New BW EFR Turbo Thread
Newbie
Joined: Sep 2011
Posts: 6
Likes: 0
From: Bham, WA
Awesome thanks for the info, I'm sure Ernie will chime in with some info. I'm just trying to figure out if I can hit 25psi by 3500 on my big 2.7 on pump gas, I will be using the smaller TS housing with the internal gate so the smaller a/r may help some as well. Also are you running just a 3" exhaust or something bigger?
Only on e85. It might get a 100 tune( in the event I don't bring enough to the track) as well.. But it won't see pump.
Audi Mike! How ya been?
I think the 7670 will hit your target pretty easily. I would get the biggest turbine possible for your 2.7L. Scratch that... i think the 7064 with the small open t3 will work great
haha. The Evo can n3v4r lose!
I think the 7670 will hit your target pretty easily. I would get the biggest turbine possible for your 2.7L. Scratch that... i think the 7064 with the small open t3 will work great
haha. The Evo can n3v4r lose!
Newbie
Joined: Sep 2011
Posts: 6
Likes: 0
From: Bham, WA
Don't worry though I won't be able to beat the evo anytime soon, I can't really go over 500wtq on on the stock bottom end so it will stay around or below 25psi until I build a motor. Then I'm coming for ya, E85 and the works.
Also we had the formula car down at the Kirkland Concours today and Marshall stopped by and chatted for awhile, he was telling me about how he got his flex fuel sensor all hooked up to the vipec on the supra, that bastard.
Originally Posted by chetrickerman
Right, but I'm just going to point out that more boost does not always equal more power
Is this rocket science or something?
Look at his chart, if the car simply held a peak boost level (instead of peaking then falling) it would make the HP/Tq curve considerably better. I'm talking a peak of roughly 25 psi is what it looks like the turbo can hold out to 8000 RPM. Hit a peak boost of 25 psi and hold it to 8000 RPM and it would make for a fairly flat HP curve above 6000 RPM, instead of falling off on HP like spiking a higher boost pressure and letting it fall to 25 psi.
Obviously spiking higher and falling giver you more power every where, just pointing out that the torque drop isn't as bad as the chart makes it look because better boost control could fix the issue.
More boost does not necessarily equal more power at higher RPMs if you're pushing the turbo past it's efficiency range.
You need to think of this in terms of airflow, not in terms of boost pressure.
In very (!!) rough terms, it's going to take almost twice as much airflow to hold 25 PSI at 4000 RPMs as it will to hold 25 PSI @ 8000 RPMs.
If you do force the turbo to hold 25 PSI @ 8000 RPMs, it will most likely be well out of it's efficiency range. Once that happens, you're pushing a lot of hot air into the motor. At that point, you have to pull timing and perhaps add fuel to compensate for the hotter air, both of which reduce power.
There's a balance to be struck here, and it's not as simple as just turning the boost up. You need to move away from the idea that more boost == more power. It's all about operating the turbo within it's sweet spot.
You can pretty clearly see in fact that more boost does make more power in his chart.
Is this rocket science or something?
Look at his chart, if the car simply held a peak boost level (instead of peaking then falling) it would make the HP/Tq curve considerably better. I'm talking a peak of roughly 25 psi is what it looks like the turbo can hold out to 8000 RPM. Hit a peak boost of 25 psi and hold it to 8000 RPM and it would make for a fairly flat HP curve above 6000 RPM, instead of falling off on HP like spiking a higher boost pressure and letting it fall to 25 psi.
Obviously spiking higher and falling giver you more power every where, just pointing out that the torque drop isn't as bad as the chart makes it look because better boost control could fix the issue.
Is this rocket science or something?
Look at his chart, if the car simply held a peak boost level (instead of peaking then falling) it would make the HP/Tq curve considerably better. I'm talking a peak of roughly 25 psi is what it looks like the turbo can hold out to 8000 RPM. Hit a peak boost of 25 psi and hold it to 8000 RPM and it would make for a fairly flat HP curve above 6000 RPM, instead of falling off on HP like spiking a higher boost pressure and letting it fall to 25 psi.
Obviously spiking higher and falling giver you more power every where, just pointing out that the torque drop isn't as bad as the chart makes it look because better boost control could fix the issue.
The only reason I said that is so that some newbie doesn't come in here thinking that "if I can turn up boost, I haz moar powar"
No, chetrickerman is correct here.
More boost does not necessarily equal more power at higher RPMs if you're pushing the turbo past it's efficiency range.
You need to think of this in terms of airflow, not in terms of boost pressure.
In very (!!) rough terms, it's going to take almost twice as much airflow to hold 25 PSI at 4000 RPMs as it will to hold 25 PSI @ 8000 RPMs.
If you do force the turbo to hold 25 PSI @ 8000 RPMs, it will most likely be well out of it's efficiency range. Once that happens, you're pushing a lot of hot air into the motor. At that point, you have to pull timing and perhaps add fuel to compensate for the hotter air, both of which reduce power.
There's a balance to be struck here, and it's not as simple as just turning the boost up. You need to move away from the idea that more boost == more power. It's all about operating the turbo within it's sweet spot.
More boost does not necessarily equal more power at higher RPMs if you're pushing the turbo past it's efficiency range.
You need to think of this in terms of airflow, not in terms of boost pressure.
In very (!!) rough terms, it's going to take almost twice as much airflow to hold 25 PSI at 4000 RPMs as it will to hold 25 PSI @ 8000 RPMs.
If you do force the turbo to hold 25 PSI @ 8000 RPMs, it will most likely be well out of it's efficiency range. Once that happens, you're pushing a lot of hot air into the motor. At that point, you have to pull timing and perhaps add fuel to compensate for the hotter air, both of which reduce power.
