in other threads, Ive been reading "get a boost controller and then a flash"...is the BC necessary?

 

lol.. you don't NEED a boost controller... it is just a recommendation for extra horsepower .. the factory boost on an evo is 20.14lbs of boost.. you can get a boost controller and run 21-23 and you get roughly 10 extra hp per each pound of boost..

usually a basic bolt on car gets.. intake, mbc, turbo back exhaust, fuel pump, and flash

 

Or you can just use retune the stock boost control system when you get reflashed to increase boost.

 

^^ I use the stock BCS to control boost from 20-25psi. It requires only a simple modification to the brass restrictor pill nearest to the turbo and a flash. I've had decent results with this approach. Other than that the only mod I have is a cheap ebay TBE.

 

How do you modify the restrictor pills??I was about to buy a MBC,but,if i can turn it up without buying one..That would be better..Anywhere that i can look to find the info??Justin

 

more boost is always good. if you want to increase your hp

 

thats maybe what it can spike to on a cold dry day...
but it usually will hold 18-16psi depending on the weather.

one thing i noticed once i put my MBC in, i now have hardly any boost spike. it hits 21psi and holds it all the way up to redline

 

Remove the brass restrictor pill near the turbo. Fill it with solder (easy). Purchase a #65 drill bit from the hardware store and drill a hole in the solder (easy). Replace brass pill. Instant 25lbs of boost that is controlled via WDC in the ECU. If you look at my dyno chart you will see it still drops off up top but they all do that. With a few tweaks I was able to remove the wave and hold boost better than with an MBC.

 

The restrictor pill mod works but spike is usually more common which can be a pain. Some people claim they don't have any spike/creep issues while others claim its the devil but if you don't feel comfortable modding your BCS MBC's are pretty inexpensive and pretty effective.

 

When I had my turbo miata, i gained 30-35whp and 40wtq from turning the boost up from 7 lbs to 10 lbs.

One day I was cruising around town. I noticed my car was ***** slow. BIG TIME. I couldnt figure out what was going on. I kept getting on it & it just didnt feel right. The *** end was actually keeping traction...which was weird for the car. I then finally decided to look over at my air vent where it held my 2 1/16ths boost gauge, and noticed it was only on 7 lbs. I was like 'ohhhhhhhh yeah!' I totally forgot that I made a 'gas saving map'. Flipped a switch to my regular map... hit the gas... and weeee goes the back end sliding around like a go-kart at 40mph. Sick car!

 

Boost tends to hold better with MBC you get less taper

 

No. More boost is only good if its within the compressors effeciency range.

 

And if you have the fuel to support the extra boost.

Technically more boost is still good even out of the efficiency range as long as there is sufficient cooling.

I remember back in the day someone ran a few tests from 17 psi, 20 psi and 23 psi on the stock T-25 2G dsm turbo and each time it increase slightly. If I recall the jump from 17 to 20 increased 18-20hp and the jump from 20 to 23 only produced an extra 8-10.

If you've ever seen a t25 it's ungodly small and anything over 18 psi is out of it's range.

 

Actually using the modified boost pill you can eliminate spike all together as the device is then an rpm dependent boost controller. Some people remove the brass pill by the BCS and that will cause a spike. That pill should remain untouched.

 

a MBC will make it easy for those days of tuning where a simple screw up or down will adjust your boost. yes you can always use the stock solenoid but the MBC will hold it a little better up top././