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-   -   Any advice on fitting replacement wastgate actuator? (

Hoojammyflip 10-27-2012 08:28 AM

Any advice on fitting replacement wastgate actuator?
My replacement wastegate actuator has arrived :cool:

I went for a like for like replacement (0.8 bar) so should not be any problems with the mapping...

Do I just set the arm to the same length as the original part and that's it - or is there more to it?

Cheers :)

bugblatterbeast 10-28-2012 12:23 PM

a few things to watch out for

1) make sure the pushrod meets the actuator arm at 90 deg. this helps keep the force vs distance curve monotonic, which in turn makes tuning easier

2) before you take the old actuator off, get hand pump with gauge and pressurize the old unit until it just starts to move. take note of the pressure. when you install the new unit, you can then adjust the preload such that the same pressure also just starts to move the actuator. this will save you tuning time. the same length for two different actuators may not result in the same preload. both manufacturing tolerances and aging of the old unit are working against you.

3) make sure the pushrod is not rubbing anything. this includes the edge of the actuator itself.

4) while the old actuator is off, check that the wastegate operates smoothly.

Hoojammyflip 10-29-2012 10:25 AM

BBB - Wow thanks mate - brilliant synopsis - I will take a note of those things to look at

Hoojammyflip 11-05-2012 10:36 AM

I believed Boon on uklegacy who did his...



they were about 50 off ebay, and dead simple to fit once you get the tutbo heitshiled off. Or get TDR to fit it if you dont want to bugger about wit the heitshield bolts (nightmare)

I didn;t have a turbo heatsheild on mine - So I 'popped out' to fit it this afternoon...

Old one in place...

New one...

The thin pipe going over the top of the actuator body had it support unbolted and a slight modification to its routing to allow withdrawl of the body of the old unit - and the boost pressure pipe was incredibly difficult to get hands to and grip anything - aaarrgggghjhh - nightmare! Trouble is - once it's off - one of them has to go back on... So it may as well be the new one
The spigot on the new unit was straight whereas the old one was curved round - bent the new one a little to try to lessen the strain on the rubber pipe - hope it doesn't fail
Anyway all bolted up and in place with just a couple of mm of pre-load - fingers crossed :D
I measured the pressure to move the units - only had a foot pump with guage - but the difference was quite noticeable - the new one took about 10 psi to start moving whereas the old one started moving at about 6 psi so looks like the spring had gone weak...

We shall see what happens at the RR day on Saturday and hopefully get it sorted...

Hoojammyflip 11-06-2012 03:02 AM

To explain my reason for wanting to swap the part...

I love the way the car drives. The only reason I have swapped it out is because I am missing some ponies from the top end (Please note - in the UK we use power at flywheel for these charts NOT at the wheel! ;)) . I bought it a year ago advertised as 320bhp :rolleyes: - If you look at the comparison between my power curve (Graphite) and Boons there is an uncanny similarity until 5750 rpm...

Graphs show uncorrected power for comparison purposes - peak corrected power for mine was 244 bhp (and 280bhp is standard)

My car is stock apart from a MillTek sports exhaust system with sports cat and quad exhaust tailpipes and an ECUTek Map, Boons car is stock apart from a new 1.0 bar actuator and having been mapped.

So having changed the wastegate actuator for one that should be the same as brand new stock pressure (0.8 bar) I am expecting that it will allow the boost to hold for the duration of the rpm range rather than tailing away as it appears to be doing at my last dyno session. So I am not expecting any change really before 5750 rpm - so no change for daily driving (and certainly not when the wife is in the car )

I have a dyno day coming up on Saturday - so hopefuly will see some improvement on the chart :lol:

Hoojammyflip 11-15-2012 05:39 AM

Dagnabit...missed the dyno day - but good news I do have a session with a mapper on the rolling road tomorrow... :D

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