Sizing concerns
#1
Full Member
Thread Starter
Sizing concerns
Hello all, I'm currently in process of building. S5 NA rotors in S5 T2 housings and irons. I am installing a mega squirt for ecu and will be making a custom manifold and exhaust most likely with a v-mount set up. Anyways, I primarily use it for autocross so throttle response is most important. I'm looking for somewhere in the neighborhood of 350hp. Here's my concern, I have a source for a very very cheap BW S366 with div .91 ex. From everything I've been reading it doesn't sound like a good option for the range I'm looking for. What sizes would you recommend. No to EFR prices though. I'm not poor but, I'm not rich either.
Holding breath for responses and other questions you have.
Holding breath for responses and other questions you have.
#2
Rotary Freak
iTrader: (7)
Borg S257 SX-E would be a good fit for under $1000. Its basically the EFR 7670 without the TiAl turbine wheel and double ball bearings. Problem is, after you spend money on a quality welded twin scroll manifold, dual wastegates, and a blow off valve, you're not too far off from an EFR with the cast Turblown manifold. Plus, the EFR will have more re-sale value if you look to upgrade down the road.
#3
Full Member
Thread Starter
Borg S257 SX-E would be a good fit for under $1000. Its basically the EFR 7670 without the TiAl turbine wheel and double ball bearings. Problem is, after you spend money on a quality welded twin scroll manifold, dual wastegates, and a blow off valve, you're not too far off from an EFR with the cast Turblown manifold. Plus, the EFR will have more re-sale value if you look to upgrade down the road.
#4
Rotary Motoring
iTrader: (9)
I would use a ~$750 or so used IRL EFR 7163 with a real HKS or Greddy wastegate (used?) for boost control to get max bang for buck for your application.
Go ahead and remove and weld the SS turbo exhaust housing to the collector to save money, time, complexity and weight (you can get another all day for peanuts).
Basically an improved Apexi RX-6 turbo kit for pocket change and easy to fab the 2-1 round collector with single wastegate (look at 3rd version of the FD HKS T04Z manifold for inspiration or get one used).
Kinda like this but no flange for turbo (weld exh. housing on) and probably a cheaper bolt on wastegate/flange.
Go ahead and remove and weld the SS turbo exhaust housing to the collector to save money, time, complexity and weight (you can get another all day for peanuts).
Basically an improved Apexi RX-6 turbo kit for pocket change and easy to fab the 2-1 round collector with single wastegate (look at 3rd version of the FD HKS T04Z manifold for inspiration or get one used).
Kinda like this but no flange for turbo (weld exh. housing on) and probably a cheaper bolt on wastegate/flange.
#5
Full Member
Thread Starter
I would use a ~$750 or so used IRL EFR 7163 with a real HKS or Greddy wastegate (used?) for boost control to get max bang for buck for your application.
Go ahead and remove and weld the SS turbo exhaust housing to the collector to save money, time, complexity and weight (you can get another all day for peanuts).
Basically an improved Apexi RX-6 turbo kit for pocket change and easy to fab the 2-1 round collector with single wastegate (look at 3rd version of the FD HKS T04Z manifold for inspiration or get one used).
Kinda like this but no flange for turbo (weld exh. housing on) and probably a cheaper bolt on wastegate/flange.
Go ahead and remove and weld the SS turbo exhaust housing to the collector to save money, time, complexity and weight (you can get another all day for peanuts).
Basically an improved Apexi RX-6 turbo kit for pocket change and easy to fab the 2-1 round collector with single wastegate (look at 3rd version of the FD HKS T04Z manifold for inspiration or get one used).
Kinda like this but no flange for turbo (weld exh. housing on) and probably a cheaper bolt on wastegate/flange.
#6
Rotary Motoring
iTrader: (9)
When I say easy to fab the 2-1 round collector with wastegate take off, I mean it is much easier to end up with a great high flowing high velocity merge than with the traditional divided T4 flange and wastegate entry which actually takes a lot of time/work to get it nice with a good transition and WG take off and is still a point of failure in use (flange warp and gasket).
Wasn't implying you suck at fabrication.
Wasn't implying you suck at fabrication.
#7
Full Member
Thread Starter
When I say easy to fab the 2-1 round collector with wastegate take off, I mean it is much easier to end up with a great high flowing high velocity merge than with the traditional divided T4 flange and wastegate entry which actually takes a lot of time/work to get it nice with a good transition and WG take off and is still a point of failure in use (flange warp and gasket).
Wasn't implying you suck at fabrication.
Wasn't implying you suck at fabrication.
My goal is to have the wastegate(s) be plumbed straight out of the ports so that they are the first path for the exhaust gases. That way the gate will vent quickly and accurately.
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#8
Rotary Motoring
iTrader: (9)
Well, on the wastegate it really is a balance on priority and placement.
I had a past with boost creep so when I converted my manifold I went "all out" on the wastegates with two high priority 44mm wastegates.
Great, but then I had the opposite problem of boost creep. Exhaust flow and pressure at high rpm would push against the bottom of the WGs' poppet valves and keep them open further than the actuator on top was driving them to and boost would drop.
Fine by me as that just lets the engine breath and I still was pretty much able to max the turbo compressor. I could have fixed it by plumbing the WGs as dual port with boost on top of the actuator.
