Conclusive B2B Dyno Tests: FD UIM & FC UIM.
05-25-07, 12:13 AM
#26
You say higher compression than before, how much higher? 9.0:, 9.4:1, 9.7:1? If you were running only 14.0 psi, and hitting 315rwtq, that seems like good torque for the psi. However, your peak torque occurs very early, and falls off early too. Most streetport engines I've built/ seen hold peak torque to at least 6500 rpms. Who did the porting? Are you 100% sure its ported? The graph looks more like a stock port engine. Give us all the details of the setup, and maybe somebody will shed more light on the problem.
Mate can I just say thank you for post some proven technical date, congrats for sharing it with us.
05-25-07, 12:59 AM
#28
Lives on the Forum
You say higher compression than before, how much higher? 9.0:, 9.4:1, 9.7:1? If you were running only 14.0 psi, and hitting 315rwtq, that seems like good torque for the psi. However, your peak torque occurs very early, and falls off early too. Most streetport engines I've built/ seen hold peak torque to at least 6500 rpms. Who did the porting? Are you 100% sure its ported? The graph looks more like a stock port engine. Give us all the details of the setup, and maybe somebody will shed more light on the problem.
They don't look like DynoJet graphs.
It's typically of a DD graph to look like that.
-Ted
05-25-07, 10:23 AM
#31
Full Member
Thread Starter
Join Date: Oct 2005
Location: England
Posts: 157
Likes: 0
Received 0 Likes
on
0 Posts
The FC manifold was a series 5
Not sure about the compression but i'm using series 5 rotors in this engine and i used series 4 in my old engine
The engine had done 500 miles after rebuild which i why i only went to 1 bar. I'm going to the Nurburg Ring in 2 weeks, when i get back it should have nearly 2000 miles i will swap the i/c and go back, i will let you know how i get on
FYI, i checked the pressure drop on my i/c and i had 3 - 4 psi more on the turbo side that at the plenum. too much>???????
The engine is most definately ported, i built it, i will attach some pictures of the ports.
Here is the i/c i use, XS power
Ported LIM which the old engine didnt have as the port runners were stock.
2ndaries
exhaust
the primaries are also huge with much bugger runners
Not sure about the compression but i'm using series 5 rotors in this engine and i used series 4 in my old engine
The engine had done 500 miles after rebuild which i why i only went to 1 bar. I'm going to the Nurburg Ring in 2 weeks, when i get back it should have nearly 2000 miles i will swap the i/c and go back, i will let you know how i get on
FYI, i checked the pressure drop on my i/c and i had 3 - 4 psi more on the turbo side that at the plenum. too much>???????
The engine is most definately ported, i built it, i will attach some pictures of the ports.
Here is the i/c i use, XS power
Ported LIM which the old engine didnt have as the port runners were stock.
2ndaries
exhaust
the primaries are also huge with much bugger runners
05-25-07, 10:44 AM
#32
Full Member
Thread Starter
Join Date: Oct 2005
Location: England
Posts: 157
Likes: 0
Received 0 Likes
on
0 Posts
would a bigger TB only make a difference if you hit the max on the current one, i mean i have seen over 500 bhp at the wheels on the stock FD LIM/UIM, TB and elbow, so if i only wanted 400 atw's the existing one should be ok,
does it work like that?
05-25-07, 12:17 PM
#34
Full Member
Thread Starter
Join Date: Oct 2005
Location: England
Posts: 157
Likes: 0
Received 0 Likes
on
0 Posts
but what if your set up can already outflow another componant in your set up. For instance, if you took a completely stock set up, FD or FC, and ported and polished the throttle body as your only Modification, would you make any more power???
05-25-07, 12:36 PM
#35
i think all areas of the motor must be considered. If you increase the exhaust, you should increase the intake. Otherwise your motor will choke on the intake and over heat on the exhaust.
Ideally, you'd do this all together, but that takes $$.
So increase your ports, get the motor together, then find a nice tubular exhaust mani w/ single turbo, eventually, go FD/Cosmo UIM (or even better, custom intake with ITB).
Ideally, you'd do this all together, but that takes $$.
So increase your ports, get the motor together, then find a nice tubular exhaust mani w/ single turbo, eventually, go FD/Cosmo UIM (or even better, custom intake with ITB).
05-25-07, 01:47 PM
#36
However, usually longer intake manifold runners lend to better low end air flow, and shorter runners are better for top end. That is what I have learned in the past, and the dyno results seem to suggest that, since it seemed to improve your numbers in a lower rpm range.
12-23-07, 12:49 AM
#41
Powered By Trochoids
Join Date: Oct 2004
Location: Philly | PA
Posts: 1,457
Likes: 0
Received 0 Likes
on
0 Posts
12-23-07, 04:46 AM
#42
Umm, there is a dyno graph on the 1st page that completely negates what you just said....
Back to back dyno runs with everything else the same reveals that at 1 bar and 350 bhp the FC UIM is a couple of BHP behind if that!
There is only a few hp LOSS in power with the FD UIM in 3 sections from the beginning of the pull to 3,500rpm.
Am I the only one reading the chart wrong or the only one that thinks more than 20hp/ torque is a bit much to expect from swapping just STOCK upper intake manifolds?
