Speed Challenger: The Bensopra 380sx

It was about three months ago, on my last trip down to the Kansai area of Japan, that I realized I was standing in front of THE car of 2013. As Ueta-san of BenSopra ran the plans he had for his 180SX-based project by me, it quickly became obvious that there wasn’t going to be one single car at the 2013 Tokyo Auto Salon that would come close to matching the sheer awesomeness of this machine. Needless to say, I was right. BenSopra did it last year with their GT-R, this year it’s the turn of the Nardó Special 380SX.

After what must have been a very long drive up from Kyoto, Ueta-san and his mechanic arrived at the Trust HQ just outside Narita last Thursday, the day before the start of the Tokyo Auto Salon. They had just finished the car the night before and rather than heading straight to the Makuhari Messe they were kind enough to meet me at the Trust so that Sean and I could shoot this impressive creation.

Once the car was unloaded from the transporter there were still some small touches that needed to be made, including applying a few stickers on the car like this custom made 380SX one. The car would then be stickered up at TAS that night by Art Factory, the guys that do about 90% of all the graphics for Japanese tuner and drift cars.

Miura-san has also driven all the way up from Kyoto, skipping a night of sleep in the process. Riding 6 hours in his very firm FR-S had given him serious back pain, but there was no time for rest, the one off BenSopra aero he had created still needed some work. The front bumper needed to be bolted to the splitter and the carbon fiber rear diffuser assembled and fitted to the car.

It all took some time but Sean and I were patient because we knew we would soon have full access to the car that will go down in history as the most extreme Japanese tuner projects ever created.

Of course what makes this car very special is that it combines a very fresh aero treatment…

…with one of the wildest engine swaps ever attempted on a Nissan RPS13.

The whole engine and drivetrain was literally ripped out of the ex-Blitz R35 GT-R that BenSopra based their 2012 project car on and then custom fitted into the much smaller 180SX engine bay. As Ueta tells us it was all a big, three-month long headache, but thankfully they had the masterminds at Trust to lend a helping hand. After creating the custom engine and transmission mounts to hold up and position both the VR38 and the Hollinger sequential transmission in place…

…it was over to Trust for a lot of custom work. The engine was firstly refreshed and fitted with a Trust 4.0L stroker kit and then dropped back in place in its new home.

With two big TD06-25G blowers and a planned V-mount intercooler/radiator set up there was a lot of work that needed to be done…

…and it all started off with a pair of custom fabricated stainless steel exhaust manifolds to position the turbines…

…in a top mounted layout, right next to the two banks of the engine. The external Trust wastegates are right under each TD06, within easy reach if the spring needs to be changed. More custom piping followed, this time aluminum that would plumb the whole intake system to the…

…horizontally positioned twin-entry intercooler. To allow this to fit the front section of the chassis and radiator mounts had to be cut away, a custom subframe fabricated up and bolted in place at the same time as the chassis was prepped prior to the build.

This is Toru Kawashima from Trust, the man responsible for all the custom work and fabrication, seen here holding up a “Nardo Special Edition TK-001″ plaque he made up for the 380SX!

Once the intake charge has been compressed and cooled it’s throttled through these billet 90 mm mechanical throttles, supplied by Osaka GT-R specialist Full Stage,

…and directed into the engine by the Trust larger capacity intake manifold. If by now your are wondering what the point of all of this is, well there is a reason this 180SX chassis needs the 1100 or so horsepower it is currently running. In a few months this car will be driven by Ueta around the famous Nardó high speed ring in the south of Italy where it will be attempting to get as close as possible to the 400 km/h mark (248.5 mph). The event is being organized by Option Magazine who has also invited tuners like Phoenix’s Power and Top Secret to join with their fastest R35 GT-Rs.

As you can imagine when the throttle is pinned to the floor this tuned VR38 has a pretty massive thirst for high octane fuel, which is contained in the 40 L ATL fuel cell…

…fished out and appropriately pressurized by a pair of Bosh Motorsport 044 fuel pumps.

It is then sent via braided lines to the Trust/GReddy fuel rails and onto the 1000 cc/min injectors which will be pretty much maxed out through all of the high speed attempt.

