1st Gen options from Borg Warner
03-18-21, 10:57 PM
#1
Full Member
Thread Starter
1st Gen options from Borg Warner
I have a '79 in which I have just started a 13B-REW swap. I'm looking to be in the 350-400rwhp zone. I'm having trouble deciding between the EFR 8374 IWG and S362 SX-E 0.91A/R
Things that may affect suggestions-
Stock port
Transmission- 6spd from an RX8
Rear- GSL-SE with NA MX5 torsen and custom Moser axles
15x7 wheels
Making my own short runner manifold
I will be street tuning myself and have experience but it's been a long time. Eventually will make it to be dyno tuned.
As you can see with my setup this is not going to be a drag car and I will not be launching. I'm just looking for a fun street car. First I was thinking the EFR 8374 IWG would be a great choice but don't know what fitment would be like with a short manifold in an SA. I also liked this idea because of the simplicity and fast spool. With dual gates, a BOV, and all the plumbing required for the S362SX-E it wouldn't cost any more than an EFR with IWG, although cost isn't that big of a variable. Although I like fabricating the exhaust manifold/EWG plumbing, I'm lacking time and want to see this thing running by the end of the summer. Although not a big deal either, it would also be nice not having to run a coolant line with the SX-E.
So my biggest concern is fitment, especially with the EFR with IWG on a 1st gen. The other concern is spool. With my car being 500 lbs lighter than an FD and not really able to hook up should I even worry about this? Would I even notice the difference in powerband? Lastly I'm worried about boost creep with the IWG but it seems porting is the answer?
Anyone have either in an SA/FB and want to chime in? Thanks
Things that may affect suggestions-
Stock port
Transmission- 6spd from an RX8
Rear- GSL-SE with NA MX5 torsen and custom Moser axles
15x7 wheels
Making my own short runner manifold
I will be street tuning myself and have experience but it's been a long time. Eventually will make it to be dyno tuned.
As you can see with my setup this is not going to be a drag car and I will not be launching. I'm just looking for a fun street car. First I was thinking the EFR 8374 IWG would be a great choice but don't know what fitment would be like with a short manifold in an SA. I also liked this idea because of the simplicity and fast spool. With dual gates, a BOV, and all the plumbing required for the S362SX-E it wouldn't cost any more than an EFR with IWG, although cost isn't that big of a variable. Although I like fabricating the exhaust manifold/EWG plumbing, I'm lacking time and want to see this thing running by the end of the summer. Although not a big deal either, it would also be nice not having to run a coolant line with the SX-E.
So my biggest concern is fitment, especially with the EFR with IWG on a 1st gen. The other concern is spool. With my car being 500 lbs lighter than an FD and not really able to hook up should I even worry about this? Would I even notice the difference in powerband? Lastly I'm worried about boost creep with the IWG but it seems porting is the answer?
Anyone have either in an SA/FB and want to chime in? Thanks
03-19-21, 09:24 AM
#2
03-19-21, 10:38 PM
#4
Full Member
Thread Starter
I don't think I'm quite that light. I think more like 2350, but still. Ok I think I'm sold on the 8374 IWG.
If I decide to cut down on fabrication time further and just get the Turblown cast manifold it appears I need the wastegate bracket, but it is unclear to me as to why. From Turbosource- "Pictured waste-gate bracket adapter is required for all chassis models. OE BorgWarner unit will not work with turbo orientation."
Does this have to do with a particular clocking in which the wastegate will hit the lower intake manifold? If I'm only using their manifold and not the rest of their kit does this still apply?
Last but not least, I've read a lot of mixed opinions/experiences on these wastegates and creep. With stock ports and running a 3 inch downpipe, resonator, and muffler, will I be able to get away without porting the wastegate?
If I decide to cut down on fabrication time further and just get the Turblown cast manifold it appears I need the wastegate bracket, but it is unclear to me as to why. From Turbosource- "Pictured waste-gate bracket adapter is required for all chassis models. OE BorgWarner unit will not work with turbo orientation."
Does this have to do with a particular clocking in which the wastegate will hit the lower intake manifold? If I'm only using their manifold and not the rest of their kit does this still apply?
