Calling Rx-8 equal length header owner
#1
Calling Rx-8 equal length header owner
Recenly purchese this old school Feed equal length header and restore it cermanic coat with Cerakote~
From Japanese user feeback, they said equal length sound different then normal unequal length header~
Although this is true equal length header
But is not popular in Japan, due to the design is too close to cabin ~
From Japanese user feeback, they said equal length sound different then normal unequal length header~
Although this is true equal length header
But is not popular in Japan, due to the design is too close to cabin ~
Last edited by Diyman25; 09-29-2019 at 05:36 AM.
#2
Equal length and unequal length will always sound different on any car. Could be wrong since I've never compared or heard equal length/unequal length but every car that has an unequal length header if you put an equal length the sound different so I'm 99% sure there will be a different's
#3
Hard to say that 'equal length' Renesis headers live up to their name as the middle port is shared by both rotors and negates the benefit of isolated and timed port pulses. The OE design and design of this header can even promote reversion from one rotor to the other instead of scavenging. Sound-wise you may hear a change in tone but I'm unsure it'd be far off from any other Renesis tubular manifold, since they all retain the merged element of the middle iron exhaust.
I'm curious how well the ceramic works at heat control -- I imagine that will serve as a notable benefit over an un-coated header or OE manifold.
I'm curious how well the ceramic works at heat control -- I imagine that will serve as a notable benefit over an un-coated header or OE manifold.
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thebubbadog (09-27-2019)
#4
Not really a good design unless you prefer equally excessive backpressure ... primaries are too small. That’s why they make the other header with larger 50mm pipes. But I would recommend the Leg Sport 50mm manifold over it. All these OE style manifolds are going to limit power though because OE size cat-back flange opening is too small and the collector piping angle into it is too sharp.
#5
Originally Posted by TeamRX8
Not really a good design unless you prefer equally excessive backpressure ... primaries are too small. That’s why they make the other header with larger 50mm pipes. But I would recommend the Leg Sport 50mm manifold over it. All these OE style manifolds are going to limit power though because OE size cat-back flange opening is too small and the collector piping angle into it is too sharp.
Here are leg sport design with 50mm primaries
And different then before is merge deign~
Well I been flow ur header tread for while , and I know ur opinion is strong and do make some sense~
So I am mainly focus on sound effect on egual length header !!!
I will take it to dyno again before I start mess with verssa tune ~
Last edited by Diyman25; 09-29-2019 at 12:23 AM.
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Federighi (10-07-2019)
#7
Originally Posted by TeamRX8
Yeah, I cut it apart to make a race header
When I see ur other thread, I can tell by the header u chop off is not from USA from the bend of it ~
But hard for me fo imagine u bought a new header and chop it !!!
One question , with all this work done
Why still keep twin exit ?
#8
Because it’s badass! Lol.
Actually because it’s easier to put two 2.5”/63mm pipes through the plastic bumper exhaust shrouds with out melting them than a single 3” pipe through one shroud. I did that a long time ago back in 2006. So a lot of things I do now from the experience of lessons learned in the past. I also have some things going on there for exhaust noise that are not obvious in the pictures.
I also made a long tube version that I can swap pipes with, but I think it was a waste of time and money to make. It won’t add any power imo, but only adds weight and possible more freedom for heat expansion.
I plan to run the short tube configuration from the first pictures instead.
I would rather make from scratch, but even though it cost more this way it was easier for me to have those pipes and then cut and add to them. I used to have full fabrication shop before, but not now. However, now that I have this it can be a pattern for duplicating in the future. I want to make a header with 22 Ga Inconel pipes some day. It would be a little lighter and stronger for high temperature than Type 321 18/20 Ga. pipes, but is kind of expensive. Like Formula 1 exhaust header
So the whole exhaust system in the previous picture; from engine exhaust port to tailpipe tip is only 15 kg total! My twin exit weighs less than most people single. It is only 20 Ga Type 321 pipe (0.032in/0.8mm thick wall).
.
