Ted B.'s HTA3582 Twinscroll Project
Evolving Member
Joined: Dec 2003
Posts: 305
Likes: 0
From: England
Thanks again everyone. Now, to answer your questions:
Manifold
The manifold is a hand-welded stainless TS T4 item. More build photos of this manifold and others can be found at MPFab. As for availability, you'd have to inquire.
Fuel System
Mark, the dual Walbro setup (mine is the Fullblown billet aluminum assy) is proven capable of delivering over 750whp (Dynojet) worth of E85. I am simply at the limit of the 1250cc injectors. I tried to eek the base FP up a little to squeeze a bit more headroom out of it, but that does not change the fact that I need larger injectors. 1450cc should get me close to 700whp if I so choose, and that is more than what I really need.
Head
The head is a work of art, and is CNC ported and hand-finished. It is virtually impossible to get more flow out of an EVO head without destroying it, and I know this to be true first-hand. Everything has been digitized and subjected to CFD analysis. Peter at ISP Racing is the one who arranged the initial meeting between the head porter and myself, so he would be the one to discuss sales inquiries.
Cams and Valvetrain
The cams are a custom grind that I chose from a couple of custom profiles. The first thing one notices about them is that the lobes AND shaft are entirely machined (not cast) from a billet (look closely at the photo). They are a very high lift (ie more than Tomei), moderate duration grind that features very aggressive ramp rates. The beehive springs are computer matched to the ramp rates, and one set is hand-matched out of about 50. These cams are suited for only the most aggressively ported heads, and cannot just be slapped on and run, even with the correct springs. Consideration has to be taken to ensure that the valves sufficiently clear the pistons (they probably won't), and cam gears are a MUST for anything short of an all-out drag racing effort. Nevertheless, I have them idling and running perfectly on the stock ECU. I can disclose the specifics of the timing (as much as I'd like to), and again, I'll leave that discretion to Peter at ISP Racing.
Shortblock
The shortblock was assembled by JAM, and features a set of custom length (156mm) Oliver lightweight billet rods. So, it's a 2.0L, but has a longer rod and uses a 2.3 Venolia piston. Had E85 been readily available at the time I planned the motor, I probably would have upped the SCR to around 9.5:1, but it's a bit after the fact. The engine has the ACL metal-backed bearings, runs like stock, has no observable increased vibration despite the removal of the balance shafts, and burns no oil.
Boost Logging
I can log boost on the street, as the 3-bar JDM MAP sensor won't cut it for me. But like I said, I am seeing 20psi in 3rd just a tick before 4000rpm, and that isn't something you see with a 35R variant and 2.0L. I should also note that the big exhaust manifold and 3" UICP are making the spool slower that would it would be otherwise, so that further enhances perspective.
CBRD
If you're running TS T4 on your 2.3 time attack car, you must be running larger turbo (e.g. 4088R) and smaller hotside? If so, we've already seen what that can do. You might want to put a couple of spare trannies aside.
Dixie Beer
Chris, I recommend it with oysters - but it has to be ice cold. It's temporarily being contract brewed in WI while the old New Orleans brewery gets back on its feet (heavily damaged in Katrina), and the contract item doesn't quite have the almost Singha-like sharpness of the original. Again, no real performance benefit (except in the mind of the imbiber of course).
Manifold
The manifold is a hand-welded stainless TS T4 item. More build photos of this manifold and others can be found at MPFab. As for availability, you'd have to inquire.
Fuel System
Mark, the dual Walbro setup (mine is the Fullblown billet aluminum assy) is proven capable of delivering over 750whp (Dynojet) worth of E85. I am simply at the limit of the 1250cc injectors. I tried to eek the base FP up a little to squeeze a bit more headroom out of it, but that does not change the fact that I need larger injectors. 1450cc should get me close to 700whp if I so choose, and that is more than what I really need.
Head
The head is a work of art, and is CNC ported and hand-finished. It is virtually impossible to get more flow out of an EVO head without destroying it, and I know this to be true first-hand. Everything has been digitized and subjected to CFD analysis. Peter at ISP Racing is the one who arranged the initial meeting between the head porter and myself, so he would be the one to discuss sales inquiries.
Cams and Valvetrain
The cams are a custom grind that I chose from a couple of custom profiles. The first thing one notices about them is that the lobes AND shaft are entirely machined (not cast) from a billet (look closely at the photo). They are a very high lift (ie more than Tomei), moderate duration grind that features very aggressive ramp rates. The beehive springs are computer matched to the ramp rates, and one set is hand-matched out of about 50. These cams are suited for only the most aggressively ported heads, and cannot just be slapped on and run, even with the correct springs. Consideration has to be taken to ensure that the valves sufficiently clear the pistons (they probably won't), and cam gears are a MUST for anything short of an all-out drag racing effort. Nevertheless, I have them idling and running perfectly on the stock ECU. I can disclose the specifics of the timing (as much as I'd like to), and again, I'll leave that discretion to Peter at ISP Racing.
