Looking for 450ish RWHP

Half bridgeport
Trust TD07-25G turbo
Greddy FMIC
700cc and 1600cc injectors
Mazdaspeed radiator
and all accompanying mods.

 

Why do you want a half bridge? It's not necessary for your power goal.

 

I love the sound . yea I'll lose some gas mileage, but no sacrifice no glory

 

you dont really need the half bridge for that power, a large street port with thoes other things will get you there.

 

Lets face it, a half bridge will make it that much easier and will help spool any turbo quicker and will improve hp across the rpm range and torque on the upper rpm range. Then if he ever wants a bigger turbo and more hp he will have the port to help out once again. Again why not go half bridge?

 

^ fuel mileage mostly and the increased difficulty of tuning.

You're going to have to push that 25G to make that kind of power... skip the oldschool Trust/Mitsu turbos and get something more modern from Garrett or Turbonetics

 

The truth of the matter is that there are pro's and con's to having a half bridgeport.
The turbo will spool faster and the idle will be more pronounced , but at the same time I will lose some engine longevity and my average miles per gallon will decrease. I'll need a stand alone EMU and obviously a full 3in exhaust ( at minimum ) . Bigger injectors lightened flywheel and maybe even some port matching. All this with 2mm apex seals. But ultimately it's what I want and it's what will give me more expandability over time. It's not like i want a Full P-port . that would be ridiculous


Although, how hard will it be to start. i know there will be some overlap so i would imagine I might need a better battery

 

I've had both an extended street port and I have a half bridge. Now both combos had different turbos so I wouldn't be able to speak about spool up.

I love my half bridge. I love the sound especially at WOT. The street port was great too and had ALOT of top end (turbo selection could be a added cause of this). I don't have an issue starting my HB, but yes it does take a extra crank or two to catch( A good battery will aid in this issue).

I must say in defense for the Street-Port is , a good Street port should be able to make the same power if not, very close to a HB. I chose the HB for the sound, without going to a Full Bridge and because I just wanted to be a tad different than most.

You have people in here making TONS of power on a street port on this forum. As in spool up issue, the fix is a turbo selection away. you can get help by many people in here to find a turbo to suit your needs.

Fuel wise, IMO, it doesn't really matter. The more power you make, the more fuel you have t0 burn to sustain that power level. If both motors make 600hp, both should burn almost the same amount. If your under the boost curve, then you should barely notice any differences.In the end, it comes down to who is tuning the car. Again this my opinion, this explanation makes sense to me. maybe one of the more experience guys in here will chime in.

Idle: well I found my HB to be little more grumpier and finicky. The SP was more stable and drew a tad bit more vacuum. Again, an experience tuner can help with this for the HB.

Hope this helps

 

Typical halfbridge is not going to make more power than a large street port. What it does is carry the HP higher into the RPM range. When a street port falls off the HB keeps pulling. We have a few customers that got a HB and wished they just did a street port because the sound got to them after a while.

 

Steady state cruising and light loads on a half bridge is a nightmare to tune. If you don't get it right, trying to drive a steady speed SUCKs because of the occassional or constant bucking and missing.

~Mike.............

 

Yes, more porting needs more timing under light load. For example, my large streetport likes to idle at 850 rpm using 20 degrees leading advance if I don't do negative split. Stock port cars are closer to 12 degrees. The car also started a lot faster once I switched to this kind of timing. I also found increased smoothness by adding between 3-5 degrees of advance in low load cruising to the PFC basemap.

I imagine a half bridge is even trickier. It's going to be an uphill battle for driveability around town. Ask other guys on the forum with a half bridge... Aaron Cake, who has a GT40 with a half bridge and 9.4:1 rotors, has talked about the difficulty of low load tuning with such weak vacuum.

 

so what would happen if I added a vacum canister.