This fuel pressure regulator keeps everything in check. A pair of Trust 13-row oil coolers keep the big V6 within operating temperature…

…while this custom made Full Stage oil separator tank catches all those nasty blow-by fumes.

During the shoot the car was set to a more show-car stance ride height, easily achieved through the custom air-suspension that Full Stage built for the project.

These, much the Roberuta air-cups that a lot of people use in Japan, feature a regular adjustable coilover damper layout with a top-mounted air bag to allow the car to be lifted and dropped by a couple of inches.

Ueta says this suspension will allow the car to be far more stable at high speeds to help with stability around Nardó.

This is of the nicest angles to appreciate the BenSopra overfenders that Miura devised for BenSopra, having a similar rear recess that exposes the tires as done on the FR-S aero.

The wheels of choice for this project are satin black Enkei RS05RRs, measuring a massive 11J across at each corner, 18-inches in diameter. They run Advan A050s semi-slick rubber, 295/30R18 all round, which will hopefully hold up to the abuse of multiple high-speed attempts.

Ueta is confident the car will be able to reach some pretty impressive numbers in Italy, thanks to its custom gearing, potentially being the fastest car there.

A little peek through the driver’s side window reveals a very race-oriented interior. Aside from the custom carbon dashboard that BenSopra created, the 380SX has no trim to speak of…

…as it was all removed and thrown in the trash when the chassis was sent to Saito Roll Cage prior to the build actually starting. There it received a multi-point cage created to not only boost torsional rigidity, but also offer high levels of safety if the worst was to happen.

Ueta purposely didn’t fit the rear gate and side windows so that people at the Tokyo Auto Salon would be able to have a good look inside and appreciate all the work that has been done to the shell.

Ueta will sit in the Bride Zeta III bucket when piloting the car…

…and will be able to keep an eye on a ton of parameters and read out through the AIM digital display. There are two wideband lambda readouts, one for each bank of cylinders, the easiest way to notice if any potential problems with the engine arise.

The custom carbon-look center console is where all switchgear has been laid out on…

…including Trust’s new Profec boost controller which looks like something out of the future!

Engine management is handled by this Vi-Pec V88 stand alone ECU which has so far been set up with a base map. Ueta would have loved to have all fuelling and ignition maps sorted out for when the twin TD06s will run full boost but there isn’t a roller or hub dynamometer out there that can read the actual torque numbers the tuned VR churns out. They have seen 120 kgm (867 lb/ft) on one dyno but then error messages followed as the system maxed out. They are left with no choice but to finalize and fine tune the mapping on the street.

It was truly fascinating listening to Ueta talk about the car and what he hopes to achieve with it. In the short year and a half BenSopra has been active he sure has made a big impact on the Japanese tuning world!

I couldn’t stop looking at the 380SX, sitting there with its massively wide stance, almost awkwardly styled hood that just barely clears the massive twin-turbo V6 that sits under it…

…and of course that raw rear end.

The rear spoiler with the big centrally mounted stays has become a defining factor of both BenSopra and TRA Kyoto and along with the carbon multi-piece diffuser will help keep the rear end firmly pressed onto Nardó’s black top as those rear A050 attempt to unleash the 1100 plus HP. The BNR34 rear end is equipped with an ATS carbon LSD that should help get the best out of the sticky tires.

Along with all the work under the hood Trust also fabricated a one-off, full-straight exhaust system which exits centrally through the diffuser. I though the BenSopra R35 was loud until Ueta started driving the 380SX around the Trust HQ!

The rear bumper wasn’t completed in time for TAS, leaving the chassis exposed. I actually quite like the way the car is at the moment, it somehow looks more functional without a bumper!

To give a little contrast to the flat white body the roof was wrapped in carbon-look vinyl. The large Speedhunters sticker is there to help with performance of course.

The next days will be crucial for Ueta and his mechanic, they need to finalize the set up and engine mapping before the car is loaded onto the container and shipped off to Italy.

If for some reason they won’t make he will have to wait for the next Option event that will be held there.

Knowing Ueta, if the car won’t make it to Nardó I’m sure he will hit a few tracks here in Japan and drift the hell out of it! After what he has told me time and time again, the cars he has so far built have been done for pure fun, so why not enjoy them!

