sports exhuaust how much more bhp

Tahrey1043 · Post by **Tahrey1043** » Tue Jun 01, 2004 5:41 am

Hm i never knew that one! Very interesting!

aparker · Post by **aparker** » Tue Jun 01, 2004 10:17 am

My 1L mk2 cruises at 80-90 on the motorway in warm weather,

That doesn't sound good that your car only does that sort of speed in warm weather, I know cars are more powerful when it is warm. I use my car all year round that these sort of speeds on the motoway, no problem.

polopowah · Post by **polopowah** » Sun Jun 06, 2004 4:00 pm

on the subject of speed with a 1.0, i've had 104 out of mine, though that was before i fitted bigger wheels, though the parkers guide only states 95 or summat hmmmmm, maybe its because its only done 19,000 miles ... maybe
-Ben-

Tahrey1043 · Post by **Tahrey1043** » Sun Jun 06, 2004 4:11 pm

you sure you were on the flat though, in still air?
every little helps

even if its a 1 in 200 downgrade and a 20mph following breeze

0ddball · Post by **0ddball** » Tue Aug 10, 2004 6:53 pm

your gonna need in the region of a genuine 90bhp to reach a genuine 115mph. no debate. a car with 45bhp is gonna reach an aerodynamically limited top speed of about 80-85.

getting someone else to sit next to you in another car proves one thing alone, their speedo is overreading too.

carmadaaron · Post by **carmadaaron** » Wed Aug 11, 2004 1:30 pm

if u have a steep long hill then ull get a very high speed.

more momentum?

polopowah · Post by **polopowah** » Wed Aug 11, 2004 3:22 pm

going on from speeds for a 1.0, ahem i've had 104 max on a sloping section of the A10 but usually struggle for 95

-Ben-

Tahrey1043 · Post by **Tahrey1043** » Thu Aug 12, 2004 1:38 am

Well i've yet to get a properly calibrated reading for my own car, both in terms of speed AND horsepower, but it's allegedly 45hp and the manufacturers stated top speed is 90.5mph (145kmh)... which I have little trouble beleiving as on the flat/still air the needle rests around 95 after a couple miles... and i know by then it's roughly over-reading by about 4mph. Plus the power is probably right within a single hp (not making a great difference to the top speed there - 40hp would still be around 80-84mph) because 0-60 can't be reliably dispensed with in less than 19 seconds (but never more than ~21, even in the wet).

It does of course make a big difference how slippery your car is! A mk2 with the same output only manages 87-88mph because it's just that bit more boxy and sharp edged - flat grille and lights, more of a drop-off on the tailgate, etc - and even the shorter gearing cant quite keep it at the power peak so well.

Which goes to a thing I was reading (randomly

) about the history of the Golf GTi... not long after they put the rebored 1.8 engine in, the bodywork was revised - slightly longer, wider, and noticably heavier. Yet the car didn't suffer much for it, it still cornered very well (more suspension drop/stiffen, wider tyres), and the straight line speed was actually a little improved - better gearing saw the 0-60 dispensed in a fraction of a second less, and the top speed was at least 5mph higher, along with better fuel consumption.

Why, for those last two points? Because the restyle/facelift of the body, despite keeping a similar line to the casual observer, smoothed it off considerably in comparison to the prior shape and dropped the drag coeffecient from an "average" 0.43 to a "very good" 0.34.... The engine having to work less to maintain the same constant speed, and able to provide a greater forward motion from the same power output.

(a better estimate for 45hp, from the general figures I've seen when car-hunting before, is 85-90... 40hp is, like i said, more the 80-85 area, covered by things like the Fiat Seicento and certain Daihatsus.. and 75-ish for the olllld 750cc / 36hp Panda)

oh god another thing for the numbers part of my brain to latch onto, save me

jezmk4 · Post by **jezmk4** » Thu Sep 23, 2004 11:35 pm

well if you need about 90hp for 115

a polo 1.6 with 75hp which has been off the clock at 120?

theirs noway the speedo is that out,

ive checked it at 80 with the gps an the speedo read 83

Tahrey1043 · Post by **Tahrey1043** » Fri Sep 24, 2004 1:27 am

dont neglect the role the wind can play

would you really notice if you had a 25mph tail wind? it would sound about the same... but your car would suddenly, at 100mph, only have 75mph worth of wind to fight against (and of course, 125 the other way), and with an allowance for the rolling resistance, be able to hold that speed and maybe improve on it a little.
up it to 30mph, give it a downslope.. voila, 115mph

i'd be well impressed to see that for REAL in a 1.0 though - you'd be pretty much on the rev limiter at that point (~17.64mph/1000rpm at 6500rpm = 114.7 (real) mph) with the 4 speed or the "short" 5 speed. Even with bigger tyres, you might see, hmm, 120 on the limiter at that point. All depends how out your speedo is at that point - did you really get someone to shadow you at 100+ to make sure it was right? (how'd you know THEIR speedo wasnt bombed?)

were you descending Shap?

david burton · Post by **david burton** » Fri Sep 24, 2004 9:30 am

jez - so the speedo is 4% out? so 120mph = 115 roughly. I guess that's possible... stated top speed is 107, must be all that torque!

mk3dave · Post by **mk3dave** » Thu Dec 23, 2004 6:31 pm

u dunno bout you guys but i dont even think my 1043 would reach 90. ive had it at 85 on a slight gradient but ive reached an island b4 ive completely topped out so i dunno. my car is insanely slooooooow. its got a jetex and the compulsary 57i, which have made a difference in acceleration, but im slight gettin overtaken by biddies in micras!

1litreheater · Post by **1litreheater** » Sun May 01, 2005 9:56 pm

my 1 litre mk 4 is totally standard (at the moment) and i had 98 mph on a flat dual carriage way and my exhaust blew haha !

carmadaaron · Post by **carmadaaron** » Mon May 02, 2005 12:51 pm

1litreheater wrote:my 1 litre mk 4 is totally standard (at the moment) and i had 98 mph on a flat dual carriage way and my exhaust blew haha !

*ahem* u mean on a private track, NOT the public dual carriageway

1litreheater · Post by **1litreheater** » Wed May 04, 2005 8:50 pm

did i put dual carriage way

shuks, i was meant to type private track ! sos guys lol !