seriesv

For a secondary Bridgeport do you need air/fuel running throw the secondary port for it to pulse,
Or will it still pulse with the fuel/air running throw the primary ports and no air going throw the secondary ports?

diabolical1

iTrader: (3)

not sure what you are asking here ...

when you say secondary bridgeport, do you mean the half-bridge (where they only do a bridgeport on the secondary ports)?

my guess at an answer to your question would be that it would depend on whether or not your secondary injectors are staged. air is going to flow through there as long as the thottle is open (unless you have a progressive-type throttle body) but the injector's firing will depend on how your EFI system is configured, linear vs. staged.

what EFI system are you using? need more info ...

Logo

I've been considering going this route on a series 1 but I'm not sure exactly how much streetability will be gained by throwing down the money to go efi considering the overlap.

diabolical1

iTrader: (3)

it depends on how you're defining "streetability" ... if you're doing a full bridge, and you have it set up optimally, then the EFI is not going to affect streetability at all, it will just give you more precise fueling/ignition.

on the other hand, if you have it set up less than optimal, (for example, with an exhaust that will get it to shut up ) then the EFI may take away some of the driving headaches on the street - but that's just my own personal speculation.

Logo

Sound isn't really much of a concern so long as it can be quieted enough not o get me pulled over every time I go out. When I referred to streetability I was referring more to the amount of power lost in the lower rpms. My question then is, would going the efi route do any signifigant reduction in low-mid rpm power loss? One more thing, I have yet to find anyone who has dynoed a 4-port half bridge. How much power you think one could get from an efi half-bridge at the wheels?

diabolical1

iTrader: (3)

ooooh ... you've got me!
i have no clue about the power of a half-bridge. that is something that i am quite curious about myself.

regarding your streetability question on the full bridge, my guess is that EFI won't do anything very significant to help the low-to-mid RPM power/torque. that's just the nature of the beast ... they live up there in the stratosphere, 5-10,000 RPM! think of it sorta like a really radical race cam in a piston engine ...

Logo

diabolical, I didn't really think it would help much seeing that it's not fuel/ignition that is really robbing the low end of a bp, it's the overlap--correct? I'm still interested in finding someone who has gone efi/bp. If I ever come up with the time/money I might try seeing how much power I can squeeze out of a large street port with a little bit of overlap. I think that 200rwhp is 'possible' with a large streetport.

On the other hand I have heard that people with injected bp's are able to get the idle down to around 1000rpms. I wonder what their dyno's look like?

diabolical1

iTrader: (3)

controlling the overlap is the key. it will help your low RPM port velocity. for the street, i would never try to use a bridge, it's just not worth it, in my opinion.

considering that the most powerful streetport i've ever come across was 230 HP at the flywheel (it was a 4-port 13B with TWM/Haltech EFI) ... i don't see why 200 HP at the rear wheels would be a problem (other than the cost ) that's the setup i'm striving for, although, i can't shake the turbo-itch ...

Logo

Somewhere on hitman's site I read that power was lost when going with a similiar setup that used smaller dual tb's like the one on the twm setup. Anyways, here is my dream setup:

12a extended port side plates
13b 4port housings w/ported exhaust
91 n/a rotors clearanced/balanced with carbon seals
13b ida manifold
55mm injection perfection tb
4 550 injectors
haltech e6k ecu
dfi
custom exhaust