Specs:

Engine: Trust 4L stroker kit, Trust exhaust manifolds, Trust TD06-25G x2, Trust external wastegaes x2, Trust custom straight through exhaust system, Trust custom piping, Trust custom V-mounted twin entry intercooler, Full stage mechanical throttles, Trust intake manifold, ATL 40L fuel cell, Bosh 044 fuel pumps x2, custom surge tanks, braided fuel lines, adjustable FRP, Trust fuel rails, Trust 1000 cc/min injectors, Trust 13-row oil cooler x2, Fulll Stage catch tank, Trust radiator, Vi-PEC V88 ECU

Transmission: Hollinger 6-speed sequential, ORC triple plate clutch, BNR34 rear end, ATS carbon LSD

Suspension: Full Stage air-cupped adjustable coilovers

Wheels & Tires: Enkei RS05RR 11Jx18, Yokohama Advan A050 295/30R18

Exterior: BenSopra X TRA Kyoto full aero, BenSopra one-off hood

Interior: Saito Roll Cage custom multi-point roll cage, spot & seam welded, Bride Zeta III bucker seats x2, BenSopra carbon dashboard, AIM digital dash unit, custom center console, custom switchgear, GReddy Profec B boost controller, custom gear shifter, hydraulic e-brake

Ben Sopra

Trust

Enkei

TRA Kyoto

-Dino Dalle Carbonare

Pictures: Dino & Sean


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222 comments
kayzakiwong
kayzakiwong

What's with the front brakes? the disk is too small ain't  it? Should been replace with a bigger one I suppose..

Karel021
Karel021

with that amount of money spent on this build.. WHY do you install 3xbosch 044  ??? sounds so stupid, if one fails you will probably end up with one rod in 2 pieces or an pistons with an ventilation hole in it. Go for one big instead.. such as weldon 2345 perhaps? 

DavidMcauliffe
DavidMcauliffe

we need videos and sound of this monster going flatout. this car is awesome, so much awsome

bigbenlee1992
bigbenlee1992

omfg that must be a fukin beast! to drive. i wish i had ten mins with it. weird engine choice though for drifting

@turbothomas
@turbothomas

will this aero kit be available to purchase in the US anytime soon?

hanablemoore
hanablemoore

206 comments on one post. love it or hate it this car has to be the most popular car in speedhunters history. LOL. i love the idea and what they are trying to accomplish. I wish them the best of luck and hopeful nothing goes wrong. Even though they are having fun crashing at 240 mph can really mess up your day cage or not it will f*cking hurt. Hope NISSAN  is paying attention to this rwd gtr (basically what it is)and build one too. Because this post generated alot of interest in such a vehicle. I like it without the rear bumper too. It looks raw. i like raw. Anyway excellent car and article. Does anyone have a clue how much is a VR (just the engine) cost in dollars? i m just curious

Miguel Newera
Miguel Newera

Heard something interesting today from the horse's mouth so to speak. The entire fuel system for this car came from www.kinokuni-e.com

Few will know why, but those who have seen their A/N fittings in their hands and know the differences in quaility will...

Nice to see little details like these.

 

JDMized
JDMized

Words on the street suggest this car was not ready to be shipped to Nardo. Not the people involved in this project will have plenty of time to fix some of those aero flaws :)

SteveKeegan
SteveKeegan

Any video of this car driving?  I'd like to hear it open up. 

tenpennyjimmy
tenpennyjimmy

I'd love to join in the controversy on this car but i can't make out the  pictures! Quite often the images on SH appear heavily pixellated on first opening the page and i have to key shift+A to bump the display resolution. Fine. But i've noticed that a few of the recent posts refuse to impove res, no matter how many times i do shift+A. It's frustrating 'cos no matter what else might be said Mr D C, i'm sure the car & photos are gorgeous... i just can't see 'em properly. Any ideas how to fix? Thanks.

Nikhil_P
Nikhil_P

:o this car is nuts!! love how raw the rear of the car looks!

please tell me someone is going to be covering the event!

MichaelOmuteku
MichaelOmuteku

pictures are cool n all, but can we get some video? :O

JMoore
JMoore

Good luck in Nardo!

EricSeanDelaney
EricSeanDelaney

Not sure if I missed it or not, but is it AWD? I assumed it was with the swap from the R35, but not too sure.

