Economy on 200-250kw atw cars?

[Guest]

Just wondering what sort of economy people get out of street cars around that 200-250kw atw mark. Im tossing up whether to get a nice tune done at 200-220kw to the limits of the 440cc injectors or decap and push it out. Obviously if economys still similar between 220-250kw Ill decap and push the envelope. More on boost Im interested in not closed loop.

[funkytown]

if you spend your life round the street sitting on curve at the point where revs = 230-250wkw then fuel economy is rubbish - as per ANY turn

If you treat it nicely with out abusing the crap out of your car you can get near normal fuel economy.

its a \'how long is a peice of string\' measurement tbh.

[B4 2000]

POOR :\'(

okish on motorway driving, just over half tank for me in the legacy to go from Palmy to Welly and back 300ish ks!

[Guest]

Is that fangin it? 300k to half tank is about right for mine stock with td04 same for foz. Id be happy with 500-600 to a tank. Obviously wb will def help.

Tell sl8r to check pm.

[B4 2000]

Fanging it? you kiddin lol, even thinking bout fanging it would get my license revoked lol (3rd gear would eat the speedometer for breakfast from bout 80 and tops at bout 166, so no thanks)

nah, normal driving with the occasional quick passes, sitting on 4th gear in 70-80 zones!

[Stoffa]

400km for 50litres. seems better with my PCV back on and reburning the fuel vapor from blow by (but that could be in my head). also im running a wideband with closed loop lambda and leans out to 16:1 at 50kms and about 15:1 at 100kms.

[funkytown]

b42000\'s car is also quite a lot heavier than ours with much longer gearing so fuel consumption will be higher.

I get 400km / tank on mine tuned to 300wheel evowrx.

on the track i get 1l/2km... trollolol

[newsuba]

I would have been very happy with B4\'s bit over half a tank Palmy-Welly return !

My old STi used to drink almost a whole tank.

:-\

[boon]

I\'m not sure I follow the question really... I\'m right in that range, 231wkw, if you drive a 240kw car everywhere "on boost" then of course you\'ll drink a lot of petrol, you\'ll also either be driving around in second gear or you\'ll be losing your license in about 10 seconds. 240kw + 4th (out of 6) + foot down = off the speedo.

I get ~450km to 50L of 98. That\'s cruising at like 104 and giving it jandle when I overtake. I think my fuel economy actually improved slightly when I went to a Link and got tuned.

[Guest]

Abdul - I was meaning you old tune but ya spose that was quick also.

Chris - Im meaning to sort out my breathers just need to find the time and waiting to see what you find out when yours is all set up. I dont track my car though so dont have to get too serious with it.

Jon - Didnt think about weight guess you pay to be different.

My old libi did about 350-400km on smaller tank and got driven bloody hard so found subaru pretty damn good.

[Guest]

 boon said:

I\'m not sure I follow the question really... I\'m right in that range, 231wkw, if you drive a 240kw car everywhere "on boost" then of course you\'ll drink a lot of petrol, you\'ll also either be driving around in second gear or you\'ll be losing your license in about 10 seconds. 240kw + 4th (out of 6) + foot down = off the speedo.

I get ~450km to 50L of 98. That\'s cruising at like 104 and giving it jandle when I overtake. I think my fuel economy actually improved slightly when I went to a Link and got tuned.

Might not follow the question but sorta the answers Im after. Basically between 200kw atw foot flat and 250kw foot flat is there big differences in gas usage?

[B4 2000]

Older turbo 230kw, i did dunedin to palmy (bout 900ks) in under two tanks with the car fully loaded with all my stuff (boot, rear seats, front seat, everywhere) on boost here and there!

hope this is a better answer!

[boon]

 evowrx']

[quote name='boon said:

I\'m not sure I follow the question really... I\'m right in that range, 231wkw, if you drive a 240kw car everywhere "on boost" then of course you\'ll drink a lot of petrol, you\'ll also either be driving around in second gear or you\'ll be losing your license in about 10 seconds. 240kw + 4th (out of 6) + foot down = off the speedo.

I get ~450km to 50L of 98. That\'s cruising at like 104 and giving it jandle when I overtake. I think my fuel economy actually improved slightly when I went to a Link and got tuned.

/quote]

Might not follow the question but sorta the answers Im after. Basically between 200kw atw foot flat and 250kw foot flat is there big differences in gas usage?

If they\'re both at the same AFR, the 250kw one will use roughly 30% more petrol. Power (kw) is just energy/second. The only source of energy you can put in your motor is petrol. Therefore if you\'re outputting 25% more power, you need at least 25% more petrol to go in, plus a bit more due to decreasing efficiency as power increases.

[Dv8er - FSTWRX]

236 kw atw tuned with Link on 95 octane I get 8l per 100km open road, 9.5-10l per 100km in town.

[funkytown]

i dont have the calculations in front of me - but thats waaay to oversimplified boon.

[Guest]

I like the logic though lol

[titian]

Compression ratio will also change the cruise economy...mine is, tuned on 98 link G4 managed, 250kw gets between 8.1 and 8.6km/litre and is @ 9.1:1 CR.

Gets 2.6km/litre around puke track.

lower initial CR will decrease cruise economy. (engine operating in a vacuum intake manifold condition)

[funkytown]

indeed it will - but remembering it has other major effects of knock limits and power potential

[Stoffa]

Im at 8.1:1 CR

[Scoobydoo]

 funkytown said:

i dont have the calculations in front of me - but thats waaay to oversimplified boon.

boon is a simple person

[titian]

 funkytown said:

indeed it will - but remembering it has other major effects of knock limits and power potential

absolutely true .Just like octane and cooler air also affects the top end of your power output.

horses for courses...each engine rebuild must be suited to its eventual application.

compromises must be made..you cannot have a road engine that will win on the track then do a 12 at the drags and do 10km to the litre.

although you could have an engine that will do each...Gues you could have three or four in the shed..Swap out as required...That would work! :)

[sultan]

i\'m not sure why the question is being asked.

it won\'t be any different in standard driving situations, perhaps slightly worse due to worse control of the injectors at low duty cycles and a worse spray pattern. when you\'re on boost, of course it will use more. but if that\'s an issue, i don\'t see why you would own a turbo at all, let alone modify one for more power output?

if you\'re the kind of driver that pushes to redline all over the place, it may make a noticable difference, but if you drive mildly sensibly with occasional bursts, i doubt you\'ll see much more use

[funkytown]

its being asked as there is a lacking in understanding of the concept.... obviously ;D

[sultan]

mmm, i\'m sure there\'s some people around in standard sti\'s that get worse economy than those asian guys with 1000hp gtr daily drivers

[Guest]

Ive never owned a quick car well not post 200kw atw been in a few fast ones but never had to pay gas for one. I would expect it to be a lot better than it is now though and possibly better than almost everything Ive owned lol cept VY commodore which was real good.

Now Im confused as to why I asked lol. Not sure which way Ill go yet guess it depends on how I feel when I drop it off. Cheers for the replies I got what I wanted.