Semi p-port n/a 20b results and discussion. 421rwhp
11-23-10, 12:10 PM
#26
[QUOTE=GtoRx7.;10332448]Why such a small gap? And where did you source these from? I went to advance next to the dyno facility with the part numbers you are describing, but there was no listing. I was crossing my fingers in hopes of doing a back to back dyno test. Guess maybe next week 
Your local auto parts store may not be able to find these. I get mine from www.sparkplugs.com. You can get them from RacingBeat and many other shops as well.
Just put the part number in the search box with the heat range- r6725-11.5
Heres a link- http://www.sparkplugs.com/results_cr...11.5&x=56&y=14
Regarding the small gap, it's needed due to the high rpm's and increased power. With larger gaps higher than .020"'s the power drops off. YOu can find this on Racing beats website under tech tips. Here you go- http://www.racingbeat.com/mazda/perf...ter-plugs.html
I hope you're not pulling my chain. With the knowledge you have of building semi pports and this looks like a well built race car, I'm surprised you don't run these plugs. Every rotary racer I know use these plugs. N/A and turbo
Your local auto parts store may not be able to find these. I get mine from www.sparkplugs.com. You can get them from RacingBeat and many other shops as well.
Just put the part number in the search box with the heat range- r6725-11.5
Heres a link- http://www.sparkplugs.com/results_cr...11.5&x=56&y=14
Regarding the small gap, it's needed due to the high rpm's and increased power. With larger gaps higher than .020"'s the power drops off. YOu can find this on Racing beats website under tech tips. Here you go- http://www.racingbeat.com/mazda/perf...ter-plugs.html
I hope you're not pulling my chain. With the knowledge you have of building semi pports and this looks like a well built race car, I'm surprised you don't run these plugs. Every rotary racer I know use these plugs. N/A and turbo
11-23-10, 10:20 PM
#27
Three rotor header-
11-23-10, 11:12 PM
#28
I just had a flashback- about 7 years ago I talked with Jim Mederer at Racing Beat for a while regarding semi p-ports. He told me that it is something that he would never recommend, and wouldn't work for many reasons. And if by some chance I did get it to work, to send the dyno chart to him. lol. So I guess RB can learn more too
Last edited by GtoRx7.; 11-23-10 at 11:40 PM.
11-24-10, 12:45 AM
#30
On the two rotor header, that is the collector I build/ tig together. Three rotor I use SPD. The transitions I get from SPD, woolf, or a local place called tubular tech. The straight piece is a slip fit expansion, to slide onto the remaining exhaust. I never run n/a with a open header. If it was a open header the megaphone would need to be much longer. The noise just isn't worth it in my opinion! Two rotor header cost is $580. All 321 stainless grade construction. Everyone uses 304, but I am not a fan, and its not cut out for n/a rotary. For a limited time we are also using Inconel tubing in the header.
Last edited by GtoRx7.; 11-24-10 at 12:48 AM.
11-24-10, 12:17 PM
#31
I meant the part inbetween the collector and where it actually megaphones, not after the megaphone,
whats the price on the inconel version ? also what's the lead time for making them ? lastly how do you have your customers measure up the total intake length, I personally have a racing beat wrap around manifold on mine and I've added another half an inch inbetween the upper and lower manifold, and theres also another quarter of an in spacer between the throttle bodies and the upper manifold.
whats the price on the inconel version ? also what's the lead time for making them ? lastly how do you have your customers measure up the total intake length, I personally have a racing beat wrap around manifold on mine and I've added another half an inch inbetween the upper and lower manifold, and theres also another quarter of an in spacer between the throttle bodies and the upper manifold.
11-24-10, 01:23 PM
#32
I just had a flashback- about 7 years ago I talked with Jim Mederer at Racing Beat for a while regarding semi p-ports. He told me that it is something that he would never recommend, and wouldn't work for many reasons. And if by some chance I did get it to work, to send the dyno chart to him. lol. So I guess RB can learn more too
Well, his knowledge and perspective are racing based; so, without knowing the context of the full conversation I would weigh his comments in this light.
In which case, he is correct.
You are about 50hp down from privateer circuit teams na 20B efforts with traditional peripheral port and no doubt much further off the mark of Racing Beat and other professional shops power numbers.
If you were specifically talking about street cars, there are many opinions on what a street car is. For instance, legality, civility, driveability are all considered. One of those criteria is unfortunately much less subjective than the others.
All that said, your engine/car is EXACTLY what I want from a street car and race car. Just the right compromises.
