turbos making boost

[lewis_willy2]

at the mo my turbo is all plumbed in via the chargecooler but the chargecooler water pipework isnt connected up neither is any type of actuator/boost controller circuit.

the question is should it still make boost?

during a little spin the other day at my mates workshop my missus said the boost gauge only went from a minus number to 0. another suggestion of no boost is my dump valve isnt operating?

[Justin..]

without an actuator fitted properly it will massivley overboost at higher RPM

[Allan]

it will boost just not slow down and keep boosting !

[lewis_willy2]

well thats the problem it didnt feel like it was boosting atall. i know it will overboost so i didnt go mad.and no dump valve sound? so as i have it setup it should make boost?

[Justin..]

yeah should do.

[lewis_willy2]

thats what i thought. im inpatient, gonna plumb the boost circuit in before i do another test and see how it goes. its well LOUD!!!!! straight through exhaust with just a scorpion back box FTW

oil feed from block has a leak and forgot a jubilee clip on the oil filter housing cooler so have two small leaks. then its complete.

[Allan]

Check you dont have a boost leak, as that would make it sluggish, do you get any turbo chatter?

Might be possible that your actuator is open ad the turbo is just boosting to atmos hence no boost.

You can check your dump valve, use the throttle cable, start engine and just watch it as you rev, on idle the valve will be open as your manifold will be under vacumm and on boost it will be closed.

If its closed your not making enough vaccum to open it or your not connected (so depeneding on your dump valve this canbe adjusted)

[stan]

what type of dump valve is it?

try bypassing it

and how much of a blast did you go for?? If its just a quick blip, you may not see +ve pressure.

[lewis_willy2]

no, no turbo chatter, didnt even seem the turbo was spinning but checked today and it spins nicely on idle. im not running an induction kit either at the mo.

its a forge dump valve. i took it to 5500rpm :oops: drove fair enough to see how quick it would be!!

[lewis_willy2]

on idle what should i get on my boost gauge

[Justin..]

wont be boost, will be vacuum as a standard engine

[stan]

-minus figure.

Im pressuming its a piston dump valve...they are prone to leaking, would be worth trying to bypass it.

[Allan]

you will get nothing on your boost gauge, unless its a boost / vaccum gauge, then it will read -ve, only when you have your foot down will it read +ve

where is your gauge taking its readings from ?

[lewis_willy2]

ye im getting a minus figure, will see what the dump valve is doing on idle 2mro. ive had it apart and given it a good clean

[stan]

check the piston and bore in the valve arent scored.

[lewis_willy2]

gauge is straight off the inlet manifold then i have a t-piece off it for the boost circuit


http://i10.photobucket.com/albums/a126/lewisredfern001/SBR-controller-cheat.jpg

[lewis_willy2]

so if the dump valve is leaking im assuming that would be my turbo pressure leaking

[stan]

yup

[Clio_GTT]

Is the actuator arm connected to the wastegate?

[Wobba]

When you fix the possible leak, and go for a burn, you'll soon know about it ;)

[lewis_willy2]

ye actuator is all good all tested ok and def closed. ive got a feeling im just getting boost leak.

wooba ye i no i wasnt overly pleased which is why ive gota cover all angles regarding the above.

[Allan]

well if your boost gauge is not reading then its leaking before its getting to your inlet, so just check it all over

[Coops]

whip the d/v out and block off the hole, then blip the throttle, eliminate that or expose it as the leak