Miguel Newera
Miguel Newera

To avoid confusion, this is the air suspension system used: http://www.roberuta.com/english/index.html

These systems by Robertura are fitted to Ferrari 458 and other supercars as factory options. They don't affect suspension performance when not in use.

Chris7opher
Chris7opher

What a crazy build, personally I don't think they will achieve 400Ks, but this is a really unique build none the less. Very cool. 

dareupgang
dareupgang

Like many have said we have to wait and see til project is completed, I think they have adequate power on tap, it comes down to the aerodynamics now, power weight ratio is great but more importantly is finding the balance between coefficient of drag and down force. A lot of people harp on the Bugatti's power but its more its shape and down force that play a key roll 

Turo
Turo

Wowww What a beautiful perfect build!@!! Very clean and innovating for an 180sx!

James Cortez
James Cortez

Folks, here is the fomula to top speed: Assuming no aerodynamics modification, standard car with say 220 HP top 220 km/r. then with 1100 HP the theoretical max achievable is: (1100 HP/220 HP) to the power 0.33333 then multiply all this by 220km/hr = 376 km/hr. 

 

Any comment / remark?

KStyle
KStyle

The best thing about this car for me is the original concept by Kei Miura. Ie without that bonnet/hood. Note that unless they are one and the same the Fuel cell is a Fuel Safe cell and not an ATL fuel cell. There seems to be a general belief that this car/kit was created to break 400km/h. I don't think this is true. Rather it was an opportunity to use a spare motor and to update the rocket bunny kit with some ideas from his (Miuras) FR-S.

I love fanboys
I love fanboys

Hella flush and hella fail, to much form and not enough function. There is 0% chance of this going 400kmph they might as well of said they where Intending to take it to the moon. Cool car I'd love to own it. It's great reading all the comments, apexdna and jdmized and a few others at least seem to have a basic idea on speed. I mean look at other cars competing for top speed records at Lamborghini in nz pushing 1400whp couldn't break 360 and down the Texas mile cars making more power aren't getting 400. Has anyone seen the surface at nardo, it's fucking shit if you wana go 400kmph choose somewhere a bit more safe and sensible. I bet the car doesn't even make it to nardo and even if it does I doubt it breaks 350 or even 330

paul
paul

 @bigbenlee1992 it's being built for top speed, not drifting... he only mentions he'll probably drift it if they don't make it to nardo in time.

speedhunters_dino
speedhunters_dino

 @JDMized Yes looks like they won't be going. I'll pass your message on to Miura-san regarding the aero.

KStyle
KStyle

@EricSeanDelaney Yep. You missed it. It is rwd. Holinger gearbox.

speedhunters_dino
speedhunters_dino

Who knows if they will, I think as Ueta pointed out, the fun will be in finding out if it will or not 

speedhunters_dino
speedhunters_dino

 @JDMized Thanks for your continuous condescending comments Alex. They in no way bring anything to the discussion people are having on here as usual, but since you continue to regurgitate assumed knowledge from your years of experience in Japan, working as a race engineer or whatever you want us to believe your background is, there is one BIG thing you actually seem to completely miss out understanding.  Unlike race teams and exotic tuners from Germany, BenSopra like a ton of shops in Japan aren't engineers, they are tuners, mechanics that have tested their theories over the years, building cars, breaking them, blowing them up, crashing them or whatever. With your vast experience in everything JDM-oriented you should know the spirit a lot of these shops have, the "let's see what the hell we can do with this car and have fun along the way" approach.  If they get results or break records while doing so, it will be a bonus, but for the most part they get on board projects for the ride.  Surely that's a good enough reason to have a bit of fun with your car?  Of course that's, as you keep on putting it, purely my opinion...but if you don't like it that's perfectly fine with me :)

Chris7opher
Chris7opher

 @James Cortez Unfortunately if it was that simple it would be well...that simple. There are so many more things that come into achieving a top speed than what you said. Gear ratios, tire sizes as someone above me mentioned, co efficient of drag, frontal area, altitude, air speed...

 

If it was as simple as you said I think we would all be well paid F1 aerodynamicists. 