Actually because it’s easier to put two 2.5”/63mm pipes through the plastic bumper exhaust shrouds with out melting them than a single 3” pipe through one shroud. I did that a long time ago back in 2006. So a lot of things I do now from the experience of lessons learned in the past. I also have some things going on there for exhaust noise that are not obvious in the pictures.
I also made a long tube version that I can swap pipes with, but I think it was a waste of time and money to make. It won’t add any power imo, but only adds weight and possible more freedom for heat expansion.
I plan to run the short tube configuration from the first pictures instead.
I would rather make from scratch, but even though it cost more this way it was easier for me to have those pipes and then cut and add to them. I used to have full fabrication shop before, but not now. However, now that I have this it can be a pattern for duplicating in the future. I want to make a header with 22 Ga Inconel pipes some day. It would be a little lighter and stronger for high temperature than Type 321 18/20 Ga. pipes, but is kind of expensive. Like Formula 1 exhaust header
So the whole exhaust system in the previous picture; from engine exhaust port to tailpipe tip is only 15 kg total! My twin exit weighs less than most people single. It is only 20 Ga Type 321 pipe (0.032in/0.8mm thick wall).
.
Last edited by TeamRX8; 09-29-2019 at 03:29 AM.
#9
My speed source 3rorot Rx8 GT header from my other,project
Is also made from inconal
Is nice material but just way too expensive for not professional used
I think is better off with good steel but with good coating
Love to see a real race header for LHD car
Most of jdm header need to compromise on RHD design
Btw
How quite is ur set up with only one muffler
That muffler look unique too "Burns" ?
Is also made from inconal
Is nice material but just way too expensive for not professional used
I think is better off with good steel but with good coating
Love to see a real race header for LHD car
Most of jdm header need to compromise on RHD design
Btw
How quite is ur set up with only one muffler
That muffler look unique too "Burns" ?
Last edited by Diyman25; 09-29-2019 at 12:23 PM.
#10
Coating is a mistake. I was told not to do it and I didn’t listen. It is worse for thin material to have coating than without. My previous manifold was T321, but I built this one to replace it because material became brittle and was always cracking. Every year I had to fix, but the more you fix the worse it becomes. Steel is no good unless you make very, very thick, then is too heavy. More than factory manifold. You can actually get good power from factory manifold if you just put bigger outlet and flange onto the end of it just past last exhaust port. Inconel or duplex stainless is best and will last a long time, but Speedsource used too small primary pipes and used to have reducer cone with to sharp collector on end. I think later they put a longer angle connector, but reducer cone is no good without overlap exhaust timing. I never bought one because it only has 1.75”/44mm pipes.
#11
Have those eBay header lay around
Decide to take some time to measure it compare to My feed
Here are some spec
Length of primary
Feed
59cm
63cm
63.8cm
eBay
Length of primary
49cm
48cm
35cm
As weight different
Feed is close to stock
And by weight of eBay one
I know it will crack by weight of it
And flang design is poor and not line up
After few hr of rethink I might not get a best way measurement
On feed, header....I use peace wire to measure it
I do the best I can to follow the shape of primary tube
But I should run peace of wire inside of primary
Decide to take some time to measure it compare to My feed
Here are some spec
Length of primary
Feed
59cm
63cm
63.8cm
eBay
Length of primary
49cm
48cm
35cm
As weight different
Feed is close to stock
And by weight of eBay one
I know it will crack by weight of it
And flang design is poor and not line up
After few hr of rethink I might not get a best way measurement
On feed, header....I use peace wire to measure it
I do the best I can to follow the shape of primary tube
But I should run peace of wire inside of primary
Last edited by Diyman25; 09-30-2019 at 08:11 AM.
#13
Originally Posted by TeamRX8
The true pipe measurement is the centerline, very hard to do accurately.
but again, not very relevant on the Renesis due to the lack of overlap port timing.
.
but again, not very relevant on the Renesis due to the lack of overlap port timing.
.
But is close enought to get forum reader a idea
Well
There is still firing order on Rx8... and with equal length it sure reduce back pressure too
Mabe not that much
Last edited by Diyman25; 09-30-2019 at 10:42 PM.
#15
The last time I looked at it the flange interface to the pipes isn’t very good.
