posted on July 02, 2012 00:00
Team America World Time Attack - ARK Design's BNR32 Skyline GT-R Part 7
By Mike Kojima and Eric Hsu
The clock is tearing itself through the calendar and there is only a week left before Team America's ARK Design BNR32 is scheduled to be loaded into a shipping container bound for Australia. Eric and the crew are determined to make it but personally I have my doubts. I have never seen a car this complex be built in such a short time for such a low budget.
A crack allstar industry crew of volunteers was swarming over the car which included guys like Gary Castillo, Eric Hsu, Tyler Hara, Ken Anderson, Peter Yeung, Brian Bridges, Hung Huynh, Kyoung Choi, Len Higa, Steve Mitchell, Kenji Sumino, Ben Schwartz, Katsu Hibio and probably a few others I don't know about.
This is being written during the car's final push, by the time you read this, the car will have been shipped. I was not around for it being involved myself with prepping two cars for the Falken Drift team heading for The Wall, New Jersey so there will be more updates to come still, probably by Eric.
Read More about Team America Here!
|The next thing was to dress the Cosworth engine to get it ready to install in the car so that fabrication of the turbo system could start as well as the plumbing. Here Eric discusses with Gary over how he wants the VQ35HR's upper pan to be modified to work with the dry sump system.
|It was quicker to weld in the pickup to the lower pan rather than re-machine a new one so that was done that way.
|Eric prepping the upper pan for another scavenge pickup so Gary could weld it in.
|Gary about to lay down some beads. It is kinda hard to lay down a clean weld in an aluminum casting due to the porosity. A used part that has been exposed to oil is also hard, the oil gets into the pores and contaminates the weld a little. Welds can be strong but they won't always look pretty.
Posted in: Magazine
, Beyond the Dyno
, Project Cars
, Time Attack
, Skyline GT-R
, 2012 WTAC
, Project Nissan BNR32 Time Attack Skyline GT-R
Monday, July 02, 2012 1:58 AM
Wow! A really comprehensive update and enjoyable read. Thanks Mike/Eric.
Monday, July 02, 2012 2:14 AM
Nice update! Just wondering what the advantages of Threebond sealer are vs the standard Permatex grey.
Monday, July 02, 2012 4:05 AM
Shipping an unfinished never-driven completely out-of-the-norm project with all custom made solutions to the other side of the planet to be finished in a borrowed shop before the event, you guys are crazy! I seriously hope you can pull it through and get the car driveable in time for the competition to make the effort worthwhile.
Monday, July 02, 2012 4:22 AM
Whats with using Carrillo rods? not saying thats a bad thing but assumed you'd use Cosworth ones, guessing your using a custom built Cosworth engine for next year and didnt have time to design it this year?
Monday, July 02, 2012 5:11 AM
Is borg warner hiding this sort of thing:
A quick spool valve that is closed on low rpm on one side of the twin entry turbine housing
Monday, July 02, 2012 5:13 AM
damn Motary beat me to it.
Monday, July 02, 2012 5:26 AM
I thought about the same as Motary, but the exhaust manifold setup seems to be divided fully all the way (as of course it should be), so I don't think it's that. Also from my experience the turbine wheel doesn't work very well if only half of the blade area is used. I could be wrong though, if they are using a modified version of that concept there.
Personally I would've expected a WRC style spool up strategy on this build, as bang-bang antilag hasn't been used there much since forever ago.
Monday, July 02, 2012 7:40 AM
I once had a piece of a wastegate flapper get stuck in one of the volutes, closing off flow to half the turbine. I still had an external wastegate after the internal (special design, long story) to control boost. Long story short, you lose spool and power, not suggested :)
Monday, July 02, 2012 9:46 AM
I see everyone else beat me to the QSV thingie... possibly a more advanced form of it; I mean, the SP version is far from optimized. As for bangbang, there's more advanced and better forms nowadays that are supposedly a lot easier on turbos while working better... which I'd reckon Eric would know full well about. I suspect they were just up against time constraints preventing full balls out solutions, you know, as opposed to the mostly balls out solutions they did do. ;)
Flat out excellent work for the time constraints. I guess that's just one of the differences with professionals as opposed to us who just do stuff for a hobby.
Monday, July 02, 2012 9:54 AM
I think it is something like that. Notice in the 2nd picture where his hand is hiding the thing, there are two separate flanges? I'm guessing the valve is designed so that when it is open, it is fully divided all the way, but when closed, allows all runners to use a single volute of the turbine housing.
Monday, July 02, 2012 10:02 AM
That "spool valve" seems to have a pretty big stack height. My guess is that instead of just blocking one volute, which wouldn't work very good on a full divorced twin scroll, it will actually divert one half and merge it into the other half. You will lose the pulse managing of the split system but the flow benefits will outweigh this during the beginning of turbo spool.
Monday, July 02, 2012 10:04 AM
sethulrich beat me to it and posted while I was typing.
