leeby
|
| posted on 9/1/18 at 09:59 PM |
|
|
st170 itb's query
hi im new here as was told by a friend you are the guys to ask.
currently building an st170 engine on gsxr 750 itb's for a mk6 fiesta project im doing (sorry not a locost), and im using the original st170
inlet, my query is and im sure its been answered a thousand times on here (and i did search), is with the vacuum pipes do i run them to a fpr also
when using the st170 manifold do i put a fitting into say number four inlet for brake servo vacuum ??
absolute noob with itb's im afraid
also using acewell dash and have been informed there is a way of converting original gearbox pickup to work with the dash
thankyou
[Edited on 9/1/18 by leeby]
|
|
|
|
|
SPYDER
|
| posted on 9/1/18 at 10:17 PM |
|
|
Hi Leeby. I take it you are using the ST170 injectors? The little vacuum takeoff should be run to the FPR.
You might need connect all four runners to achieve sufficient vacuum for the brake servo. You'll probably need a vacuum reservoir too. And one
way valves in the right places. Many ITBs don't hold much vacuum once they are opened even a small amount.
I put a bigger throttle quadrant on mine. The standard one is tiny and lends itself to on/off operation with little modulation.
Good luck with it.
|
|
|
leeby
|
| posted on 9/1/18 at 10:23 PM |
|
|
yeah im using original st injectors and thankyou for the info about fpr, the reason i asked about the brake servo is because a lot of aftermarket
manifolds seem to come with just the one take off for the servo ?? ill be using or modifying original servo hoses with the valve in place.
and as im new to this most of what you said about it went straight over my head lol, but ill dig some more thankyou
|
|
|
big_wasa
|
| posted on 10/1/18 at 08:03 PM |
|
|
You know the fpr on an st170 is not an fpr but a damper ?
|
|
|
leeby
|
| posted on 11/1/18 at 10:13 AM |
|
|
yes im using a mondeo mk2 1.8 injection rail with st injectors, i prefer the mondeo rail as can swap supply and regualtor to either end for
positioning and the supply is flexible unlike the focus one
|
|
|
Angel Acevedo
|
| posted on 11/1/18 at 06:33 PM |
|
|
quote:
Originally posted by leeby... is with the vacuum pipes do i run them to a fpr ...
[Edited on 9/1/18 by leeby]
Depending on ECU configuration, a connection to vacuum line may not be needed on a Normally Aspirated setup as necessary adjustments to Injector Fuel
Flow are taken care of at the computer....
quote:
Originally posted by leeby... also when using the st170 manifold do i put a fitting into say number four inlet for brake servo vacuum
??
[Edited on 9/1/18 by leeby]
As stated above plenum and check valves may be the route...
A more accurate answer may be given if you factor brake effort at pedal according to preference.
[Edited on 1/11/2018 by Angel Acevedo]
Beware of what you wish.. for it may come true....
|
|
|
leeby
|
| posted on 11/1/18 at 06:46 PM |
|
|
ecu wise ill be running a motorsport electronics ME221 but was told to use a fpr when i was originally going to use the gsxr 750 injectors, but have
now changed that and am planning it running st170 inlet and injectors so id presume fpr will still be needed.
Using a mondeo mk2 1.8 zetec injector rail as they have a fpr and no messing about as would have had if using the st170 setup.
Its the brake vaccuum that is wrecking my head more than anything as aftermarket inlets have the take off for them and the st doesnt. my original
servo to manifold hose has a oneway valve fitted, so do i use an 8mm barbed fitting from one of the intake or use same fitting in all intakes and
daisychain them back to oneway valve and servo ?
i really dont want to build this car for a brake fail on first run
|
|
|
SPYDER
|
| posted on 11/1/18 at 07:43 PM |
|
|
You could always fit an electric vacuum pump to make your servo worries go away. Not the cheapest solution I grant you, but probably the most
reliable.
And, trust me, reference your FPR to the manifold vacuum. If you don't the injectors have to work against a varying inlet pressure. This
variation can be accounted for by the ECU, if very accurately mapped, but it can only do this by changing the pulsewidth. If your voltage compensation
and dead time aren't set perfectly that compensation won't be correct.
AlphaN ( if you use it ) isn't a totally accurate measure of load at the best of times. Why introduce another variable.
I know the idea of having a fixed fuel pressure might seem tempting but ask yourself why most manufacturers don't do it.
|
|
|
Angel Acevedo
|
| posted on 11/1/18 at 07:46 PM |
|
|
Fuel pressure regulator will be needed regardless if you install vacuum line to it.
If the rail has no regulator, it may be part of the pump arrangement, either in-tank or external.
If your pump arrangement does not have FPR, you will still need one.
On your Vacuum line for brake servo, I will refrain to comment as someone may chime in with better knowledge than mine.
Beware of what you wish.. for it may come true....
|
|
|
leeby
|
| posted on 11/1/18 at 08:06 PM |
|
|
thankyou guys
|
|
|
