Early 70s Japanese race car aero

[Mikelly]

One of the issues the windtunnel engineer keyed in on at our dyno test in North Carolina was the issue of all the sharp and abrupt edges on the S30. the edges at the top to side of fender transition, the sharp edges at the nose and headlight buckets. He refered several times to my 996Turbo sitting in the parking lot as contrast to the 30+ year old technology of these Early Zs. Here's the real issue though, Do you change the look of the Z so much that it loses all resembelance of a Datsun Z car? I think we need balance here, and maybe baselining a period correct works racecar would show great benefit for improving on the chassis without making it into some transformer-ish car that sort of looks like an early Z... Sort of... It' depends on each owner's goal.

 

And I'm 110% sure you couldn't take $500 in materials and make a Gnose... No way, no how. I almost bought into a fiberglass/composit business. To do it right and make a quality part that will last will cost you a lot more in time and materials than one could imagine.

 

Mike

[JMortensen]

I like the "probably" above. PROBABLY Nissan had more substantial butget than $500, and tested more than one type of G-nose (as ilustrated by posts right on the begining). PROBABLY while at it, they have tried various configurations of: cooling ducts, vents, undertray plates, wheel arches, side sils and maybe EVEN rear spoilers.

Reality is in direct conflict with your statement here. If they tried all these things, why did we end up with a car that is so poor aerodynamically speaking??? Or are you saying that they only did the testing for the G nose, and none of it for the production car that sold over 1,000,000 copies? I don't think they tried any of this stuff or if they did, they didn't evaluate it in terms of drag and lift. I think a person penned a design and they built it. The G nose is the same way. I swear I read only a week or so ago that they changed the ducting or added some ducting to it as a result of overheating problems. Seems like they would have had all of that figured out had it been so thoroughly tested. I don't think aerodynamics was really on the radar too much at that time. In fact I'd be really surprised if the Z wasn't advertised as aerodynamic by Nissan purely based on the way it LOOKS, even though the design is less that aerodynamic in actuality.

 

What has changed all those years in aerodynamics? Look at planes to get your answer. What can you change on your Z car to make it more slipery and still look like Z instead Pikes Peak Audi sport quattro? Not much.

Cars on the road now have cd's of less than .3. An internet group can get together and procure a day's testing in a wind tunnel. We have had 35 years of advancements to draw from. I can go to a bookstore and buy a book like Race Car Aerodynamics: Designing for Speed. What HASN'T changed?

 

As to the appearance of the car, this is Hybrid Z, not classiczcars.com. If I were looking to design a new nose specifically to have less drag and lift, it WOULDN'T look like a Z front end when I was done, and I would be absolutely fine with that. And if I were trying to make the front end more slippery about the LAST thing it would look like is a Pikes Peak car. Pikes Peak cars are built for 1000s of lbs of downforce, not low cd.

 

Also, what is a point of comparing - don't get me wrong, I think it is great idea in itself, if done right - stock car with g-nose car and than admiting of shortcoming of g-nose instalation?

Absolutely nothing. Go for it.

 

Maybe Alans G-nosed Z - which I belive is true replica of period racing Z, with the ducts and all - has to be wind-tunel tested and used as a benchmark for all subsequent comparisions.

Again, go for it. Make sure you use the same wind tunnel so our comparisons can be accurate.

 

Looks like we are trying reinvent a wheel here, just can not agree if it should be square or more like a triangle.

You do realize what site this is, right???

 

And I'm 110% sure you couldn't take $500 in materials and make a Gnose... No way, no how. I almost bought into a fiberglass/composit business. To do it right and make a quality part that will last will cost you a lot more in time and materials than one could imagine.

Maybe blueovalz or 74_5.0L_Z will give us an idea of what it takes, but the materials invovled are not that expensive. Making molds to mass produce parts is one thing. Doing a glass over foam type of deal in your garage is not.

[29PGC10]

This tread is definitely not about "Early 70s Japanese race car aero". I think I do have something to contribute to the above tread - period pictures of Z racing in South Africa - some of them before the cars were painted, revealing all the additional parts/spoilers on those cars. Than what is the point: the loudest of you know better.