Shortblock
The shortblock was assembled by JAM, and features a set of custom length (156mm) Oliver lightweight billet rods. So, it's a 2.0L, but has a longer rod and uses a 2.3 Venolia piston. Had E85 been readily available at the time I planned the motor, I probably would have upped the SCR to around 9.5:1, but it's a bit after the fact. The engine has the ACL metal-backed bearings, runs like stock, has no observable increased vibration despite the removal of the balance shafts, and burns no oil.
Boost Logging
I can log boost on the street, as the 3-bar JDM MAP sensor won't cut it for me. But like I said, I am seeing 20psi in 3rd just a tick before 4000rpm, and that isn't something you see with a 35R variant and 2.0L. I should also note that the big exhaust manifold and 3" UICP are making the spool slower that would it would be otherwise, so that further enhances perspective.
CBRD
If you're running TS T4 on your 2.3 time attack car, you must be running larger turbo (e.g. 4088R) and smaller hotside? If so, we've already seen what that can do. You might want to put a couple of spare trannies aside.
Dixie Beer
Chris, I recommend it with oysters - but it has to be ice cold. It's temporarily being contract brewed in WI while the old New Orleans brewery gets back on its feet (heavily damaged in Katrina), and the contract item doesn't quite have the almost Singha-like sharpness of the original. Again, no real performance benefit (except in the mind of the imbiber of course).
Flow test your pumps and you will see they deliver less than the 1250cc injectors can flow.
Mark
Mark, I understand what you're saying, but let's be sure we are talking apples to apples.
According to AMS' publicized flow testing, two Walbro 255HPs in parallel at 14V at 75psi (30psi indicated boost) flow around 350lph. My wiring is upgraded, so that should be reflective of my setup. 350lph = 5833cc/min, which approximates four 1450cc injectors at 100% IDC.
If you're telling me that you've noted a disparity between these test results and what you've observed, that is worthy of a discussion in itself.
According to AMS' publicized flow testing, two Walbro 255HPs in parallel at 14V at 75psi (30psi indicated boost) flow around 350lph. My wiring is upgraded, so that should be reflective of my setup. 350lph = 5833cc/min, which approximates four 1450cc injectors at 100% IDC.
If you're telling me that you've noted a disparity between these test results and what you've observed, that is worthy of a discussion in itself.
Evolving Member
Joined: Dec 2003
Posts: 305
Likes: 0
From: England
Mark, I understand what you're saying, but let's be sure we are talking apples to apples.
According to AMS' publicized flow testing, two Walbro 255HPs in parallel at 14V at 75psi (30psi indicated boost) flow around 350lph. My wiring is upgraded, so that should be reflective of my setup. 350lph = 5833cc/min, which approximates four 1450cc injectors at 100% IDC.
If you're telling me that you've noted a disparity between these test results and what you've observed, that is worthy of a discussion in itself.
According to AMS' publicized flow testing, two Walbro 255HPs in parallel at 14V at 75psi (30psi indicated boost) flow around 350lph. My wiring is upgraded, so that should be reflective of my setup. 350lph = 5833cc/min, which approximates four 1450cc injectors at 100% IDC.
If you're telling me that you've noted a disparity between these test results and what you've observed, that is worthy of a discussion in itself.
The test on the car is real easy to do, First check you have the correct volts at idle or bridge out the relay to have 13v+,
Then remove the fuel return pipe and run in to a large fuel can then run the engine for 1min and x results by 60 and you will get lt PH,
Do this at base fuel pressure and the max pressure you run and I think you will be suprised at the results,
My own testing has found a single walbro is on its knee's at 500hpatf and 2 the same @under 600hp atf,
A single walbro with a 044 Bosch in front of it out flows 2 buy nearly 100hp in fuel flow at 5bar+ Fuel pressure.
Mark
Mark, are you referring to E85 with those power figures?
If I have to splice an 044 Bosch in series with the dual Walbros in order to divide the pressure load, I'm not going to be thrilled about having 3 fuel pumps.
If I have to splice an 044 Bosch in series with the dual Walbros in order to divide the pressure load, I'm not going to be thrilled about having 3 fuel pumps.
Evolving Member
Joined: Dec 2003
Posts: 305
Likes: 0
From: England
Mark
Yes, two pumps in series reduces the overall pressure steps for each pump, and as we both know, it's the step-up in pressure that sharply reduces volumetric capacity, so your solution makes sense. Two pumps in parallel provide greater volume at nominal pressure, but each still has to make the same magnitude of pressurization, so it doesn't solve the pressure issue.
Thanks for that info Mark, I really appreciate it. It also tells me that the 'ATF' figures you are quoting appear fairly comparable to a Dynojet's 'whp' figures.
