P-PORT debate........
 

WHAT WAS THE REASON FOR CLOSING THIS THREAD ???
Everything is under control and ROTARY related !!!
This could be very informative for some of us that care about this little engine.

As of today P-Ports ONLY dominate the NA world....as far as PP-boosted rotaries there's a few here and there but nothing like Jesus is doing on the NA world.

Side port 13B's have come along way as well... racers are making alot more power with them then few of us here care to admit, thanks to fuels, electronics, new turbos and let's not forget properly ported/built motors.

Ok, I agree that everything needs to be sized properly...most critical the turbo and the balance between inlet pressure and turbine inlet pressure. I know these issues lessen as rpms go up.
You even admit it....PP being very sensitive to different tunes/loads/set ups.
It must be difficult because not many have a successful engine program using PP+ turbo dominating anything !!!
But we do have have "monkeys" doing quite well with the sideport and making quite a bit of power on the public's eye.
Why do we have to wait for few years ???? Doesn't your ultimate PP-turbo motor exist already ???

Sorry, but those were all valid points that make the PP shine in NA form but when boosted become issues that need to be addressed.
why do we need wait for that one day ? obviously those issues are still being addressed for the time being....

Rice Racing: Thanks for at least taking the time to reply with your thoughts.

JD

I thought the whole point of having this forum is to put theories, opinions, and ideas about rotaries and/or rotary related items to be actively discussed?. How will anyone benefit if any of this is not being allowed?

I agree these threads are very helpful and shouldnt be closed.. NO rules were broken. sometimes I feel like the Rx7club admins\Moderators work like the US Gov. Is this secret information that the public shouldnt know about?

That's just the tip of the iceberg. :)

B

Guess that would explain the "Test Area 51" section of the forum!

I don't see what the big deal is. So what if you have to read trough a little BS to get to the good info. That just keeps things from geting boring. There is still alot of info there, for instance now i know crispeed likes his eggs, over easy.

But back on track. Would a bridge port be a good compermise between a street port and a Pport? Or does it also have its own faults?

Its good to have a valid debate, keep it that way and it will stay open this time ;)

JD

There is quite a few PP motors out there, some at the very pointy end both in 2 and 3 rotor form... like i said in the other thread if you read betweent he lines, you can make enough power to turn a rotary engine to shit with a street port and boost alone, hence here in lies the problem the engine is not good enought to sustain what the mighty PP can achieve.

In a limited class where there are arbitray restrictions in place and you dont exceed the emchanical limits of the rotary PP's have always dominated be it NA or Forced.

Full bridge motors area good balance for most tuners and racers etc for a number of reasons, mostly though economic.

What measures "besides dowling" can be taken to handle the pport turbo power?



I think that mabe turbo sizeing is the key to a good pport turbo. The closer you could get to a 1to1 presure ratio the better. You could eliminate reversion/blow trough if there was very little pressure diff between the exhaust and intake.

Here's a link to the original page from the post that started all of this:
https://www.rx7club.com/showthread.p...8&page=7&pp=15

And the second post which was locked for no reason:
https://www.rx7club.com/single-turbo-rx-7s-23/p-port-vs-b-port-vs-street-port-turbo-13b-491629/

I listed both of these to get people who haven't been watching this get caught up on it.

Since I'm a fan of high overlap turbo setups, I'd like to hear more points from both JD and Peter. Peter, you've said "no" several times and asserted statements like "everyone will go wow", etc. but you've declined to give substantive reasons for why you believe what you believe. Could you post up some of that, please?

B

Maybe he said no because those might not be issues for people who know what they are doing. Just because the 'TOP GUYS" or you guys havent had success with a PP dosnt mean that a side port is better. Especially when you havent done the research yourself and are just taking other peoples word for it... I wouldnt be so quick to argue about it either without any real evidence. I guess some people are in for a rude awakening when the turbo PP guys finally get there $hit together and come out of hibernation

Seems to me if we are talking about the most power from a Turbocharged engine at WOT the PP will win hands down. I just don't see the overlap being an issue with recirculation of the exhaust mixing with the intake charge...etc at high RPM's. it could be a propblem at lower RPM's but if this is for drag racing, then the engine is set up for little or no back pressure and can idle at 3000 RPM if need be. Now if your talking about street driving it might be a bit much to sit at the red light idleing @3k :D

lol...yea true plus most drag guys launch at 50psi and are pretty much WOT the whole way down the track. But I thought we were talking about most power here not street driving. Anyway forget the idle, 800-1000 hp would be a bit much for the street dont you think.

