WTF???? Why didnt anything post!

 

Ok, ill retype the question.

What i want to know is if a higher spring rate on a wastegate spring increases the speed that your turbo boosts to a certain boost level.

For example, Lets say i want to run 10 psi low, and 15 psi high on a given turbo. Now i COULD just get a 5lb wastegate spring and use my boost controller to get my 10psi minimim. OR i could get a 10lb wasteagate spring and also have a minimum of 10psi.

What i want to know is, will the 10lb spring cause the turbo to reach 10psi FASTER than a 5lb spring with the boost controller dialed for 10psi??????

 

Are you talking about a electronic boost controller or a ball/spring type?

It should certainly spool a bit faster than the electronic boost controller because the EBC starts cycling the wastegate slightly before 10psi... while the spring doesn't care... it open exactly when 10 psi is reached.

EBC's are very good though and I doubt you'd notice much diff. Being able to change boost settings is nice too.

 

Yes, i have an EBC. Its the Greddy Profec B. But regardless, what you seem to be saying is that the boost will get to 10psi faster since the EBC isnt cycling yet. Is that right?? Or am i misunderstanding?

 

I really don't think you will gain anything by going with the lighter spring. I have heard that running a very light spring can sometimes make problems when using a controller to jack it up to a higher pressure.

Sounds to me like you need a 10 psi spring

 

The heavier spring you use, the faster you will boost. If you run a 15lb spring as opposed to a 10lb spring you'll reach 15 faster although, you won't be able to run less the the spring weight in boost. (ie....15lb spring/15psi) I only know this because I had the 10lb spring and switched to the 15lb spring. It was night a day in the response.

 

Thank you ernie, thats just what i wanted to know. It seemed like this would be the case, but i wasnt too sure. Thanks for your help

Graham

 

I found the same thing when increasing the spring "pre load" from 14.5 psi to 20 psi via a screw and plate system to compressor the spring (variable boost)

The responce was MUCH better even on a TO4S !

 

the longer a wastegate stays closed the faster the boost will rise. a lighter spring will creep open before its real load setting. so it is leaking some of the exhaust before its put to work.

paul

 

MY mechanic can change the spring in the 3rd gen stock actuator in order to get faster spool up . Brian at BNR and rotobrain have seen this and like the idea. With the modifed part you can put in a spring to match your target psi for quicker spool up.

 

Your not going to gain anything on stock twins. They already spool very fast. This was intented for single turbo applications.