VersaTune User Forum

Dump valve.there are lots of threads on mazdaspeed forum regarding bad cores in them intercoolers . Just a thought. Try piping your stock tmic back up and see how she runs

Ok, so your BPV (BPV=ByPass Valve, diverter valve, dump valve, however you want to call it but the official name is BPV) is a forge. When was it serviced last time or for how long have you been using it?

mps6dave wrote:Dump valve.there are lots of threads on mazdaspeed forum regarding bad cores in them intercoolers . Just a thought. Try piping your stock tmic back up and see how she runs

Might do that one night this week.

mituc wrote:Ok, so your BPV (BPV=ByPass Valve, diverter valve, dump valve, however you want to call it but the official name is BPV) is a forge. When was it serviced last time or for how long have you been using it?

I bought it second hand and ive had it apart and oiled it up about a month ago if thats what you mean?

Yes, that is what I meant, it sounds good.
Do you happen to know if there are several spring options for your valve and which one you're actually running?
I'm thinking that your turbo is currently maxed out just because the air is escaping from the intake manifold back into the intake due to the BPV opening too soon. The reason for this may be a too soft spring for the boost you're hitting (over 1.3BAR, so 19-20PSI).

I looked at Dave's logs and his turbo can push more. Of course, he has another solenoid, but even so I remember that at load 1.6@6000rpm my wastegate duty cycles were around or below 80%.
So assuming that you don't have any boost leak (this is something you confirmed by testing IIRC) the BPV must be the culprit.

mines the forge recirc one and running the base spring,think its yellow

Mine currently Has the blue spring in it which is the middle spring so i can put the stiffer red one in and see if makes a difference.

that should be too much tbh,stick ya stock cooler on and try that,i think your turbo is struggling to keep up with flow now,if it had the dp it may fair better.

mps6dave wrote:that should be too much tbh,stick ya stock cooler on and try that,i think your turbo is struggling to keep up with flow now,if it had the dp it may fair better.

I may as well try the stiffer spring as its only a 2 minute job. Will try the stick intercooler during the week.

Ok so tried the red spring before and did some datalogs. Only really seemed to bring down the WGDC another 0.5% so no real difference so ive refitted the blue spring with 1 shim. So tomorrow im going to refit the standard recirc valve and see if it makes any difference.

Anyway here are the logs from before.

Checked my spring and im on the yellow spring no shim and 19psi boost.forge says that's just right and will need the blue spring once 22psi reached .I'd do ya tmic now instead of wasting time messing with other stuff.