[QUOTE=RICE RACING]JD

There is quite a few PP motors out there, some at the very pointy end both in 2 and 3 rotor form... like i said in the other thread if you read betweent he lines, you can make enough power to turn a rotary engine to shit with a street port and boost alone, hence here in lies the problem the engine is not good enought to sustain what the mighty PP can achieve.

In a limited class where there are arbitray restrictions in place and you dont exceed the emchanical limits of the rotary PP's have always dominated be it NA or Forced.
QUOTE]

What's considered very pointy end for both 2 and 3 rotor form?
or what has been the mechanical limitions for both 2 and 3 rotor engines regardless of port?

With those limitions addressed (some how) what would you consider the hp potential for either 2 or 3 rotor in PP mode with all issues aside.

Thanks
JD

isnt it something like 500hp per rotor..?? but most break before that lol...

The point here TurboR1 is that many of us have done our research, John D included. As far as I am concerned, John D is a "top guy" and, while I disagree with some of what he asserts, I feel he has some valid points. I am a fan of overlap/turbo combinations. For those of you that've kept up with what I do, I promote the half-bridgeport/turbo combinations rather fiercely. I believe they work. However, John D doesn't seem to as much anymore. Here's the kicker -> he had a setup similar to that years ago. He has a fairly extensive background that includes his having a daily-driven/10-sec FC that was a high overlap/turbo setup similar to the ones I use todya. For reasons unbeknownced to me, he switched back to a side-port only kind of setup. For this alone, while I personally don't agree with everything he states, what he does have to say does deserve some careful consideration.

I personally would li ke to hear the technical merits for both sides of the issue and not this jibber-jabber of "it will work" or "it will perform later and everyone will be wow'd". That doesn't prove anything. It doesn't even lend any credulity to a particular point-of-view. Facts and good 'ol hard-earned experience, however, do.

B

I'm sticking to my story in the other thread, big overlap becomes less and less of an issue at high engine speeds. Aside from poor low end and fuel economy it will always win out. It allows a higher volumetric efficiency and the delay in cylinder pressure increases allows you to run more agressive boost/timing/compression without detonation. With technology advanced as far as it has its totally doable. While rotaries are unique, the same general principles apply that work in the piston engine world, and alot of the big power piston engine cars are running high boost, high rev, high overlap setups now making big power.

As already stated, the biggest issue is that there are already ways to make power that exceeds the mechanical limits of the engine assembly with side porting. But technology marches on, perhaps as we find weak points near the top end of the power spectrum someone will come up with new parts to go further.

I totally argee with you BDC. But iam not speaking jibber jabber either.. I wouldnt say anything if I was all hopes and dreams of it one day working.. Im around a PP turbo on a reg basis and I have seen what it can do. whether or not there are other reasons why you or anyone else hasnt heard of this yet is beyond me.. Im not the owner of the car so Im not in the position to brag or give any details about it.. thats up to him. But I can assure you that power is not the reason why this car hasnt been down the track yet.

all im saying is dont be so quick to say a side port is better cause thats just stupid..

oh and whats so special about having a 10 sec daily driven car.. I got one too and im a nobody... all it takes is 450 rwhp and a 2700 lb car with some power shifting and you have a 10 sec pass... big deal...

I'd like to see some more stuff on this PP Turbo car. Got any pictures or other info about it regarding the setup? I'm interesting in checking it out.

I'm not saying a side port is better; I think somebody else here is arguing that. I hold the opinion that it's not. I was originally against it but stumbled upon it more because somebody else pushed me into it. I think the high overlap/turbo setup is a great platform.

"big deal"? 10sec is a very big deal. In all reality, that's an extremely quick car that takes alot of work to achieve. 10sec in the 1/4mi is something that is still not very common at all and is not to be taken lightly. Most everyone on this forum still hasn't reached that (nor gotten close). Did you build this car yourself?? I'd like to check it out.