There's a balance to be struck here, and it's not as simple as just turning the boost up. You need to move away from the idea that more boost == more power. It's all about operating the turbo within it's sweet spot.
Last edited by chetrickerman; Sep 12, 2011 at 09:36 AM.
The only thing you're missing is if you oversize your heat exchanger and chemically cool the intake charge. Then you can run your turbocharger outside of it's efficiency range and STILL generate more airflow from the turbocharger. :P
To further elaborate:
I disagree with your comment about operating a turbocharger at it's sweet spot. If you run a turbocharger through it's peak efficiency range and no where near the choke flow line, you'll always be making less power with worse spool characteristics.
Think about this. It's not efficient because it generates more heat while compressing the air. The compressor map shows wheel speed and mass flow. Although you may be less efficient at compressing the air, you'll notice that running a higher pressure ratio in most ALL cases will increase the mass flow of the compressor.
We can fix high post compressor air temps... easy. It's called a heat exchanger - ala "teh Intercoolah". Combine that with using E85 to chemically cool the intake charge and you've got a pretty cool intake charge temp. Of course this means you have to oversize your intercooler, but that's not hard to do.
To further elaborate:
I disagree with your comment about operating a turbocharger at it's sweet spot. If you run a turbocharger through it's peak efficiency range and no where near the choke flow line, you'll always be making less power with worse spool characteristics.
Think about this. It's not efficient because it generates more heat while compressing the air. The compressor map shows wheel speed and mass flow. Although you may be less efficient at compressing the air, you'll notice that running a higher pressure ratio in most ALL cases will increase the mass flow of the compressor.
We can fix high post compressor air temps... easy. It's called a heat exchanger - ala "teh Intercoolah". Combine that with using E85 to chemically cool the intake charge and you've got a pretty cool intake charge temp. Of course this means you have to oversize your intercooler, but that's not hard to do.
The response looks great and it makes great power, but I'm having a hard time understanding why people are so excited about this turbo. It looks like the exact same as an FP black. Since FP is now doing ball bearing, I can't see any upside.
Here is my dyno thread. My build is what you would call the stereo typical off the shelf build. There is nothing special about my motor. I hit 570 ftlbs at 4k rpm and 440 ftlbs at 3500. This is a journal bearing black and my setup is no where near maxed out. I peak at 33 psi.
What is the appeal of the borg warner turbos over the FP turbos?
-Acree
Here is my dyno thread. My build is what you would call the stereo typical off the shelf build. There is nothing special about my motor. I hit 570 ftlbs at 4k rpm and 440 ftlbs at 3500. This is a journal bearing black and my setup is no where near maxed out. I peak at 33 psi.
What is the appeal of the borg warner turbos over the FP turbos?
-Acree
Titanium aluminide turbine wheels!
the MOI on these is insane! The difference in transient response will still trump a FP Black by a LARGE margin.
First you have the FP black which has ~80-82mm exducer on the compressor versus the BW with a 76mm exducer. Smaller MOI.
Then you have the fact that the FP black uses an inconel(ish) turbine wheel versus the TiAL wheel on the EFR.... MUCH lower MOI.
So the rotating assembly has a much lower MOI, which means it'll be far more responsive than your black will... and still far more response than a BB Black.
Imagine having a 45 pound wheel/tire combo...then swapping them out for a 30 pound wheel and tire combo. Same sort of savings here... except the turbo is turning at 150k+ RPMS!
The static dyno pull doesn't tell the whole story, but if you look at the rate of gain of torque I think that lends a bit of insight into the reduced MOI of the TiAL wheel and reduced drag from the EFR CHRA.
I think that Robert himself would admit that his BB CHRA doesn't compete against the BW unit. Mostly due to the fact that Robert has a space limitation and BW doesn't.
the MOI on these is insane! The difference in transient response will still trump a FP Black by a LARGE margin.
First you have the FP black which has ~80-82mm exducer on the compressor versus the BW with a 76mm exducer. Smaller MOI.
Then you have the fact that the FP black uses an inconel(ish) turbine wheel versus the TiAL wheel on the EFR.... MUCH lower MOI.
So the rotating assembly has a much lower MOI, which means it'll be far more responsive than your black will... and still far more response than a BB Black.
Imagine having a 45 pound wheel/tire combo...then swapping them out for a 30 pound wheel and tire combo. Same sort of savings here... except the turbo is turning at 150k+ RPMS!
The static dyno pull doesn't tell the whole story, but if you look at the rate of gain of torque I think that lends a bit of insight into the reduced MOI of the TiAL wheel and reduced drag from the EFR CHRA.
I think that Robert himself would admit that his BB CHRA doesn't compete against the BW unit. Mostly due to the fact that Robert has a space limitation and BW doesn't.
the BW is still more expensive.
1800 -turbo
200 - oil & coolant lines
1500+ - FR or custom manifold, dp, & dumptubes
500 - Twin tiAL MVS gates
150 - custom Intake
150 - custom LICP
@4300 dollars... i can see where 2500 is a bargain. (that's assuming you already had all the supporting mods on your stock turbo)
IMO...it's still worth every penny! (mostly because I can weld stuff together! hahah)
1800 -turbo
200 - oil & coolant lines
1500+ - FR or custom manifold, dp, & dumptubes
500 - Twin tiAL MVS gates
150 - custom Intake
150 - custom LICP
@4300 dollars... i can see where 2500 is a bargain. (that's assuming you already had all the supporting mods on your stock turbo)
IMO...it's still worth every penny! (mostly because I can weld stuff together! hahah)
Well, maybe not. There's some interesting engineering inside the FP CHRA that's patent pending. I'd not be surprised to see some of the big guys sending licensing fees FP's way in the future...
Still, the ultralight wheels in the BW may be advantageous...