hi i own a mazda rx7 2nd gen could anyone help me out! i want to change the standard bosch dump valve to an upgraded one!
does any one have any ideas,plus ,where to get one,and how much it would cost ,and how easy it is to fit!!cheers colin
i think there is a cue forming for a nice shiney dump valve - but im not paying the 120+ that people want for a new one :(
I\'m tempted to make my own tbh. Just a question of finding a spring that will do the job.
didnt think it would be that simple
you could make a killing though if you could :)
does the valve have to be rx7 specific - or can you use any - im not really clued up on these things
so if some ( cough brett ) could explain what you need ( ie pipe work and the such like ) - it would be a huge benefit !
surley there must be some company some where that makes a dv upgrade for a 2nd gen r7!!!anyone doing any research lol
i think pip @ WGT can get them for about £85 or something like that
could be worth a call to him ?
anymore details on that 1,like a web address or contact number cheers grinder....colin
errrrrrr ....
runs off to check favourites ...
http://www.wgtautodevelopments.co.uk/rx7.htm
Technically its a very simple device. Its simply a one way valve placed in line with the high pressure side of the induction system. When the pressure reaches a set point it overcomes the force of the valve spring, this opens up a vent to the atmosphere where the stored pressure can escape instead of back pressurising the intake route to the pooint of stalling the compressor. :cool
All I need to do is find out the maximum psi I want in the High pressure side of the intake system, find a suitable place to fit the BOV (turbo to intercooler hose sounds like a good place), get hold of a suitable poundage spring, turn and mill a suitable diameter body, polish it up and fit it to the car.
Its almost too easy.... :D
sounds good brett if u come up with one let me know cheers colin
I\'ve never been too sure about BOVs in rotaries. The stock valve vents back into the air intake system and BOVs vent to the atmosphere.
This means that with a BOV the fluel mixture to your engine becomes temporary rich when it vents. Not sure if this is a problem our not but it\'s always made me shy away from them.
True, but I\'m talking about fitting a BOV that will only operate at pressures that I consider iffy, not sure what those are going to be yet, I\'ll have to do some more research. I may have to wire up a n/o switch on one side of the BOV which is closed when the BOV operates, that will give me an input signal I can use if fueling during the BO cycle becomes an issue.
vent to atmo valves will not cause a problem on a rotary as u are not running a maf sensor..on cars with maf air is metered as it enters and on lift off the measurement is altered so the maf immdlty injects more fuel screwing up the mixture...any dump valve will work on a rx7 just depends on how ur car is plumbed in ie twins or single aftermarket intercooler or standard
STandard single turbo on the FC.
Anybody know what the upper safe limits are, in regard to what bhp you can run with the stock turbo?
The bloke who built a few engines for me whilst I was in oZ designed and built his own blow off valve. I think he only ever made 2 of them and they worked reasonably well. I dont think he fully developed them as most of his customers wanted to supply known brabd names. And plus as we all know development takes alot of time. Something of which he never had too much of!
Hi sname is Kevin webb and his buisness is South coast Rotaries.
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 £150+ for £15 of materials and labour is rather excessive.
what is wrong with the standard one ?
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
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.
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
i have a turbo II would it make a major difference??does any boby know anyone or companies that make one???cheers colin
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.
do u happen to know a company that sells them??
cheers colin
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.