disabling a turbo

[kramer]

just wondering, and there's prolly a way....

can u disable your turbo, to save fuel etc etc...?

like so that it's not just always spooling and forcing air back in?

and is it easy / safe hehe

[fatmanracing]

2 ways, one is your right foot, the second is forcing the wastegate open.

[Android 360]

why???

it may save a little fuel but u wont have boost!
as fatmanracing said, if you dont put your foot to the floor and drive with the rpm needle near the top of the guage, the turbo wont spool, keep the rpm low and you won't get the boost.

however, if you mean taking the turbo off, you need to deal with stuff like raising the compression...

for the little amount of fuel you would say, i dont think its worth it!

[kramer]

umm no... see, i dont know about u guys, but MY exa with a t2, starts spooling @ 1500rpm, and boosts just after that... so yea, driving slow dont help, it still boosts, i can hear the fucker ;)

also i'm thinking that the bov might be worth taking off, and being plumbed back into the inlet etc...


now, about the wastegate being open, wont that just make the turbo spool constantly, and thus wear out the turbo fast?


another question... u can get adjustable boost controllers, so cant you just set the boost to nothing, and say 6 psi (on a stage 2 boost controller? )

[kekilepep]

I've asked about this too
and so far nobody has been able to answer it

as for your turbo spooling at 1500rpm thats abit, strange ?

my t2 kicks in at around 2800rpm

[boostinhard]

Hey,
just because a turbo spools at 1500rpm doesnt mean you have to let it boost up to 7psi... You should be able to hold it at 0 or less, if you cant, how do you think your going to be able to drive it without any artificial aspiration? With setting the wastegate at 0 psi, you would need to have a 7psi air source from somewear that you could force into the acutator line which would keep the wastegate open until you flick your switch reverting back to normal operation. Your other option is to fit a much larger turbo like I have which will give you a very peaky engine which doesnt come on boost unless you really want it to.
Sam

[kramer]

thanks sam, now i'm starting to understand...

so, if i can hear the turbo spooling, and keep my foot enuff on the gas so that it's at negative boost, or 0, then it wont be forcing extra fuel in then , yea?

i dont quite understand the concept of negative boost yet, could you explain that to my "n00bish ass" ? ;)

[Jimi]

"negative boost" is the vacuum in the inlet manifold.

if you have a non turbo and you put a "boost" guage on, it won't read 0psi, it will read a vacuum level, which is measured in some murcury level..

the vacuum in the inlet manifold is caused by the sucking of air by the pistons on their intake stroke, this sucks the air into the engine.

when your reading 0psi on your boost guage, your turbo(s) are actually spinning quite fast, and forcing a bit of pressure into the manifold, enough to negate the vacuum anywhoo.

if you want to save fuel, just keep your eye on the boost guage and don't use 100% open throttle. if you gently accellerate with say.. 40% throttle, you should make no where near full boost, thus keeping fuel down..

are the E15T's MAP sensor or air flow meter?

turning "off" the turbo would involve, as fatman said, keeping the wastegate open, waste of time me thinks!

[Android 360]

E15ET is AFM but some modified ones have aftermarket MAP

[kramer]

hmm..well, i drove the g/f home today - she lives 30k's away, and so i have to cruise down a sorta highway....but i'm just keeping the car moving, foot is JUST on the gas, and the car is boosting at like 2 psi...like, to get up a hill, even goin putzing in top gear, it still is on boost, sometimes 3/4 psi...feck

[boostinhard]

Hey,
yeah well with such a little turbo, any sort of lag will allow it to spool up and make boost. Dont worry about it so much, if your really worried about fuel consumption, just accelerate slowly and you'll be fine...
Sam

[kramer]

i've done 200k's on 3/4 of a tank (driving slowly)- i'm worried immensly

[Paul Smith]

Sounds like it might need some attention. I'm getting 10 km to a litre using boost often. That's with a T25 turbo.

[kramer]

sorry, my figures were wrong...

the car did 178k's off 36$ of fuel @ 88.5c/pl

that was standard leaded...

so today i put 10$ of bp ultimate in, and i hope it wont do any damage to the valve seats...

