LOST 12MPH!!?

[Nova1.2itrip]

Wen i brought my 1.2SPi Nova 6months ago it was completely standard. I poured in a Tub of Nitrox Engine cleaner which helped me achieve 102MPH out of it. I have fitted a Green Induction kit with cold air feed, Peco backbox and fixed the oil leak! However i have only got 90MPH out of it afta doing that work!? Theres no oil leaks, no mechanical problems, or problems wit the ECU. Wot has happened?

[burgo]

lost back presure possibly and if youve been raging it which it sounds like you have then there is gonna be engine wear which will effect it aswell

[wisewood]

When was the last time you had it serviced? Plugs, leads, oil change etc.

[parrington21]

put any alloys on or anything like that?

[Nova1.2itrip]

It was erviced 6months ago. I got 14inch GTE alloys now and used to have 13inch steelies that were tiny. I cant c how i lost so much tho. How can i sort out my back pressure then?

[Stuart]

speedo getting more accuracte with age? lol


ps losing back pressure HELPS

[robb]

To a certain extent.

Exhaust gas flow is a touchy subject.

[gary_1.2Merit]

I got 14inch GTE alloys now and used to have 13inch steelies

doesnt fitting bigger wheels make the speedo less accurate the faster you go. because the speedo is run of the gearbox n is set up for 13in wheels. by fitting bigger wheels you have a larger circumfrance (*spelling) so the wheels have to move a larger distance, thus showing a slower speed. maybe wrong tho

[robb]

correct..........but 12mph is a fair bit, in fact 12.24% less compared to 1.82% less on the wheel diameter.
43.96 circumference of the RIM on 14", 40.82 circumference of the RIM on 13". This is a 17.944% difference.

These figures prob don't mean anything but it's useful to know I can still work with the mathematical pie.

[Philsutton]

would depend what the profiles are on the tyres for each wheel size, as they could end up having the same overall circumference

[robb]

Yes it would, the figures above are taken from or worked out from the diameter of the rim.

Is any of the above useful??? I just got a calculator out and started button bashing lol

[Stuart]

in a word .... no lol

its cmplex as its got the tyre profiles and tyre pressures to take into account etc

[robb]

I didn't think so, still made me feel clever for a minute or two

[MC]

The alloys will be wider and possibly heavier. The width will increase road and wind resistance.


Which way was the wind blowing on both occasions?

MC

[Riggy]

were you goin down a hill the first time :D :D



:oops: sorry i had too lol

[-Bruce-]

were you goin down a hill the first time :D :D



:oops: sorry i had too lol

yeh with a tail wind, and a masive big sail on the back!!

also :oops: sorry i had too lol

bruce

[maxpaine]

the dimesion os the whell only will be a problem if the wheel and tire the group of the two its smaller or bigger from the original one, what car is it

[Jim]

Speed limit is 70mph anyway :P

Jim

[danny-g-]

I think the exhaust is losing you power put your old one back on and see the difference.