Paddy McGrath
Paddy McGrath moderator

 @James Cortez Your theory is sound but the numbers are out slightly - Stock 180SX with 205PS & quoted top speed of 230KM/H with 1100PS = theoretical top speed of 402.662KM/H. Obviously this doesn't take into consideration an awful lot of things...

apex_DNA
apex_DNA

@ I love fanboys

 

Thank you, sir.

AdamMcCorriston
AdamMcCorriston

You know those lambo's curb in at around 1500-2000 pounds more though, right?  Power to weight bro.  As a 700hp 240sx owner, I can attest to the fact that the car is light as hell.  That being said, I haven't recorded speeds higher than 250kms/hr  (A lot of that having to do with aero - or lack thereof)

tenpennyjimmy
tenpennyjimmy

 @sean klingelhoefer Thanks for getting back to me Mr Klingelhoefer. So far tried Firefox and Rastafari, no joy. It's a shame 'cos i had some killer points to make on the debate - was going to sort the whole thing out for you guys ;) Peace.

Chris7opher
Chris7opher

 @speedhunters_dino Oh for sure. It will be awesome to see what they achieve. It's a completely insane build and it made me do one of those head tilts dogs do when they dunno wtf they just saw haha. 

 

As for 400ks though...just a hunch from looking at the shape of the body and some of the open gaps in the front area of the car...it just looks like it has too much drag. I could be wrong and I might eat my words later on, but it just looks like it has enough drag at 200 + mph those gaps are going to be taking a lot of wind resistance in my opinion. Not to mention I don't recall seeing any car break 250mph (correct me if I'm wrong please) with a fixed angle wing that isn't retractable or can change its shape at speed. 

 

One things for certain though: there better be video of this monster at Nardo! 

James Cortez
James Cortez

 @PaddyMcGrath Paddy, read my words carefully, I said "say 220 HP". I don't know how much power the stock 180 sx exactly it puts out. If it's true at 205 HP then yes 1100 HP will, theoretically, give a top speed you quoted. With that size rear wing..... it takes some km/h away at the end... drag

BenS867
BenS867

 @AdamMcCorriston You do realize power to weight matters very little in a top speed car, right? A lot of cars that run at the Bonneville salt flats have ADDED weight to keep them more stable. All about aero and power at that kind of speed

Chris7opher
Chris7opher

 @AdamMcCorriston Are you serious? I have a 335i that has maxed at 250km/h with a factory engine producing maybe 280whp. I find that really hard to believe you can't get to 250k with a 700hp 240SX.

 

I should mention that was non GPS verified and speedo indicated. My 2nd Gen Miata got up to 132mph indicated with 142bhp also non GPS verified but speedo indicated. 

James Cortez
James Cortez

 @PaddyMcGrath Paddy, this formula on max speed applies if everything else remains the same (weight, aerodynamics, friction etc). That's physics they teach in college! My college, OU

SubieNate
SubieNate

 @James Cortez  @PaddyMcGrath Also, aerodynamic drag increases with the square of velocity.  Cd=(2Fd)/(rho*V^2*A)  Basically, given the same frontal area, if V doubles drag goes up by 4x.  If V triples, drag goes up by 9x.  This renders this type of, "If 200 hp gets me to x, then 1000 will get me to y" calculation using simple ratios highly unrealistic.

R
R

 @James Cortez  @PaddyMcGrath i see no sense in these theories... what about different weight, different wheel size, different gearing, aero...

AdamMcCorriston
AdamMcCorriston

 @BenS867 Actually, I did not know that.  Makes perfect sense though.  It's still my favorite ratio though. hahaha

Chris7opher
Chris7opher

 @BenS867  @AdamMcCorriston I was actually going to make that point, thanks for bringing it up. I've never been to Bonneville, but guys do add weight as you said. Interesting point to note when you hear so much about power to weight being everything these days. 

Chris7opher
Chris7opher

 @AdamMcCorriston I hope it cracks 400 as well, it has a certain x factor that I can't really put my finger on. It's just down right bad ass. It's gritty looking and it's raw. I think the chances are slim, but my fingers will be crossed. Good luck guys! 

varilight
varilight

@AdamMcCorriston Read slower/more carefully and you'll see where.

