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Did some tweaking of timing today . Very ecouraged by the result!
I'm thinking it will be very close to the 20whp gain I had hoped for ..maybe a little more. Which would put it over 240whp. Fingers xd , dyno next week hopefully.
Put this up on the Purely site and someone correctly guessed where the port is ...so I may as well post it here too. The port runs through one of the through bolt holes ..................
Here is where the PPs are :
The through bolt where the arrow is , is gone . And the small PP exits through that hole and out the side of the housing . Hence no need for any welding or interfering with the water galleries...just a little machining and die grinding.
Here is where the PPs are :
The through bolt where the arrow is , is gone . And the small PP exits through that hole and out the side of the housing . Hence no need for any welding or interfering with the water galleries...just a little machining and die grinding.
well please excuse my pedantic, feminine tendencies, but how did you ever translate that into a “s-it ton of overlap”?
well please excuse my pedantic, feminine tendencies, but how did you ever translate that into a “s-it ton of overlap”?
You must have missed the the fact that it also has a bridgeport.
It would seem there is too much overlap and the extra flow I'm seeing is just air bypassing the combustion chamber . I think it may actually make more top end power with the PPs connected to the main exhaust, giving them some ........dare I say it .............backpressure.
Yeah man it was worth a try and like you said maybe the back pressure will be beneficial for this application?
Nonetheless I enjoyed this and now we know. It’s not just in theory anymore. Hopefully more to come Brett and thank you for the thread thus far.
I hope the quest has just begun!
Well .....it's a big fat 'F' I'm sorry to say .
Lost power all the way to 6000
very slight gain 6000-7000
loss 7000-9000
What a disappointment when you think you are on the track of something.
But my slogan is "You really learn when you are wrong". By that I should be f*****g Einstein by now, I assume I'm the exception that confirm the rule.
When you are right, its just a confirmation of what you already know. If we can find out why we're wrong, its a stepping stone, as jcbrx8 say.
From the hip, could it be an idea to move port to next bolt, to remove overlap? Far from sure(from the hip again) I'd would not expect high RPM gain, really.
Thanks for the support guys .... really appreciate it !
Some random observations:
More airflow everywhere in rpm range particularly 7000-9000
Less power below 6000
Slightly more power 6000-7000
Less power 7000-9000
Engine seems to be more prone to lose power on a hot day than a stock engine (dyno was done on 27C day)
Results in 2nd gear seem better than 3rd and way better than what I saw on the dyno (5th).
Seems to be some benefit in increasing timing in 5500-7000 range
I wonder if the bridgeport is the "problem". Great work though, and I will be surprised if your efforts don't result in some improvement after all the dust settles, and you and others consider why this didn't work as expected.
I wonder if the bridgeport is the "problem". Great work though, and I will be surprised if your efforts don't result in some improvement after all the dust settles, and you and others consider why this didn't work as expected.
Thanks Kevin . Yeah , I originally wasn't going to put the bridgeport in there ...but couldn't see how the pp would actually do anything beneficial without it ...so decided it had to have one.
I'm trying to make sense of the dynamics ...it's certainly a complicated thing to get right.
I feel that adding backpressure to the pp will reduce the shortcircuiting going on ATM ...but doubt it will increase power .... something to try anyway.
I might disagree on the learning part. The premise from the start was not wanting any input out of fear/avoidance of perceived criticism, but it also eliminates knowledgable people with sound intentions from pointing out and guiding you away from obvious mistakes.
The bridgeport overlap reply pretty much cements my previous position that the basic understanding of the principles at work are fundamentally misunderstood and not being applied properly. I’m not here to argue or cause strife though. So I’m going to back out for a while again and pop in at some point in the future just to see where your at.
I might disagree on the learning part. The premise from the start was not wanting any input out of fear/avoidance of perceived criticism, but it also eliminates knowledgable people with sound intentions from pointing out and guiding you away from obvious mistakes.
The bridgeport overlap reply pretty much cements my previous position that the basic understanding of the principles at work are fundamentally misunderstood and not being applied properly. I’m not here to argue or cause strife though. So I’m going to back out for a while again and pop in at some point in the future just to see where your at.
If you knew what you were talking about ...you would back that up with some constructive criticism .... I have my doubts though because you often take this "I know everything and you don't" approach without ever delivering anything of substance to back up your position.
So I got the pps routed back into the main exhaust system :
Sounds really nice now ...still a bit loud for me but not over the top.
Performance the same as before ...no better ,no worse .
I suspect the car is quicker than the dyno is suggesting so think i'll organise a roll race against another strong rx8 ....just as another way to test it.
So, if I understand correctly...this PP set-up essentially enhances the engine's ability to evacuate exhaust. Obviously a enhancement to any engine...but most useful when the engine has the capability to leverage the increased exhaust *flow potential*.......on the intake side. It seems to me that a NA Renesis is only marginally able to do so...and as testing indicated largely in the upper rpm range. But the PPs implemented on a FI'd Renesis c/b another story...: providing the capability to more effectively evacuate a larger volume of exhaust....somewhat compensating for the drawbacks of the Renesis sideport exhaust design..., and resulting in raising the engine's *flow capacity* ceiling you discuss in the "450 wHP Renesis Engine - Why it will Never Happen" thread.
Great to see you still exploring for more power!
