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Naturally Aspirated Performance ForumDiscussion of naturally-aspirated rotary performance. No Power Adders, only pure rotary power!
From the "12A" to the "RENESIS" and beyond.
Took her out for a spin yesterday, she's running crazy rich, but pulls strong "the power never stops" lol torque is a distant memory, but she's still building compression. Going to drop the exhaust tonight to paint and then wrap it. She doesn't brap at idle anymore, she's very happy at a 12.4 idle at 1200 rpm.I'll keep updating with my tuning trials and tribulations and hopefully a dyno run before world of wheels March 4th
what do you have on it for a muffler? Are you using the Racing Beat exhaust diameter of 2" O.D. all the way down then collect to 3"? How long is it from the header flange to the crotch of the collector?
what do you have on it for a muffler? Are you using the Racing Beat exhaust diameter of 2" O.D. all the way down then collect to 3"? How long is it from the header flange to the crotch of the collector?
2" o.d. The whole way, then collects to 2.5" (it's using the collector from the header still) and iirc its 103" from the front runner to the end of the collector"
The muffler is a subaru spt muffler from a legacy with the tip cut and extended out a little.
Interesting. I was just wondering since Racing Beat has suggested primary lengths, diameters, and collector size although there is a rather unfortunate typo in the collector diameter suggestion which would pertain specifically to bridgeports. I am assuming they meant 2-1/8th hole diameter not 28...
Interesting. I was just wondering since Racing Beat has suggested primary lengths, diameters, and collector size although there is a rather unfortunate typo in the collector diameter suggestion which would pertain specifically to bridgeports. I am assuming they meant 2-1/8th hole diameter not 28...
I just kinda put it were it for best, honestly I have a twin scroll turbo that will probably end up back there eventually, so this just made sense for now
Just road tuning so far, but the afrs are Pretty well where I want to see them 12.0-12.5. She still building compression so the tune keeps changing a little so I'm staying conservative until I get a little bit more stable with where at in the fuel map wot sits.
Get on with the dyno already! I want to compare the numbers as I will getting a dyno tune later this month - I extended the primary runners on the RB header 3' before they collected which is similar to what you have.
Well, their ignition pick-up kept getting interference, so Ill have to do some math to figure out torque, but she hit 172 hp, three runs opening the aux ports at different points
Blue was 4.5k
Red 3.5 k
Green locked open
I'll get the videos uploaded tonight, blew a tire on the third run....so that was interesting.
Here's with the TQ roughly figured via speed vs gear ratio to find rpm, then hp*5252/rpm=TQ
On the left I did with the aux ports closed till 4500 "top" and with them open "bottom"
notice the tq dip when the aux ports open, from this they can stay closed until 5300rpm and I'll keep 136ft/lbs from 4200rpm
I'm wondering with the intake manifold is really limiting the 7-9K range. It makes sense with the aux ports open at different points won't affect your peak power but interesting...
I'll be going to the dyno wednesday and see how my streetport compares with the same manifold. However I am using a 4 port block and port matched S4 NA LIM.
What are you using to tune with the stock ECU? RTek?
I'm wondering with the intake manifold is really limiting the 7-9K range. It makes sense with the aux ports open at different points won't affect your peak power but interesting...
I'll be going to the dyno wednesday and see how my streetport compares with the same manifold. However I am using a 4 port block and port matched S4 NA LIM.
What are you using to tune with the stock ECU? RTek?
rtek 2.0
I'm running about 12.0 AFR I can pull more fuel and likely make more power out of it, I just want to stay conservative while the engines getting broke in
rtek 2.0
I'm running about 12.0 AFR I can pull more fuel and likely make more power out of it, I just want to stay conservative while the engines getting broke in
Got it Dyno'd yesterday at my friends shop needless to say I am happy with the numbers, and with a redline of 9000rpm its great to have that much over-rev capability.
megasquirt II
Rx8 e-shaft
S5 NA rotors
S4 t2 irons
S4 NA housings (w/ turbo inserts)
pineapple large streetport
Aluminum flywheel
RB underdrive main pulley
S4 NA intake system (no aux ports)
ported/polished throttle body
true dual RB header with the primaries extended 3'
Moroso spiral flow resonator
RB rotary shaped muffler
catalytic converter
the last engine and setup dynoed at 132whp and 121tq @ 6400rpm this is was 182whp and 134tq @7500rpm but even the old engine managed to run a 14.9 in the quarter mile at 81MPH I will be curious to see if this can dip into the 13's or a 14 flat this spring with the gearing improvements and mass reductions.