As far as John D is concerned, he had a 10sec car years and years before places like this forum ever existed; before people were doing this sort of stuff. That puts him in a special category, I feel, that ought to lend more consideration towards what he's got to say.

B

What turbor1 is saying is has JD built a PP motor before? What do you guys consider research? reading info online/magazines/etc is not considered research to me. Research for me is testing a motor by actually doing the legwork. It's all i've been doing for the past decade whether it's piston motors/rotary's, drag racing or marine applications.

I have been working on the PP turbo motor my brother is talking about for over 9 months now. We have run over 70gals of M1 thru the same motor. So i actually speak from experience because i have both a pp motor and my own dyno that has logged a shitload of data from this motor. I'm still learning what these motors want and how to get the most out of them. Im doing this thru actual R&D not assumptions of what i believe would work or what so and so told me should work. I also have a rotary adapter plate(almost finished) and will have a spare 13b strictly for engine dyno research. So you could rest assured when i say something will work it in fact works.

These are the points some of us are trying to make. BDC, i know you have been working on half bridges and you find that they work very well. That's great. You have done a lot of work with them and figured out a combonation that works for you. A bridge of any sort has quite a bit of overlap but yet thru your research you have found something that works very well. So you know that motors with what some people think is "excessive overlap" do work in turbo applications. I dont' have to prove anything to you your smart enough to know already.

Peter stated it's going to take a few years for most to realize this because of monkey see monkey do. Nobody likes to actually do things for themselves they rather wait for others to do it and then build the same shit. This is very common in this industry. It'll all happen in time.

Again i hate to bring in honda's as an example but back in 97/98 there were only a few of us making 600+ hp with a honda. We had to have everything custom made from headers, rods, pistons, cams, etc. We went thru turbo's like they were going out of style, trying to figure out what works. Now you can simply buy everything out a summit catalog and have a 600hp honda. Once everyone figures out what to do it becomes textbook.

Problem is the people who are actually building PP motors are not going to share anything with anybody, at least not yet. Everyone is very tight lipped about this right now and you would probably be shot before they tell you there port timing!

Hahaha......You guys need to give the "TOP GUYS" a hand of knowledge then...
You tell me what turbo-PP has a successful engine program ?????
and we still need to wait for the turbo PP guys to get there shit together !!!!!

JD

Enzo,
great post..but lets face it 99% of the people on this board are not interested to build the ultimate drag engine. They are just curious to know but will never invest the money to actually do.

Winning teams have the money and patience to try and try again and eventually hit the jack pot. I don't think they care about what people say on this board even if someone cares to share their secret...they want to stay a step ahead. Also, rules change and technology advances, two very important aspects of making power in a race event and again very expensive aspects.

One thing that amazes me over my few years on this board is the ignorance when it comes to simple physics. Flow (air) depends on the size of your pump (combustion chamber size) and your pumping action (rpms) and the efficiency of this pump at certain rpms (holes in your pump to exchange the matter or ports in our engine optimized for certain rpms and heat loss). Saying holes or ports, all they do is optimize the entry and exit of matter that needs to be exchanged in relation to engine size and rpms. All we can do is optimize this exchange to a certain RPM range, since we can't change anything else. This is not depended on how much the matter is compressed. The volume of matter stays the same since the size of the chamber hasn;t change.

So optimizing our force or work to the highest RPM will give us the most power, since power is measured by the force over time. So the later Tq peaks in the rpm range the more likely we will see higher maximum HP. That is true for NA or turboed.

I am sure by now you got my bias interms of what engine can make the most HP. The real question is "will this maximum HP engine win the race??? "

CW

BDC, thanks for the kind words :-)
Yes, I remember quite well our conversations regarding the half-bridge setups when you started to mess with them...
Well...I found out I could make the same power, use up ~25-30% less fuel under boost and not deal with the brap..brap..brap idle which was cool at first but became annoying whenever you pulled to a station the attedant would tell you it needed a tune up ! hehehe

You put alot of effort/hours into your porting but when people run stock intakes and rev to 7-8krpm and make less the 500rwh it was just for the brap...brap...brap...

BDC: hw much more fuel do you add to half-bridge motor compared to a street port motor with same size turbo?

