Running off external wastegate spring.

[dwdsm]

Anyone ever run off their wastegate spring only? I was thinking of running the two blue springs for my tail 38mm. It says it's 23.5psi with the two together. I wonder if it will spike before it opens, or open early. I want to switch because my turbo smart boost controller likes to leak at idle.All because of the small fittings it has. I could step it down but thought running off the spring wouldn't be a bad idea. Currently my tune if for 24psi.

 

[bastard dsm]

you an run it off the spring,you souldnt have any prob. with the boost spike.

 

[dwdsm]

MY God look at your tourque!

 

[csgsx23]

I run my Evo3 at spring pressure (19psi) on my TiAl 38mm all day long and it holds boost like a champ. No spiking or creeping at all.

 

[1992awdlaser]

When I was first tuning my car I had it running off spring pressure with my Turbonetics external gate.

 

[bastard dsm]

MY God look at your tourque!

i said the same thing,thanks

 

[dwdsm]

Put in the 23.5 rated springs and boosts to 25.5 and holds!.. Damn .. Well I guess I'll have to give up some more timing..

 

[T9S1i]

either that or your boost gauge is a little off!

 

[aero_sallee]

either that or your boost gauge is a little off!

I agree. Sounds like my autometer 30-30 guage.

 

[dwdsm]

Could be.. I would hope for the money I dished out for those gauges it would be on the spot. It's the Autometer Cobalt electronic gauge.

 

[Mr Peepers]

The only downside would be slightly slower spool up, maybe not even enough to notice though.

A ball and spring type MBC keeps the WG from seeing ANY pressure up to a certain point, holding the wastegate completely closed then suddenly opening it once you are near the target boost pressure.

Running WG spring pressure(a line directly to it) is more linear since the WG sees the same pressure as the turbo is putting out, cracking it open sooner/at a lower psi. This approach is also the least likely to spike.

 

[dwdsm]

I am seeing a quicker spool with this.. Although I did add an aluminum driveshaft???

 

[1992awdlaser]

An aluminum driveshaft won't provide quicker spool. It will just let the engine rev faster.

 

[xxraptor660xx]

An aluminum driveshaft won't provide quicker spool. It will just let the engine rev faster.

Which theoretically provides a quicker spool?

I've been using my wastegate spring as a sole boost controller for months..No problems.

 

[1992awdlaser]

Which theoretically provides a quicker spool?

No, quicker spool would mean that you get boost at a lower rpm. You will not get boost at a lower rpm from an aluminum driveshaft or any other light weight drivetain part like a flywheel. All the light weight parts do is make the car rev/accelerate quicker. Spool isn't based on the time it takes to get to a certain rpm, it is based off what rpm needs to be reached to get boost.

 

[dwdsm]

Tru that.. So my Boost controller was a POS and probally leaked way more then my external gate does. I see a quicker response from the car. Due to a quicker rev from the loss of unsprung weight. There, now it's worded better. Boost is made sooner then before in the sense of time not RPM's