Got it Dyno'd yesterday at my friends shop needless to say I am happy with the numbers, and with a redline of 9000rpm its great to have that much over-rev capability.
megasquirt II
Rx8 e-shaft
S5 NA rotors
S4 t2 irons
S4 NA housings (w/ turbo inserts)
pineapple large streetport
Aluminum flywheel
RB underdrive main pulley
S4 NA intake system (no aux ports)
ported/polished throttle body
true dual RB header with the primaries extended 3'
Moroso spiral flow resonator
RB rotary shaped muffler
catalytic converter
the last engine and setup dynoed at 132whp and 121tq @ 6400rpm this is was 182whp and 134tq @7500rpm but even the old engine managed to run a 14.9 in the quarter mile at 81MPH I will be curious to see if this can dip into the 13's or a 14 flat this spring with the gearing improvements and mass reductions.
I wonder how much more you could get with a s5 intake setup
Got it Dyno'd yesterday at my friends shop needless to say I am happy with the numbers, and with a redline of 9000rpm its great to have that much over-rev capability.
megasquirt II
Rx8 e-shaft
S5 NA rotors
S4 t2 irons
S4 NA housings (w/ turbo inserts)
pineapple large streetport
Aluminum flywheel
RB underdrive main pulley
S4 NA intake system (no aux ports)
ported/polished throttle body
true dual RB header with the primaries extended 3'
Moroso spiral flow resonator
RB rotary shaped muffler
catalytic converter
the last engine and setup dynoed at 132whp and 121tq @ 6400rpm this is was 182whp and 134tq @7500rpm but even the old engine managed to run a 14.9 in the quarter mile at 81MPH I will be curious to see if this can dip into the 13's or a 14 flat this spring with the gearing improvements and mass reductions.
That's interesting your power peak was at 7500, It proves it's not the intake that's the restriction but the 6 port irons themselves. But roughly 10 horse less than a 4 port With slightly higher compression rotors. I'm gonna go ahead and pat myself on the back, great job on your build, what kind of a Afr's and timing are you running
I wonder how much more you could get with a s5 intake setup
0-10hp tops, but the peak could be shifted up to 7800-8000rpm I'd imagine because the runners are shorter. However with making the VDI system functional I could gain equal more power likely in the mid range too.
It was conservative half bridge 4 port with S4 NA rotating with a 48 down draft it made 200whp and 125tq but peak power was at 8200. The runners are only several inches long with the RB manifold maybe 12" at best. I think he was running 13:1 I was somewhere high 12s, I have no idea on timing I would have to check.
I disagree that its just the 6 port irons being the cause but the intake as well, I would be sure you are getting enough fuel up top because your peak power is pretty low and we have the same intake system and a similar exhaust you should have peak power closer to 7500-8000.
I drive around at 2700-3200 rpm all day so aux ports seem kind of pointless to me its giving me power where its not a huge difference and when racing I don't really drive the car below 4500rpm anyways but we don't have much drastic tq differences between two totally different port styles but the torque for us is made on the intake/exhaust manifolds.
0-10hp tops, but the peak could be shifted up to 7800-8000rpm I'd imagine because the runners are shorter. However with making the VDI system functional I could gain equal more power likely in the mid range too.
It was conservative half bridge 4 port with S4 NA rotating with a 48 down draft it made 200whp and 125tq but peak power was at 8200. The runners are only several inches long with the RB manifold maybe 12" at best. I think he was running 13:1 I was somewhere high 12s, I have no idea on timing I would have to check.
I disagree that its just the 6 port irons being the cause but the intake as well, I would be sure you are getting enough fuel up top because your peak power is pretty low and we have the same intake system and a similar exhaust you should have peak power closer to 7500-8000.
I drive around at 2700-3200 rpm all day so aux ports seem kind of pointless to me its giving me power where its not a huge difference and when racing I don't really drive the car below 4500rpm anyways but we don't have much drastic tq differences between two totally different port styles but the torque for us is made on the intake/exhaust manifolds.
im running 550cc injectors all around. And my afr's are under 13 all the way to redline., And if you notice that Dyno sheet is giving torque at the flywheel " so is that adding a % drivetrain loss to hp*5252/rpm"? my calculations are for torque at the wheels. Did you do the pull in 4th? I notice on a lot of bonzai's dynos if you look at the speed they were done in third gear which wouldn't be 1:1
02-12-17, 10:45 AM
