Ami

iTrader: (5)

Hi,

I'm thinking of Forge adjustible actuator with stronger spring for my vf37.
But... many people use them I guess... however I heard from some people they're
waste of money and no good.
But unfortunately I still don't know why actually they're not good in their opinions.

So would be really happy to read some opinions here from users/mappers.

Is it really "no go"?

cheers

apac

iTrader: (2)

same question here! turbo dynamics could not provide me with an off the shelf solution for my vf36 twinscroll so was thinking about a forge. What spring rating would i need to crack the wastegate at 1 bar?

cossie_eater

iTrader: (5)

i was intersted in one of these when i upgraded. but speaking to mappers they say that the springs they come with are not strong enough so they have to be changed. so they are only really a cosmetic look. no performance increse at all.

scoobiewrx555

The problem with IHI turbos is you can't adjust the wastegate actuator arm, well certanly not on the single scroll IHI turbo's i've ported. With Mitsubishi TD series turbos you can so rather than change the spring rate in the actuator just shorten the wastegate arm by ex amoiunt of turns dependent on your needs, half a turn to a turn each time. If that's still not enough for you then get an aftermarket actuator.

I'm surprised you would want a higher spring rate in your VF37 as they are good for over 350bhp and spool really quickly from low rpm. The best way to get more boost from your VF's is to get your car remapped. Adding more boost by changing the wastegate actuator spring rate without mapping for it may get you into trouble from over boosting. The more air you push into your engine the leaner it runs. There's only so far the ECU can compensate for the extra boost by richening your AFR's and retarding timing. Thereafter when the ECU can go no more you get lots of lean running, serious detonation, and then BANG!! If you're very lucky you'll trigger wastegate duty and fuel cut along with timing retard, throw some cell errors and go into limp mode but again to that too often and your engine will let go eventually.

My best advice to you would be to get a remap.

HTH

Badbird

agreed we blew a engine by doing exactly that waste gate spring was weak so we shortend the rod till we liked the boost..engine diddnt.........no different to fitting a stronger spring same result
The forge actuator on our turbo was the main reason the mapper couldnt get more boost when it was mapped so we decieded to Fix the problem.that was a £4000 2.5 shagged

Ami

iTrader: (5)

It's not about the spool or getting more power just by changing actuator.
I'm thinking about stronger spring/modified actuator to keep higher boost to the end of revs - where standard actuator is making boost going lower.
Of course not without the remap - no worries

cheers

scooby-tc

iTrader: (2)

I got an uprated adjustable actuator for my VF36 twinscroll from Turbo Dynamics (1.3 bar actuator from memory) as i was told that the standard actuators can be a weak piece of the boost jigsaw.I noticed that during and after mapping the boost was held much better than with the standard one so i rekon its £130 well spent

scoobiewrx555

I remapped a 2003 STi a little while back. The owner had a forge dump valve fitted with the weakest spring ever. I couldn't get boost much over standard. I asked him to refit the standard OEM recirculating Air Bypass Valve. I went back shortly after that to try and remap the car again and we were seeing 19-20psi boost with no issues. The standard setup is a cracking bit of kit and will be good for well over 400BHP.

scoobiewrx555

There's only so far you can go with a standard turbo before you start to turn it into a flamethrower. With the standard actuator spring rate your VF is doing exactly what it was designed to do and providing plenty of boost for decent power.

Holding high boost so high up the rev range isn't such a good idea and will definately be detrimental to your engine. One of the main things that kills a scooby engine is high revs. Add to that high boost to the redline and your engine will go bang bigtime. Why do you think mappers tail off boost after x amount of high rpm and throttle angle, even on built bottom ends.

If you're that keen on higher boost levels get a bigger turbo that won't be working as hard to get you where you want to be. Changing the actuator for a higher spring rate type is a cheaper way to raise boost but equally you may end up killing the turbo as well as your engine. Don't mean to scare you into not doing what you want to do with your car but just stating the facts.