AdamMcCorriston
AdamMcCorriston

You guys sure seem to know what you're talking about.  I gotta be honest, I glazed over a bit reading all the comments.  Thread Hijack aside, This 380sx is bad-ass.  I hope it breaks 400.  I'd love to see my favourite chassis beat the big boys.  Lord knows she's light enough to have a shot.  A few years ago I remember reading something about it being top 5 in least aerodynamic drag, Prius one the top of the list.  (I assume it's for it's class. Cause I imagine lotus' and ferrari's, Bugatti's, etc....are a fair bit more aerodynamic)

AdamMcCorriston
AdamMcCorriston

 @varilight  I searched this whole page, and at no point did anyone mention a mazda.  The referance to my car was stating just that. that the car doesn't have the aero required to go that fast. perhaps this sexy 240 does. 

Chris7opher
Chris7opher

 @SWR If they cracked down on us for having a positive side conversation I would stop visiting this site permanently. With all the garbage going on on these blogs the least speed hunters shoudl be concerned about is two guys having a good side conversation. 

 

We should be able to talk about whatever we want so long as it was sparked by the original post. No one has to read this if they don't want to. We're not calling each other names or belittling Speedhunters so who cares. I don't think Dino or anyone has a problem with it. 

Chris7opher
Chris7opher

 @SWR Shoot me an email or yours, mine is Nb8ch@Hotmail.com

 

Would like to know more about your company etc. 

SWR
SWR

 @chris7opher  "That was well said and in line with what I have been told and read from various experienced engine tuner and designers."

 

Thank you, I hope so or else I would have to quit this engine building business and get a new day job.. :D  I'm a fan of two opposites, I like small turbocharged ones like my GSX-R1342 Turbo or turbocharged ones in general really, and old aircraft engines, Merlins, Allisons, Griffons, you name it. But now we're MILES away from topic of this thread, so maybe we should shut up before they bring the Ban Hammer down on us? :) 

Chris7opher
Chris7opher

 @SWR That was well said and in line with what I have been told and read from various experienced engine tuner and designers. 

 

I'm a huge fan of both types of motors and I suppose it all depends on the application. It's fascinating to me when you consider the amount of variables and design parameters that go into creating a motor with a usable powerband for circuit racing or a top end power band for top speed racing. You reminded me of a couple things I had forgotten over the years. It's been a while since I've built a motor or even gone to a track day with my kart. Need to get back at it, managing business projects just drains that free time! 

 

I like 2 valve and 4 valve engines, V8s and 4 cylinders, I really don't have a preference, but I do love the feeling of big torque. I've raced things that weighed 1200lbs with 300hp K20s and I've driven as I mentioned a 2013 twin turbo V8 mercedes. 

 

It all depends on the application. I wouldn't build a hill climb car the same way I would build a circuit car nor a top speed car. Right now I'm really into karting, but I would love to do a Zcars mini eventually with a turbo K24.

SWR
SWR

 I talk about most any 2-valve head, really. You can only stuff "that big" of a valve in there for a given bore size before the bore itself - or the fact you need an exhaust valve to share the room with it - becomes the masking of the flow curtain. 53.5-54% of the bore area is what we work with these days. Any more and you're on the path of diminishing results as the achitecture itself becomes the limiing factor. 

 

And the lifts you need to make that valve really flow some when you can't stuff a bigger valve in there is easily outpaced in cfm's by a moderate sized 4-valve head (using maybe just 50% of the bore area) with a much gentler peak lift value. Most ALL single-intake engines are valve limited flow-wise, that's the stick in the spokes that holds the design back. Not dissing the Cup guys in any way, they do an awesome job with what they got.

 

Sure, you CAN make a maxed out 2-valve flow the same as a 4-valve one if you spend enough hours and cubic dollars at it, but the latter has an easier time by far. As for the engine, it just knows what flow it's getting at that point in the cycle, it has no idea if it has 1, 2, 3 or 4 intake valves and you can open up a considerably bigger window sooner with twin intakes. Neither does the engine know the valve angles, the port shape, or anything. All that comes down to how much flow is available to fill the "piston demand" when the cylinder asks for it and a 4-valve can deliver that a lot easier.

