Porting for T5s

[r32wa]

Im new to all this and have a set of T5s, VF3s, +4 timing , 310 mains with Toomey needles, stock box no lid running a uni filter. I have a set of stock barrells that I would like to have ported. Im 200lbs and ride a mixture of dunes and trails and occasionally some big open straights at sea level so Im aiming for a wide and useable powerband. What kind of porting really suits the T5s?

Many thanks

[redwings]

I think your looking for what most places call a dune port... I have researched this question and have asked around. I wanted good usable power for all around riding. My set up is like yours but with cpi inframes. I sent mine off to flowtek....hope to get them back soon so I can start roosting..... :biggrin:

[r32wa]

Is the trail port more of a clean up of the ports rather than changing the port timings like a dune port? I have done some reading and found a bit about the dune ports but not a lot on the trail ports and the differences.

[donkeypuncher]

what kind of trails do you ride? tight or wide open?

[r32wa]

The trails vary from tight with soft sand to hard packed gravel to some more open type trails.

I forgot to mention Im in Australia so sending them to someone in the US is difficult.

[Wildcardracing]

The porting should be matched to the pipes. That being said, every pipe has a given window of exhaust duration it will work best with...usually about a 4-6 degree window. The lower the duration the more low to mid power and less top end power. The higher the duration the more top end power and a little less bottom to mid. That is if the transfer ports are modified correctly to match the exhaust porting. One builders idea of what a dune port or trail port is may differ from anothers. A good builder will be able to match the porting to your riding style reguardless if they call it a trail or dune port at their shop. You should call some builders and get a feel for them, a good builder will ask you some questions about riding style, terain, weight, altitude and fuel choice...and should be able to answer any of your questions as well. Tell them what you want out of it and they will help you achieve that goal.

[deckheight]

IMHO, slobanshee06 pretty much nailed it...

With your weight and type of riding I would probably go a little conservative on the durations. T-5's make peak horse power at apx. 8900 rpm with very little over-rev. A 190 deg. exhaust duration with an appropriate time area should work with that rpm and your weight. Higher compressions allow a little more aggressive exhaust port durations/power curves and blow down timings. But, in general, blow down timing should be in the 30-36 deg. range with the lower values for lower compressions and/or heavier riders. What octane fuel and head dome volume you planning on?

Edited December 19, 2008 by deckheight

[peterlocal22]

Im new to all this and have a set of T5s, VF3s, +4 timing , 310 mains with Toomey needles, stock box no lid running a uni filter. I have a set of stock barrells that I would like to have ported. Im 200lbs and ride a mixture of dunes and trails and occasionally some big open straights at sea level so Im aiming for a wide and useable powerband. What kind of porting really suits the T5s?

Many thanks

 

ya trail/mx port