I belive that any works racing outfit has the reason and means to develop the technology to win, therefore it is worth to look back and study those efforts. Datman might have access to wind-tunel in England, that where Alan lives. Alan, please for the forum knowledge sake, contact Datman and just do it. I don't know much about wind-tunels but somehow don't belive the results from two different sites would be different.

 

For those who do not mind your Z to look nothing like one, I have solution for you: Just stick Z emblem on whatever machine you fancy, providing it has drag coeficient of less than .3 and of you go: different engine, suspension, drivetrain, body that does not resemble Nissan at all. You realize what site it is right???

Than if you think that reading A book makes you an expert in aerodynamics, I will have to rest my case.

 

Regards m

[HS30-H]

The Gnose isn't the magic bullet. Never was, never will be.

 

If they tried all these things, why did we end up with a car that is so poor aerodynamically speaking??? Or are you saying that they only did the testing for the G nose, and none of it for the production car that sold over 1,000,000 copies? I don't think they tried any of this stuff or if they did, they didn't evaluate it in terms of drag and lift. I think a person penned a design and they built it. The G nose is the same way.

 

There's some pretty fundamental misunderstanding going on here. I'll try to keep this short and to the point, but here are a few facts that I hope will help keep this discussion of the 'G-nose' in focus:

 

First of all, the 'HS30-H' Fairlady 240ZG model - as sold to the public in Japan - was not an exercise in selling a prettied-up ( or uglied-up, depending on your viewpoint ) version of the S30-series Z just for the hell of it, or a statement in state-of-the-art aerodynamics. It was an 'HOMOLOGATION SPECIAL', built and sold specifically to legalise the use of special body parts in the JAF/FIA Group 4 race category. Unless Nissan made and sold over 500 of these so-equipped cars during a stipulated period, they would not be allowed to use the parts as a base on which to build their Gr.4 and Gr.5 race cars.

 

So nobody said that the Fairlady 240ZG model - or by association the special G-nose parts sold separately - was any kind of "magic bullet". It did improve the top speed capability of the road car slightly, and it was claimed to aid high speed stability too, but it was never sold as some kind of 'cure-all' for the shortcomings of the standard S30-series Z body. The Fairlady 240ZG only existed because it was necessary for it to exist.

 

Here's what people seem to be forgetting: The factory race G-nose was always intended to be used with an additional front spoiler / air dam, and as long as these were freely available to be bought over the counter by the general public, and would fit the standard road 240ZG, then they were legal for race use. Testing the standard road car style G-Nose ( without a spoiler or air dam ) as though it is a race car part ON ITS OWN is to completely miss the point.

 

As for the standard body of the S30-series Z car; anybody who thinks that the factory and the designers never paid a thought to aerodynamics is not in command of the full facts. Aerodynamics were tested, but any radical changes to the basic design as a road car were thought unnecessary, as the car would perform well enough in the parameters of normal ( legal! ) road use. Is everybody forgetting that these were road cars we are talking about here? The road car was good enough for the times and people it was created for.

 

I swear I read only a week or so ago that they changed the ducting or added some ducting to it as a result of overheating problems. Seems like they would have had all of that figured out had it been so thoroughly tested.

 

Again, you are getting data for the road model mixed up with your thoughts about the race cars. Do you not understand that the road ( homologation ) model - the 'HS30-H' Fairlady 240ZG - was only made in order to legalise base body parts for the race program. Citing the road model in your discussion of the aerodynamics of the race cars is to completely miss the point of what the road car was made for.

 

I see people on this thread saying they can do "better" now than Nissan did over 36 years ago. So what? "Go for it". Maybe they can. But don't forget that replicas of the factory works-style G-nose, with the final version deep front air dam / spoiler and all the associated Gr.4 / Gr.5 parts are still readily available and will fit a car without too much pain. They were used to good effect in-period, and are pretty much a known quantity.

 

Feel free to draw, design, build and test whatever you want - but don't write everything from the early Seventies off as though it is some sort of prehistoric junk. I think you'll find that a lot of the time - even given a clean sheet of paper - you'll come up with something that doesn't look a million miles away from what was done 36 years ago.

