General Dump Valve

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General Dump Valve

T-Jet 120

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Can one of these be fitted to my T-JET (when i get it), if so what difference does it make apart from the noise. :slayer:
 

stumac1985

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Differences??? how about invalidating the warranty for a start.

Hate it when people say this as its simply not true. It will only invalidate the warranty if the modification can have caused whatever part or item that has failed to fail.

EG: Lowering the car 60mm on standard shocks and the shocks go, they wouldnt replace under warranty.
 

sledge

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Fair comment, now are you going to state with 100% certainty that fitting a dump valve wont dmage or have an adverse affect on any other components?
 

grandemike

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i dont know how a turbo works really but i think its got something to do with forcing air into the engine. i thought that when revs suddenly drop like at a gear change, a lot of unwanted air is released. putting a dump valve on just means the air is put through a valve which makes a noise. thats my guess anyway. it wont hurt anything and all dealers mechanics will know this. they work a lot better on a petrol than a deisel though.
 

AlanHod

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Dump valves are fitted between the turbo outlet and the throttle body. When going from 'boost' state to a closed throttle state the turbo continues to pressurise air, but the closed throttle prevents the compressed air from entering the engine. The dump value releases this pressure into the atmosphere.

Without the release the pressure can cause the turbo to slow down and due to pressure differences the air can flow into the turbo backwards.

The dump value prevents this and should improve getting onto 'boost' when accelerating inbetween gear changes.

It won't make any noticeable performance difference on a T-Jet but would give the characteristic noise when driving.
 

AlanHod

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I did use Wikipedia, but i am an automotive engineering graduate so knew it anyway. Wikipedia just worded it better so i used that. :p
 

StevenRB45

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tbf...if anything or an engine or gearbox explodes enitirely within 3 years who actually expects to get a warranty pay out?...they fob it all of as wear and tear anyway!
 

puntokris

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Diesel turbos work differently to petrol turbos,

and like already mentioned wouldn't make any difference to a diesel other than sound. A petrol it would make difference.
 
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Don't need one its a VGT (Variable Geometry) Turbo which alters the pitch of the fins on the turbine to generate what boost is required at x RPM. This negates the purpose of a blow off valve as it will just alter pitch to generate next to no boost and not stall when you close the throttle. They still have a waste gate to expose of 'excess boost pressure'
 

D4nny8oy

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Yep, still here.
Don't need one its a VGT (Variable Geometry) Turbo which alters the pitch of the fins on the turbine to generate what boost is required at x RPM. This negates the purpose of a blow off valve as it will just alter pitch to generate next to no boost and not stall when you close the throttle. They still have a waste gate to expose of 'excess boost pressure'

Erm, no.... variable geometry turbo's do not have a wastegate- the actuator operates on the fins to manage the maximum turbine speed, and even now are only fitted to Fiat's diesel range- none of the petrol T-Jets use them, not even the Bravo 150.

The T-Jets use the common actuator/ wastegate combo, controlled via a solenoid valve. They have a built-in recirculating "dump" valve that runs off the inlet piping to the throttle body and sends the charge air back into the compressor inlet when opened, and is controlled by the ECU. A recirculating valve generates very little noise compared to the aftermarket atmospheric varieties.

(y)
 
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T-Jet 120

T-Jet 120

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in the same boat as grandemike here, not an expert on these things lol. only thought about it as a friend has just fitted one to his leon cupra R, so is a dump valve not recommended? is it best to keep the "recirculating dump valve"?
 

abarth_178

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Kept a resirc on my old Punto GT, never wanted to attract the attention of 'chavs', think dump valves only work Suburu's and the like to be honest.
 
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Erm, no.... variable geometry turbo's do not have a wastegate- the actuator operates on the fins to manage the maximum turbine speed, and even now are only fitted to Fiat's diesel range- none of the petrol T-Jets use them, not even the Bravo 150.

The T-Jets use the common actuator/ wastegate combo, controlled via a solenoid valve. They have a built-in recirculating "dump" valve that runs off the inlet piping to the throttle body and sends the charge air back into the compressor inlet when opened, and is controlled by the ECU. A recirculating valve generates very little noise compared to the aftermarket atmospheric varieties.

(y)

cool :D I stand corrected (y). Does that mean getting a 'atmospheric' dump valve fitted could actually make the turbo spool up slower as the charged air is getting lost and not shoved back through the intake to spool the turbo up again?. :chin:
 
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T-Jet 120

T-Jet 120

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cool :D I stand corrected (y). Does that mean getting a 'atmospheric' dump valve fitted could actually make the turbo spool up slower as the charged air is getting lost and not shoved back through the intake to spool the turbo up again?. :chin:

I was thinking this, lol, if this is true i'll keep my recirc on. :slayer:
 

joeraz

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I did not manage to block off my recirc so in effect had both working in unisin,, the HKS SSQV makes a nice whistle.
 

Cheesecake

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Just hopping back to the question of warranty invalidation - I think it would. I mean you invalidate it just by missin a regular service.

Consult Fiat first and they will either a) fit one for you, b) put you in touch with an accreditated company or c) tell you no way, do it and your warranty is fkd.
 
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