virgin

what would it do in a air field ? i know without ppp there 144 ? but does the ppp effect top end speed ?

apoligies, i realise its a boy Q , but it would be good to know

MadMark

Mine is non PPP - but chucks out 260bhp and I've seen an indicated 155mph on a flat (and and very long runway) ........ does that help?

virgin

thanks, is yours an 04 uk model ?
which mods have u done ? (i assume yours is not std)

oakey100

I have a 54 WRX, non modified, got 150 mph on the flat. Still had 1000 rpm left till redline. Maybe get 160.

RRH

when compared with a gps speedo you'll usually find the MY04 clocks over-read by about 10%

Harry_Boy

My MY02 over-reads by about 6 MPH at an indicated 100 on my private test track.

RRH

when mine is showing 100 on the clock the gps is showing 90ish

jmk

Similar, at 100mph my GPS is showing 92. Odd though, my old GPS showed 100mph and matched the speedo exactly.

gso

good job the speedos work like that otherwise you would have all been shafted by speed cameras

Harry_Boy

Interesting point...

We all assume that GPS is inherently 100% accurate, but how well can we 'hold' an exact constant speed for a sufficient time for the GPS reading to 'settle'?

My experience with the GPS unit I have is that there is some 'latency' built into the device. So, it takes a couple of seconds to 'catch up' with the car, and hence takes a little while for the correct speed to be displayed.

Echo

My GPS had a glitch and then registered my highest speed to date as over 8,000 MPH

Dave uk blue mica

my MY99 classic puts out 292 bhp and goes off 160mph and reads 158mph on the GPS

MikeWood

Virgin

We haven't done an exact test but it is over 144mph although it can't be any higher than 250kph because that's where we set the speed limiter.

Mike

Steve vRS

=155mph. Will that be an indicated speed? Surely the ECU reads the same speed that the speedo displays.

Steve

MikeWood

Steve

The speedo is a mechanical gauge and doesn't necessarily accurately show what the ECU is seeing. Having said that it's within 1 or 2mph up to 100mph when we've tested it against our Datron equipment on our test track with an STi (am I the only person to post on here 'on a private road/test track' and actually mean it!!! )

Mike

T5NYW

iTrader: (4)

LOL

virgin

Thanks mike, sounds like you know your stuff

If you where to gestamate a true Tspeed none mechanical what would u say ?

And forgive this, whats 250kmh in mph ? and when you say restricted do you meen its something programmed in the ECU by prodrive on the PPP ?

RRH

I certainly hope Mike knows his stuff, being prodrive's best representation on scoobynet

virgin

Excellent

MikeWood

Virgin

Difficult to say, depends on lots of variables such as body type, wheel and tyre spec, fuel used, wind direction etc. We tend not to be too concerned about it anyway as it's largely irrelevant in the UK as it can't be done on the public highway.

What's much more important is how quickly you get there and in the end it's only pub talk! If someone is telling you that his car must be better because it will do 150mph and your's will only reach 144 then he's deluding himself.
As an example, BMW325Ci top speed 149mph but 0-60 is 7.1. WRX PPP is therefore much faster in the real world as you accelerate every day but you don't ever run flat out at high speed.

Mike

Mike

virgin

Thanks mike



But on the reach to 60 note, I could never understand why an Audi tt for example with 225 bhp, awd, with good power 2 weight etc is slower to 60?



Even some high power fwd & rwd cars with say 240 to 300 something plus bhp are slower than a wrx04 to 60, if it was down to awd traction, then how comes the tt theory makes sense?



I.e. whats makes a wrx ppp so quick to 60 ? 4.8 etc



So, other than bhp, awd and torque etc than is it that the car is

Mechanically better than most cars at delivering it or something?



Sorry people! always wanted to know the answer to that one ! there’s a few car out there that should be in theory quicker than 4.8 ,I mean the wrx 04 ppp feels quick-ish, but certainly doesn’t feel like 4.8, and trust me, I can get the car of the line quick, although I hate to do it because I don’t want to break it !

chrisp

gearing, diffs, traction and suspension, no use having the power if you cant lay it down

bluepolarbear

The other point is when people quote power and torque they are talking about about peak which to a degree is meaningless, it is the shape of the power / torque curve that makes the difference and determines useability.

0-60 is a fairly meaningless measure of performance, with a lot be determined by the need to use 3rd or not.

In the modern world everyone wants things on a plate, a single number, if you do then I suggest you use 0 - 100 - 0.

If you do, list in a table and draw a line at 20secs then if you are under you have a quick car in the real world, if you are over you don't.

MikeWood

The precise method used to get to 60 in 4.8 is as follows

dial in rev limiter
release clutch
select secong gear
lift throttle when rev limiter intervenes

Brutal and not something you should ever do to your own car but that's how the mags do it. The WRX reaches 60 in 2nd, hence the good time

Mike

Sti_Lad

Sorry to hijack the thread in a way, but what would you suggest is best method you guys use to get your 1/4 mile times??
I've MY03 sti ppp and had it at the pod recently.. just wondering how I should launch and when to change to 2nd and 3rd for best effect, I presume holding to redline 2nd doenst really give best figures as the power drops off at high revs...
I managed 13.4 secs so I was afterall quite happy with that! but hey any tips are good!

virgin

good question mate, i would like to know that myself, hope someone answers !

Do hold at a certain revs like 4000 rpm and just release the clutch or something ? or is it more revs and and a dump or gradual release ?

i tend to rev up hit the bitting point like i am trying wheel spin the car, but with the awd it just launches

some nutter with clutch money to burn must have loads of advice on this one ?

merlin71

I got a WRX PPP 04.

Took it to santa pod and got a 13.80, exactly per Prodrive's website figures.

6000 rpm, sharp up with the clutch and floor on the gas at the same time, i didnt need to sidestep the clutch, was getting 1.8seconds 60 ft so thats good enough.

Redline 1st and 2nd and 3rd, over the line, and breathe.

Sti_Lad

Is Redlining in those gears the best thing to do though? Peak power and torque are produced lower than the redline?? So surely if you change earlier it would be better as you can get back into the power band???

BTW your method was what I used at the pod!

virgin

good point, would like to see the answer on that myself

Engineer@Uni

Well, two points to make:
1 0-100 honestly doesn't tell you much about the car as a whole, and neither does HP. Someone commented that it's the shape of the torque-curve that is most important, and he couldn't be more right. Point of proof: A civic type-R in JDM spec is 220 horses from naturally aspirated 2litre engine. Does anyone in this forum believe that a WRX with the same amount of horses is unequivocally easier to drive (and a lot easier to go fast in) than the CTR? Transmission and suspension are the dog's privates as far as track-times are concerned, not engines and clutches. Anyone doubting this should see the pricetag on a super-1600 rally car. Although they sport only 1600 engines with no turbo, pulling circa 200 horses, it's the transmission and LSD that bring their cost up to a hair-raising 50k squid or so. And thats for a lowly Fiat Stillo!
2 to answer a previous question, virgin, 250km/h is actualey a legal requirement as a speed limiter in many EU countries. BMW limit the M3 and the M5 with variable valve timing to it, and UK Evos are cut short at (lo and behold) 157mph, which, non-coincidentially, is 250km/h