mwp

i did 12.68 @ 90mph.

.
.
.
on 17" wheels

[Edited by mwp - 10/1/2003 1:13:30 PM]

hawkeye

saxo boy i realise they are different things but the figures DONT add up at all

how can a car that does the quater mile with a terminal speed of 90 mph and 12.68 secs be quicker than a car that does 0-100 in 12.20 secs ie prodrives figures



could that be it tyre sizes the smaller the tyre the faster you need to be going to conver 1/4 mile surely it wont make that much difference???

ps edited due to hopefully my stupidity and saxo boy's greatness

[Edited by hawkeye - 10/1/2003 1:35:08 PM]

mwp

i didn't say i couldn't do 0-100 in 12.2 ... it just doesn't look right.

.. although i probably can't

anyone got a 1/2 mile driveway nr Cambridge ?

[Edited by mwp - 10/1/2003 2:35:06 PM]

bobfrog1

saxo boy, yep! he was running slicks, I know a 1.8 60ft is up with the RWD v8 boys but I didn't know what AWD times were like

I've got a scan of the slip and a video somewhere, I'll dig them out later. Do you still have your slips?

[Edited by bobfrog1 - 10/1/2003 5:12:48 PM]

RB5SCOTT

What may be mixing things up a bit is that i don't think the speed trap on sunday was 100% true. Jonno was pulling 110mph on the speedo at the end of the quarter and i know his speedo is slow!

Jonno's car has 400bhp! also its true about the extra gear change on an STI, having to just grab 5th 30metres from the quarter will affect times?

[Edited by RB5SCOTT - 10/1/2003 11:31:35 PM]

( R6 CDW )

Perhaps i could give you mine!



[Edited by ( R6 CDW ) - 10/2/2003 10:38:25 AM]

mwp

i think dazza's right, flat out in 4th in a PPP is just over 100mph. in reality just under given the overstated speedo readings next to a road angel.

BUT ... we're still no nearer the answer to the prodrive 1/4 vs 100.

[Edited by mwp - 10/2/2003 7:48:35 PM]

johnfelstead

just to show the gearing comparisons.

STi8 TypeUK

True road speeds per 1000 rpm:
Rpm: 1000 2000 3000 4000 5000 6000 7000 8000
1st: 5.24 10.48 15.72 20.96 26.20 31.43 36.67 41.91
2nd: 8.02 16.04 24.06 32.08 40.10 48.12 56.15 64.17
3rd: 10.82 21.63 32.45 43.27 54.09 64.90 75.72 86.54
4th: 14.15 28.31 42.46 56.61 70.76 84.92 99.07 113.22
5th: 19.62 39.24 58.86 78.47 98.09 117.71 137.33 156.95
6th: 25.20 50.40 75.59 100.79 125.99 151.19 176.38 201.58

True rpm for road speeds:
Speed: 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
1st: 1909 3817 5726 7635
2nd: 1247 2494 3740 4987 6234 7481 8727
3rd: 924 1849 2773 3698 4622 5547 6471 7395 8320 9244
4th: 707 1413 2120 2826 3533 4239 4946 5653 6359 7066 7772 8479 9186
5th: 510 1019 1529 2039 2549 3058 3568 4078 4588 5097 5607 6117 6626 7136 7646
6th: 397 794 1191 1587 1984 2381 2778 3175 3572 3969 4365 4762 5159 5556 5953


My STi5 TypeRA

True road speeds per 1000 rpm:
Rpm: 1000 2000 3000 4000 5000 6000 7000 8000
1st: 5.25 10.51 15.76 21.02 26.27 31.53 36.78 42.04
2nd: 7.86 15.71 23.57 31.43 39.28 47.14 55.00 62.86
3rd: 10.49 20.97 31.46 41.94 52.43 62.92 73.40 83.89
4th: 14.08 28.15 42.23 56.30 70.38 84.45 98.53 112.60
5th: 19.64 39.28 58.91 78.55 98.19 117.83 137.46 157.10

True rpm for road speeds:
Speed: 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
1st: 1903 3806 5709 7612
2nd: 1273 2546 3818 5091 6364 7637 8909
3rd: 954 1907 2861 3815 4768 5722 6676 7629 8583 9536
4th: 710 1421 2131 2842 3552 4263 4973 5684 6394 7105 7815 8525 9236
5th: 509 1018 1528 2037 2546 3055 3565 4074 4583 5092 5602 6111 6620 7129 7638


So the gearing in 3rd/4th/5th of my car and the STi8 TypeUK(PPP) is almost identical, the reason my car is quicker is down to weight, plus posibly slightly lower transmition losses due to the diference between DCCD and VC centre diff setups.

