I did a blower outlet port, around 1/8-5/32 - and I'm only showing 11.25 psi.

I've ran this car open dp, and the only other mod is ABM. Perhaps I've blown a piece of cat out the dp?

I won't be able to check the housing until next month.

I shouldn't have seen manifold pressure drop at all, should I?


Did I take too much?

 

U will show less boost with less back pressure aka running open downpipe. Its normal

 

I realize, but I'm showing 11.25 on a stock exhaust.

 

Check if your bypass valve is sticky at all, did you tighten down your SC properly? Doesn't sounds like a boost leak anywhere?

 

my bad, i read it wrong.

 

No.


Everything is fine, no leak.

 

Boost bypass valve, see if it is at all sticky. You shouldn't be loosing boost unless it gets stuck partially open or your leaking boost or your exhaust changes. The only reason to lose boost is less restriction.

Unless you completely pwned your rotors by doing the porting with them in or something like that I guess, I'd imagine you'd need to do a fair amount of damage though. I don't think porting would cause over a 1PSI boost drop (Your stock are you not?).

Joel

 

Yeah, it's a stock car.


I removed the rotors from the housing and cleaned the housing well after porting.


I can't see anything that appears to be damage looking through the inlet, but I won't be able to tell until I go to a 2.8 and have everything off.

 

how does it drive? same power?

 

Flow more air, less pressure. Boost is a measure of restriction. You make more power running the same amount of boost on a tvs because you're flowing more air with the tvs.

 

Doesn't flowing more air through something while retaining the same amount of restriction increase the PSI. You'd need a lot of mods to be running the same PSI as a M62 with a TVS. Not to mention he doesn't have a TVS? Unless I've completely missed something here.

Anyways, porting it would not be good enough for a 1.25PSI drop, I'm still banking boost bypass valve.

Joel

 

well he doesnt have the same amount of restriction because he ported

 

He ported an 1/8th of an Inch, I guess anything is possible though. I just think that is a big reduction for such a little amount removed.

Joel

 

Ya you missed what I meant. I didn't mean he was flowing as much air as a tvs. I simply meant that you make the same amount of power in any boosted application if you flow more air, with less boost pressure. A TVS boosting 12 psi makes more power than an m62 boosting 12psi. I was just trying to say that because he has more available air flow, he will make less boost while flowing the same amount of air.

side example, if you measure the pressure from a 3 inch exhaust, the pressure of the air flowing out of it would be less than a 2.5 inch exhaust, if both were flowing the same amount of air through it. Same amount of air, different pressures. That's why on the LNF if you run an aftermarket charge pipe you may see a drop in boost, but you'll still make the same power and flow the same amount of air.

 

blah blah blah...

 

Yeah, but I don't think taking material away from the outlet would mean less restriction. More likely less flow.

 

Car seems the same as it was before, it's been so long since I've done this that I don't even remember.


I did this over a year ago.

 

I did boost bypass mod to check, still showed low.


I double checked the blower bolts, still low.

I guess its on to the IM next, if that doesn't do it - I'll blower swap.

 

Is it even worth it to port the M62?? seriously?

 

I'm confused by this post..

 

If the car is running the same and u don't feel a power loss then I would just chalk it up to restriction....

 

I bet it was the porting man. Im in the same boat as you, Im stock minus an intake and I show about 11 psi too. Just make sure everything is back together correctly and im sure your fine.

 

Its worth porting the inside for sure. But i would leave the outlet alone