Bridgeport RX8
05-22-2009, 01:56 PM
#104
BDC Motorsports
Below is one of my bridgeports on a Turbo II. The "bridgeport" is the second intake port that's been cut that's to the right of the main port and to the left of the water jacket square ring land. The "bridge" in bridgeport comes from having a bridge of iron leftover inbetween the stock port and the newly-cut bridgeport that allows the corner seal and side of the apex seal to ride across without falling into the port.
As Fred (RG) said already, the bridgeport for a Renesis iron would look a bit different but this is what it basically is.
B
As Fred (RG) said already, the bridgeport for a Renesis iron would look a bit different but this is what it basically is.
B
05-22-2009, 04:14 PM
#106
Registered
Not quite true. Sort of. That's only completely accurate in an all peripheral port engine as only the apex seal opens and closes the ports. However in a side port engine it's the location of the ports to the side seals that determines when a port opens. A 13B with it's side intake and peripheral exhaust ports still has port overlap as the intake and exhaust ports are open at the same time. Briefly. In the all side port Renesis only the side seals control when the ports are open or not. They just so happen are never open at the same time as each other. There is 6 degrees of dwell. If you could open the intake port earlier or close the exhaust port later, you only have to make up 6 degrees of eccentric rotation before you get overlap.
Hold a rotor in a housing that has a side plate on it. Orient the rotor so that an apex is pointed exactly halfway between the spark plugs. Now look at the other side, specifically for the ports. You can move the rotor back and forth to see when the intake opens or the exhaust closes. Remember if you can see light through each one at the same time, and you can't on a stock Renesis, that means you have overlap. The rotor face is dished which is what allows the overlap to happen. Without a dish we wouldn't get overlap but we also wouldn't have a usable compression ratio!
Hold a rotor in a housing that has a side plate on it. Orient the rotor so that an apex is pointed exactly halfway between the spark plugs. Now look at the other side, specifically for the ports. You can move the rotor back and forth to see when the intake opens or the exhaust closes. Remember if you can see light through each one at the same time, and you can't on a stock Renesis, that means you have overlap. The rotor face is dished which is what allows the overlap to happen. Without a dish we wouldn't get overlap but we also wouldn't have a usable compression ratio!
05-22-2009, 04:15 PM
#107
Registered
05-23-2009, 04:31 AM
#108
Rotary lover
Thread Starter
Hi
as RG said, the renesis rotors are beveled, but only on exhaust side, it might help to do same on intake side of rotor, but then you must strip motor for that only, then you can just as well cut a bridge in.
Here are another link for a clip i just did on you tube, i gave it some revs,
i do add approx 200ml of 2strooke oil to a tank of fuel as extra protection aspecially now.
I will send another clip which shows while i am driving, soon very soon
http://www.youtube.com/watch?v=ilkzok3CrWU
BDC that porting is done very nice, clean, good job.
mine is the same idea but the bridge itself a bit narrower and the port part is the same width as on there, all following the standard port shape, but we did make the port a bit longer, it is to the same place at top as yours but a bit down to bottom of port at bottom
NEMESIS8
my exhaust setup is as follow,
the small precilenser as on the standard exhaust is still there, but i removed the cat and just inserted a 2,5" pipe in its place, straight and i put the oxygen sensor back at same spot it used to be and it is connected as well.
to the back it is the same, but right at back close to diff, where the clamp is for the big standard box we took the big standard box of and made a new pipe to fit and split in Y shape, a long curve (no sharp curves) to one box with 2" in and exit on the left and exactly the same to the right, the boxes are approx 300mm (12")long and 170mm diameter (7") but a bit oval for space at bottom, it exits to the same standard exit pipes, thus looking standard from outside.
main differances is then the cat removed and 2 small boxes, 2" straight through, one on each side.
the middle section of exhaust is still standard, we didnt go to 3" we kept same size, but the split makes the 2 boxes at 2" each.
that is it.
other change i did was the relacement of standard air filter with a BMC F1 washable drop in filter, it flows better and are a bit thinner than standard, i wash / clean / oil it regularly.
I hope this helps,
it is a bit more noisier than before the porting
RG
true on the overlap as renesis ports are on side not peripheral, that is why the peripheral port is totally differant in overlap.
I will keep all posted,
will send more clips
Philip
as RG said, the renesis rotors are beveled, but only on exhaust side, it might help to do same on intake side of rotor, but then you must strip motor for that only, then you can just as well cut a bridge in.
Here are another link for a clip i just did on you tube, i gave it some revs,
i do add approx 200ml of 2strooke oil to a tank of fuel as extra protection aspecially now.
I will send another clip which shows while i am driving, soon very soon
http://www.youtube.com/watch?v=ilkzok3CrWU
BDC that porting is done very nice, clean, good job.
mine is the same idea but the bridge itself a bit narrower and the port part is the same width as on there, all following the standard port shape, but we did make the port a bit longer, it is to the same place at top as yours but a bit down to bottom of port at bottom
NEMESIS8
my exhaust setup is as follow,
the small precilenser as on the standard exhaust is still there, but i removed the cat and just inserted a 2,5" pipe in its place, straight and i put the oxygen sensor back at same spot it used to be and it is connected as well.
to the back it is the same, but right at back close to diff, where the clamp is for the big standard box we took the big standard box of and made a new pipe to fit and split in Y shape, a long curve (no sharp curves) to one box with 2" in and exit on the left and exactly the same to the right, the boxes are approx 300mm (12")long and 170mm diameter (7") but a bit oval for space at bottom, it exits to the same standard exit pipes, thus looking standard from outside.
main differances is then the cat removed and 2 small boxes, 2" straight through, one on each side.
the middle section of exhaust is still standard, we didnt go to 3" we kept same size, but the split makes the 2 boxes at 2" each.
that is it.
other change i did was the relacement of standard air filter with a BMC F1 washable drop in filter, it flows better and are a bit thinner than standard, i wash / clean / oil it regularly.