Last but not least, I've read a lot of mixed opinions/experiences on these wastegates and creep. With stock ports and running a 3 inch downpipe, resonator, and muffler, will I be able to get away without porting the wastegate?
03-21-21, 05:38 PM
#5
www.AusRotary.com
You will have trouble with traction, even with a 7670. 350-400rwhp in a 1st gen is a lot.
And even with the 7670 you will quickly destroy the RX8 gearbox. A used FC turbo gearbox might even struggle depending on how aggressively you drive.
With the rear end, the torsen should be ok, with the axles usually the next weak point to break. The Moser axles might be OK with the 26 spline GSL-SE configuration, but the diff housing would be the next weak point. 1st gen RX-7s pushing over 400rwhp are a dime a dozen in Australia and most go for a Toyota Hilux diff, which are pretty much indestructible at this power level without being nearly as heavy as a 9".
IMO whether you go for a 7670 vs 8374 depends on what quality fuel you use and whether you will be using a cat and restrictive exhaust. You will need to run higher boost to wring 350-400rwhp out of a 7670 but it should be fairly stable. With a 8374, you can get that power at a much lower boost level (which will be safer with pump fuel), but you may experience boost creep issues with a free flowing exhaust. For many people, the minimum boost you can run on an IWG 8374 without modifying the wastegate is 14+ psi. This will put you well over 400rwhp and out of the safe zone for pump fuel.
With a 3 inch straight through exhaust and no cat, you may get boost creep or you may not, it depends on how restrictive the mufflers are.
With a 7670 you could safely run a bigger better flowing 3.5 inch dump, with much quicker spool, and not need to ever worry about boost creep.
And even with the 7670 you will quickly destroy the RX8 gearbox. A used FC turbo gearbox might even struggle depending on how aggressively you drive.
With the rear end, the torsen should be ok, with the axles usually the next weak point to break. The Moser axles might be OK with the 26 spline GSL-SE configuration, but the diff housing would be the next weak point. 1st gen RX-7s pushing over 400rwhp are a dime a dozen in Australia and most go for a Toyota Hilux diff, which are pretty much indestructible at this power level without being nearly as heavy as a 9".
IMO whether you go for a 7670 vs 8374 depends on what quality fuel you use and whether you will be using a cat and restrictive exhaust. You will need to run higher boost to wring 350-400rwhp out of a 7670 but it should be fairly stable. With a 8374, you can get that power at a much lower boost level (which will be safer with pump fuel), but you may experience boost creep issues with a free flowing exhaust. For many people, the minimum boost you can run on an IWG 8374 without modifying the wastegate is 14+ psi. This will put you well over 400rwhp and out of the safe zone for pump fuel.
With a 3 inch straight through exhaust and no cat, you may get boost creep or you may not, it depends on how restrictive the mufflers are.
With a 7670 you could safely run a bigger better flowing 3.5 inch dump, with much quicker spool, and not need to ever worry about boost creep.
The following 2 users liked this post by KYPREO:
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Howard Coleman (03-21-21)
03-21-21, 10:02 PM
#6
Full Member
Thread Starter
Thanks for the advice. I guess I will have to be prepared to port my wastegate. For right now, not having traction is my "slip clutch" for not blowing the drivetrain. I had an s5 t2 engine/trans in an FB with a BW S362 many years ago. I never had issues with the drivetrain, but I didn't race the car. I thought the same thing about the RX8 transmission, and I think some people on here told me they have synchro issues when raced, but can take a good amount of torque. The SA is also like 800 lbs less than an RX8. I would use my FD transmission but the shifter is a good 6 inches off. The SA and FB have a totally different shifter location. Someone has recommended to me the Toyota Hilux before, must be the way to go. I will be upgrading the rear in the future. I want to be able to run pump gas and would like to stay at a bar or less of boost, yet still make 350+ RWHP, so I think the 8374 is more up my alley. I drive like an old man most of the time, which should give me time to plan a rear end and possibly transmission upgrade.
