Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: L18M on May 24, 2011, 03:42:02 PM

Title: Flappy wastegate flap
Post by: L18M on May 24, 2011, 03:42:02 PM
would this just be a gone spring in the wastegate and be fixed by replacing the spring?
or is there more to this than meets the eye?

cheers
Title: Flappy wastegate flap
Post by: Prof on May 24, 2011, 04:38:56 PM
It might rattle a bit, but the arm of the actuator should hold it pretty much in position - most likely you\'ve lost the little circlip and the actuator arm has come off the flapper.  OOH err :Hammer
 
It\'s a bugger to put back on with the tubby on the car in the stock position - but you\'ve an aftermarket manifold haven\'t you ?  So might be a little easier.
 
Dave.
Title: Flappy wastegate flap
Post by: L18M on May 24, 2011, 04:56:28 PM
cheer prof, i guess i need to have a poke around now i know what to look for and measure what circlip size i need.
would any circlip do? as long as is right size?
Title: Flappy wastegate flap
Post by: Prof on May 24, 2011, 07:08:13 PM
Quote from: L18M;764589cheer prof, i guess i need to have a poke around now i know what to look for and measure what circlip size i need.
would any circlip do? as long as is right size?

As long as it\'s the right size and isn\'t made from cheese or some other melty stuff.  You are looking for the outside type of circlip - not the ones that go inside - I think they are called E-Circlips.
Title: Flappy wastegate flap
Post by: bumpstart on May 27, 2011, 03:04:21 AM
if the wastegate arm doesnt pull the gate closed tight then the issue is with the clock positions of the front and or rear housings

you may have to back off the compressor cover backing bolts and clock the cover to pull the arm and the gate closed tight
Title: Flappy wastegate flap
Post by: L18M on May 27, 2011, 01:10:01 PM
Quote from: bumpstart;765054if the wastegate arm doesnt pull the gate closed tight then the issue is with the clock positions of the front and or rear housings

you may have to back off the compressor cover backing bolts and clock the cover to pull the arm and the gate closed tight

eh? :Hammer
so i guess i need to take the thing off then realign the flap?
Title: Flappy wastegate flap
Post by: bumpstart on May 28, 2011, 02:52:09 AM
if the wastegate moves a little ( with C clip fitted ) then you need to clock the ( usually ) the front cover slightly to pull the wastegate arm tighter
- else boost will be slow to build and will have a low peak

this usually happens as a result of the turbo pulled apart for overhaul or rear turbine swaps


if you are good, you can do this clocking on the car
( bolt down by the drain is tricky but not impossible )

if your install demands the clock position you have now,, then you have to shorten the can arm
( in this situ i do cut shut on the arm with the bladder end in cooled a tub of water )

the wastegate should be firmly shut,,and the tighter you get that arm the higher the boost threshold will be

this is why some stock turbos only manage 6 psi,, others 8
( have seen one that maxed at 4 psi due to poor clocking )
Title: Flappy wastegate flap
Post by: L18M on May 28, 2011, 01:23:47 PM
just had a re-read. i have an external wastegate if that makes a difference?
Title: Flappy wastegate flap
Post by: TiddlesRX7 on May 28, 2011, 01:58:18 PM
Quote from: bumpstart;765243if the wastegate moves a little ( with C clip fitted ) then you need to clock the ( usually ) the front cover slightly to pull the wastegate arm tighter
- else boost will be slow to build and will have a low peak

this usually happens as a result of the turbo pulled apart for overhaul or rear turbine swaps


if you are good, you can do this clocking on the car
( bolt down by the drain is tricky but not impossible )

if your install demands the clock position you have now,, then you have to shorten the can arm
( in this situ i do cut shut on the arm with the bladder end in cooled a tub of water )

the wastegate should be firmly shut,,and the tighter you get that arm the higher the boost threshold will be

this is why some stock turbos only manage 6 psi,, others 8
( have seen one that maxed at 4 psi due to poor clocking )



Basically you mean put some more preload on the actuator spring? Im thinking of doing this after my mapping session this morning as im only getting 0.6 bar of boost. I was thinking I could cut the actuator arm. Thread each end of it and make an adjustment nut up to suit. That way I can play around with it to the level I require by tightening or slackening the nut. Effectively shortening the arm to give more tension on the spring.



Ade
Title: Flappy wastegate flap
Post by: bumpstart on May 28, 2011, 02:27:29 PM
Quote from: L18M;765280just had a re-read. i have an external wastegate if that makes a difference?
disregard then,, though it should still be tight shut,, broken spring is pretty common

QuoteBasically you mean put some more preload on the actuator spring? Im thinking of doing this after my mapping session this morning as im only getting 0.6 bar of boost. I was thinking I could cut the actuator arm. Thread each end of it and make an adjustment nut up to suit. That way I can play around with it to the level I require by tightening or slackening the nut. Effectively shortening the arm to give more tension on the spring.



i also drill a small hole in the mount for the can ( not the can ) so to attach helper springs from there to the nuts welded onto the arm
(  if necessary )



(http://img822.imageshack.us/img822/2311/pic0103634.jpg) (http://img822.imageshack.us/i/pic0103634.jpg/)
(http://img694.imageshack.us/img694/3492/pic0103635.jpg) (http://img694.imageshack.us/i/pic0103635.jpg/)
(http://img217.imageshack.us/img217/6124/pic0103636.jpg) (http://img217.imageshack.us/i/pic0103636.jpg/)
Title: Flappy wastegate flap
Post by: TiddlesRX7 on May 28, 2011, 06:12:00 PM
Yeah thats the kind of thing. I\'ve got a spare turbo/actuator so I think I\'ll do a test with that one when I\'ve done the mod. Bike pump-pressure gauge-actuator to see at what pressure it lifts at.
Title: Flappy wastegate flap
Post by: L18M on May 28, 2011, 06:32:25 PM
thanks bumpstart :)
i should of mentioned earlier lol
Title: Flappy wastegate flap
Post by: L18M on June 30, 2011, 04:43:25 PM
took apart my wastegate earlier and all seems to be ok. spring ok, no loose nuts etc.

from looking at it, it seems the wastegate opens by the pressure difference of the inlet pressure (off the ic) and the inlet mani pressure (nipple on uim)
is this right? as thats how mine is pluged in.

also does the wastegate open at idle?
Title: Flappy wastegate flap
Post by: m1tch on June 30, 2011, 08:51:13 PM
Depends if the wastegate is a 2 port one, my Greddy one has an extra port to hold it closed when off boost up until it needs to open, then it switches to the other port and the vacuum is used to open the wastegate....my wastegate was £850 though lol