Turbo Efficiency Range for RX-8
#352
rev it up
20 PSI will not work on the renesis. Early power is nice however the drop after peak is alarming.
Motor like this would be good for drags and street but a pain at the track.
Motor like this would be good for drags and street but a pain at the track.
#354
Registered
iTrader: (3)
20psi has not worked on a renesis yet, that doesn't mean it's impossible. I agree with the idea of having a higher pressure down low and intentionally dropping off into the higher RPMs. It gives you a better area under the curve, and I believe the engine can support it better than pushing high boost at higher rpms.
#355
No respecter of malarkey
iTrader: (25)
It's well documented that I recommend a 13B swap for turbo. At a minimum, a turbo Renesis should have rotors machined for deeper 13B apex seals. OD was one of the few that listened. Otherwise, who here has run E85 or 110+ octane with a solid build capable of running there?
Brettus, you crack me up. The undersize turbo is on your car
Unless you watched the FD3 video several posts back then you missed what the real potential was once they put a fresh built motor in. The fall-off dyno was from several years ago with an old, tired original factory FD motor.
Here's the FC with the 7670 above doing a 4th gear acceleration from 50 - 130 mph (if I read the speedo correctly)
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Brettus, you crack me up. The undersize turbo is on your car
Unless you watched the FD3 video several posts back then you missed what the real potential was once they put a fresh built motor in. The fall-off dyno was from several years ago with an old, tired original factory FD motor.
Here's the FC with the 7670 above doing a 4th gear acceleration from 50 - 130 mph (if I read the speedo correctly)
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Last edited by TeamRX8; 01-25-2015 at 12:22 AM.
#356
Boosted Kiwi
iTrader: (2)
Yes it is(turbine wise) .... yet the compressor flows more than the 7670 one...............
Unless you watched the FD3 video several posts back then you missed what the real potential was once they put a fresh built motor in. The fall-off dyno was from several years ago with an old, tired original factory FD motor.
Here's the FC with the 7670 above doing a 4th gear acceleration from 50 - 130 mph (if I read the speedo correctly)
Here's the FC with the 7670 above doing a 4th gear acceleration from 50 - 130 mph (if I read the speedo correctly)
Aside from all that ......... no it wouldn't fit on a greddy manifold
Last edited by Brettus; 01-25-2015 at 02:58 AM.
#357
No respecter of malarkey
iTrader: (25)
Sorry that I forgot about you making the apex seal conversion and some other aspects of your current build. You've done a great job BTW. But as you finally figured out, a compressor only actually chugs out what the turbine is capable of driving it to. The number of blades is a minor consideration. It's the actual sizing ratio that matters most. Flow maps also don't tell the whole story which all these latest EFR builds are demonstrating. Not only are the EFR compressor/turbines combination well matched for rotary builds, they provide low end response and boost well beyond past expectations/experience. I understand why you see it that way.
Both those setups are cranking out lowend torque like mad. You're at around 260 lb-ft at 5500 or so? You seem to be undervaluing the real power being demonstrated; area under the curve. There's no choke point to drive past. When an engine makes 300+ lb-ft @ 3200 rpm what you do is .... shift gears.
The show-us comment is a valid arguement. I'd love to, but it's not the direction for me yet. Tried to work together with a few people to demonstrate a few things, but nothing panned out yet. Not the same thing either since everyone always has their own ideas ...
Both those setups are cranking out lowend torque like mad. You're at around 260 lb-ft at 5500 or so? You seem to be undervaluing the real power being demonstrated; area under the curve. There's no choke point to drive past. When an engine makes 300+ lb-ft @ 3200 rpm what you do is .... shift gears.
The show-us comment is a valid arguement. I'd love to, but it's not the direction for me yet. Tried to work together with a few people to demonstrate a few things, but nothing panned out yet. Not the same thing either since everyone always has their own ideas ...
Last edited by TeamRX8; 01-25-2015 at 08:55 AM.
#358
Boosted Kiwi
iTrader: (2)
The only way the 7670 could make that much power without overdriving the turbo would be if they were somehow able to defy the laws of physics that govern the 13B rotary engine . I accept that it makes the power ............. but way over the choke line for the turbo and thus at very high intake temps. How or even if they are dealing with that you didn't go into.
