Semi p-port n/a 20b results and discussion. 421rwhp
11-17-10, 01:37 AM
#1
Semi p-port n/a 20b results and discussion. 421rwhp
Here is the link for more photos and video-
https://www.rx7club.com/20b-forum-95/defined-n-20b-semi-p-port-421rwhp-931068/
dyno chart
side port only stock intake dyno vs. 90mm/ semi p-port dyno
So, this is the testing I have been up to. Now we can take a look and discuss anything regarding semi p-ports. Its a little late but tomorrow I can post more info, and observations. This is definitely the upper end of power, but I am pretty confident by next monday we might see more. Lots more testing to be done without a doubt. But as of right now its looking to me that the p-port manifold is mis-matched to the header length. This header is a inconel version, and is using some new techniques. I thought ahead and also made it fully adjustable
At its current length, it resonates strongly at 6500-8500. This matches the side port manifold perfectly. I of course found this through testing on the 13b-re 230rwhp engine over a year ago. You can see however that the p-ports do not GAIN much torque, but rather push it out further. I noticed virtually no torque LOSS, even at 1500rpm. So I am hoping to shorten the header, and start to resonate at the 7500-10000 rpm range. Hopefully this will see a increase of torque 10+ ft-lbs. If this happens, 430-440rwhp might be on the table......
https://www.rx7club.com/20b-forum-95/defined-n-20b-semi-p-port-421rwhp-931068/
dyno chart
side port only stock intake dyno vs. 90mm/ semi p-port dyno
So, this is the testing I have been up to. Now we can take a look and discuss anything regarding semi p-ports. Its a little late but tomorrow I can post more info, and observations. This is definitely the upper end of power, but I am pretty confident by next monday we might see more. Lots more testing to be done without a doubt. But as of right now its looking to me that the p-port manifold is mis-matched to the header length. This header is a inconel version, and is using some new techniques. I thought ahead and also made it fully adjustable
At its current length, it resonates strongly at 6500-8500. This matches the side port manifold perfectly. I of course found this through testing on the 13b-re 230rwhp engine over a year ago. You can see however that the p-ports do not GAIN much torque, but rather push it out further. I noticed virtually no torque LOSS, even at 1500rpm. So I am hoping to shorten the header, and start to resonate at the 7500-10000 rpm range. Hopefully this will see a increase of torque 10+ ft-lbs. If this happens, 430-440rwhp might be on the table......
11-17-10, 02:40 AM
#2
Exhaust Manifold Leak
looking nice, what diameter are the P ports? what suprises me is that torque is so flat even at low rpm.. if you compare with a full PP engine where you can usually see the that the intake runner lentgh is clearly visible in the torsue curve
Do you have any pictures of the setup?
Do you have any pictures of the setup?
11-17-10, 10:30 AM
#3
looking nice, what diameter are the P ports? what suprises me is that torque is so flat even at low rpm.. if you compare with a full PP engine where you can usually see the that the intake runner lentgh is clearly visible in the torsue curve
Do you have any pictures of the setup?
Do you have any pictures of the setup?
11-18-10, 11:54 AM
#4
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wow power # is a lot higher than i expected....
11-18-10, 08:48 PM
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You sir are the man! This is very inspiring!
Now i'm curious what a 13b with a similar setup would do
421*(2/3) = 280whp maybe? I think that would be awesome in a street car
Now i'm curious what a 13b with a similar setup would do
421*(2/3) = 280whp maybe? I think that would be awesome in a street car
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11-19-10, 01:04 AM
#9
Exhaust Manifold Leak
anyone has a feeling what it would do on a renesis? we have now one in the miata, 177kW at the flywheel is what it says without airfilter installed, so there's definatly room for improvement, but I don't know if the side exhaust might be too restrictive to prevent the torque from tapering off at high rpm..
11-19-10, 09:19 AM
#10
The exhaust of the Renesis is what is preventing it from making more power. The intake side flows quite well. Mazdatrix did a semi p-port Renesis that hit the same peak numbers as some other modified Renesis engines out there. It had a nice wide powerband but the ultimate top end hits a brick wall at about 260 hp due to the exhaust ports.