03-29-21, 11:01 PM
#7
You will have trouble with traction, even with a 7670. 350-400rwhp in a 1st gen is a lot.
And even with the 7670 you will quickly destroy the RX8 gearbox. A used FC turbo gearbox might even struggle depending on how aggressively you drive.
With the rear end, the torsen should be ok, with the axles usually the next weak point to break. The Moser axles might be OK with the 26 spline GSL-SE configuration, but the diff housing would be the next weak point. 1st gen RX-7s pushing over 400rwhp are a dime a dozen in Australia and most go for a Toyota Hilux diff, which are pretty much indestructible at this power level without being nearly as heavy as a 9".
IMO whether you go for a 7670 vs 8374 depends on what quality fuel you use and whether you will be using a cat and restrictive exhaust. You will need to run higher boost to wring 350-400rwhp out of a 7670 but it should be fairly stable. With a 8374, you can get that power at a much lower boost level (which will be safer with pump fuel), but you may experience boost creep issues with a free flowing exhaust. For many people, the minimum boost you can run on an IWG 8374 without modifying the wastegate is 14+ psi. This will put you well over 400rwhp and out of the safe zone for pump fuel.
With a 3 inch straight through exhaust and no cat, you may get boost creep or you may not, it depends on how restrictive the mufflers are.
With a 7670 you could safely run a bigger better flowing 3.5 inch dump, with much quicker spool, and not need to ever worry about boost creep.
And even with the 7670 you will quickly destroy the RX8 gearbox. A used FC turbo gearbox might even struggle depending on how aggressively you drive.
With the rear end, the torsen should be ok, with the axles usually the next weak point to break. The Moser axles might be OK with the 26 spline GSL-SE configuration, but the diff housing would be the next weak point. 1st gen RX-7s pushing over 400rwhp are a dime a dozen in Australia and most go for a Toyota Hilux diff, which are pretty much indestructible at this power level without being nearly as heavy as a 9".
IMO whether you go for a 7670 vs 8374 depends on what quality fuel you use and whether you will be using a cat and restrictive exhaust. You will need to run higher boost to wring 350-400rwhp out of a 7670 but it should be fairly stable. With a 8374, you can get that power at a much lower boost level (which will be safer with pump fuel), but you may experience boost creep issues with a free flowing exhaust. For many people, the minimum boost you can run on an IWG 8374 without modifying the wastegate is 14+ psi. This will put you well over 400rwhp and out of the safe zone for pump fuel.
With a 3 inch straight through exhaust and no cat, you may get boost creep or you may not, it depends on how restrictive the mufflers are.
With a 7670 you could safely run a bigger better flowing 3.5 inch dump, with much quicker spool, and not need to ever worry about boost creep.
How did you come to the conclusion that an 8374 will make the same or more power at less boost?
The engine will only flow X at a given pressure regardless of the turbo assuming the turbo isn't maxxed out. At 350-400rwhp a 7670 is not near its max.
I recently did a back to back showing this, Went from a 9180 to an 8374 in the same day on the same car. Made the same peak power(Smaller turbo actually showed 5 more hp but I put this down to temperature change) and obviously came on boost earlier. The 9180 did NOT make more power on the same boost. IT WAS EXACTLY the same. Common misconception that bigger turbos will make more power on the same boost. THIS IS INCORRECT. A bigger turbo will only make more power then a smaller one for a given boost IF the smaller turbo cannot keep up with the engine.
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05-01-21, 08:59 PM
#8
I'm running a s366, 13b turbo bridgeport with s4 N/A rotors, 4x 1000cc injectors, megasquirt ecu 12 pounds of boost. No clue on power just street tuned but it feels like a lot, then again anything over 200 hp in a first-generation feels like a lot.
05-01-21, 09:38 PM
#9
Old [Sch|F]ool
The axles have problems because the rearend housing is a noodle. I wouldn't bother with Moser axles, their axles are usually smaller/weaker than stock for domestic applications.
