Any Borg Warner Efr IWG builds on a half bridge out there?
Any Borg Warner Efr IWG builds on a half bridge out there?
I am considering going from a stock port to a half bridge with my EFR 8374 IWG. Curious to know if the IWG will work with a half bridge or if the half bridge will overwhelm the waste gate? Thanks
Joined: May 2005
Posts: 3,243
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From: Kennewick, Washington
Considering the broad powerband of a stock port or mild port with the efr8374: from 2500rpm through 8000.
bridge port shifts the powerband to the right. This doesn't help unless you are not running anything near the factory intake manifold setup. There is absolutely zero reason to run a bridge or half bridge with the 8374.
bridge port shifts the powerband to the right. This doesn't help unless you are not running anything near the factory intake manifold setup. There is absolutely zero reason to run a bridge or half bridge with the 8374.
shawnm565
Has anyone ever done a back to back( HB vs SP)?
I have yet to be impressed with a turbo BP dyno sheet.
I don't know what impresses you, but many people misunderstand what porting with overlap will do on a turbo rotary.
An overlap port on a turbo rotary increases spool a bit (more air fuel driven exhaust expansion) and increase spool a bit more by moving the engine operating parameters Right of the surge line through more air flow (out the exhaust) and finally increase the engine Volumetric Efficiency a bit.
None of these will raise peak power on a turbo operating already at the choke line.
The peak power potential of a given turbo actually decreases a bit as some of the compressor flow is "wasted" (you did like the spool though right?) out the exhaust.
However, unless you are on race gas looking for peak power you won't be maxing out your turbo flow.
Therefore, it is useful to port for overlap with a turbo (bridge or semi p-ports that are physically blocked at some point) for power under the curve through better spool as well as making more power per PSI boost run (while operating under the max potential of the turbo).
Circuit FDs in Japan commonly use a T04Z turbo on low boost with bridge or semi-p ports for 500-580rwhp. Big midrange torque!
Compared to this set-up Keiichi Tsuchiya has been heard to say of NA 4 rotors "lacks torque".
Look at similarities of T04Z and EFR 8374 turbo specs...
EFR 8374 with bridge/semi p-port should be a real torque monster if it doesn't shake the engine apart with surge.
Has anyone ever done a back to back( HB vs SP)?
I have yet to be impressed with a turbo BP dyno sheet.
I don't know what impresses you, but many people misunderstand what porting with overlap will do on a turbo rotary.
An overlap port on a turbo rotary increases spool a bit (more air fuel driven exhaust expansion) and increase spool a bit more by moving the engine operating parameters Right of the surge line through more air flow (out the exhaust) and finally increase the engine Volumetric Efficiency a bit.
None of these will raise peak power on a turbo operating already at the choke line.
The peak power potential of a given turbo actually decreases a bit as some of the compressor flow is "wasted" (you did like the spool though right?) out the exhaust.
However, unless you are on race gas looking for peak power you won't be maxing out your turbo flow.
Therefore, it is useful to port for overlap with a turbo (bridge or semi p-ports that are physically blocked at some point) for power under the curve through better spool as well as making more power per PSI boost run (while operating under the max potential of the turbo).
Circuit FDs in Japan commonly use a T04Z turbo on low boost with bridge or semi-p ports for 500-580rwhp. Big midrange torque!
Compared to this set-up Keiichi Tsuchiya has been heard to say of NA 4 rotors "lacks torque".
Look at similarities of T04Z and EFR 8374 turbo specs...
EFR 8374 with bridge/semi p-port should be a real torque monster if it doesn't shake the engine apart with surge.
bridge port shifts the powerband to the right.
Incorrect.
A bridge with the same port closing as a streetport moves the power to the LEFT (more low end power) with all other factors the same.
It is common on NA Bridge to port for later closing as RPM + Maintaining torque = how to make NA power.
Late closing is NOT a requirement of bridge porting and you could do the same on a street port.
Incorrect.
A bridge with the same port closing as a streetport moves the power to the LEFT (more low end power) with all other factors the same.
It is common on NA Bridge to port for later closing as RPM + Maintaining torque = how to make NA power.
Late closing is NOT a requirement of bridge porting and you could do the same on a street port.
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bridge port shifts the powerband to the right.
Incorrect.
A bridge with the same port closing as a streetport moves the power to the LEFT (more low end power) with all other factors the same.
Late closing is NOT a requirement of bridge porting and you could do the same on a street port.
Incorrect.
A bridge with the same port closing as a streetport moves the power to the LEFT (more low end power) with all other factors the same.
Late closing is NOT a requirement of bridge porting and you could do the same on a street port.
A common term back home is "overlap & escape"!
Joined: Mar 2001
Posts: 30,807
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From: FL-->NJ/NYC again!
Blue TII, my current setup is the 8374 with internal waste gate. Short runner manifold with 1.682 ID runners. Stock ports. 93 octane. Boost is set at 20 psi but creeps to 24 psi from 6800 on up. I am ok with that cause its tuned for it and I am dumping a lot of water/meth. My knock is in the teens. I've been beating it all summer and everything seems good so far.
If I am understanding you correctly, your saying my midrange and spool will improve with a half bridge over stock ports?
Do you think a half bridge will overwhelm the IWG and amplify the boost creep or not effect it? I don't want to go north of 25 psi on 93 octane.
Do you have any recommendations for half bridge templates?
Thanks
If I am understanding you correctly, your saying my midrange and spool will improve with a half bridge over stock ports?
Do you think a half bridge will overwhelm the IWG and amplify the boost creep or not effect it? I don't want to go north of 25 psi on 93 octane.
Do you have any recommendations for half bridge templates?
Thanks
Blue TII, my current setup is the 8374 with internal waste gate. Short runner manifold with 1.682 ID runners. Stock ports. 93 octane. Boost is set at 20 psi but creeps to 24 psi from 6800 on up. I am ok with that cause its tuned for it and I am dumping a lot of water/meth. My knock is in the teens. I've been beating it all summer and everything seems good so far.
If I am understanding you correctly, your saying my midrange and spool will improve with a half bridge over stock ports?
Do you think a half bridge will overwhelm the IWG and amplify the boost creep or not effect it? I don't want to go north of 25 psi on 93 octane.
Do you have any recommendations for half bridge templates?
Thanks
If I am understanding you correctly, your saying my midrange and spool will improve with a half bridge over stock ports?
Do you think a half bridge will overwhelm the IWG and amplify the boost creep or not effect it? I don't want to go north of 25 psi on 93 octane.
Do you have any recommendations for half bridge templates?
Thanks
^ Yes, 18-20psi boost only.
With just a streetport and a T04Z you might get 420rwhp @ 18psi and have to do 26psi boost to get into 500rwhp territory.
https://www.rx7club.com/single-turbo...-5-psi-672972/
With just a streetport and a T04Z you might get 420rwhp @ 18psi and have to do 26psi boost to get into 500rwhp territory.
https://www.rx7club.com/single-turbo...-5-psi-672972/
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