I hope this helps,
it is a bit more noisier than before the porting
RG
true on the overlap as renesis ports are on side not peripheral, that is why the peripheral port is totally differant in overlap.
I will keep all posted,
will send more clips
Philip
05-23-2009, 02:13 PM
#110
Video Embedded For 'Ya
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05-24-2009, 09:32 PM
#115
05-24-2009, 10:42 PM
#116
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Youtube is the best.
http://www.youtube.com/watch?v=4j5m2FuFC48
And no, this isn't considered street racing because it was in a movie
http://www.youtube.com/watch?v=4j5m2FuFC48
And no, this isn't considered street racing because it was in a movie
05-24-2009, 10:55 PM
#117
Super Moderator
/\ So the moral is....???...the Supra is a better car than the Ferrari because it can go faster????...
What a load of
What a load of
05-24-2009, 11:30 PM
#118
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I'd take that Supra minus the graphics. Targa top FTW.
05-25-2009, 03:38 AM
#119
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bridged rotary sounds better imo..... i would just like to see the reaction and looks from people while sitting at a stop light. probably the last sound people would expect out of a japan import
05-25-2009, 09:32 AM
#120
Rotary lover
Thread Starter
I hoped to get you guys clip when driving,
just cant get a quiet time to do it, will do it tomorrow, doesnt matter what,
so far no problems
and yes a bridged rotor sounds nicer, i had a lot of heads turn already, you can see they wonder what it is or what motor it is, but i love when i drive of with them behind me...
Philip
just cant get a quiet time to do it, will do it tomorrow, doesnt matter what,
so far no problems
and yes a bridged rotor sounds nicer, i had a lot of heads turn already, you can see they wonder what it is or what motor it is, but i love when i drive of with them behind me...
Philip
05-25-2009, 10:42 AM
#121
BDC Motorsports
I hoped to get you guys clip when driving,
just cant get a quiet time to do it, will do it tomorrow, doesnt matter what,
so far no problems
and yes a bridged rotor sounds nicer, i had a lot of heads turn already, you can see they wonder what it is or what motor it is, but i love when i drive of with them behind me...
Philip
just cant get a quiet time to do it, will do it tomorrow, doesnt matter what,
so far no problems
and yes a bridged rotor sounds nicer, i had a lot of heads turn already, you can see they wonder what it is or what motor it is, but i love when i drive of with them behind me...
Philip
B
05-26-2009, 08:48 AM
#123
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As far as I can remember, all attempts at bridging just the aux ports (at least, on RX7's) were unsuccessful. Maybe someone from the 7club will come in and correct me.
Edit: Aha. A quick search on 7club came up with this post. Don't take it as fact, as I'm not sure on the references.
Originally Posted by j9fd3s
mazda has published some SAE papers, and you can look at port timings too
the stock 6 port engines close at between 75 and 80 degrees ATDC and the PP engine which is the full race max hp engine closes at 80 ATDC.
if you bridge the aux port you keep it open longer. at that point you're open way later than even the full race motor, and well into the compression stroke.
the stock 6 port engines close at between 75 and 80 degrees ATDC and the PP engine which is the full race max hp engine closes at 80 ATDC.
if you bridge the aux port you keep it open longer. at that point you're open way later than even the full race motor, and well into the compression stroke.
Last edited by AdRoCK3217; 05-26-2009 at 08:51 AM.
05-26-2009, 12:58 PM
#124
Rotary lover
Thread Starter
Yes,
well its not that it is not running right, it runs fine and runs better than before, but we are sure it will run much better to make better use of the porting if we have a other management system to fuel more at high rpm,
to be honest, my budget dont allow more spending at moment (the whole rebuild and new fuel pump and coils and clutch was a hard one!), although i want to, and i dont want to have a piggyback system on, thus rather wait a while, and do it properly with complete other system like microtech or so.
it is not running too lean to create problems, but needs more fuel from about 7000rpm, it is run in now and i will still take it for just simple test on oxygen readings, i was there today but the guy helping me normally want there,
i will keep all up to date,
one thing i saw was my traction control light on dash flashes more often and longer when changing gears, if it means something
Philip
well its not that it is not running right, it runs fine and runs better than before, but we are sure it will run much better to make better use of the porting if we have a other management system to fuel more at high rpm,
to be honest, my budget dont allow more spending at moment (the whole rebuild and new fuel pump and coils and clutch was a hard one!), although i want to, and i dont want to have a piggyback system on, thus rather wait a while, and do it properly with complete other system like microtech or so.
it is not running too lean to create problems, but needs more fuel from about 7000rpm, it is run in now and i will still take it for just simple test on oxygen readings, i was there today but the guy helping me normally want there,
i will keep all up to date,
one thing i saw was my traction control light on dash flashes more often and longer when changing gears, if it means something
Philip