JD

Ok...then tell us what this PP turbo motor could do ....why is it always a top secret with teh rotaries !!!
The supra guys exchance the knowledge and explains why they're making over 1800hp !!!

OK, so what's the reason? motors coming apart from too much power???

I hate to break the news to you, but so far side ports are better....they have gone quicker and faster !!!
WHY ??? now that's the question that sparked this debate.
Why we don't see de-tuned PP-turbo motors running side by side ?

JD

this happened back in 1998-99 :-) good old days..

JD

Its this kind of attitude that will get this thread locked too, do you want that?

I did not think so ;)

The truth is staring you in the face and your answering your own questions, if you have no self imposed boost pressure limit then the +5% extra power a PP will give over a full house BP is neither here nor there, same for the 15% power differential to goos street ported engine........ And lets not forget that you fuck up any one element in the heavier ported engine and you wont even get the gains possible through the porting. You know being an old head like me how many times you have seen this ! Hence you get street ports making 900bhp and some boys with bridges making the same power (not more) on the same boost !

Hehe......that's not fair:-)


Agree 100%
You'll see more loss then gain sometimes!!!

any development team ever try adding those good ole values like pistons engines uses for timing?
i know its kind of counter productive ( just like carbing rotarys :-P ).
or would the shear RPM of the rotary be to much for a cam/valve setup?
just a thought...

This is the kinda...stuff...that gets your foot in your mouth.

JD did this about 10 years ago and with the STOCK ECU...on an FC.

Still think any "nobody" can claim this?


-Ted

Here is a P ported/turbocharged engine that someone could buy and "test". :)

http://www.racingbeat.com/resultset....tNumber=Engine

[QUOTE=RETed]This is the kinda...stuff...that gets your foot in your mouth.

JD did this about 10 years ago and with the STOCK ECU...on an FC.

Still think any "nobody" can claim this?


you missed my point and your way off topic. what does having a 10 sec car having anything to do with knowing whether or not a PP turbo works better then a side port.

10 years ago yea thats a great acomplishment congrats. JD is the man when it comes to that, even did it on stock twins. that proved many wrong right there..good for him

but it is 10 years later now, building a 10 sec RX is pretty easy I think. and how much farther has he come from that 10 sec pass 10 years ago???????????????????

ur using him having a 10 sec car as evidence of him knowing what he is doing when it comes to PP motors, sorry thats not enough proof for me.. for you that might be... to each is own.

Peripherial porting is just bumping up the VE curve and trading total flow for velocity. Its not typical to do this much for a boosted engine unless youre doing top end drag racing but hey, if you want to, why not?

Duh, you can turbo a PP engine just like any other. But it will spool late because the VE% curve is higher, and youre most likely going to be using a big turbo anyway if youre going to bother to do, so this would most likely be best for drag racing. Tractability of that kind of powerband would most likely be craptacular for anything on the street and even road racing Id be surprised, but Im sure it oculd be done.

As far as making a 10 second rx-7, you need 416 whp with traction to get a 2800 lbs car to run a 10.9. Thats not hard. Getting more power or less weight isnt exactly difficult.

The real challenge will be in tuning it, getting it to idle, and putting the power down. You'd also prolly do well to get a strong stat. gear and e-shaft (and well make sure your rotors are balanced, good seals, blah blah blah) to rev high enough to take full advantage of the porting youre doing.

As far as a drivetrain, I'd say do what the big boys do and get a built automatic with a slip stall converter so you can leave the line under boost. If youre talking about doing this for racing then expect to need some short ass gears and a BUILT rear end and dog engagement... and one hell of a suspension setup.

Unless of course this is for a dyno queen, then go get some 18" dubs so it spools up from higher load and put stickers everywhere :bigthumb:

Yes, building a 10sec RX is much easier now then it was 10 years ago....all you have to do is duplicate setups which have been proven by others....
order the right turbo kit, ECU, fuel system, clutch..etc...but you still have to go out there and get your 10sec RX to RUN 10's.

This is not about me or any of my cars.....this is about you guys proving the proof or examples of turbo-PP cars making xxxx hp or running x.xx numbers !!!
You or your brother have yet to mention what kinda power levels you have your turbo-pp engine at.