 

Then again, BIG flow is not the most needed (any idiot can make a big hole that flows like a drain pipe IF he can physically fit the valve, which is the REAL showstopper, not the port) at all, screw up the port areas, shape and velocity and you can have all the flow on the bench you want, it will be a dog until you're far up in midrange, then it will just rocket off (if it ever gets on song before it hits the limiter). The tricky thing about porting not making the cfm, but making the most efficient shape to manage the velocity (priority 1!) and then make it flow enough through that shape. :)

 

Chris7opher
Chris7opher

 @SWR  @AdamMcCorriston Are you referring to a push rod style motor when you talk about a 2 valve engine? I've seen it debated that 1 large intake valve can flow just as much air as a 2 valve because you are dealing with less area when you try to stuff 4 valves into the head of a motor. 

 

As far as air flow capacity that does have to do with the valves, but it also has to do with so many other things: the way the air gets to the head, the porting of the head itself, angle the valves and seats are cut at. You can certainly flow air on a 2 valve head. When I was studying Nascar engines at school I came across an interesting article. If you're interested check this out. It's a comparison of F1 V8s to Nascar V8s with some very interesting results: 

 

http://www.epi-eng.com/piston_engine_technology/comparison_of_cup_to_f1.htm

 

Obviously the F1 engine is going to be lighter and uses materials that are leaps and bounds beyond Nascar, but consider what the Cup guys are using and it's actually extraordinary what they are able to accomplish. 

 

 

SWR
SWR

 @AdamMcCorriston

 As for the stroke being a limitation to the rpm you make power at, it isn't as long as long as it's strong enough to hold together. A Pro Stock engine has about 95mm stroke and make NA power at about 10500 rpm these days. Boost it or drop 4-valve heads on it and it would go further. It's all about airflow capability, a 2-valve head within the PS rules just can't breathe to much more. I have seen 100+mm (that's 4" stroke) rev 14 000 rpm in a 4-valve turbo import drag application and no, they did not tear it down after every run, so it did have decent life for such an extreme application, 25 passes or so. :)

Chris7opher
Chris7opher

 @varilight  @AdamMcCorriston Will not do * damn I'm telling you these typos are killing me. I need to get a PA to proof read all my posts lately. Blame it on Le Blond. 

Chris7opher
Chris7opher

 @varilight  @Chris7opher  @AdamMcCorriston We were having a side conversation that was independent of the main topic by the original poster. 

 

They aren't relevant to the 400kmh challenge at all haha. However, I do not think the car in this feature will do 400km/h because of the huge rear wing and the over all shape of the body. I'm not a pro aerodynamicist so I could be talking complete and utter shit, but I've studied guys like Luigi Colani in depth (who is one of the worlds leading aerodynamicists) and just based on the shape of the front end and the rear wing I don't think this car will achieve 400ks.

 

It's a super badass build and I think it would be an absolute monster on a circuit, but as far as top speed I just don't see the aero. I'm really hoping there is video coverage of this car so I can see how accurate my initial observations were. I'm just speculating, but I know it takes a lot of power to achieve 250 + mph and it takes aero more than top speed. 

 

Research Luigi Colani, he is a brilliant designer who has been designing cars since the 40s. He's getting very old now and it's a shame he was never a "tuner" of sorts. Here is a link to some of his work: 

 

http://www.youtube.com/watch?v=xEhm416KXYo

Chris7opher
Chris7opher

 @AdamMcCorriston I wouldn't imagine long. I trained under guys who built Nascar V8s and the piston speed of a motor has a large influence on how long components will last if I recall correclty. This is why all F1 motors are such short stroke. If you have a shorter stroke you have to rev the hell out of a motor to produce power and if you have a longer stroke you run a risk at higher revs. Yeah I mean a lot of engine packages are good to x RPM it just depends on how long they'll last at the aforementioned limitations.

 

I forget all the tiny nuances because it's been so long since I've studied this stuff in depth, but I know 12,000 RPM on a stroked SR20 set an alarm off in my head.  Peak at 9k and redline at 10,200 seems like you are already approaching the limits of a stroked motor. If someone with engineering experience can chime in on this I would greatly appreciate it. I'll do some research after I post this to see what I can dig up. 

