How-to: +2psi for a cheap $5

[msp35]

Yes, I wouldn't cut the spring!! I'm sure you have a boost leak somewhere. The stock pipes expand and contract and leak at the joints. Unless your wastegate actuator has a slight tear. What is your vac at idle?

And why not? If you take off 1/8" at a time and drive you'll see small gains. You'd be effectively preloading the spring a little more. I boost 9psi across the board. You simply need to play with the length/tension.

 

[shane02pro5]

The EGR cleaning thing is way over rated it hasn't done anything for me and with most unless the plunger is stuck it is only temporary. I could almost guarantee it is a boost leak somewhere that is not big enough to effect your vac at idle but enough to show up under boost. There is a do-it-yourself boost/vac leak tester thread here somewhere. http://vfaq.com/mods/ICtester.html

 

[Velocifero]

I guess it depends on how you bend it to begin with, I installed it one time and went to 9.5 PSI steady and held for a long time. I took the spring off because I boost and hold at 9 PSI with the ATP WGA, but I think I will put it on occasionally for fun days, my afr are staying real rich so as long as I watch those and keep my intake temp down it shouldn't get too bad. Once the MS goes in there won't be any reason for me not to reinstall it if I want to boost over 10.

 

[shane02pro5]

My point is that the spring should not cause spikes. It is just losing boost. I had my Hiboost kit at 8psi for quite a while and have always read of MBC's and alot of EBC's causing spikes. With the spring, there should be no spikes. I bumped my 8 to 10psi with the spring and then stretched the spring a little further to get 11psi now I converted to CAI and am at 12psi and I never spike.


If you have no supporting mods I don't see hitting 9psi being a very safe thing. I have a Haltech, exhaust FMIC intake and J&S Safeguard!

 

[hotrodf1]

There's a guy supposedly hitting 13psi for the last 46,000 miles, I think the car was stock, but not sure. Seemed a little crazy to me, but ???? I think his name is yashoa or something.

So I guess I need to look for a boost leak.

I guess one thing I don't understand - how does the stock BPV know when to open? If it's set at 6psi for the stock boost, and then we increase to 8psi, won't the BPV be open all the time, above 6 psi?

 

[Velocifero]

Sub 10s is proving to be just fine for these motors, sure some people have popped, but some people's have popped at stock. I am confident that my car individually can take the 9 right now, I ran it for 16 for two weeks and never noticed a ping, knock or any other evidence to suggest it was on the way down. I watch my afr and listen to the car, no problems and well over 20K with the boost up. Besides I can't turn down my boost now anyways if I wanted to, I would have to remove I/IC/E to lower it. Every car is different though, I don't want anybody thinking I just threw this together and blast away. I take my time with the car and search out its limits slowly so I can back away from them. And I agree that he has a problem somewhere causing the boost to back down, everybody else that has down this holds steady and maybe bleeds down at the end of the power band, but not just a spike and back to stock.

 

[Velocifero]

There's a guy supposedly hitting 13psi for the last 46,000 miles, I think the car was stock, but not sure. Seemed a little crazy to me, but ???? I think his name is yashoa or something.

So I guess I need to look for a boost leak.

I guess one thing I don't understand - how does the stock BPV know when to open? If it's set at 6psi for the stock boost, and then we increase to 8psi, won't the BPV be open all the time, above 6 psi?

it opens because there is no other way for it to go when that throttle plate closes, except back through the turbine, but in this case, out through the BPV is the course of least resistance. Air will flow that way always, it won't come out the BPV when under acceleration because there is less resistance to continue flowing to the TB. If your BPV goes bad and isn't giving any resistance then air can leak out there, but more air would be going to the TB, just not nearly as much as your MAF has already accounted for, hence the crap response from the car when that happens.

 

[mspHtown]

.

hot picture in your signature

 

[Dugg E Fresh]

I actually do spike a bit with the spring. I was hitting close to 6psi then falling to 5.5 stock. I put the spring on and shortened it up a bit. Now I spike pretty close to 10psi and it drops to around 8 throughout, then bleeds out to about 7.5 @ redline.
Not sure if this is typical with y'all or not. My AFR's seem to be right in line tho, so I guess I'm not too worried at this point. I'm desparately needing some supporting mods, this Mazda ECU sux.

 

[hotrodf1]

So,

my car pulls real good until the boost bleeds off after the spike and then it really "bogs". I think it would be due to the MAF reading more air than is going to the motor (if I really do have a leak allowing the metered air to escape.)

Does that sound right?

You other guys with boost spikes, do you feel a performance change after the spike?

I'm thinking something is definetely not right with my IC tubing.

 

[Velocifero]

So,

my car pulls real good until the boost bleeds off after the spike and then it really "bogs". I think it would be due to the MAF reading more air than is going to the motor (if I really do have a leak allowing the metered air to escape.)

Does that sound right?

You other guys with boost spikes, do you feel a performance change after the spike?

I'm thinking something is definetely not right with my IC tubing.

Check the BPV nipple on the hot pipe to ensure it isn't cracked

 

[hotrodf1]

Check the BPV nipple on the hot pipe to ensure it isn't cracked

Hmm. I was tugging on the piping pretty hard to get the spring in there.

Yup. Could have damaged that guy during that bout.

Good thought, Thanks!!

 

[Velocifero]

Hmm. I was tugging on the piping pretty hard to get the spring in there.

Yup. Could have damaged that guy during that bout.

Good thought, Thanks!!

If that is the case you can use jb weld on it to fix it for a bit but I highly recommend either getting the samco hose or the sls motorsports one (they are having a sale for the hot pipe, $99 shipped!)

 

[hotrodf1]

I'll check it out.

Probably will fix it temporary for now . . . going to probably put a custom FMIC and hardpipes when I get a little more money. That oughta fix it

 

[slomsprotege]

I just put the spring on there for sh*ts and giggles, hit 8-8.5 constant...but im paranoid as hell still....grinnin still from the test drive...I think i might take it off soon before my right foot does something bad to it oh i took the bolts off the heat shield and moved it outta the way barely not needing to take off the 02 sensor, and also put a flashlight pointed down at the link through the second and third runner, lit it up enough to see the gold differentiate from the iron....then hook, five minutes and done.

 

[shane02pro5]

I wouldn't recommend that unless you have a few supporting mods. Mid-pipe and upgraded IC at least.

 

[Wiggles422]

I put the spring on just to see what 8psi felt like instead of 6. My boost gauge shows it going to 10 and leveling off at 9-9.5psi. My butt dyno doesn't give enough data to justify the added stress on the engine and I don't wanna join the boom-boom club so I'll probably be taking it back off soon.

Here's a question though... how come the boost goes from 0-8 in a normal, expected fashion. But 8 to 10psi is instantly. Is that normal? What would be causing that?