Fun though it is to read comments on multiculturalism and the joys of government I thought I might ask a question that is more suitable for this forum than anywhere else.
Dump Valves, those noisy things attached to modified Subarus and the ProDrive P2, what exactly do they do?

release excess pressure to allow the turbo to spool up quicker..i think...essentially reduce turbo lag...??

I understand their use but they also cause numpty driving of the highest order in an attempt to get a good pffffffft.

actually dumpvalves work too well to the point of being detrimental to performance...

when they release, the exhale ALL the pressure from the IC and all the vacume piping, which means there is a slight increase in lag when you get into the next ger/re-apply the throttle because all of the piping and the IC has to be re-pressurised by the turbo.... which takes time.. not much, but enuff.

the best option is to just use an aftermarket recirculating dumpvalve, some of them are noisy, but they maintain pressure and airflow in the system meaning there is no need to re-pressurise the system, and less chance of feeling that lag.

the other option is to just run valveless, and u get the georgous turbo chatter shound MMMmmmmmmm

not really any benifits, but by golly it sounds good

quote:

the other option is to just run valveless, and u get the georgous turbo chatter shound

And ruin your turbo bearings and shafts within 5k miles. Nice.

nahh... ive been running my GT28R turbo for the past 20k valveless, and its still going strong... i suppose the lifespan will be shortened... but it wont effect me in the time i own this car and turbo unit.

just make sure u treat the thing well and all is well..

i only run 16psi tho.


if running silly boost levels like 2bar ect... then deffo just get a recirc.


if you want to kill a turbo quickly... try running anti-lag lol

thatt'l do the job

I'd check the play in the shaft if I was you.

What are you driving, Papa? Cars come with a recirc as standard, you won't find a single standard turbo car with an atmospheric..

the standard recirc's nore often than not arnt very good above 14psi, so an aftermarket soloution is favorable.

im driving an old F reg nissan silvia, have a 200sx ca18det engine installed with 444cc skyline gtr injectors ( would preferr 555's ), garrett GT28R rollerbearing turbo running at 16psi, and a norris stage 2 chip in the ecu.


theres more but u get the idea

Is that the 1.8? must be looking good for 260-280bhp on that.

eheheheh yeah the turbo itself can push 310bhp max, i know ill not get that, and i have no plans to take it to a rolling road, so yeh, around that ballpark figure


the welded differential makes it fun lol

im just terrified of the big ends going tho lol

non of the turbo technics twin turbo sierra's were fittted with valves when thay were built not ever the minker 323's.

the turbos on mine have done about 40k, i checked the free play not long before eurofest and thay were fine.