11-24-10, 02:15 PM
#33
Old [Sch|F]ool
Legally, even a single turbo conversion on the stock 13B in an FD isn't a street engine...
I can only imagine how this thing drives. I'm picturing like my half-bridge engines only a whole hell of a lot more of it. Once you have a little overlap in your life, nothing else satisfies.
I don't see how the MFR 13G engines could be 50hp down on this... the MFR 13Bs were ~300 at the crank, so the 13G would be appx. ~450hp at the crank.
I can only imagine how this thing drives. I'm picturing like my half-bridge engines only a whole hell of a lot more of it.
Once you have a little overlap in your life, nothing else satisfies.I don't see how the MFR 13G engines could be 50hp down on this... the MFR 13Bs were ~300 at the crank, so the 13G would be appx. ~450hp at the crank.
11-24-10, 08:55 PM
#34
And thanks for the compliments!Legally, even a single turbo conversion on the stock 13B in an FD isn't a street engine...
I can only imagine how this thing drives. I'm picturing like my half-bridge engines only a whole hell of a lot more of it. Once you have a little overlap in your life, nothing else satisfies.
I don't see how the MFR 13G engines could be 50hp down on this... the MFR 13Bs were ~300 at the crank, so the 13G would be appx. ~450hp at the crank.
I can only imagine how this thing drives. I'm picturing like my half-bridge engines only a whole hell of a lot more of it.
Once you have a little overlap in your life, nothing else satisfies.I don't see how the MFR 13G engines could be 50hp down on this... the MFR 13Bs were ~300 at the crank, so the 13G would be appx. ~450hp at the crank.
11-25-10, 12:09 PM
#35
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not true! HKS used to offer a couple C.A.R.B. legal turbo kits, even the T51 kit fits with the air pump. nobody cares now though, and it seems like most of the country doesn't have smog checks anymore anyways
11-25-10, 03:06 PM
#36
Yes they are some of the best but sometimes when you are on top, it's easy to forget that are others who remain determined to find ways to improve on something. Just because they MAY have exhausted all efforts and CLAIM it's not possible, doesn't mean us little fish can't make a dent in things.
11-27-10, 01:25 AM
#38
I meant the part inbetween the collector and where it actually megaphones, not after the megaphone,
whats the price on the inconel version ? also what's the lead time for making them ? lastly how do you have your customers measure up the total intake length, I personally have a racing beat wrap around manifold on mine and I've added another half an inch inbetween the upper and lower manifold, and theres also another quarter of an in spacer between the throttle bodies and the upper manifold.
whats the price on the inconel version ? also what's the lead time for making them ? lastly how do you have your customers measure up the total intake length, I personally have a racing beat wrap around manifold on mine and I've added another half an inch inbetween the upper and lower manifold, and theres also another quarter of an in spacer between the throttle bodies and the upper manifold.
11-27-10, 12:35 PM
#39
When I built my header, I cut up some old garden water hose to length. Then I went to the hardware store are bought some of that water pipe black insulating foam tubing and wrapped around it. I would just cut small donut sections and randomly space them the length of the hose so that anyplace they would contact the other hose, the foam would automatically space them for me. The flexible water hose and foam perfectly simulated my exhaust pipe diameter. I could then route my design anyway I wanted, then copy to metal. I've never built headers before so I thought this is what everyone did. You should try it!
11-27-10, 07:44 PM
#40
When I built my header, I cut up some old garden water hose to length. Then I went to the hardware store are bought some of that water pipe black insulating foam tubing and wrapped around it. I would just cut small donut sections and randomly space them the length of the hose so that anyplace they would contact the other hose, the foam would automatically space them for me. The flexible water hose and foam perfectly simulated my exhaust pipe diameter. I could then route my design anyway I wanted, then copy to metal. I've never built headers before so I thought this is what everyone did. You should try it!
11-27-10, 10:26 PM
#41
Whoops, missed that question, sorry! The inconel version is $750 but only until I run out of inconel. Being that inconel is normally $300 a bend, I wont be able to sell at that price again anytime soon. It will take me two weeks to build. Measuring the intake, I usually take specs from the intakes I have at the shop. Since you have a intake I DONT have here, easiest way (kinda crude) is to take a wire and follow the Center line radius (CLR) of the bends. Takes a little practice, but it will be accurate enough to get the header length correct. Remember to measure all the way to the end of the trumpet. And on the megaphone, well so far I like the results better with the straight. But there is still a chance in the future I will revisit that area. With the importance of one change at a time, I focus on the largest percentages of gain first, and the smallest last.
