Bridge Porting Query

[matthewbellamy]

Hi does anybody know how you go about bridge porting an FD3S? Is it expensive and what places would you reccomend to get it done? What power gains have you noticed? Which type of porting would be more advantageous?Do you need any special mods to go with it?
 
Thanks!

[Grant Monkhouse]

Bridge porting can be done 2 ways, full bridge or half bridge. A half bridge is where only one of the side ports is bridge per rotor. A full bridge is both inlet ports bridged.

Are you still on the standard twin turbos? If so then I would maybe suggest a large street port I stead as a bridge port will only really benefit from having a mid to large single turbo. However if you plan to go to a single then a bridge could be done.

Ultimately the deciding factors for porting are power goals? And if you want to have the iconic rotary brap brap that you get with a bridge port.

A bridge will yield earlier spool up on a good sized single turbo whereas top end power compared to a large street port will be near enough similar if not the same.

I had a large street port on my twin turbo and it was a fast car, very fast. Now I have got a full bridge port engine built at Hayward Rotary to go with a big single turbo, I specifically went for the bridge for earlier spool on my turbo and the brap brap sound, wasn\'t too bothered about peak HP but it should be near 500 fwhp anyway, at around 14psi.

Don\'t forget that getting your engine ported means a rebuild on your engine plus you will need to upgrade other things like the fuel system, rad and intercooler etc.

As for people available there are many, Hayward rotary, Oldone porting services, Reworx, power gains, WGT, Dragon performance(he has moved into GTRs but may still do rotaries) there are a few more but I can\'t think of them at the moment.

I personally use Haywards even though he is Newbury and I am in Huddersfield which is 3 hours drive away.

[matt p]

I have gone for a half bridge on a T72 will update once it\'s all done

So nearly went for a full bridge but kept it to a half as I would still like to use the Rex most weekends. I\'ll post some pics up later of the Pinapple racing half bridge templates that I have just had delivered.

[RyanT]

What\'s the mpg difference with a bridge ?

[matt p]

A lot. :p

Depends on mapping etc but don\'t expect great figures regarding mpg.

[Grant Monkhouse]

Rotaries and MPG should not be in the same sentence. If your concerned about that then buy a diesel.

On my street port I got 22mpg motorway. Driving hard it went down to single figures:D on my bridge I\'m not expecting much more than 8 mot hard driving and maybe 19mpg motorway driving.

[JayDee]

Send Yehreally a pm Matt on the other site


QUOTE=matt p;816218]A lot. :p

Depends on mapping etc but don\'t expect great figures regarding mpg.[/QUOTE]

[a.tapos]

some people see the same power figures on street half or full biggest difference is when the power comes and peaks,i wouldnt go full bridge on anything you were using on the road as there just not nice to drive below about 3k
large street is making greast power on alot of cars but if you want a bridge and its a daily/weekend id go for half with a larger exhaust port
 
like mr monkhouse says though wouldnt bother with anything other then street if its on twins as they spool early anyway and run out of legs with a bridge port