as above, today looking at the 3dr which is standard the dump valve is on the left side of the IC when facing front on.. why do all cosies that run a valve run them on the right side? is it just down to space? ease of fitment? or is there an advantage to running on that side just after the TB?

 

Did you ask pete at spec.r about this today mate

 

Yh i did mate.

 

Could be heat?

 

How could heat be a factor mate? My understanding is its dumping cooled air which isnt ideal but is it making that much of a diffrence? Its a fair distance away from the turbo its right behind the headlight so cant see external heat being an issue either.

 

It's simple -Lot of people have non standard intercoolers. After market intercoolers don't have the dump valve take off that the standard cooler does. To fit them on the left you need to copy the RS 500 setup. With the crossover pipe etc. That's alot more work than just fitting one between the throttlebody and intercooler.

 

The standard item is of recirculating type as well, so the air recirculates through the filter, whereas aftermarket ones 'dump to atmosphere.

It's the same principle as the boost solenoid, they should reconnect back to the airbox, but they don't seen as most no longer have one

Martin

 

Why does it need to be like the rs500 setup paul? Surley thats only to have to receirc setup?

 

The standard valve is of the recirculating type, another factor is the vacuum source which the atmospheric type need, so it makes sense to have it on that side of the engine.

Martin

 

Place the dump valve as close to the throttle butterfly as possible! that is the best thing to do!

This minimizes the amount of stationary / stalled air to move next time you open the throttle when the turbo is spinning quickly.

The idea is to keep as much air flowing as possible when you come off the throttle, when the turbo is spun up. Also this limits back pressure and stress across the spindle & turbine blades!

This means the turbo is never pressurizing against a dead end of a closed butterfly!

 

I read a thread the other day saying you must run a dump valve on a cosworth or it will snap the turbo shaft is this true as mine hasn't got one but don't need it to bugger my turbo up so will get one if that's the case

 

I have no space on the TB side so iv had to mount it on the turbo side now.

 

I maybe wrong but I was always told to run one on the cool side .

 

i heard the same but cant really see there being an issue if ford ran it on the "hot" side.. maybe not as efficient but shouldn't cause any problems.

 

^^^^^^^^ this.

 

Why have you no room to run it on the cool side mate

Steve

 

at higher boost levels on some gt series turbos they are allegedly a must due to weak/thin turbine shafts and relativley weak plastic bearing cages, but they are not neccesary on t series turbos as they are very strong. i have noticed on a few cars i have owned there has been a little quicker (just noticable) in being "on boost" between gearchanges with a dump valve fitted and just a touch (minute) bit of "lag" without one fitted. but if you have a cone filter the car without dumpvalve sounds far better imo

 

Iv got a harvey inlet mate and a spec r cooler, on thr inlet the Tb sits down real low so had to mod the Ic and take the long neck off and as the Tb is lower and theres no neck on the IC i cant use a straight pipe or a alloy pipe so iv got silicon pipes with no space for a dv take off.

 

Why did you not fit the lowering kit airtec sell the have a 25mm pipe welded into the inlet 90 degree bend like mine has due to lack of room

 

I had already spaced the IC out and still encoutnred issues so this was the best option. If i have any issues with thr DV on the turbo side i can always mount it to the end tank of the IC on TB side.

What my issue was that the TB sat 40mm lower then the standard position so when i had spaced it lower i was having issues with the rad being in the way etc

 

So who builds stuff wrong Harvey or Pete?

Funny i have a Hart inlet the same as Airtec's and an Airtec cooler and everything lines up perfect so what's wrong with above?

Plus Gav diamond has a Harvey inlet and Airtec cooler that lines up so it must be Pete's cooler, did you tell him you were running a Harvey inlet?

 

Nope as i changed spec after i had the IC so not really anyones fault either Harvey or Pete could have sorted it if it would have been in the UK. The mounting brackets are positioned diff on the spec R to the airtec one.

 

There's a lot of bad info about dump valves, where they should be, and what they do.

To do the only thing they do, which is help prevent the turbo going in to the surge part of the map when you close the throttle, they should be as near to the compressor outlet as possible.

Rubber diaphragms etc dont like the many hundreds of degrees C that compressor outlet temps are though, so after the intercooler is often a more reliable bet with little disadvantage.

If you want to keep turbo response as fast as possible (and haven't got a AFM or something that requires a dump valve to operate correctly) the best position for the dump valve is in the dustbin or on ebay.

Turbos dont stall btw, the airflow from them does, but the turbos dont. If you watch a turbo RPM gauge they actually slow less with no DV fitted than they do with one fitted. Which is why you get chatter/surge, as the compressor goes to a far left part of the map where the airflow is almost zero but the turbo rpm is still high as fook.
A dump valve basically allows the compressor to keep flowing air and slows it down, which brings it back in to normal areas of the compressor map.

On that note, if you've got a DV that chatters THEN dumps, you may as well not have one at all, as the initial surge is the bit that will cause stress on the turbo to be honest.

 

As WTF has said, the DV is there for a reason and if its not doing that then it really has no need to be there.

R5FORD, if you really wanted to have it on the cold side you can have a takeoff from the cooler end tank.