 

I race two stroke karts and I'm a humble student by all means. The engine I race can rev to 17,000 rpm but peak power is produced somewhere around 14-15 thousand. We run a restricted carb that tops at 15,500rpm and the life of the motor is improved around 40% just be revving 2-3k under the maximum RPM possible. 

 

After 15,500 there isn't really an increase in horsepower or torque produced so it's almost pointless to rev to 17. In fact on some kart tracks you actually pick up time in the corners because the air flow of the smaller carb produced more midrange which is essential to maintaining power in a corner. The tighter the track the more the smaller carb is favored. The bigger carb pulls on the straights which makes up a ton of time, but if you ran a track that was made of constant corners you would struggle to get in the power band of the larger carbureted engine. 

 

Either way, 700whp in anything is pretty badass. I drove a 600 + hp 2013 Benz a few months ago and even though the car was 3800lbs or so I was still amazed at how fast it was on the street. Unless you're doing time attack and seriously competing with a car IMO 500-600whp is mental on the street. I've been in a Carrera GT before too which was absolutely insane and over kill. 

 

Thats what I think keeps me interested in cars though...they are so dynamic and what is fast in one application is slow or cumbersome in another. It's such a dynamic world of tuning and philosophy. Speed Hunters brings it all to the table and has something for everyone. Cool to talk to someone as humble as you who clearly gets it and seems practical in his quest for speed. 

 

 

varilight
varilight

@Chris7opher @AdamMcCorriston I don't see how your 335i or Mazda are relevant in any way. You do know as you go faster you need much more horsepower or failing that, being very slippery(aerodynamic).

AdamMcCorriston
AdamMcCorriston

 @AdamMcCorriston A few on my facebook, but the swap only about a season old, so not much vid.  Tomei and Mazworx say it's good to 12'000 rpm.  I don't know how long it'd last there though.  I made peak power at 8700 with the old turbo,, (well,,,,,,,, that's the point the rollers spun) right now it's tuned to 10'200 rpm with the current setup. but makes peak at 9k

Chris7opher
Chris7opher

 @AdamMcCorriston Understandable. 12,000rpm redline? I've never heard of that in an SR, but then again I don't really follow that scene a whole lot. Are there any videos of it? 

AdamMcCorriston
AdamMcCorriston

@AdamMcCorriston Ahhh no sir, that's WHP.  lol  SR. tomei 2.2 stroker. but she's closer to a 2.3.  9.5:1 comp pistons,, 284 cams, half inch head studs, bully built race motor, spared no expense, Built and balanced by mazworx.  T42 turbo, 2000cc Injector dynamics.  12k rpm redline.  made 680 wheel @ 28psi and spun the dyno.  We assume it would have hit higher than 7, but we didn't get it on paper. Since then It's  been paired with a GTX38 at 16psi and wayyyy smaller injectors, and is making only 580,, but is much more streetable.  HAve to ditch my Power FC and get a differant standalone to tune low end drivability - And - peak power.  (right now i have to sacrifice one for the other due to limits in Apex'i and datalogit's software

Chris7opher
Chris7opher

 @AdamMcCorriston Good points, it all depends on what youre going for with your build. Top speed isn't a huge deal (to me) and to be honest if I had a 240SX with a good cooling system and 700bhp I would probably gear the car to top out around 170mph (if I had enough money to buy a customer trans for the application). Sounds like you need to look at your cooling system's flow and the size of your radiator etc. 

 

If you're into designing and doing work yourself I would advise reading A. Graham Bell's book "forced induction tuning." lots of good information on cooling systems, formulas for radiator sizes etc. 

 

A properly built 240 with 700bhp would be an absolute monster on the track. Are you running a turbo SR20 or are you working with a swap like an LS or something? 

 

 

AdamMcCorriston
AdamMcCorriston

Couldn't hold it for long enough to climb higher.  I was watching my intake and water temps climb by the second.  Also, this was on public roads,  Haven't had a chance to get her on an airstrip or anywhere safe enough to do it. I'm kinda depressed now, hearing that your stock 3 would hit that.  She pulls hard as fuck to 240. then she slows off a bit, but still climbs.  Gearing is a factor too. I'm running an R32 GTR Diff, so my final drive suffers. but accells quicker.    If I put a 300zx trans in and swapped my final drive it would make worlds of differance

 


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