ok I am trying to figure out how to fight the boost creep problem on a modded rx7's..I have a fcd,, but now I really dont wanna port the stock turbos wastegate what should i do??
Will a pop off valve work instead of porting the wastegate??My question if i do get a pop off valve installed right before my throttlebody.Will this relieve excess boost pressure that the wastegate won't??
I understand the stock wastegate dosen't blow off enough exhaust pressure at high rpms(blow by) so can a pop off valve work effectively is my question.Or should i just go with porting the wastegate or both??
My believe this pop off valve will relieve excess boost pressure the wastegate can't will it work??
thanks

 

The main risk is running too lean at high power.
I ran 11psi in the cold air yesterday morning.
(Gotta love cold mornings)

Of course porting the waste gate is best, but in the meantime you can:
Check the air/fuel ratio under load.
Check fuel pump voltage. (maybe rewire)
Check fuel pressure.
Check injectors & connectors (maybe have them cleaned)

I thought pop-off valves installed after the TB?
BOV or CPV's go before the TB..
I'm not an expert on turbo plumbing - so verify this..

 

A pop off valve is not a good idea to control boost..... it WILL work, however.. it is only for emergencies... The problem is that if you are using the popoff valve to control boost creep, its going to be opening a lot. When the popoff valve opens while you are on the gas, the pressure is released off the compressor wheel while the turbine wheel is still under exhaust pressure. This will cause the turbo to spin out of control, possibly exceeding its RPM design and can cause serious damage to the turbo.

Popoff valves are a safety item so that mechanical problems do not cause sudden boost spikes or extreme boost pressure. They should't be used in place of a wastegate.

(some people do use them on superchargers, reason being is that the supercharge is belt driven and will not spin up after the popoff valve releases!!)

Try putting your stock airbox back on, this will give you enough restriction at high RPM to limit the boost creep.

The simple fact is that the RIGHT thing to do is port the wastegate.

 

Thank you ..
That sounds Right..
I just needed someone's opinion and this should be what i will do..Port the wastegate and add the pop off valve..=)
thanks again Yearsofdecay

 

Why not? It's the correct way to solve boost creep. Do you actually have a boost problem? You didn't mention how high you're boosting.
It will work up until your turbo dies from being repeatedly oversped. POV's are a safety device only and should not be used for boost control. Don't do it.

 

Thank you..
Well I installed a full RB downpipe to tips..
Boost should go above 11 psi and i dont have my fcd in yet..I just got my S-AFC 2 today and it will be going in over the weekend..
Also Will just a Open wastegate mod work with boost creep(atmosopheric release instead back into the exhaust where we get blow back..Will this work?

 

I ran 5.5 lbs on my '90 TurboII, dynoed 193 rwhp on a mustang dyno (about 240ish at the flywheel) with a custom 2.5" exhaust turbo-back, cone intake, and stock engine/turbo, and had NO boost creep hardly at all, except for 4th gear going uphill for a LONG time, it'd hit 7 lbs (woooo)

 

Ok, from the way I read this you do not have a boost creeep problem yet.

If you do have the problem of the boost creeping beyond your fuel system abilitys the waste gate porting is your only option.

However, if you do not want to do this. You have anouther option. Restrict either intake or exaust. IE put the stock intake back on or some sort of silencer in the exhaust.

That is your only other option.

Besides. Put the exhaust on and see if you do have a problem. Then if you do you can stress your self about. But why stress your self if you dont have the problem?

James

 

Today i hit boost cut about 2 times at 1\2 throttle only about 5000 rpms..!!!I guess my TURBO is running well ..
The Racing Beat Full System is Beautiful at keeping sound levels low..But at the same time it flows well.
I raced a RSX type S today and smoked it at 1\2 throttle.
Damm fast now after this exhaust and has much more low end power.Turbo Spools up way faster and is more responsive..Untill I get my FCD I guss Im waiting..