hi friends ,i own 1.9TDI 90 bhp skoda octavia ,fitted with power box from PSI, larger injectors from kerma tdi, k&n air filter used in american truck dodge ram of 6000cc turbodiesel, the problem is iam unable cross the speed of 150 KMPH , and the fuel consumption is at 7.5 litres /100km at 5th gear. how to increase the top speed ? is there any electronic limiter ?. or do i have to go for remap? another interesting feature is .in 1st & 2nd gear the consumption of diesel is shown as high as 15 to 22 litres /100 km .then why not at 5th gear ? where is the limiting factor? can i alter air flow metere .need your valuable suggestion friends bye

The computer will show incorrect values with larger injectors and some tuning boxes cause overfueling so that might also make the computer misread. Also that is 22liters of fuel per 100km as opposed to x miles per gallon, so lower is more efficient.

your consumption in lower gears is never going to be the same as 5th as the engine speed to road speed is more efficient in higher gears.

you'll probably find that you are maxing out in top gear because you have enough power to hit top revs but the ratios of the gearbox are only designed to reach a certain speed.

StuartJ was maxing out his 4x4 in top gear so went for a higher ratio vRS box and more power...

hi friend but the top speed is mentioned as 180 kmph ?is it the fuel ?

Are you base somewhere at altitude per chance?

You should be able to crack the 150kmh barrier easily, I had a bog standard 90bhp TDI as a loan car and that would do an indicated 115mph (184 kmh) with no trouble....

Oh and welcome :wavey:

You're using a tuning box which essentially just over fuel and doesn't play with the boost settings...I think.

With the mods you have you'd be better off having a custom map to enable them all to be taken into consideration. You could have the rev limit raised..for high top speed and the map would also enable engine to run more efficiently. This potentially means better economy.

Note: all my ususal disclaimers apply.

The computer will show incorrect values with larger injectors and some tuning boxes cause overfueling so that might also make the computer misread.

Surely the ECU is still in control of the amount of fuel that is injected though? It just adjusts this based on the values the sensors (ie the tuning box) supply it with? In fact, is the car taking advantage of bigger injectors without the ECU being remapped? :confused:

Chris

Surely the ECU is still in control of the amount of fuel that is injected though? It just adjusts this based on the values the sensors (ie the tuning box) supply it with? In fact' date=' is the car taking advantage of bigger injectors without the ECU being remapped? :confused:

Chris[/quote']

But it won't know about the bigger injectors though will it. So more fuel will flow in. I saw a guide about doing this somewhere. and it said the 90 are basically the same and bigger injectors are just one of the things.

If the ECU doesn't know they are there, how can it cope?

hi friends ,i found smoky exhaust at idle ,itried to cut out tuner box ,pick up had come down,and there is no smoke at idle.but iddnt check the max speed minus tuner box i will let know , the another problem ,there is no info about the volume(cc)of new large injectors so as to go for remap ,which may alter the boost pressure .to go beyond 150 kmph,hope briskoda net friends can let cross this barrier.anand