If you don't run a rear stabilizer bar, and do drive aggressively in cornering, the twisting loads caused by the stock 4 link's geometry combined with power inputs will cause the rearend housing to actually twist the middle up, or rather twist the ends down. The end result is the pinion angle keeps climbing. Running a stabilizer bar keeps the suspension from articulating as much, which hurts traction but keeps the rearend happy. Also helps keep from ripping the upper link mounts off of the body.
Going to a 3 link style suspension eliminates these problems, but creates the new problem of splitting the back of the rearend housing up like cracking an egg.
If you don't run a rear stabilizer bar, and do drive aggressively in cornering, the twisting loads caused by the stock 4 link's geometry combined with power inputs will cause the rearend housing to actually twist the middle up, or rather twist the ends down. The end result is the pinion angle keeps climbing. Running a stabilizer bar keeps the suspension from articulating as much, which hurts traction but keeps the rearend happy. Also helps keep from ripping the upper link mounts off of the body.
Going to a 3 link style suspension eliminates these problems, but creates the new problem of splitting the back of the rearend housing up like cracking an egg.
05-16-21, 06:36 PM
#10
Full Member
How did you come to the conclusion that an 8374 will make the same or more power at less boost?
The engine will only flow X at a given pressure regardless of the turbo assuming the turbo isn't maxxed out. At 350-400rwhp a 7670 is not near its max.
I recently did a back to back showing this, Went from a 9180 to an 8374 in the same day on the same car. Made the same peak power(Smaller turbo actually showed 5 more hp but I put this down to temperature change) and obviously came on boost earlier. The 9180 did NOT make more power on the same boost. IT WAS EXACTLY the same. Common misconception that bigger turbos will make more power on the same boost. THIS IS INCORRECT. A bigger turbo will only make more power then a smaller one for a given boost IF the smaller turbo cannot keep up with the engine.
The engine will only flow X at a given pressure regardless of the turbo assuming the turbo isn't maxxed out. At 350-400rwhp a 7670 is not near its max.
I recently did a back to back showing this, Went from a 9180 to an 8374 in the same day on the same car. Made the same peak power(Smaller turbo actually showed 5 more hp but I put this down to temperature change) and obviously came on boost earlier. The 9180 did NOT make more power on the same boost. IT WAS EXACTLY the same. Common misconception that bigger turbos will make more power on the same boost. THIS IS INCORRECT. A bigger turbo will only make more power then a smaller one for a given boost IF the smaller turbo cannot keep up with the engine.
Do you have any data for this back to back comparison?
I am currently running an efr7670 on my 12A. I have an 8374 and a 9180 from another car I'm also currently building a 2jz. Trying to decide which path I should upgrade to.
My 7670 is currently maxxed from. 26psi to 32psi there is no power increase or difference on the dyno. Hence we are out of turbo. I'm normally shifting at 6500 and have an extendport so I'm not really getting the benefit of the larger porting. Trying to deicide if I should go with the 8374 for slightly more powerband or 9180 with more lag yet more top end power.
05-25-21, 01:36 AM
#11
Do you have any data for this back to back comparison?
I am currently running an efr7670 on my 12A. I have an 8374 and a 9180 from another car I'm also currently building a 2jz. Trying to decide which path I should upgrade to.
My 7670 is currently maxxed from. 26psi to 32psi there is no power increase or difference on the dyno. Hence we are out of turbo. I'm normally shifting at 6500 and have an extendport so I'm not really getting the benefit of the larger porting. Trying to deicide if I should go with the 8374 for slightly more powerband or 9180 with more lag yet more top end power.
Do you have any data for this back to back comparison?
I am currently running an efr7670 on my 12A. I have an 8374 and a 9180 from another car I'm also currently building a 2jz. Trying to decide which path I should upgrade to.
My 7670 is currently maxxed from. 26psi to 32psi there is no power increase or difference on the dyno. Hence we are out of turbo. I'm normally shifting at 6500 and have an extendport so I'm not really getting the benefit of the larger porting. Trying to deicide if I should go with the 8374 for slightly more powerband or 9180 with more lag yet more top end power.
i post everything on my instagram @raceonlygarage
26psi on a 7670 on a 12A is well out of its comfort zone. Your emap would be over 2:1 at 32psi and that would explain why your not making any more power.
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