It would be nice to have a 6 speed box in mine, i wouldnt lose any acceleration yet would improve cruising economy. They are a bit heavier though, so maybe not.


[Edited by johnfelstead - 10/4/2003 4:49:34 PM]

Andy555

Saxoboy says this was done in a 30 year old VW Beetle, heavily modified running slicks, with a 2332cc and lots of nitrous, Good weight transfer, as engine overhangs rear wheels.

Gearbox is only a four speed, and was probably hitting well over 7.5K at the trap. Car was built for the quarter mile. What I am saying is that the ET cannot be worked out from the Terminal speed, and Terminal Speed cannot be calculated from the ET.

[Edited by Andy555 - 10/4/2003 8:34:47 PM]

hawkeye

While idly browsing prodrives web site I noticed the following figures

std wrx sti 0 - 100 13.69 secs

ppp wrx sti 0 - 100 12.20 secs (1.49 secs quicker)


std wrx sti standing quater 13.99 secs

ppp wrx sti standing quater 13.44 secs (0.55 secs Quicker)

Duuuuhh where has the difference gone?????
if the std sti gets to 100 in 13.69 and quater in 13.99 it is doing just over 100 miles and hour

why is the ppp sti only .55 secs quicker when at 100 it is 1.49 quicker??

they dont seem to add up

please someone enlighten me ive looked also at the firgures from the shoot out the other weekend and they seem really wierd??

hawk

Puff The Magic Wagon!

iTrader: (2)

Not seen any PPP STi's (otherwise unmodded) doing 12.20 on Sunday...

hawkeye

my thoughts exactly however the 12.20 is to 100 not the quater the figures just dont seem to add up.

wierd

Dazza's-STi

Looks like i'm not the only one working this out... I can't get my head around it... I've seen this quite a bit though whare the 0-100 time is less than the quarter. It's very odd, I did a 13.04 quarter but at 97mph, how can you get to 100 in less time is i didn't get to 100 when I was really trying in 13.04... It don't compute! the strange this is you can pass the quarter with a slower time at a faster speed! Anyhow thiers no way my car will do 0-100 in 12.2 seconds when i allready blown prodrives quarter mile time away... @13.04 for the STI

Any maths and physics gurus out there?
If you look at top fual drag times they can be very strange fast time slower speed.

LG John

Because 0-100 and 1/4m measurements are both different things! The ppp may get to 100mph quicker but that doesn't mean it'll be the same margin quicker over the 1/4m! Andy F's car used to do 0-100 in 8s (a good 4.2 faster than the sti) but was only about 1.6s faster over the 1/4m. Similarly 10s 1/4m cars are hitting 100mph in about 6s.

hawkeye

Really wierd this one mwp you did quater mile in 12.68 90 mph surely that cant be right

ppp sti does 100 in 12.20 according to prodrive???

the figures dont add up by a long way

come on guys what are we missing???

mwp

... so i doodle off the line on sunday and get to 100 in let's say 13 seconds and then get to the 1/4 in 14 seconds at a terminal 90ish ... f**k I must have hit the brakes on that last gearchnage .. i coulda been a contenda with that Harvey fella

bobfrog1

Just out of interest what kind of power/torque figures are required to do a 12.2 1/4 mile in a scooby?

