i believe that mr. judge ito did something like that not too long ago, colin. It was a tubeframe drag car though. An old friend of my fathers drove a PPort rx3 on the street for a few years with a 48ida on it. Looking quickly at a spec sheet i googled, the lt8s has the resolution (every 500rpm) and its table is a 16x16 blockset. Upgrade to the 32x32 block set and the motor will be as smooth as glass. 16x16 isnt the BEST for streetability.







my 2 cents, feel free to tell me im wrong

when an engien is ported a lot it doesnt use pull a lot of vacuum and with little throttle opening the map sensor sees full atmosphere already, so tuning the engien vie a map sensor becomes pretty useless. with a pport and i am asummign individual throttle body set up that one woudl run this would bring it even further.

engien load will have to be tuned with a tps instead of a map sensor. the actual resolution of the ecus is not very important since it interpolates between the values and most standalones are adjustable enouf to suit pretty much any need.

you could run some sort of airflow meter too.

[quote name='TYSON' date='Jul 21 2005, 04:27 AM']I'll have mine done soon, you can come down to London and check it out.



I don't know about the Coffee Time drive thru though, they use pretty crappy speakers and mikes, I can barely understand them even in the Intrepid. https://www.nopistons.com/forums/pub...#>/biggrin.png


[/quote]



Yeah Tyson, I will be coming to London on Monday for the meet, I'd love to see your progress and ask you some questions

The MS EFI controller is flexible enough to work with this type of setup..





FYI anyone looked at the FD3S UIM + TB setup closely?



for my application the PPort runners are individual from the primary side port runners, and each pport would have it's own throttle plate essentially. The idle and cruise settings would be part throttle which is mainly just the primary throttle plate, thus saving a bit of fuel and not having such drastic intake timing..



What do you think

The roughness at part throttle is due to the port allowing exhaut gases to be pulled up into the preceding chamber due to the vacuum in there at part throttle. Doing idle and part throttle through side ports will not be doing much good, the "internal vacuum leak" still exists. I am thinking that half-side/half-peripheral may actually make things worse in this regard, since the peripheral part would still be under "high" vacuum even at part throttle, before the secondary throttles open up. Might as well eliminate that other pair of side ports, too.



All rotaries that I am aware of have been peripheral port, except for Mazda and a few air cooled models such as you would find in a lawnmower or chainsaw. Made it easier to pull intake air from the "crankcase" 2-stroke style, donchaknow.

[quote name='kahren' date='Jul 21 2005, 04:30 PM']when an engien is ported a lot it doesnt use pull a lot of vacuum and with little throttle opening the map sensor sees full atmosphere already, so tuning the engien vie a map sensor becomes pretty useless. with a pport and i am asummign individual throttle body set up that one woudl run this would bring it even further.

engien load will have to be tuned with a tps instead of a map sensor. the actual resolution of the ecus is not very important since it interpolates between the values and most standalones are adjustable enouf to suit pretty much any need.


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Load points are load points, no matter how they are derived.Interpolation on fuels maps is a large problem, and always leads to a compromise in tuning, ask anyone that ever ran a wolf 3d in high boost mode...Resolution is everything, especially when running one large injector on a N/a with single throttlebodies. Not to many ems's will handle something like a 120 or 160 lb/hr injector at idle, and give you enough control over it, to maintain accurate stable idle, sharp throttle transition, and stable air fuels, all of which are important on something like a p=port motor. What made people term p-ports and bridgeports unstreetable in the past, was the fueling characteristics of carbs, what makes it streetable is good efi..Alot of p-ports used to idle on the low speed circuit...

After playing with a microtech with 720's , getting it to idle a p-port with a 1200 cc njecotor would probably be not better than running a sidedraft.. The reason stuff like the motech is so popular, is the features like fuel map magnification which let you split fueling ranges in order to achieve more load points in specific areas, an ass saver on p-port. The more porting the engine has, the more picky it becomes on fueling at lower rpms, often a fine line between fouling and running lean..

From my observations of p-port cars, I know the motec is expensive but its very good at what it does. I think the autronic would also be a very good candidate for running a p-port on the street, Hks fcon has been used with moderate success.. I cant speak for the newer haltechs, but the e6k wouldnt be a great choice either, its control of large injecotors on ported engines is limited..

A way around this would be to run staged injection, but it means double fuel rails, etc etc, p-ports are about simplicity..Max

the nsu motor has 2 pp's, one teeny port with moderate timing, and the big one. its hooked to a 2 barrel carb. it still idles like poop, although it is a 1 rotor engine.



the white and green 79 factory imsa gtu car runs great. it fires right up and idles nicely at around 900rpms, with a 48ida, they spent lots of time tuning it though.

Heretic and Max



As far as the idle situation goes, back to my side/pport idea (sorry to sidetrack and centre myself out, but we are talking about a streetable pport)



The centre iron has the injector bungs already, I understand what you mean by this "internal vacuum leak", but fact remains the sideports and there and so is the stock primary fuel rail, is it really going to make that much of a difference with the pport pulses hitting the closed throttle plates?



Also, yes, with the custom LIM will have it's own fuel rail, so there is a set of primary and secondary fuel injectors, and it will be staged.. Essentially, to think outside the box for a minute, the basic idea was to replace the secondary side ports with peripheral ports. Each pport has its own injector just as if it was the stock LIM going to the secondary side port. Each pport has it's own throttle plate, just as if it was the stock secondary side port. Motor still uses the primary ports for the idle and BAC circuit, etc...



How well have people set up secondary side port bridgeports on N/A engines for idle (no primary bridge)? Considering they are using bolt on stock manifolds and still have staged injection with fuel rails for primary and secondary?



Results have been pretty good no?



Now substitute the secondary intake circuit of a bridgeport(sideport) with smaller pports......







Curious about input, I may flake on my decision and go straight up pport (no side port), but to me, my idea is just a different way to run a bridgeport N/A engine...

The side ports' injectors are already there and and fuel rail is already there and that means less fabricating required. Nothing at all wrong with that in the big picture. Good enough and on the road beats perfect and never completed.



Don't even think of the vacuum column in the secondary port runners (runner: the length of tract between the port window and throttle blade!) in terms of pulses. The same vacuum that the rotor generates against the side ports will be acting against the peripheral port, and for the last few dozen degrees of travel before the side port closes, that "other" intake port will be exposed to the next chamber in the midst of its exhaust cycle.





Should be better in a way because of the greatly reduced port timing with a peripheral compared to a bridge, so the time exposed is much lessened. On the flip side, there's more exposed area with a peripheral port compared to just the bridge part of a BP, so you get more potential flow per time.



Six of one, half a dozen of the other. Probably the best thing is to not worry about the idle and part throttle so much as where you want your powerband.