blachie

c'mon guys someone must know!

Scott.T

iTrader: (2)

IMHO a stiffer actuator will make no difference as the boost control of the ECU will re-compensate for it. It may even cause slight fuel-cut/overboost on a standard ECU as it overshoots the target level before the ECU can catch-up.

If a remapped ECU is used the actuator would still not require uprating/adjusting as the remap should work well enough with the standard actuator.

Stiffer Actuator were always used in the past as the standard one were near to the fuel cut/ ECU limit i.e old Ford RS Turbo's and Cosworths.

A standard RS Turbo ran 7psi, you could probably get 8 or 9 psi out of the standard actuator. If you chipped the ECU you would then need an actuator capable of 14psi+ i.e a garratt -31. This is mainly due to a much more primitive ECU.

With newer designs which use Boost Control Solenoids, the actuator are designed to work at much lower boost levels than the car actually runs (mainly for safety/limp home mode of operation). These are only able to supply approx half the boost. The boost control solenoid then bleeds air away from the actuator, thus allowing more boost.

The ECU remap then increases the air bled via the boost contol solenoid and hence allows more than standard boost.

blachie

i totally agree with you,the thing is that subaru greece officialy puts a stiffer spring in the actuator of both the std 03wrx+03sti with a parallel ecu of "unknown"origin and quality.
why would they have to do this?
in particular the 03 sti uses a vf22(!)with a stiffer actuator as well.
the mod is supposed to take the std wrx from 225 to 260bhp and the sti from 265 to 330bhp.
what do they know that we don't in order to use such a crude and old method of "controling" boost curves?
please guys i need as many opinions as i can get on this one cause 2 of my friends bought the converion(one for the wrx and one for the sti)and both think that they got ripped off.
thanks.

dowser

Some Swiss tuners fit a FCD and tighten the actuator. Leads to a short burst of overboost while the ECU madly tries to get hold of things.

Believe it or not, it wasn't a bad solution - the customer even complained (after we'd removed it all and remapped) about the loss of the 'kick in the back' the overboost caused.

He was OK when we asked him to see what speed he was hitting at the end of his home straight, compared to before

Richard

Scott.T

iTrader: (2)

It may be a way of improving the low down torque

OR

The parrallel ECU just uses a boost clamp, so the stiffer Actuator will allow more boost, but the processor in the ECU still thinks it is running standard boost.

This can be done in a similar way on MY93 - MY00 by using an external Fuel Cut Defender/Boost Clamp and adjust the length of the Actuator (if the Actuator has adjustment).

I know my old MY94 and current MY00 have adjustment.

brickboy

I reckon it's worth checking the wastegate actuator arm: if I remember right some people here have found their actuator arm wasn't adjusted right, so the wastegate wasn't closing properly.

One or two turns tighter on the adjustment can improve part-throttle response and spool-up, without problems with fuelling.

submannz

The other way is to bleed the vacuum

blachie

"Some Swiss tuners fit a FCD and tighten the actuator. Leads to a short burst of overboost while the ECU madly tries to get hold of things."
thanks for that!
is it not funny that the "ecu" that they are using(subaru-greece) is from a "respectable"(???) swiss company...that nobody knows it's name!?
i hope my friends did not pay 3200euros for a boost clamp or fcd and a spring...

blachie

hi.
what effect would a stiffer wg actuator spring have in an otherwise oem td04l turbo on a MY03n wrx?
my understanding of the matter is that with a stifer spring you can delay the opening of the wg thus enabling the turbo to spool up earlier,am i wrong?
the reason i m asking is that subaru greece officially sells 03wrx's with that mod on the wg which to me is strange to say the least.
they claim that they can get 265bhp out of the my03 just with that mod plus an unknown parallel ecu(???)with the std td04l std exhaust std ic and std airfilter.they sell that mod for 3200euros...(2260 gb pounds)
what do u guys think?
ps.i drove the car and it felt a lot laggier and a LOT slower than my MY00 which is fully decated 3in,dawes@1bar,samco hoses,jr panel filter with cold air intake.

[Edited by blachie - 6/10/2003 5:30:21 PM]