11-21-10, 09:59 PM
#18
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I've run B9EGVs back to back with SD10s and it was impossible to pick a consistant difference... however, I run the SDs because they last longer. I've not tried the BUR-EQs...
11-22-10, 10:46 AM
#19
I am using the r6725-11.5 gapped at .015".
I will be testing the r7420-11.0 in two weeks but from what I have heard these 7420's are really good. Make sure you have a very good ignition system and your tune is on point because these plugs will foul easily. I hear the 7420's don't foul like the 6725's. Be prepared to spend some money, these plugs aren't cheap.
11-22-10, 07:30 PM
#22
I wish you had shower injectors on the P-ports so you could do a little test.
I would suspect you should have more low end power with the sideports closed and just the P-ports openening- then open the side ports when you need a higher volume of flow.
This is from looking at dyno charts of the development of the wankel engine with variations of both porting configurations tried- though this was likely with short runner carb manifolds on both sideports and p-ports.
You already have low rpm compression reversion through the p-port into the next intake stroke even with the p-port ITB closed and that is the only power disadvantage to the P-port (the other disadvantages are driveability). This may be a Low low rpm disadvantage with how small your p-port is- like cranking speed low.
P-port has smaller volume for higher velocity, higher velocity from no bends, better tumble off the rotor for more chamber fill/VE and likely earlier intake opening- which should all improve the low end power compared to the sideport.
You could plug/pull the LIM&block injectors or grab some spare injectors and just reroute the fuel hoses and test this out on the dyno.
Streetmode- sideport to combi port for driveability.
race mode- p-port to combi port for low end power out of the pits, if you miss a shift and faster rev matching.
I would suspect you should have more low end power with the sideports closed and just the P-ports openening- then open the side ports when you need a higher volume of flow.
This is from looking at dyno charts of the development of the wankel engine with variations of both porting configurations tried- though this was likely with short runner carb manifolds on both sideports and p-ports.
You already have low rpm compression reversion through the p-port into the next intake stroke even with the p-port ITB closed and that is the only power disadvantage to the P-port (the other disadvantages are driveability). This may be a Low low rpm disadvantage with how small your p-port is- like cranking speed low.
P-port has smaller volume for higher velocity, higher velocity from no bends, better tumble off the rotor for more chamber fill/VE and likely earlier intake opening- which should all improve the low end power compared to the sideport.
You could plug/pull the LIM&block injectors or grab some spare injectors and just reroute the fuel hoses and test this out on the dyno.
Streetmode- sideport to combi port for driveability.
race mode- p-port to combi port for low end power out of the pits, if you miss a shift and faster rev matching.
11-22-10, 11:44 PM
#23
It's not just the colder heat range that helps, it's the overall spark plug design.
I am using the r6725-11.5 gapped at .015".
I will be testing the r7420-11.0 in two weeks but from what I have heard these 7420's are really good. Make sure you have a very good ignition system and your tune is on point because these plugs will foul easily. I hear the 7420's don't foul like the 6725's. Be prepared to spend some money, these plugs aren't cheap.
I am using the r6725-11.5 gapped at .015".
I will be testing the r7420-11.0 in two weeks but from what I have heard these 7420's are really good. Make sure you have a very good ignition system and your tune is on point because these plugs will foul easily. I hear the 7420's don't foul like the 6725's. Be prepared to spend some money, these plugs aren't cheap.
Thanks, its work in progress!
Hey Blue TII! Any new projects going on? Oh, and why wish? The p-ports each have their own injector, TBI. The cc is only 270 though. Soon, maybe next week I will focus on isolating the different systems and seeing the effect. This will let me optimize and continue to develop for best overall power.
11-22-10, 11:54 PM
#24
update: 428rwhp
So had a chance to do some adjustments and go back to the dyno. 428rwhp and 248 rwtq. Basically shortened the header 4" (made it adjustable), then lengthen the p-port manifold 1". Results weren't too bad considering. But back to the lab for more tuning!