Thanks for that info Mark, I really appreciate it. It also tells me that the 'ATF' figures you are quoting appear fairly comparable to a Dynojet's 'whp' figures.
Evolving Member
Joined: Dec 2003
Posts: 305
Likes: 0
From: England
Yes, two pumps in series reduces the overall pressure steps for each pump, and as we both know, it's the step-up in pressure that sharply reduces volumetric capacity, so your solution makes sense. Two pumps in parallel provide greater volume at nominal pressure, but each still has to make the same magnitude of pressurization, so it doesn't solve the pressure issue.
Thanks for that info Mark, I really appreciate it. It also tells me that the 'ATF' figures you are quoting appear fairly comparable to a Dynojet's 'whp' figures.
Thanks for that info Mark, I really appreciate it. It also tells me that the 'ATF' figures you are quoting appear fairly comparable to a Dynojet's 'whp' figures.
I have run a GT4088 twin scroll at 2.6bar boost and 4bar base fuel pressure and still 95% injector duty on RC 1000cc injectors and still had more pump left,
As the 044 pressure rises it will reduce its capacity but as this happens the walbro increases its back pressure to it so again adds a bit more pump out of the 044.
Mark
Ted
I have run a GT4088 twin scroll at 2.6bar boost and 4bar base fuel pressure and still 95% injector duty on RC 1000cc injectors and still had more pump left,
As the 044 pressure rises it will reduce its capacity but as this happens the walbro increases its back pressure to it so again adds a bit more pump out of the 044.
Mark
I have run a GT4088 twin scroll at 2.6bar boost and 4bar base fuel pressure and still 95% injector duty on RC 1000cc injectors and still had more pump left,
As the 044 pressure rises it will reduce its capacity but as this happens the walbro increases its back pressure to it so again adds a bit more pump out of the 044.
Mark
Very exciting project Ted!
Thanks for the comments gents.
Aeromotive Compact EFI
The issue with E85 is that is demands 25-30% greater BSFC, which really taxes the volumetric capacity of the fuel system. I'll look into the Bosch. I need to have Drifto engineer a surge tank anyway to prevent starvation in the corners, so we'll do it all in one shot.
Aeromotive Compact EFI
The issue with E85 is that is demands 25-30% greater BSFC, which really taxes the volumetric capacity of the fuel system. I'll look into the Bosch. I need to have Drifto engineer a surge tank anyway to prevent starvation in the corners, so we'll do it all in one shot.
Evolving Member
Joined: Dec 2003
Posts: 305
Likes: 0
From: England
Thanks for the comments gents.
Aeromotive Compact EFI
The issue with E85 is that is demands 25-30% greater BSFC, which really taxes the volumetric capacity of the fuel system. I'll look into the Bosch. I need to have Drifto engineer a surge tank anyway to prevent starvation in the corners, so we'll do it all in one shot.
Aeromotive Compact EFI
The issue with E85 is that is demands 25-30% greater BSFC, which really taxes the volumetric capacity of the fuel system. I'll look into the Bosch. I need to have Drifto engineer a surge tank anyway to prevent starvation in the corners, so we'll do it all in one shot.
All the cars I have come in with that reg always have problems with fueling,
I would only recomend a Small Sard or Kingsler fuel pressure reg,
The last car I had come in with a rated 1000hp fuel system maxed out at 550hp added a bosch and sard reg and it dropped 30% Injector duty and then had to totaly remap transiont enrichment also.
Mark
Thanks again Mark, that info is duly noted and invaluable. I really appreciate your observations. I'll swap in a Sard unit and see if it makes any difference. If it does, I'll pass the Aeromotive onto the BMW.
To everyone else, two products I want to note specifically:
SparkTech Ignition
I've seen this product evolve from a good grass-roots effort to something that looks like it belongs on the space shuttle. It was a bit touchy getting it to work cleanly with the factory ECU in the early days, but that's all been sorted. It works as well as it looks, without so much as a hiccup.
Synapse Synchronic BOV
Initially I was skeptical, but it turns out that this is the quickest, quietest, most foolproof BOV on the market. It works so well, I forget it's there. I only know it's working because there is not a trace of flutter. If you want a toy that chirps and burps, get something else. If you want performance without leakage, get this.
To everyone else, two products I want to note specifically:
SparkTech Ignition
I've seen this product evolve from a good grass-roots effort to something that looks like it belongs on the space shuttle. It was a bit touchy getting it to work cleanly with the factory ECU in the early days, but that's all been sorted. It works as well as it looks, without so much as a hiccup.
Synapse Synchronic BOV
Initially I was skeptical, but it turns out that this is the quickest, quietest, most foolproof BOV on the market. It works so well, I forget it's there. I only know it's working because there is not a trace of flutter. If you want a toy that chirps and burps, get something else. If you want performance without leakage, get this.