10-08-09, 03:16 PM
#44
I've been revisiting this issue (made a thread in the single turbo forum).
What I'm most concerned about in this dyno sheet in terms of how "scientific" it may be is that there is no log of rpm vs boost. Changing the UIM could have changed the boost curve without careful adjustment of the EBC. Maybe with the same boost control adjustments, boost peaked earlier with the FD UIM and then fell off, which could exaggerate changes in the powerband. And eyeballing an in-cabin boost gauge doesn't tell you much about the boost curve at a specific rpm, the analog ones usually have a damper to reduce oscillations and the digital ones read too slow.
Even a change of 1-1.5 psi in some part of the rpm range can make the whole "scientific back-to-back dyno run" premise murky. It's like when people say that an exhaust system on a T2 gives you 50-60whp but part of that change in power/powerband comes from a different boost curve.
Also, we know that relatively large plenums (s5 UIM, 13B-RE) are better for topend but not so much for mid range. Honda acknowledged this by designing a variable volume intake plenum for the NSX:
What I'm most concerned about in this dyno sheet in terms of how "scientific" it may be is that there is no log of rpm vs boost. Changing the UIM could have changed the boost curve without careful adjustment of the EBC. Maybe with the same boost control adjustments, boost peaked earlier with the FD UIM and then fell off, which could exaggerate changes in the powerband. And eyeballing an in-cabin boost gauge doesn't tell you much about the boost curve at a specific rpm, the analog ones usually have a damper to reduce oscillations and the digital ones read too slow.
Even a change of 1-1.5 psi in some part of the rpm range can make the whole "scientific back-to-back dyno run" premise murky. It's like when people say that an exhaust system on a T2 gives you 50-60whp but part of that change in power/powerband comes from a different boost curve.
Also, we know that relatively large plenums (s5 UIM, 13B-RE) are better for topend but not so much for mid range. Honda acknowledged this by designing a variable volume intake plenum for the NSX:
10-10-09, 12:17 AM
#45
I believe the power difference between the FC and FD intakes definitely has to do with 1 or 2 psi more boost as you indicate, but it isn't from the turbo.
It is the pressure increase at the port at those rpms from the dynamic effect pressure waves that the FD UIM is designed to increase with its opposed facing 2ndary port runners and small plenum.
With the very quick spooling sequential turbos on the FD Mazda was free to redesign and shrink the plenum in an effort to maximize dynamic effect supercharging without sacrificing too much low end power.
This dynamic supercharging is more efficient than a turbo compressor so you gain more power per psi boost.
The S4 NA RX-7 made nearly 2psi boost at the port stock and required a plenum for low end power/driveability.
When I ran my set up with the S5 TII LIM and 3rd gen UIM naturally aspirated I originally had the MAP sensor line off of one of the nipples on the runners and data logs would show several psi at WOT from the dynamic effect waves.
When I put the turbo on I switched the MAP line to the plenum to help damp the boost fluctuations.
It is the pressure increase at the port at those rpms from the dynamic effect pressure waves that the FD UIM is designed to increase with its opposed facing 2ndary port runners and small plenum.
With the very quick spooling sequential turbos on the FD Mazda was free to redesign and shrink the plenum in an effort to maximize dynamic effect supercharging without sacrificing too much low end power.
This dynamic supercharging is more efficient than a turbo compressor so you gain more power per psi boost.
The S4 NA RX-7 made nearly 2psi boost at the port stock and required a plenum for low end power/driveability.
When I ran my set up with the S5 TII LIM and 3rd gen UIM naturally aspirated I originally had the MAP sensor line off of one of the nipples on the runners and data logs would show several psi at WOT from the dynamic effect waves.
When I put the turbo on I switched the MAP line to the plenum to help damp the boost fluctuations.
10-10-09, 10:22 PM
#46
Senior Member
iTrader: (4)
Join Date: Jun 2006
Location: Miami, Florida
Posts: 618
Likes: 0
Received 0 Likes
on
0 Posts
I would love to see more info and debate on this topic as i am considering this kind of setup on my car... seems like there is alot of theorizing but not alot of experience and dyno proof lol.. I hate when that happens 
10-13-09, 07:07 AM
#47
U.S. Army Recon 93-04
Join Date: Feb 2007
Location: Seminole,Fl
Posts: 428
Likes: 0
Received 0 Likes
on
0 Posts
The S4 NA RX-7 made nearly 2psi boost at the port stock and required a plenum for low end power/driveability.
When I ran my set up with the S5 TII LIM and 3rd gen UIM naturally aspirated I originally had the MAP sensor line off of one of the nipples on the runners and data logs would show several psi at WOT from the dynamic effect waves.
I too have seen this happen. I have seen spikes up too 3 psi, on my S4 N/A. I thought I was crazy!!!
Thank you
10-02-10, 07:52 PM
#49
NIKOCRX
Join Date: Dec 2005
Location: greece
Posts: 616
Likes: 0
Received 0 Likes
on
0 Posts
As i see too many people did the fd uim swap...can somebody inform me the steps to do it?i know that you need,the fd uim,adapter,flanges etc.my question is what did you do with the oil filler neck?can i use one from fd?and what did you do with the tps?how did you connect the wires?is there any diagram?i'm going to use apexi power fc...thank you!