Dazza's-STi

nope if i can't reach 100mph in a 13.04 second quarter i'm not going to get to 100 in 12.2 .

i was flat out the whole way, thiers no way i could have made a second up in getting to 100...
I left point A and got to point B as fast as possible 13.04 seconds later and hadn't reached 100 simple! Speed was 98mph 13.40 would have seen 100mph I can't see as it can be shorter!
dazza

hawkeye

bobfrog i dunno the prodrive figures state 0-100 in 12.20 secs

look at this

5 John Trauty - 12.41/100 take directly from the shootout day this guy was 5th on the day

he got from 0 - 100 in 12.41 secs (quatermile terminal speed 100mph)

therefore according to prodrive a ppp sti is QUICKER????

what the hell is wrong

i ask again AM I TRULY STUPID???

hawkeye

dazza i realise your point therefore im saying prodrives figures must be bo@@ox!!

they state black and white 12.20 secs 0-100

LG John

I'll give you a moment to think about that statement and retract it before we start the slagging match

Re your post: Its possible that the testing conditions for the 1/4m and 0-100 were different, etc.

hawkeye

Know im really confused come on someone technical put me out of my misery why do these figures compared to mwp's and prodrives look wierd

5 John Trauty - 12.41/100 0 -100 = 12.41 yes????
14 Martin Metcalfe - 13.33/100 0-100 = 13.33 yes???
23 Mark Winson-Pear - 13.68/90 0-90 = 13.68 yess??

prodrive ppp sti 0-100 = 12.20 no??????

hawkeye

help me out saxo and slag me off please ive been awake like 36 hours my brain hurts im being really stupid?????

if you have a 17" rim on a car to get that rim to 100 mph it will travel a given distance yes so if that rim gets to 100 in 10 secs it must travel twice as quickly to get get to 100 in 5 secs yes??

the distance being????? now ive lost myself??

Dazza's-STi

bobfrog1,
I reckon circa 350+ bhp with an equal amount of touque!

Paul Woodward

So Hawkeye, do you think that if it takes 3 seconds or 3 minutes to get to 100mph, you will cover the same distance?

The quicker you do it, the shorter the distance, otherwise what is the point of accelerating any faster?

LG John

Ok, this will help you understand. Prior to stipping my car car it would do 0-100mph in about 12.5s. It did a 1/4m of 13.401 @ 104mph. An E46 M3 will do 0-100 in about 11s and IS faster than my car. However due to the traction off the line that I have and it doesn't my car would usually beat an M3 down the 1/4m stip depite the fact that when I crossed the line at 104mph after 13.401s it would be further behind but doing say 110mph and closing in fast.

The best way to think about it is how short a distance an Impreza driven flat out takes to get to 100mph. Now imagine driving a 1.4 saxo flat out to get to 100mph. You'd get there but it would take a number of miles.

I suppose your argument of wheel size would perhaps apply if all four wheels were at the absolute edge of giving up grip and spinning for ALL of the test. It would be a powerful car that is still spinning all four wheels at 100mph though

P20SPD

iTrader: (1)

Sti has 6 speed box, so whilst quicker to 100, say still in 4th, it may have to change to 5th for the 1/4 mile, whereas wrx wont, it will still be in 4th.

could be a reason

hawkeye

paul woodward - i hold my head in stupid shame at that comment and will do 10 minutes in the muppet forum!!!!

saxo boy yes i do understand where you are coming from BUT we are talking about similar cars here mwp has an sti8 the prodrive figures are for an sti8 they still dont add up!!!!!

look at my post ref the 3 cars all are scoobies!!! 2 are sti 7/8's

if you have a smaller diameter say a 17" wheel will that not get to 100 mph quicker than a 19" wheel assuming you were using identical cars??? because as you state it would have to travel less distance.

akshay67

Its to do with different rates of change of velocity (acceleration) at different speeds. The same rate of change at a higher speed will cover more ground. Changes in these rates will alter the final speed at the end of 1/4 mile. This is why you get random final speeds.

Easiest way to understand this is to look at a plot of Velocity Vs Time and measure gradients at particular points. Integrals at these points will show distance travelled...

hawkeye

akshay67 that really hasnt helped m8 you seem to be forgetting something


IM STUUUUUUUUUUUUUUUUUPID!!!!!!!!!!!!!!!!!!!!!

5 John Trauty - 12.41/100 0 -100 = 12.41 yes????
14 Martin Metcalfe - 13.33/100 0-100 = 13.33 yes???
23 Mark Winson-Pear - 13.68/90 0-90 = 13.68 yess??

prodrive ppp sti 0-100 = 12.20 no??????

can somebody else please agree with me that these figures dont seem to add up


hawk