Monday, July 02, 2012 10:26 AM
Or hell, look at the title image dealie; whoops! Googling quickly I actually came across a few other examples where people have built devices of this sort that retain twin scroll function after it switches over (as opposed to the SP one) so it's not rocket surgery.
Monday, July 02, 2012 12:11 PM
QSVs are garbage and won't hold up to real race use; they are just bandaids for being cheap and not doing a proper twin-scroll setup. This seutp however is a proper twin-scroll setup with each bank of cylinders being compeletly separated from each other all the way to the turbine wheel.
Let's just say it is a QSV. Either #1, it completely blocks off one bank of cylinders turing the 3.5L V6 into a 1.75L inline-3, or the two flows from each bank merge together eliminating pulse separation and a significant benefit of going twin-scroll in the first place.
My guess? A quick adapter to allow for an anti-lag system instead of having to modify your exhaust manifold for anti-lag.
Monday, July 02, 2012 12:18 PM
Very exciting! I can't wait to see power output. The Tibuc should allow for enough bypass and if not, the throttle can be opened. I wouldn't worry about keeping it spooled with a 3.5 liter and proper antilag.
Monday, July 02, 2012 12:35 PM
Even with a fresh air valve in the exhaust, you still need air to pass the throttle. You also need a pretty sophisticated "boost pack" with an accumulator and a number of high speed valves if you are using a pneumatic wastegate type valve or a very expensive electronic valve. All of the fresh air systems used in WRC/SuperGT/LMP are custom made and mega expensive if you aren't a fabricator/machinist. I don't see borg warner (or garrett for that matter) offering this to the public.
Monday, July 02, 2012 1:04 PM
The concept isn't retarded though, even if SP's implementation is. What's the fundamental difference between a valve that closes off one volute of a twin scroll housing and a VGT, aside from number of steps it can adjust the turbine AR to? I mean you have to admit that an 0.52AR housing is going to have a boost threshold a lot lower in the RPM band than a 1.05AR housing and a magical black box that would let you switch from one to the other at whatever point in the powerband you wanted would be handy. And it's not that difficult to imagine a mechanism whereby, when not closing off one of the volutes, the flow through both sides remains separated with no real additional flow restriction.
Monday, July 02, 2012 1:14 PM
@Kenku, the concept of the QSV is basically two-step A/R (big and small) on a turbo system not designed as twin-scroll; hence why I say it's a bandaid design. Though, this type of design was used on the Acura RDX with the 2.3L K-series and an IHI turbo (I think IHI, maybe MHI). Note that engine/turbo setup is no longer sold and no one else has bothered using it. There's a reason for that.
I could design you a QSV right now that keeps the volutes seperated when the valve is closed preserving the pulse separation. However, durability is still an issue. I could design it to be pretty robust I think, but the actuator forces are going to be pretty damn high too so you'd need a beefy actuator, beefy bracketing, etc. Anyways, I'm just not a fan of the concept as I see compromises in performance and durability.
@Bill, so when's that anti-lag system article coming ;)
Monday, July 02, 2012 1:25 PM
Yes, I was just about to say that I need Bill to tell us some more about his antilag knowledge. I am only aware of the details of operation of the bang bang systems and not the newer technology.
Monday, July 02, 2012 1:29 PM
So did it make the container and if so how much time do you have prior to the event to work on it out in Aus?
Monday, July 02, 2012 1:44 PM
@spdracerut, I could design one like that myself, was my point. Yeah, it's not going to be twin scroll when it's choked to one volute, but it's going to be a lot easier to make robust than would a "real" VNT setup. I also have a suspicion than when you got the flapper off its seat (the position where it's closing off one of the volutes) the actuation force would drop quite a bit. Durability doesn't seem that hard; yeah it's exposed to exhaust gas, but the twin scroll dividers tend to be something like 1/8th to 1/4" thick... a similarly thick piece of stainless in the exhaust path should be relatively troublefree.
Not to say it wouldn't take development and whatnot to get it all to work right, but... fundamentally, from having studied antilag shit a bit, I can't think of any implementation that would use something looking like that, whereas somethng to close off a volute driven by a wastegate actuator or somesuch would.
FYI, Mazda did the same thing as the SP QSV on the S4 RX-7s, though I'll not try to defend it as a good implementation.
Monday, July 02, 2012 2:53 PM
Any concern over the secondaries from the manifolds to the bellows cracking? Seems like a lot of metal is hanging off of there.
Monday, July 02, 2012 3:22 PM
The secret Borg part has me laughing. I was working on a similar part/patent when I was at Volvo Powertrain but found some old patents that were too similar and would have relied on prior art. Nissan had an old one and International had one from 07 and Borg had one pending as well...so I'm think I know EXACTLY what that is...think
All in all looking good for being so rushed. I know the feeling personally. Time for me to get to back to rushing up a new intake manifold for UTCC.