And no, if you want to reduce back pressure on the Renesis the answer is piping flow. Equal length is for pulse tuning, which again doesn’t exist without overlap timing.
And no, if you want to reduce back pressure on the Renesis the answer is piping flow. Equal length is for pulse tuning, which again doesn’t exist without overlap timing.
#16
Shop say is bitching to install the header !!!
Imagine this is RHD car , no wonder they disconnected this design....
Update engine mount (hardrace) at same time too
Imagine this is RHD car , no wonder they disconnected this design....
Update engine mount (hardrace) at same time too
Last edited by Diyman25; 10-03-2019 at 05:58 AM.
#19
Is the 4.777 matched to an S1 trans? How much of an MPG hit did you take with it?
I've been looking for at pairing an S2 trans with a 5.125 ring/pinion set, which should gear similar to an S1 trans with a 4.777.
I've been looking for at pairing an S2 trans with a 5.125 ring/pinion set, which should gear similar to an S1 trans with a 4.777.
#20
Originally Posted by furansu
Is the 4.777 matched to an S1 trans? How much of an MPG hit did you take with it?
I've been looking for at pairing an S2 trans with a 5.125 ring/pinion set, which should gear similar to an S1 trans with a 4.777.
I've been looking for at pairing an S2 trans with a 5.125 ring/pinion set, which should gear similar to an S1 trans with a 4.777.
Beside taller the third and very tall sixth
If I remember correctly
As y can see the clip it seen to match well
But on cruise I was cruising at 4000rpm with
115km, since my pcm still stock, so my MPG seem to be very bad compare to 4.4.....
On 5.1 are u plan to run cooler ?
#21
Yea -- pretty damn similar, though the beefiness of the transmission between S1 and S2 is welcomed.
Gears
S1 1st - 3.76
S2 1st - 3.81
S1 2nd - 2.27
S2 2nd - 2.26
S1 3rd - 1.65
S2 3rd - 1.53
S1 4th - 1.19
S2 4th - 1.17
S1 5th - 1.00
S2 5th - 1.00
S1 6th - 0.84
S2 6th - 0.78
Final Drive
S1 4.30
S2 4.77
I think with a 5.1 you can squeek by on the street without a cooler, but for track use it will be required. I'd likely run a small unit just to be safe.
Gears
S1 1st - 3.76
S2 1st - 3.81
S1 2nd - 2.27
S2 2nd - 2.26
S1 3rd - 1.65
S2 3rd - 1.53
S1 4th - 1.19
S2 4th - 1.17
S1 5th - 1.00
S2 5th - 1.00
S1 6th - 0.84
S2 6th - 0.78
Final Drive
S1 4.30
S2 4.77
I think with a 5.1 you can squeek by on the street without a cooler, but for track use it will be required. I'd likely run a small unit just to be safe.
#22
it’s not beefy, just easier to rebuild. If you need to use 2nd and 3rd like in autox then the S2 3rd gear ratio is a big fail because it drops you below the APV opening.
overall the S1 ratios are best for any R&P choice
S1 Trans - Redline Rev Drop - 1st to 2nd - 5,434 / 2nd to 3rd - 6,542 / 3rd to 4th - 6,491 / 4th to 5th - 7,563 / 5th to 6th - 7,587
S2 Trans - Redline Rev Drop - 1st to 2nd - 5,349 / 2nd to 3rd - 6,133 / 3rd to 4th - 6,879 / 4th to 5th - 7,647 / 5th to 6th - 7,470
overall the S1 ratios are best for any R&P choice
S1 Trans - Redline Rev Drop - 1st to 2nd - 5,434 / 2nd to 3rd - 6,542 / 3rd to 4th - 6,491 / 4th to 5th - 7,563 / 5th to 6th - 7,587
S2 Trans - Redline Rev Drop - 1st to 2nd - 5,349 / 2nd to 3rd - 6,133 / 3rd to 4th - 6,879 / 4th to 5th - 7,647 / 5th to 6th - 7,470
Last edited by TeamRX8; 10-11-2019 at 04:13 PM.
#23
#25
yeah, there’s some wrong info in there so be careful