Anyways- found some pics.
This is all the FD RX-7 HKS T04Z turbo kit manifold (fits FC depending on turbo though WG flange hits subframe a bit).
Version 1
Version 2
Version 3
My dual WG conversion
A look at dat merge
I had a past with boost creep so when I converted my manifold I went "all out" on the wastegates with two high priority 44mm wastegates.
Great, but then I had the opposite problem of boost creep. Exhaust flow and pressure at high rpm would push against the bottom of the WGs' poppet valves and keep them open further than the actuator on top was driving them to and boost would drop.
Fine by me as that just lets the engine breath and I still was pretty much able to max the turbo compressor. I could have fixed it by plumbing the WGs as dual port with boost on top of the actuator.
Anyways- found some pics.
This is all the FD RX-7 HKS T04Z turbo kit manifold (fits FC depending on turbo though WG flange hits subframe a bit).
Version 1
Version 2
Version 3
My dual WG conversion
A look at dat merge
Last edited by BLUE TII; 10-20-17 at 01:15 PM.
#9
Full Member
Thread Starter
Well, on the wastegate it really is a balance on priority and placement.
I had a past with boost creep so when I converted my manifold I went "all out" on the wastegates with two high priority 44mm wastegates.
Great, but then I had the opposite problem of boost creep. Exhaust flow and pressure at high rpm would push against the bottom of the WGs' poppet valves and keep them open further than the actuator on top was driving them to and boost would drop.
Fine by me as that just lets the engine breath and I still was pretty much able to max the turbo compressor.
Anyways- found some pics.
This is all the HKS T04Z turbo kit manifold.
Version 1
Version 2
Version 3
Dat merge
My dual WG conversion
I had a past with boost creep so when I converted my manifold I went "all out" on the wastegates with two high priority 44mm wastegates.
Great, but then I had the opposite problem of boost creep. Exhaust flow and pressure at high rpm would push against the bottom of the WGs' poppet valves and keep them open further than the actuator on top was driving them to and boost would drop.
Fine by me as that just lets the engine breath and I still was pretty much able to max the turbo compressor.
Anyways- found some pics.
This is all the HKS T04Z turbo kit manifold.
Version 1
Version 2
Version 3
Dat merge
My dual WG conversion
#11
Full Member
Thread Starter
#12
Rotary Motoring
iTrader: (9)
When you had boost creep were the gates only using the spring or was there pressure being applied to the top of the dome as well?
I put a 60mm external vented WG on it, but it still had boost creep.
I had to max port the stock exh. manifold and turbo inlet up to the WG inlet as well as widening the turbo scroll slot entry into the exhaust wheel to stop the boost creep. Which slowed response (how fast boost came up), but did not affect spool (peak boost per rpm the turbo made).
#13
Rotary Motoring
iTrader: (9)
I like it.
That is $900 in wastegates and if you use cheaper ones they will fail.
The HKS T04Z manifold V3 evolution is a thing of beauty with simplicity, strength/reliability, flow and boost control- while being easy to replicate on a budget.
#14
Full Member
Thread Starter
Thanks, but do as I say not as I do LOL.
That is $900 in wastegates and if you use cheaper ones they will fail.
The HKS T04Z manifold V3 evolution is a thing of beauty with simplicity, strength/reliability, flow and boost control- while being easy to replicate on a budget.
That is $900 in wastegates and if you use cheaper ones they will fail.
The HKS T04Z manifold V3 evolution is a thing of beauty with simplicity, strength/reliability, flow and boost control- while being easy to replicate on a budget.
Hopefully the S300sxe 8376 will be a decent size for what I want to do.
Thanks Blue!
#15
Rotary Motoring
iTrader: (9)
I tried the divider up to the WG poppet flange twice (version 2 shown in that pic of stock hybrid). It only welded itself to the poppet valve once and cause overboost LOL.
It also had a couple failures. First time the stainless plate broke the welds and then folded up like paper.
2nd time I used thick 3/16" stainless and made it so it could expand so as not to put stress on the welds (welded divider to a ring that was free in the pipe on the WG end). It lasted longer, but it ended up tearing the stainless divider right where it met the tube in half.
So, I left the divider out and it barely made any diffrenence- just a bit less spool off idle to 2,000rpm.
Just a word of warning on how veracious the rotary exhaust is.
It actually also bent in the cast iron walls between runners on the exhaust housing and turbo manifold a bit- pushing it toward the rear straight runner as the snakey front runner had more exhaust manifold pressure. But that was after 7 seasons of racing.
It also had a couple failures. First time the stainless plate broke the welds and then folded up like paper.
2nd time I used thick 3/16" stainless and made it so it could expand so as not to put stress on the welds (welded divider to a ring that was free in the pipe on the WG end). It lasted longer, but it ended up tearing the stainless divider right where it met the tube in half.
So, I left the divider out and it barely made any diffrenence- just a bit less spool off idle to 2,000rpm.
Just a word of warning on how veracious the rotary exhaust is.
It actually also bent in the cast iron walls between runners on the exhaust housing and turbo manifold a bit- pushing it toward the rear straight runner as the snakey front runner had more exhaust manifold pressure. But that was after 7 seasons of racing.