some 4efte questions

A

allpr0h

Member +
hi there

i just brought my setup home for next summer (finally w00tw00t) and now have few questions about running a 4efte on a td04l turbo

actually i have 440cc with the resistor box and i was wondering should i change the fuel pump for a walbro255 or it should be okay with the stock one?

at the moment the external wastegate is set at 0.7 bar, i am running stock ecu for now with an safcII (which im gonna all change for a standalone ecu) and then i will be planning on getting a boost controller to increase boost to 1bar (with an upgraded manifold). Once there, at 1bar, will i need to upgrade the fuel pump, or do i keep the original one and increase the fuel line pressure with a regulator? (im unsure...)

also, since im using an external wastegate, should i get the turbo wastegate welded shut so there would be no chance of leak?

another one; would dumping the intake pressure back into the turbo inlet when throttle is closed reduce spooling lag instead of blowing it out to atmosphere..?

okay this is pretty much what comes to my mind for now, i will probably have some more q's as i think of my ongoing swap :cool:

thanks a lot
nate
 
rage

rage

Lifer
I would advise using a uprated fuel pump.
the stock one could cope with it but depending on age and wear it might struggle (mine coulden't cope with 1 bar on a ct9 anymore and underfueled at high rpm's)
besides, it's cheap to swap out and prevent problems with the engine.

you need to weld the internal wastegate if using an external one.

dumping the air into the mani sounds interesting. the blast of air could keep the turbo spinning a bit longer but it would require you to directly feed the blow off valve into the mani. doubt that any bov would like that very much. and if the pressure in the exhaust mani is high then you won't be able to drop pressure and even get burnt air into the intake.
atleast, that is what i think might occur (could be wrong)
 
A

allpr0h

Member +
rage said:
and if the pressure in the exhaust mani is high then you won't be able to drop pressure and even get burnt air into the intake.
atleast, that is what i think might occur (could be wrong)
Click to expand...

well what i mean is dump the pressure thats in the intercooler piping right back on the turbo turbine (not in the exhaust manifold)
thanks for advice mate
 
J25GTi

J25GTi

Lifer
Its like the one that is on gt's/v's as std, it dumps the air back into the intake tract. Helps spool up time of the turbo.

Forge make quite good recirc valves.
 
A

allpr0h

Member +
cool, thanks
if it helps spooling time why would someone want a blow off then? for the show off only or there is any practical reason ?
 
G

garry goodall

Member +
allpr0h said:
cool, thanks
if it helps spooling time why would someone want a blow off then? for the show off only or there is any practical reason ?
Click to expand...

a blow off valve works by dumping the boost when the throttle is closed, this prevents compressor stall on the turbo (chatter), which in turn keeps the turbo spinning when the next gear is selected, i cant see a rec dv aiding spool times.
 
J25GTi

J25GTi

Lifer
It is supposed to, as you are dumping pressurised air back into the inlet tract so the compressor doesn't have to compress it so much,

In theory
 
A

allpr0h

Member +
this is also what i think, but theres nothing like trying it and i will
actually i have a bov, im gonna look for a recirculating dump valve

thanks folks, much appreciated
 
T

TheStarletGT

Member +
Having the air dumped back before the compressor doesnt garantee that all the air will go back throught the turbo. Cos it may dissipate past the air filter. the air is random when its dumped.
 
T

the_names_james

Member +
Dump valves and blow off valves are essentially the same thing, the difference being that the pressure is either "dumped" into the pipe between the filter and turbo, or released into the atmosphere.

Logic should tell us that if you dump the air into the atmosphere, you're wasting air that could otherwise be fed back into the engine.

You should view the engine as an air pump. You can always match the correct amount of fuel, it's the air which is the limiting factor. The more efficient you can deliver the air (colder, denser and more of it) the more potential you have for big power (providing it's set up right)
 
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