dump valve

Brett · April 06, 2005, 09:49:49 PM

the developement is whats holding me back. Once the car is running perfectly I will look at making my own parts. With the application of a little knowledge I see no reason why I cant manufacture my own BOV and many other parts come to think of it. Its just time and repeated trials of different techniques. When you buy a brand you are buying someones collected knowledge. However I think Â£150+ for Â£15 of materials and labour is rather excessive.

MikeLMR · April 06, 2005, 09:59:05 PM

what is wrong with the standard one ?

colinrx7surrey · April 06, 2005, 10:05:59 PM

i dont think theres anything wrong with the standard one as such---just fancy a modification change!!!apparntly my mate has fitted an updated dv and i quote \'\'the gear changes are a lot smoother\'\'....well thats wat he says anyway...just fancy a new whhhhooossssshhhh noise too lol!!!!:D

antnicuk · April 06, 2005, 10:13:26 PM

are people getting a little confused between pop off valves which only open if too much boost is in the charge pipe as a precaution for a wastegate fail to stop you blowing up your engine. A Blow off valve or dump valve which is what a most standard car have fitted, although they recirculate the air into the air box, makes the nice sound when you lift as they have a pipe from vacume side of the inlet plenum which dumps boost between gear changes and when you back off so you dont have all your boost trapped between you throttle body and your compressor whel on the front of the turbo.

In answer to the original question (presuming you mean BOV), you can put what you like on an FD as it doesnt use an airflow meter, a turbo II does so you have to fit a strong spring other wise the extra strong vacume that a rotary has on idle compared to a boinger will suck it open and unmetered air into the intake system bypassing the airflow meter, and the car wont idle properly or at all.

Hope this makes sense and i\'m not teaching people to suck eggs but it appeared that people were talking at cross purposes.

colinrx7surrey · April 06, 2005, 10:32:36 PM

i did actually originally mean dump valve instead of pov!!!! i was getting confused my self as well!!!!any news on dvs does it have to be a recirculating dv??easy to fit etc etc etc!!! any news would be really handy:D cheers guys colin

colinrx7surrey · April 06, 2005, 10:34:14 PM

i have a turbo II would it make a major difference??does any boby know anyone or companies that make one???cheers colin

antnicuk · April 06, 2005, 10:50:02 PM

The only difference it will make is a nice sound......
Its job is to dump the air, thats it, so i am pretty sure you will not notice any difference in the drive, you will notice more performance with out one as you dont have to recreate all you boost everytime you change gear. recirculating keep its quiet and on the turbo II it means that if it opens due to suction from the engine its sucking in filtered and metered air so wont effect the AFM.

colinrx7surrey · April 06, 2005, 11:01:21 PM

do u happen to know a company that sells them??
cheers colin

antnicuk · April 06, 2005, 11:32:32 PM

you can pick one up from absolutely anywhere, the stock rx7 fitting is the same as most dump valves so all you need to is block of the hole left in the inlet duct. slip the new dump valve in the old hole and connect the vacume pipe from the stock one to your new one, it should take you no more than 10 minutes to fit.
Just make sure its adjustable or it comes apart so you can either put washers in to strenghten the spring or put another one until your car idles with the new dump valve. Your only gain will be a nice sound when you come off the throttle.