I was only getting 230 HP out of my car when it should give around 300HP so I left it at the mechanic and he tried removing the cat and putting a straight through. It could then dyno at 275 HP but probably needs a tune to get its proper horsepower.

Anyway, I took it to this straight where I go to push the car hard due to being in the middle of nowhere. So on my first pull as I was reaching 180 km/h in 4th gear, the power suddenly dropped. I looked at the boost gauge and it was reporting 4-5 PSi stable. Now the car only boosts to 4-5 PSi but it runs perfectly fine. I'm guessing it was a vacuum hose, could it be anything else? Would it be possible for me to find out or should I just let the mechanic worry about it. The car did feel much better on the pull until it lost power.

On another note, when things break I like to replace them with better parts like when my stock radiator broke, I replaced it with a Koyo rad. If I need to replace the hoses, is there something I could do for an upgrade? Thanks.

thewird

 

what were your mods when that happened?

 

rebuilt engine with street port and 3mm apex seals
Walbro 255lph fuel pump
dual filter K&N intake with heat sheild
3" down pipe and 3" cat-back exhaust
Koyo Performance radiator
Aluminum AST (Fighter's Version)
PowerFC ECU installed (I also have a Petit ECU)

thewird

 

How many miles do the turbos have on them? Check all of your couplers for tears/rips/holes/cracks. You could just have a boost leak that got worse. I wasn't getting much power from my FD either (back in the day) until I found a hole in one coupler the size of a dime (maybe 1/2 a dime). Do you hear the sound of air escaping anywhere?

 

So your mechanic pulled off your stock main-cat and put on a midpipe and DIDN'T tune for the air volume increase?

Time for a new mechanic?

 

It had a high flow cat on before that broke so it was choking the car. He just lent me a straight through test pipe to see if the car was better. I was gonna tune it after the test once I got the Racing Beat dual-tip and possibly intercooler.

thewird

 

If you can get a hold of some Viton hoses, that'd do the trick. Though, if you were to replace all the hoses, Mazda offers (or at least used to) a kit with all the pre-bent/cut hoses along with various check valves for a reasonable price (they used to be around $90).

But yeah, at 4-5psi, it's most likely you have a boost leak, not a vac hose.

 

I'll just take it to the mechanic and he can fix it. I wouldn't know what to look for myself... I'm a noob sigh...

thewird

 

Dude...it's easy. Look where the air flows. Check first at the filters, then down to the turbos, then from there to the intercooler, then from the intercooler to the elbow. Just check the couplers and make sure that they are all ON for one...then see if any look visibly worn or cracked. If you don't see anything, take them off one at a time, or try revving the engine at the throttle body and listen for any air escaping, then focus on that spot.