all depend on diff ratio one would think

Are you running slicks

[mitchg]

Just a guess but i reckon 280rwkw in a torana gets you a mid 11 consistently. With 235rwkw id say in the mid to low 12 region.

Only one way to find out though.

[ls2lxhatch]

This is a typical formula used by a simple HP calculator.

 

HP = ( MPH / 233 ) ^ 3 * lbs

 

This is the formula used by a simple mph calculator.

 

MPH = ( (HP / lbs ) ^ .333333 ) * 233

 

This is a typical formula used by a simple ET calculator.

 

ET = ( ( lbs  / HP) ^ .333333)  * 5.825

 

 

They are handy calculations to be used as a rough guide but that's about all it is. Relying on a formula with two variables to accurately predict the performance of a car on a drag strip is rather optimistic.

 

At the end of the day such a simple formula will only be able to produce a rough guess that is not bad for a NA engine. If you have a forced induction engine then it is going to be even more inaccurate. According to the simple formulas a 600 hp 3.0L turbo engine will perform exactly the same as a 600 hp 8.0L naturally aspirated engine over the 1/4 mile.

 

 

 

This is what the parameters for a more comprehensive computer model looks like. If you were to input the figures from a dyno run into this sort of computer model then you would expect it to be reasonably accurate.

 

You can download a free trial from here.

http://performancetr...ag_race_pro.htm

 

 

 

 

 

 

 

 

 

[Lima31]

I have a Moroso slide rule, 425bhp and 3,130lbs indicates 10.9s ET @ 122mph.

 

Same power and weight with the above equations from lslxhatch is 11.3s @ 120mph.

Edited by Lima31, 09 October 2013 - 11:47 PM.

[gtrboyy]

Auto,big stallie,minimum 26" slicks & 3.9-4.11 gears yes probably can.

 

With t5 if it doesn't explode on you for driving car like you stole it most likely low 12 although with right setup & you can really drive stickshift with perfect set up 'maybe' if all comes together.T5 won't like big launches on slicks or hard/fast changes with 400hp engine for long imho.

 

Slicks? Diff gears? clutch?

[ls2lxhatch]

I have a Moroso slide rule, 425bhp and 3,130lbs indicates 10.9s ET @ 122mph.

 

Same power and weight with the above equations from lslxhatch is 11.3s @ 120mph.

 

 

I have seen the constant 233 in the formula above vary between 230 and 234. You will probably find a number in that range that lines up the Moroso slide rule. Any answer that is generated by a slide rule or two variable formula should only be considered as a wild guess at best. The peak HP of an engine tells you nothing about the power curve of the engine.

 

A far more complicated computer model with 100 plus variables like the Drag Race Pro software plus accurate dyno results throughout the rpm range and vehicle weights with driver and fuel is required if you want to get a more accurate idea of a vehicles 1/4 mile potential.

Edited by ls2lxhatch, 10 October 2013 - 02:16 AM.

[LXCHEV]

Auto,big stallie,minimum 26" slicks & 3.9-4.11 gears yes probably can.

 

With t5 if it doesn't explode on you for driving car like you stole it most likely low 12 although with right setup & you can really drive stickshift with perfect set up 'maybe' if all comes together.T5 won't like big launches on slicks or hard/fast changes with 400hp engine for long imho.

 

Slicks? Diff gears? clutch?

 

I completely agree with what gtrboyy said above regarding E.T.

 

I'm probably a good person to make comment here, as our cars are near-identical in power levels.

 

At it's peak, my old 383 SBC produced 245 rwkw. Car weighed around 1480kg with driver. With loads of torque, a 3200 hi-stall (TH350), and 3.7's, with M/T ET Street Radials, it ran a best of 11.77 @ 115MPH. There was nothing left in it. Perfect traction, 60 foot times of 1.69 from memory.

 

In other configurations (smaller exhaust), my car made 235rwkw and ran 11.9's and 12.0's.

 

Hope this helps.