[Paul Smith]

It won't. They are unleaded engines even though the early ones were released in Australia as leaded. If you're nervous just use Morey's upper cylinder lubricant but it's not necessary.

[TimBeau]

i agree with the morry's upper cyl lube
and i run a servo

btw what is the largest turbo i can it on my e15et without exhaust mod

i have just blown the oil seals in mine

( what's that smoke , fuck it's me )

[Nisman]

when i had my engine reco'd i asked them to fit unleaded valve seats, they had a look and they are hardened valve seats standard, so you dont have to worry about damage, the only thing to worry about is pinging due to the lower octane rating. on stock boost it should be fine.

as for fitting another turbo, you can easily fit another t2 without exhaust mods, anything else will have to have a custom dump made.
i know people are going to try and shoot me down with the "i have a t25 and the custom dump bolts up, 3 out of 5 bolts hold it on"
but in my opinion this is dodgy and will only lead to future headaches and problems.
a custom dump is only around $200 for 3 inch mandrel bent, so i would definitely budget that in.
another factor to consider is that if your turbo isnt water cooled you will have to run all the lines to fit the new turbo.
while this is an easy job, if you are not good with cars then it could turn into a nightmare.......
come to think of it, if you are not good with cars then owning an exa could be a nightmare.

[Nisman]

and on the case of crazy fuel consumption, i used to get up to 600km of highway driving to a tank of petty, and that was with the car tuned to run 15psi.

check the basics like your timing, poor ignition timing can cause the motor to constantly labour and use heaps of petty.
also other things like clean your plugs, check your sensors are all hooked up properly. check your ecu for diagnostic codes to see if it is having trouble with a sensor.
also check your vacuum leads to your fuel pressure regulator, and wires on the knock sensor.

[Paz]

Originally posted by kramer
sorry, my figures were wrong...

the car did 178k's off 36$ of fuel @ 88.5c/pl

that was standard leaded...

so today i put 10$ of bp ultimate in, and i hope it wont do any damage to the valve seats...

holy shit ..... mine does 500kms on $29...... and comes onto boost at about 2700rpm

[n12mitch]

Guys the ECU is programmed to deliver X amount of fuel at certain load (measured by the AFM) and certain RPM. It is slightly altered by boost pressure but because it is an AFM located before the turbo, it measures the amount of air going in and adjusts the fuel to suit.

Opening the wastegate all the way will stop the turbo boosting but you will run very rich because of the reduced amount of air delivered to the engine. To get better fuel consmption buy a car that isnt turbo or drive very slowly.

If you want to disable the turbo, pull the wastegate actuator off the wastegate itself. It will now swing like a door.
The lowest boost setting available is by putting the vacuum line straigt onto the actuator with no leaks, boost controllers or any interruption in the line. It will then run standard boost (6 or 7 psi).

Those figures are crap, i drive my exa with lots of mods flat to the floor a lot and i still get 400 - 500 kms to a tank of premium.

Get your car checked out there is an obvious problem there.


Mitch

[Nisman]

another alternative is to have the actuator rod extended by a few mm's. this will lower the boost a bit. Could run a min of 2 or 3psi depending how far you extend it.

n12mitch, while you are 100% correct in what you said, by reducing the boost, the amount of air drawn by the engine/turbo will reduce, and the afm will pick this up (as less air will flow through it). For this reason the computer will adjust and deliver less fuel than it would at the same revs with higher boost. Thus resulting in lower fuel consumption. It will however still run rich.

if you want a turbo car that uses no fuel, i would suggest you go buy a charade turbo, they are still carby so you could put tiny jets in them but still be able to boast that you own a turbo car :moonsmili

[[YMMIJ]]

hey i used to get 200 km/tank pussy footing on my old t2
with the t25 i got in upwards of 500

[EXA ACE]

i think you need to stop havin a cry bout fuel its a fucken 1.5 to start with i would hate to see u own a 5l v8 cry u all day and takin your turbo off is just fucken stuped how bout you sell the exa and go and by one of those 800cc suzikis


ACE