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 !!!