Half Bridge port
 

I'm starting to consider half bridge port for my t2 rebuild. Now that I think about it will I need a stand alone to take care of it?? and what is the life expectancy of a half bridge port

i think it all depends on tuning and how ofter you boost/redline.

but im guessing with a port like that youll be redlining a lot to benifit from its effects and it is also a lot bigger than stockers, so the life is probably significantly less than say a stock motor.

and you will need standalone.

what is the next step up from the street port

a bigger street port i would guess, you can only go so far though before you wont be able to do other ports.

Yes, you will need a standalone for the most painless way to run a 1/2 bridgeport. I have heard of a person that ran one with the stock ECU, but I realy don't know the details. I'm sure these was SOME form of engien management used, though.

Life expectancy will be a bit shorter, but that can be addressed to an extent by leaving a decent amount of material for the 'bridge' part of the port. (I think 2.5-3 mm is good).

It is true that your low end will suffer a bit due to the porting, but how often are you driving around below 3K anyway? Cruising in 5th on the highway doesn't count.

Gas mileage will usually suffer, but BDC has managed to get 20+ on his 1/2 BP with proper tuning. Not bad at all, in my opinion!

I hope this helps!

Reese

i was thinking about going half bridge on a possibly carbed or fuel injection. but i wont have a turbo, mainly cus i cannot afford 93 octane. lol.

Yes, you will need a standalone. And a turbo upgrade if you're running stock, which means an intercooler upgrade as well.

Life expectancy should be no shorter then any other type of port. If the bridge is formed properly (ie. doesn't pinch the side seals and has plenty of support) then there are no issues.

Hey guys,

Yes, a standalone EFI system is all but absolutely necessary for this setup. I've been fooling around with half-bridgeport (HBP) turbo setups for right at two years now on a daily-driven basis. I've had alot of time to experiment with these as a result and I wholeheartedly believe that, for the goal of making them an alternative to a streetport for practical streetability, there must be an EFI system in place that has precision control of both fuel and leading adv/trail-split at varying loads. As we speak, I am generating a 5th ignition map for my own car (my 23rd actual Haltech map) that has had this engine setup running for only 6 months. That ought to give you an idea of what kind of changes I've gone through in making these streetable.

http://home.comcast.net/~bdc196/Cust...Secondary2.jpg

http://home.comcast.net/~bdc196/Cust...Secondary3.jpg

I've built many HBP engines now; somewhere in the neighbourhood of 25 or so in the past couple years, excluding any times where one was rebuilt to be modified or made more aggressive. The only system manufacturer I use is Haltech. I've used the E6K and E6X with the HBP with great success. I don't believe, in my opinion, that the Microtech LT8 system (even in Matrix mode) is capable of handling this setup because of its lack of multiple-load point versus RPM ignition control.

Reese was right on the money earlier. I made 20.3mpg on a highway trip from here (Dallas, Tx) to New Orleans in late January. I was keeping right at 80mph in 5th gear or around 3400rpm. The car had some issues then, too. I had a leak in the throttle body and I had three intake manifold gasket leaks which I've since fixed. I also had about 300lbs of engine parts and tools in the hatch weighing the vehicle down. Under a more, normal circumstance, I'm anxious to see how well it'd do. The tank usage came out to about 75 miles per 1/4 tank, or right at 300 miles on the full tank. Have a look at the TripBack videos and you'll see with your own eyes: http://bdc.genxracing.com/videos/Bri...BP_GasMileage/

In short, these can be made to be a viable and beneficial alternative to your run-of-the-mill street porting, but only if there's some careful consideration given to the EFI system to control it rightly. Otherwise, in my opinion, it's a shot in the dark as to how well it will work.

B

yeah i was going to do a half bridge and use the stock efi, but screw that. i like gas mileage. and the way gas prices are goign up, it would be just bad for a daily driver

It would be bad on the stock EFI system and that's assuming the thing would be able to run on it in the first place.

B

Thanks for the info!

I am sold on this, if it wasn't for the e-test :(