A question here !!! how would i know OR how do i adjust for the actautor to run at 7-8 psi, what tools is needed to check its correct?
Cheers
J
Cheers
J
Turbo PSI rating -----------
- Thread starter --alpina--
- Start date
OP
OP
ok, my turbo and actuator did come from an Ford Escort RS Turbo, not sure what PSI that car runs as standard otherwise if i were to floor it with a guage and see that bosst pass 7 upwards pass 8 psi, im looking at internal engine damage, i want to keep the PSI to minimum that the standard engine can take.....
J
J
pollyp
Club Member
how to find the amount of boost produced? fit a pressure gauge.
how to alter the boost? two/three things to consider:
1. the natural/stable boost level is determined by the wastegate actuator spring. there's alot of science in balancing between how much the actuator moves per PSI of boost vs how much exhaust energy is wasted via the WG. all sorts of variables including spring rate, preload, natural length, etc etc.
generally lower spring rate = earlier WG opening = lower peak boost
2. all boost controllers basically delay/manipulate the boost feed going to the actuator to keep the WG shut long as possible so turbine receives 100% exhaust pressure to either improve spool response and/or increase boost above the actuators intended pressure. once the boost feed reaches the actuator, its still up to the spring to determine how much the WG opens.
3. all turbos have a certain efficiency range shown by their compressor maps and matching the right turbo size, set with the right peak boost, to work with a certain engines gas flow is very important.
too small = only good for low-end, runs out of steam or restricts at the high-end.
too big = high boost threshold, very laggy, can reach high boost which might exceed engine capacity
setting peak boost too low on the compressor map (under-working the turbo) = laggy, wasted potential
setting peak boost too high on the compressor map (over-working the turbo) = inefficient, just heats up the air, potential turbine failure from over-spooling
I think ideally a turbo would be regulated by a fast & accurate solenoid controlled WG actuator rather than an old fashioned pneumatic sprung plunger but they're prob not as reliable and might be why all turbos stuck with the reliable old method
how to alter the boost? two/three things to consider:
1. the natural/stable boost level is determined by the wastegate actuator spring. there's alot of science in balancing between how much the actuator moves per PSI of boost vs how much exhaust energy is wasted via the WG. all sorts of variables including spring rate, preload, natural length, etc etc.
generally lower spring rate = earlier WG opening = lower peak boost
2. all boost controllers basically delay/manipulate the boost feed going to the actuator to keep the WG shut long as possible so turbine receives 100% exhaust pressure to either improve spool response and/or increase boost above the actuators intended pressure. once the boost feed reaches the actuator, its still up to the spring to determine how much the WG opens.
3. all turbos have a certain efficiency range shown by their compressor maps and matching the right turbo size, set with the right peak boost, to work with a certain engines gas flow is very important.
too small = only good for low-end, runs out of steam or restricts at the high-end.
too big = high boost threshold, very laggy, can reach high boost which might exceed engine capacity
setting peak boost too low on the compressor map (under-working the turbo) = laggy, wasted potential
setting peak boost too high on the compressor map (over-working the turbo) = inefficient, just heats up the air, potential turbine failure from over-spooling
I think ideally a turbo would be regulated by a fast & accurate solenoid controlled WG actuator rather than an old fashioned pneumatic sprung plunger but they're prob not as reliable and might be why all turbos stuck with the reliable old method
OP
OP
Thanks for your replys, fitting a gauge , yes i guess its the only way maybe there is another, i have a heavy foot and if i enjoy what i feel from the car i might get too happy exceeding the PSI that the car is happy and stable with!, ill just have to play around i guess, thanks for the info pollyp.. will be updating the turbos thread soon!!! mapping will probably get done in a couple months.
J
J
OP
OP
ill give that a try frank!!
cheers
J
cheers
J
frank
Club Member
here,s how the actuator moves with a footpump J, the 1st one is without a manual boost controller ( the rod moves well before the psi setting, and its only the preload that holds it shut)
and the 2nd one is delayed by the boost controller
OP
OP
Nice one frank, with the manual boot in place i see theres like a delay in the actuator opening and closing like you says, is that a bad thing in the sence for the boost, also what can be done to the actuator to close quicker? also was told of an actuator called -31 i think, what does that exactly do frank?
http://www.ebay.co.uk/itm/Garrett-3...CarParts_SM&hash=item41706294bb#ht_2795wt_806
J
http://www.ebay.co.uk/itm/Garrett-3...CarParts_SM&hash=item41706294bb#ht_2795wt_806
J