You also posted an amazing dyno for the 8374 . Now that turbo IS big enough to flow enough for a 13B in the 2.0PR and above range .
And yes I do fully appreciate the torque being made by those combinations .
#359
No respecter of malarkey
iTrader: (25)
Your concept of physics is the issue. His Pr down low is closer to 2.75 tapering off to 2.36. The general rule of rotary thumb is 10 lb/min for every 100 hp so your earlier 60 lb/min @ 2.1 Pr Renesis claim is a bit misguided IMO. Getting that kind if efficiency at that rate us a challenge unto itself let alone not blowing the engine.
There are other realities too. He had a low mount BNR Stage4. The 7670 was an easy bolt on. The 8374 moves up to a larger compressor. the basis of this thread was low mount too. 7670 likely can't fit, 8374 no way. This is why I posted up the 7163 instead. The reality is your end goal vs the results. We are only discussing the 7670 because you dismissed it based on perception. He wanted low end response and power for short sprints and autox, not extended high rpm max power.
There are other realities too. He had a low mount BNR Stage4. The 7670 was an easy bolt on. The 8374 moves up to a larger compressor. the basis of this thread was low mount too. 7670 likely can't fit, 8374 no way. This is why I posted up the 7163 instead. The reality is your end goal vs the results. We are only discussing the 7670 because you dismissed it based on perception. He wanted low end response and power for short sprints and autox, not extended high rpm max power.
This vid shows response in 5th, 4th, 3rd and back to 5th.
I don't know how it compares to 8374, but it is better than my 60-1 was.
https://www.youtube.com/watch?v=XpkJ...ature=youtu.be
I don't know how it compares to 8374, but it is better than my 60-1 was.
https://www.youtube.com/watch?v=XpkJ...ature=youtu.be
Last edited by TeamRX8; 01-26-2015 at 06:02 AM.
#362
BECAUSE RACECAR
iTrader: (10)
Also I thought EFR dimensions were published. Try here and select Performance Turbos or Google it. I know I have a dimensions sheet for my 9180 that I found online.
Performance Turbos | BorgWarner Turbo Systems
Performance Turbos | BorgWarner Turbo Systems
#364
SARX Legend
iTrader: (46)
Well I will measure the brand new BNR 60-1 I have at the house but I don't think the 7163 will fit.
A guy selling one (single scroll, T25) measured and gave me these measurements:
"11.25 inches overall length. about 7.75 inches wide."
A guy selling one (single scroll, T25) measured and gave me these measurements:
"11.25 inches overall length. about 7.75 inches wide."
#366
SARX Legend
iTrader: (46)
Yeah it doesn't give me the width from wastegate actuator to the other side of the compressor housing though, that is the one I needed most. And according to that .pdf over length is 10.1" so an inch off of what the guy who is selling them gave me. I hate people.
Last edited by 9krpmrx8; 01-26-2015 at 10:45 AM.
#368
SARX Legend
iTrader: (46)
I just got off the phone with Full Race, they measured it and said 9.25" from the outer edge of the wastegate actuator to the other side of the compressor housing. So, who knows, the guy selling it is going to send me pictures with the measurements, he says his measurements are accurate. BTW, Full Race has some great prices.
#369
Boosted Kiwi
iTrader: (2)
Your concept of physics is the issue. His Pr down low is closer to 2.75 tapering off to 2.36. The general rule of rotary thumb is 10 lb/min for every 100 hp so your earlier 60 lb/min @ 2.1 Pr Renesis claim is a bit misguided IMO. Getting that kind if efficiency at that rate us a challenge unto itself let alone not blowing the engine.
There are other realities too. He had a low mount BNR Stage4. The 7670 was an easy bolt on. The 8374 moves up to a larger compressor. the basis of this thread was low mount too. 7670 likely can't fit, 8374 no way. This is why I posted up the 7163 instead. The reality is your end goal vs the results. We are only discussing the 7670 because you dismissed it based on perception. He wanted low end response and power for short sprints and autox, not extended high rpm max power.
There are other realities too. He had a low mount BNR Stage4. The 7670 was an easy bolt on. The 8374 moves up to a larger compressor. the basis of this thread was low mount too. 7670 likely can't fit, 8374 no way. This is why I posted up the 7163 instead. The reality is your end goal vs the results. We are only discussing the 7670 because you dismissed it based on perception. He wanted low end response and power for short sprints and autox, not extended high rpm max power.
