SRI 2.0 Turbo Dump Valve????

[bobbin]

Hi, has anyone fitted a dump valve to there 2.0T? Just fitted a K&N induction kit and was thinking, would a dump valve make any difference, your thoughs are appreciated

[Duncan]

Nooooooo, don't do it - you'll sound like a chav!! LOL

The 2.0T actually has a charge release valve anyway, that's what makes the psst noise when you're changing gears quickly or the chatter when you accelerate hard and then ease off.

Why do you want to fit (another) dump valve?

D

[simonali]

Dunno about the Veccy engine, which I think is based on a Saab unit (it's shared with the 9-3 anyhow), but on my Astra the boost pressure is all governed electronically. A pressure transducer opens a wastegate solenoid at a set boost pressure, so no winding springs up! I would imagine, because of this, that if it was possible to fit a dump valve, the set-up would have to be designed specifically for that one car and pretty complicated. Some of the Astra boys have tried dump valves and couldn't get them to work very well.

As I said though, the Vectra engine is different, so no doubt there will be someone along with more knowledge!

[simonali]

The 2.0T actually has a charge release valve anyway, that's what makes the psst noise when you're changing gears quickly or the chatter when you accelerate hard and then ease off.

This venting of pressure is probably silenced somehow, or routed back into the air intake system. Your best bet would be to find where it's vented and let it go straight to atmosphere, where it'll be louder. If it does go back into the airbox, or whatever, remember to blank off the hole that's left.

This is all guesswork, so don't quote me!!

[2ltrT]

I dont know about other 2.0T owners but mine psst's from standard, well somedays it does somedays it dusn't, that might be a change in my driving style tho.
now and again at low speed I get wastegate chatter, that sounds nice, lol
Apparently the bsr ppc tuning unit, makes it a little louder too.

[Bainie]

I think Robward had a dump valve on his ?

[Ste]

surely the wastegate just diverts exhaust gasses around the turbine and down the exhaust pipe, and not to atmosphere? hence little noise.

Sorry mate, but to fit one that exits to atmosphere is a complete waste of time / money and you will look like a ****. IMO


BTW, what do you expect to gain by doing this???

[Duncan]

Dunno about the Veccy engine, which I think is based on a Saab unit (it's shared with the 9-3 anyhow), but on my Astra the boost pressure is all governed electronically. A pressure transducer opens a wastegate solenoid at a set boost pressure, so no winding springs up!

That's exactly how the turbo works in the 2.0T (it's a Garret GT2052S).

I would imagine, because of this, that if it was possible to fit a dump valve, the set-up would have to be designed specifically for that one car and pretty complicated.

Yep, you'd have to find a suitable place to put in a separate dump valve. Although I don't know what the point is of doing it - just to get a bigger 'psst' when you change gears etc?

Apparently the bsr ppc tuning unit, makes it a little louder too.

It certainly does!! One of the variables that the remap alters is the turbo boost, so the turbo is generating higher levels of boost which when released give a louder 'psst' and chatter.

I was at a rolling road today and they had a really good set-up, so I was able to see not just bhp and torque, but other data such as turbo boost. Because of the BSR unit I was able to do two runs - one remapped and one original spec. On the original spec the boost pressure was a maximum of 9.5psi. Remapped it was up to 13 psi (almost 1 bar) so this is why the psst and chatter is louder after the remap.

D

[2ltrT]

you cant tell us you have been on the rolling road without telling us the results!!

i foned up bsr uk today to order, and n' they don't work saturdays i dont think

[Duncan]

you cant tell us you have been on the rolling road without telling us the results!!

LOL, okay - here goes.....

Standard - 185.7bhp / 201.1 lbft
Remapped - 211.4 / 232.6 lbft

That tallys with a previous RR of 183/212bhp standard and remapped. These guys were very good, explained things like how well the car was running, fuelling etc - you got the pressure your fuel was running at and mine was running just right, not lean or rich.

In fact, when we get round to doing a rolling road day in the SE region, they'll be on the top of my list for doing it.

i foned up bsr uk today to order, and n' they don't work saturdays i dont think

Probably not, you'll have to wait until Monday!

D