extra bhp for 2secs off the 1/4 mile?

I'd be interested in people's guesstimates for the power needed to clip off two full seconds from the quarter mile times.

Let's assume (for argument's sake) that a stock supra does 320hp

cheers guys

Take my stock time of 14.1, - 2 secs and ask Monkey roughly what BHP hes running.

surely it's dependent on torque rather than bhp?

Maybe just 40-80BHP if run in conjunction with an Autobox featuring a 3800+ Hi Stall and Drag Radials.

I'd be interested in people's guesstimates for the power needed to clip off two full seconds from the quarter mile times.

 

Let's assume (for argument's sake) that a stock supra does 320hp

 

cheers guys

John this may also be heavily dependent on people driving style as well.....ie launch, shifts etc

If I was estimating I would prob say 100-150maybe

My Car runs 11.8 full trim with a passenger and a spark plug giving up mid run, on its last outing on sunday, Running 1.6bar it "should"be making about 550flywheel power.

It has a T67, Emanage, 650s, TC3800, MT 16inch drag radials (rear) 18 inch wheels on the front.

K.

K you should be aiming for the 10's - you've only just beaten a stocker

What's your 60ft like?

1.9 secs to 60ft

To give you the just of it, I had just drove 2 hours to get to the drag strip, Went straight to the start line, Done a quick run non timed to get heat in the tyres, Pulled back round still with my mate in the car, Staged , Got the launch ok could have been beter, As it was my first time using the ET Radials i wasnt sure how to do it, About 8/10's of the way up the strip the car lost a lot of power and was running like a sewing machine. Spectators says they seen a puff of Yellow smoke from the back.

So i coasted over the line, With more heat in the tyres, without my passenger , removing all the sterio equipment and spare wheel ect and a few more runs to get it all right i think id have seen a very low 11.

And the 10s are coming soon hopefully, Crails surface is terrible, My friends skyline ran a 11.03 at shakespear country raceway, It cant beat 12.8 at crail..... :thumbdown

Im coming to Santa Pod on the 9th with a few cars from uphere, So hopefully set a good time down there.

I also have a wizards of NOS kit im toying with the ides of fitting, Just need to find out why the IK24 gave up.

Anyway, My 11.8 is respectable i think for me, Ive only owned the car 2 months and been drag racing it in twice, Looking at the drag chart im joint 5th, Not bad for a privatly owned entry.

K.

you should be able to get 1.5 60' times, I managed 1.8 with the manual.

John the set up is more important. Are you talking with road tyres/boost

I am talking about the exact same setup & launch technique.

Same gears (o/d off perhaps), T/C off, same fuel, same road, same weather, same EVERYTHING save horsepower.

The tests I'm doing currently are all 40-100 so that I don't have to care about autobox stresses until 40mph

My take is that the 40-100 is a whole chunk of the 1/4mile, so if you chop off 2 seconds of this, it is roughly like chopping off 2 seconds off the 1/4 mile (for bhp comparative purposes!)

So let's say that on a particular stretch of road you do 14.5 secs with stock power, how much power would you estimate to have if you did it again at 12.5?

That is the question.

Might as well nigh on double it if you're not going to improve your grip...

My problem is that I have a series of comparative dyno printouts, but none with a baseline of the stock car.

I also have highly repeatable bhp estimates from the accelerometer, including baseline of stock car, but these figures look seriously low, certainly not explaining the 2 seconds difference in 40-100. I am sort of trying to tally together the dyno and accelerometer figures - maybe it's futile, who knows...

There is no wheelspin or loss of traction to speak of, tyre pressures etc are identical, so are the auto gearchanges, so the figures are very repeatable -- I do them in pairs anyway

I also have highly repeatable bhp estimates from the accelerometer, including baseline of stock car, but these figures look seriously low, certainly not explaining the 2 seconds difference in 40-100. I am sort of trying to tally together the dyno and accelerometer figures - maybe it's futile, who knows...

John,

I tried to do this a while back using 1/4 mile timeslips and dyno figures. The power estimates were coming up anywhere from nearly spot on to 25% too low. I couldn't find the error either.

...The power estimates were coming up anywhere from nearly spot on to 25% too low. I couldn't find the error either.

The good thing about 40-100 is that it doesn't have any of the standing-start malarky. Any wheelspin, bogging down etc will probably be over by 40mph, so you datalog nice, repeatable figures.

If the road isn't dead flat and straight, the full 1/4 mile figures are flawed anyway -- standing starts aside.

But the thing gives me bit more than 15% increase in hp (while on-boost) and the 40-100 figures drop by 2 seconds. Surely something's amiss...

Actually something like this is what I was looking for.

How close to reality does it look?