is this type of port the best type to use on a strip only 13b drag car ?
what are the advantages and disadvantages ?
would a monster port be better ?
:Talking1 :cheers
Hi Jamie, for track/circuit only imho. It wont idol at less than approx 3000rpm, will drink fuel like its got shares in Shell and will be very loud. It moves the power band way up at the top of the rev band so you will have little power until approx 5000rpm or more. Which is ok if your reving up to 9 or 10000 rpm on track.
you can get the same volume of air through a fully bridgeported engine with bigger runners, and ported out intakes on all plates, actually its more if you work it out in mm2 through 4 bridges using big tube runners.
I toyed with both ideas perephial and bridge.
the diference is the port is open for a longer duration on a perep than a side port, ie perep will let air in for longer because its not the side of the rotor opening and closing the ports, its the rotor tips.
So its
higher cfm for full bridge with custom runners plenum ,bigger 50mm runner piping.
vs
lower cfm for perep port but longer duration of port being open.
thats how i understand it anyway
which method will get more air in before firing will need some serious science boff to calculate!!
with my full bridge i have 4 -50mm runners
with perep you will have 2-50mm runners oper longer.
You can run a PP on the strip no probs. A guy I know runs in the low 11\'s with a 13B PP but as Gary said you will need very close gearing and the PP has less power down low and the power band starting from around 5 or 6 rpm in most cases. Idelly it is more suited to the track but adding fuel injection makes a huge difference to driveability.
Forget the monster port. They were basically only used where motorsport rules outlawed the PP.
Quote from: stuart wizyyou can get the same volume of air through a fully bridgeported engine with bigger runners, and ported out intakes on all plates, actually its more if you work it out in mm2 through 4 bridges using big tube runners.
I toyed with both ideas perephial and bridge.
the diference is the port is open for a longer duration on a perep than a side port, ie perep will let air in for longer because its not the side of the rotor opening and closing the ports, its the rotor tips.
So its
higher cfm for full bridge with custom runners plenum ,bigger 50mm runner piping.
vs
lower cfm for perep port but longer duration of port being open.
thats how i understand it anyway
which method will get more air in before firing will need some serious science boff to calculate!!
with my full bridge i have 4 -50mm runners
with perep you will have 2-50mm runners oper longer.
I agree with what your saying Stuart but the PP defentely flows more. Maybe it\'s because the PP has a much more direct path directly to the rotor housings while the BP has to go through the side plates. The timing would be better for the PP because the ports are always open whereas the BP always has part of the port obsecured by the rotor as it passes.
EDIT: Just re-read your post properly and it seems you know the above anyway!!!!!!!!!, doh!
would a perep port and a secondary side port mixed together through 4 -50mm tube runners with the itermediate plate ports blocked up work?
or would one cancel the other out timing wise?
its possible to do, easier than my runners actually.
imagine flow through that lot :rollin
I\'ve seen an extend port with PP secondaries via a fairly complex carb setup - I have a pic around somewhere! Will try and dig it out!
using both works ... have a look for Judge Ito\'s RX3 , theres some sort of theory to having a small peripheral port that blows air past the side ports (bridged) that helps draw the air in ... not sure it would have same effect with a blower though ?
Quote from: MikeLMRusing both works ... have a look for Judge Ito\'s RX3 , theres some sort of theory to having a small peripheral port that blows air past the side ports (bridged) that helps draw the air in ... not sure it would have same effect with a blower though ?
Yeah I believe it\'s a setup Mazda\'s factory race team used back in the 70\'s before the were allowed to use a full PP.
wow thanks for the information.wasnt expecting such a huge reply. do you know if there is a place where you can buy housings already ported in the uk ? i\'m whipping the engine out to put on a stand in my kitchen for the rebuild in the next few days.
phone tim at rx motors on 01725516462 for ported housings.
If you want perep port housings, I can bore and weld 50mm ali tube in your rotor housings but be prepared to wait a while because they will be done as forigners in overtime only when shop foreman is out!!!!!!!!!!
you supply rotor housings and we will get them done for you cheap.
lovely cheers. i\'ll give him a ring soon when i ve got the lump out.
A PP works well on both turbo and N/A engines for the strip.
There are quite alot of PP engines running good numbers and they are really a better port for total out and out power and reliability.
Regards
Carl