And that 10lb/min x 0.7 for a rotaryrule of thumb .......... is for flywheel hp not wheel hp . So if you do the maths ; to make 400WHP you need approx. 60lb/min . Put that on the 7670 flow map and then tell me it's running efficiently .........
I want to thrash this out with you because I think by suggesting that turbo would be good for the Renesis you are heading us down the same path we have been on for years . IE fitting turbos that are too small. I think (because of the high compression ratio) for the renesis we need even more efficient turbos ( bigger) than what the older engines are running .
And sure ... that 7670 would make great torque and make the car a rocket out of the blocks . But to run it efficiently at high rpm (6500 on up) you would need an EBC that was capable of reducing duty cycle as rpm increased.
Last edited by Brettus; 01-26-2015 at 01:26 PM.
#370
BECAUSE RACECAR
iTrader: (10)
I just got off the phone with Full Race, they measured it and said 9.25" from the outer edge of the wastegate actuator to the other side of the compressor housing. So, who knows, the guy selling it is going to send me pictures with the measurements, he says his measurements are accurate. BTW, Full Race has some great prices.
Their manifolds are definitely badass though and priced reasonably for what you're getting.
#374
No respecter of malarkey
iTrader: (25)
The owner doesn't want or need to run out full rpm because he can shift early without penalty. It's easy to do an area under the curve comparison given a specific rpm range to see which is actually superior; low rpm with short-shift or high rpm revved out fully. It's also not fully tuned out there yet. We'll keep tabs to see how it develops.
Again, I don't disagree that an 8374 is more efficient for mid-top power. We don't need to keep rehashing it because that will never fit in the low-mount RX8 position without re-fabricating the front RH frame rail & subframe.
I was wrong to quote 100 hp per 10 lb/min mass. It's 7 hp per 10 lb/min. I actually repeated an old posting mistake made by RotaryGod . If God can make a mistake, I won't run away and hide in shame
TeamStubbedmytoe
Again, I don't disagree that an 8374 is more efficient for mid-top power. We don't need to keep rehashing it because that will never fit in the low-mount RX8 position without re-fabricating the front RH frame rail & subframe.
I was wrong to quote 100 hp per 10 lb/min mass. It's 7 hp per 10 lb/min. I actually repeated an old posting mistake made by RotaryGod . If God can make a mistake, I won't run away and hide in shame
TeamStubbedmytoe
#375
Boosted Kiwi
iTrader: (2)
The owner doesn't want or need to run out full rpm because he can shift early without penalty. It's easy to do an area under the curve comparison given a specific rpm range to see which is actually superior; low rpm with short-shift or high rpm revved out fully. It's also not fully tuned out there yet. We'll keep tabs to see how it develops.
Again, I don't disagree that an 8374 is more efficient for mid-top power. We don't need to keep rehashing it because that will never fit in the low-mount RX8 position without re-fabricating the front RH frame rail & subframe.
I was wrong to quote 100 hp per 10 lb/min mass. It's 7 hp per 10 lb/min. I actually repeated an old posting mistake made by RotaryGod . If God can make a mistake, I won't run away and hide in shame
TeamStubbedmytoe
Again, I don't disagree that an 8374 is more efficient for mid-top power. We don't need to keep rehashing it because that will never fit in the low-mount RX8 position without re-fabricating the front RH frame rail & subframe.
I was wrong to quote 100 hp per 10 lb/min mass. It's 7 hp per 10 lb/min. I actually repeated an old posting mistake made by RotaryGod . If God can make a mistake, I won't run away and hide in shame
TeamStubbedmytoe
I'm leaning towards the Precision 6266 myself . Not because it's the best turbo .... but because it will actually fit in a low mount position and is big enough to run at 2.0PR efficiently , right out to the redline .
Also toyed with the gtx3076 but even that is marginal at 2.0PR ...... the problem is no-one designs turbos specifically for rotaries .We need high flow at low PR. We could use smaller turbos if they just played around with the compressor trims to give us the ideal flow map.
Last edited by Brettus; 01-26-2015 at 03:53 PM.