max boost?

[Quicktime_GT]

Hey this is my first post.. but my friend has a mazdaspeed protege. It has full exhaust, but other than that I believe is stock. It usually makes about a max of 9 -10 psi boost. Is this normal?

Just wondering how much boost you can run on stock bottom end. Some of us was hangin out and got a little crazy and unhooked the wastegate vacuum line. It made 21 PSI! WAYyyyyy much moree than we thought it would... so we eased back home and hooked it back up.


So say even if the bottom end can hold this much boost.. what kind of fuel system mods is needed to handle it? 255lph fuel pump? injectors.. colder plugs maybe... and def a tune? Just speaking from ford experience.. sorry

Here is a video:

http://s37.photobucket.com/albums/e84/neilpg/NEATSVILLE%20TEST%20N%20TUNE/videos/?action=view&current=kyle21lbboost.flv

 

[FF Racer]

21psi and it didn't blow up... good for you!


The car runs stock at 6psi. I wouldn't even run more than 10psi without supporting mods to be on the safe side.

 

[kamon8404]

21psi and you didn't hit fuel cut?! Goodness, I would say that 10 psi is safe on the stock bottom end when you have a full exhaust, FMIC, intake, 440 injectors, and maybe even a fuel pump, and the most important part, some type of EMS (ie afc, unichip, microtech, haltech). The actual block and crank aren't the problem because they are solid, its just the dink rods. Replace the rods and pistons and have at it!

 

[hopupimports]

i would lower it down. you are going to blow that POS up!

 

[mspHtown]

i wouldnt even mess around with 21 psi at all. you WILL destroy the engine.

 

[msp35]

No way guys, these rods can hold elevnty billion lbs of boost. (hand)

 

[fr0st]

how cold was it when you tried that?

 

[Quicktime_GT]

hmmmmmmmmm

Well thanks for the replys guys.. We had no idea it would jump to 21 lb. didnt really think the turbo was that stout.

We put everything back to the way it was.

One other thing, why would his car be making 9 -10 anyways then?

 

[ChopstickHero]

zooom zooom boom!

 

[zumzumzoom03]

zooom zooom boom!

21lbs would definately be going out w/style.

 

[Kansei]

hmmmmmmmmm

Well thanks for the replys guys.. We had no idea it would jump to 21 lb. didnt really think the turbo was that stout.

We put everything back to the way it was.

One other thing, why would his car be making 9 -10 anyways then?

because he has a free flowing exhaust (probably without cat you horrible horrible person you) and other mods.

 

[AandPmechanic]

I just bought a mazdaspeed protege and I keep reading through these forums. All my experiance has been with a 92 talon. What a weak engine the msp has. I think mazda overlooked that they may be selling a car that is going to be in the hands of boost hungry people like myself. 10 lbs. max!!?? Looks like the msp is going to be my daily driver/show car with the rest of my money going into the talon. I've set the msp to 10 psi and it seems to overrichen itself and bog. I've set it to 7 psi and just today got smoked by a almost stock prelude. I want to put my dsm motor into the msp. Then I'll have the ultimate car; good looks, awesome handling, and a motor that will take anything I can throw at it with parts that are easy to come by and cheap.

 

[Wbriggs19061]

im only running 8-9psi with mods in sig, ill put it at 10 whenever i get to installing everything else i have.

 

[hotrodf1]

I think part of the problem running higher boost with the stock setup and eating parts is the inability to easily modify the timing curve. Unichip seems like it would fit the bill, but I want to attempt to tune myself.

Wish I could just dial in a little more boost reference timing retard like on a MSD box. The mallory CD ignition in my camaro will do it.

If only I could find a way to make that work. that would be sweet. Would probably go a LONG way toward not blowing things up. When we increase the cylinder pressures with more boost, we need to back the timing off. I've been hearing that the MSP computer does not really "sense" boost, and so probably does have a chance to dial the timing back when the boost is higher, which possibly gets you some knock and maybe broken parts.

 

[Quicktime_GT]

hmm... thanks for the advice guys.. anyone else?