Monday, July 02, 2012 4:38 PM
Micah by the time you finish your car there wont be any fossil fuels left mate :)
Monday, July 02, 2012 4:53 PM
Haha I actually owe you a call. As for my personal cars, I don't have time, though I have more now that I'm done consulting for OEMs :)
The manifold I mentioned, you should see in NJ or we may just bring it to you at Buttonwillow.
Monday, July 02, 2012 4:54 PM
I am however bummed to see the turbo location make this car non-GTA legal.
Monday, July 02, 2012 5:57 PM
Does it really? I figured mods like this are on a case by case approval basis. I know if they put it to the teams at all I would vote to let this car run GTA!
Monday, July 02, 2012 10:07 PM
I always wondered what the most genius minds in the sport compact world could do if given free reign over any car they chose. This car definitely shows what ingenuity is still left in the tuning world. Hopefully more shops get the idea to be more creative and build some more crazy cars like this.
I'm looking forward to the second iteration of this car once it gets home. It should be wicked!
Tuesday, July 03, 2012 1:50 AM
I'm surprised no one even thought about variable vein on the turbo over a QSV....
I'm a little surprised you are going with a big single over twins. There is not much room, but it is possible to fit 6258 in a V6. It would be more weight in turbos, but less in exhaust manifolds & intercooler piping. There is a give & take with everything though.
Tuesday, July 03, 2012 9:34 AM
Yeah Mike, I'm hoping they get a waiver or relocate the turbo...or something as I'd like to see them play stateside. As called out in the rules and further explained via text and numerous phone calls; the stock floor pan cannot be altered. This was then explained to be as the area of the car form the front bulkhead back to the rise for the rear seat (where the factory tank is in our Imprezas).
Tuesday, July 03, 2012 11:04 AM
We will never be relocating the turbo so if GTA would like us to run, they'll have to give us a pass on that one. Hopefully I can get Nads to let us slide.
Twins are heavy, present packaging issues, introduce way more plumbing to the car with only benefit being transient response. On the street, tight little track, or autocross that might be critical, but on a large, high speed course like Eastern Creek, it means very little with anti-lag, TiAL turbine wheels, a sequential transmission, and shift cut strategies.
We have no fear of bellows cracking. I've found that the longer pre-turbine exhaust plumbing, the less you need to worry about cracking. The shorter, the shittier unless you are using cast pipe (e.g. Full-Race style).
We can't wait for the second rendition of this car either!
Tuesday, July 03, 2012 11:40 AM
Eric: I wasn't concerned about the bellows cracking, or cracking near the bellows, but cracking near the manifolds themselves. It seems that's a pretty big cantilever from the length of the secondary pipes coming from the manifolds.
That being said, the location of the turbo is pure genius. Hopefully a waiver will happen, as I believe your reason for messing with the pan doesn't violate the intent of the rules, just the letter.
Tuesday, July 03, 2012 12:59 PM
Steve, there looks to be a brace supporting the weight of the turbo which should take the load off the manifold.
Tuesday, July 03, 2012 3:30 PM
Tuesday, July 03, 2012 3:33 PM
Eric, I'm not upset at all. The whole reason we front mounted the turbo this year instead of doing the passenger foot well was because of the current floor pan rule. If you guys can get it passed, I'll be right behind you in asking for permission!
-your fellow rulebook studier/nazi/whore....whatever :)
Tuesday, July 03, 2012 11:42 PM
Even though the team has heard it many times before, I can't wait to see how this project does and hope you guys have a good time.
Wednesday, July 04, 2012 12:44 PM
I was suprised no mention of an AEM filter because last night I saw that a Motoiq Senior Editor and Chief Engine Tuner of the Sierra Sierra Evo recomends them ;)
As a point of question for the turbo placement, had you guys ever thought about an STS style mounted near the rear diffuser to put the weight back even further and not compromise the main pan? Just wondering about the thought process, because I know it's somewhere floating in the Pacific!
Sunday, July 08, 2012 2:39 AM
Bruce: AEM filter mention coming in the next installment :)
As for turbo placement, going to far back behind the rear axle isn't ideal either. You know how the old 911's handled right? There's this giant weight on the right hand side of the car called a Tarzan. So using the turbo, exhaust, and wastegates to offset the Tarzan is actually a pretty ideal situation. Or at least this was our thought process. We'll see after the car goes on the corner weight scales.
Tuesday, July 17, 2012 3:50 PM
Did the car make it onto a container? or Did you guys not make the deadline? Let me know! So I can decide if I should buy tickets to Sydney or not!
Wednesday, July 18, 2012 9:46 PM
Thursday, July 26, 2012 2:36 PM
I am chomping at the bit here... 14 days!
I really thought a portion of that "asain nascar" team was going to be locked up in that shipping container with the r32, working away, lol.
Congrats on making the top ten tuners of the past 10 years Eric.
Friday, July 27, 2012 1:38 PM
Bwahahaha! Imagine what the customs folks would say in Australia? A shipping container coming FROM America full of spent PBR cans, human excrement, Asian dudes, and a sick Skyline...
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