Thanks
11-28-10, 10:44 AM
#42
This is what I did to me SDJ headers, I placed this megaphone in there, and you'll notice right after where the 2 pipes meet collect I've directly megaphoned through there:
If you compare that to this one from him, you'll notice before it actually megaphones and where the 2 pipes from the collector actually meet, you'll notice a more straight piece in between there.
11-29-10, 11:51 AM
#46
Ya I built a couple of them , I have a whole thread about it:
rx7club.com/showthread.php?t=781212&highlight=muffler
my collector off my SDJ header cracked all along the weld of it, and its impossible to reweld it because its such a thin metal that is extremely contaminated, I've had I for 5 years or so daily driving through it, those headers aren't exactly meant for that. I did my best to keep it together by welding, but it wasn't pretty, and I just covered up the rest with some furnace cement. The next ones I'm getting I'd rather have made out of slightly thicker stainless I think, and ill be sending them out for ceramic coating.
rx7club.com/showthread.php?t=781212&highlight=muffler
my collector off my SDJ header cracked all along the weld of it, and its impossible to reweld it because its such a thin metal that is extremely contaminated, I've had I for 5 years or so daily driving through it, those headers aren't exactly meant for that. I did my best to keep it together by welding, but it wasn't pretty, and I just covered up the rest with some furnace cement. The next ones I'm getting I'd rather have made out of slightly thicker stainless I think, and ill be sending them out for ceramic coating.
11-29-10, 01:23 PM
#47
Ya I built a couple of them , I have a whole thread about it:
rx7club.com/showthread.php?t=781212&highlight=muffler
my collector off my SDJ header cracked all along the weld of it, and its impossible to reweld it because its such a thin metal that is extremely contaminated, I've had I for 5 years or so daily driving through it, those headers aren't exactly meant for that. I did my best to keep it together by welding, but it wasn't pretty, and I just covered up the rest with some furnace cement. The next ones I'm getting I'd rather have made out of slightly thicker stainless I think, and ill be sending them out for ceramic coating.
rx7club.com/showthread.php?t=781212&highlight=muffler
my collector off my SDJ header cracked all along the weld of it, and its impossible to reweld it because its such a thin metal that is extremely contaminated, I've had I for 5 years or so daily driving through it, those headers aren't exactly meant for that. I did my best to keep it together by welding, but it wasn't pretty, and I just covered up the rest with some furnace cement. The next ones I'm getting I'd rather have made out of slightly thicker stainless I think, and ill be sending them out for ceramic coating.
Seriously though this winter I will be selecting certain participants to use our headers and get dyno feedback. Bascially we will send the header out, test user pays a discounted price. After testing they can decide to keep it, or return it for a refund. Should I put you on the list?
11-29-10, 02:27 PM
#48
Hmm ... that sounds like something that I could be interested in ... I'm currently at 165 whp with my street ported 12a. Here's the graph of that :
rx7club.com/showthread.php?t=904766&highlight=dyno
Now I do plan on supercharging this engine early next year with the rotrex supercharger that I have in development for it, but the better NA performance before then, the better it will be supercharged.
I would of loved to stay NA as that's where my heart is, but to be more competitive at the track in a more reasonable fashion and keep it a daily driver, boosting is the better way I believe. But I have always liked the idea of developing the engine NA first instead of upping the boost a bit to hide any imperfections in the over all efficiency of the engine.
Here's my supercharging thread if your interested in that:
rx7club.com/showthread.php?t=921875&highlight=rotrex
... I'm currently at 165 whp with my street ported 12a. Here's the graph of that : rx7club.com/showthread.php?t=904766&highlight=dyno
Now I do plan on supercharging this engine early next year with the rotrex supercharger that I have in development for it, but the better NA performance before then, the better it will be supercharged.
I would of loved to stay NA as that's where my heart is, but to be more competitive at the track in a more reasonable fashion and keep it a daily driver, boosting is the better way I believe. But I have always liked the idea of developing the engine NA first instead of upping the boost a bit to hide any imperfections in the over all efficiency of the engine.
Here's my supercharging thread if your interested in that:
rx7club.com/showthread.php?t=921875&highlight=rotrex
11-29-10, 09:55 PM
#50
I checked out the dyno charts, and muffler build. Nice TIG welds btw, looking good. With the torque you are producing and where the torque is at, a improvement with the header is not going to be a walk in the park. But I think its possible! How long are your ITB's? And how aggressive is the street port? And how is the exhaust port? Earlier or later opening/closing? both? Next week I will be starting on some headers, so testing can happen soon