Side ports are still on top as far as 2 rotor or 3 rotor hp but you're ignoring that fact.
I do understand the fact that these engines are reaching their physical limits but I'm sure many are addressing that as well:-)

It's easy to see how on paper the turbo-Port is the obviuous answer but in the real world things are much different.

You think I'm against a turbo-PP 13Bmotor making 1000+hp or a turbo-PP 3 rotor making 1500+hp ??? HELL NO.

JD

not saying a pp won't make good power, but honestly a big street port with a big turbo and lots of boost will make more power than the motor can handle anyway. any gains in flow that a pp will give, will also be given up by the loss in combustion efficiency. it's pretty narrow minded to think that a pp will automatically be a better choice no matter what, because the reality is that it is a give and take situation. plus you guys should realize that turbo engines make really good power from the exhaust flow. look at the sport compact drag cars and you'll see the trend the past few years have been to give up some intake flow to get more exhaust flow.

Exhaust flow is very important on a PP port.

So what is the most a side port 2 rotor has made from boost alone no juice and at what psi? A number you can back up and not from someone you dont know.

wtf? why does the side port side have to back up anything when the pp side just argues from conjecture? we already know what a sp engine can do from guys like adam s., abel, ari, dee, carl martin, carlos montano, jose vidal, etc. let's see what the pp side can bring to the table.

You can't even read what I wrote and then you tell me I missed the point?
Hmmm...you started to insult JD on his accomplishments and then you tell me I'm OT?
Boy, I love your sense of reality...


Guess you missed the part where I said *FC*...


-Ted

LOL. I never insulted JD or his accomplishments. I simply said that his 10 sec car really holds no value in this debate so it shouldnt be brought up. Im sure he feels the same way. We are comparing turbo Peri ports VS side ports and which makes the most power lb for lb. Whether or not he went 10's with an "FC" ten years ago means nothing here plus we are talking about enough power to put you in the 7 sec range so yes that would be off topic here.

Now I understand why these threads get closed and why the people who know what they are talking about dont even bother to respond. Cant even have a normal debate to compare notes without having the idoits throw there 2 cents in.. Another good thread down the drain..

A daily driven 10sec RX is still not very common to see today now imagine going back almost a decade !!!

Forget all that....
Individual accomplishments is what drives others to push further with these engines and not calling it quits.

Other thread was closed for no apparent reason and hopefully this one will continue and we all will benefit from it one way or another.

Name calling is not needed and the thread will continue with you or not!

JD

Is there anyone on this forum who has a BP or PP turbo setup with dyno sheets to post so we can compare? Wonder if anyone from pistonsvsrotor will come and discuss this topic.. I personally know a few Ricans that are running Street port turbo setups, when 1-3 yrs back they were running Semi-PP, PP and BP setups..

That is interesting...the Ricans were always cutting edge....wish we could get some inside scoop on this.

Yeah this forum has all the info you want... Enjoy...

This is s good thread! Thought I would share a pic of Abels car engine from two years ago.

http://www.hostdub.com/albums/rbr20/DSC00342.jpg

Another surprise for me. The primary injectors are in the stock postion. I thought they were there for drivability and for top end you mount injector as far away as you can from the combustion chamber.

CW

It aint going to happen!

Rafaelito's car had a BP + small PP back when he was using the webbers, his best time at the time was a 7.6; I don't know if his 7.4 (when he switched to EFI) was on the same motor, or if his new car is sporting the same combination.

I do know that some of the 3/4 chassis starlets, DO run at least a small pport.

I'm not taking away from those accomplishments with Rafaelito's car, BUT alot of people seem to forget that Rafaelito's car, and some of the cars that you're mentioning are NOT AT THE NHRA LEGAL WEIGHT!!, let's slap the NHRA weight requirements on those cars and then see what ET and MPH results you get(Therefore showing that they're not making as much HP as you think), I can bet you it won't be as fast as the times that you're mentioning.

Ohhh but you are WRONG!

http://www.nhraimport.com/2001/event...sults/pro.html

So tell me, if him and those cars that don't meet the NHRA weight requirements, how come they are allowed to race on the NHRA events?

It is now a misconception that the PR cars are underweight, the only ones that are under weight (and probably because there is no class for those on NHRA) are the NA + Nitrous cars ;)