 

Throwing in those "this isn't classiczcars.com" comments seems so unnecessary. We all know what forum we are on here, and I think that what we are discussing here is relevant and appropriate to what HybridZ is about.

 

 

 

Alan T.

[ZROSSA]

Made my own front end.

 

http://album.hybridz.org/showphoto.php?photo=6307&cat=500&ppuser=8086

 

This is an old photo as the car now has flares as well. It did cost somewhat more then $500.00 to make the molds and took a really long time to sand and get the shape right. Hopefully with the undertay and ducting to the radiator it will be an improvement.

 

Douglas

[Mikelly]

There's some pretty fundamental misunderstanding going on here. I'll try to keep this short and to the point, but here are a few facts that I hope will help keep this discussion of the 'G-nose' in focus:

 

First of all, the 'HS30-H' Fairlady 240ZG model - as sold to the public in Japan - was not an exercise in selling a prettied-up ( or uglied-up, depending on your viewpoint ) version of the S30-series Z just for the hell of it, or a statement in state-of-the-art aerodynamics. It was an 'HOMOLOGATION SPECIAL', built and sold specifically to legalise the use of special body parts in the JAF/FIA Group 4 race category. Unless Nissan made and sold over 500 of these so-equipped cars during a stipulated period, they would not be allowed to use the parts as a base on which to build their Gr.4 and Gr.5 race cars.

 

So nobody said that the Fairlady 240ZG model - or by association the special G-nose parts sold separately - was any kind of "magic bullet". It did improve the top speed capability of the road car slightly, and it was claimed to aid high speed stability too, but it was never sold as some kind of 'cure-all' for the shortcomings of the standard S30-series Z body. The Fairlady 240ZG only existed because it was necessary for it to exist.

 

Here's what people seem to be forgetting: The factory race G-nose was always intended to be used with an additional front spoiler / air dam, and as long as these were freely available to be bought over the counter by the general public, and would fit the standard road 240ZG, then they were legal for race use. Testing the standard road car style G-Nose ( without a spoiler or air dam ) as though it is a race car part ON ITS OWN is to completely miss the point.

 

As for the standard body of the S30-series Z car; anybody who thinks that the factory and the designers never paid a thought to aerodynamics is not in command of the full facts. Aerodynamics were tested, but any radical changes to the basic design as a road car were thought unnecessary, as the car would perform well enough in the parameters of normal ( legal! ) road use. Is everybody forgetting that these were road cars we are talking about here? The road car was good enough for the times and people it was created for.

 

 

 

Again, you are getting data for the road model mixed up with your thoughts about the race cars. Do you not understand that the road ( homologation ) model - the 'HS30-H' Fairlady 240ZG - was only made in order to legalise base body parts for the race program. Citing the road model in your discussion of the aerodynamics of the race cars is to completely miss the point of what the road car was made for.

 

I see people on this thread saying they can do "better" now than Nissan did over 36 years ago. So what? "Go for it". Maybe they can. But don't forget that replicas of the factory works-style G-nose, with the final version deep front air dam / spoiler and all the associated Gr.4 / Gr.5 parts are still readily available and will fit a car without too much pain. They were used to good effect in-period, and are pretty much a known quantity.

 

Feel free to draw, design, build and test whatever you want - but don't write everything from the early Seventies off as though it is some sort of prehistoric junk. I think you'll find that a lot of the time - even given a clean sheet of paper - you'll come up with something that doesn't look a million miles away from what was done 36 years ago.

 

Throwing in those "this isn't classiczcars.com" comments seems so unnecessary. We all know what forum we are on here, and I think that what we are discussing here is relevant and appropriate to what HybridZ is about.

 

Alan T.

 

Alan, That "magic bullet" comment was geared at the masses. We got a LOT of requests from people wanting to test that piece with the clear misunderstanding (one that several of us had before the windtunnel test) that this one piece could possibly correct all of the areas that impact the aero numbers on the chassis as a whole. It just isn't so, as there are many many areas that simply need to be "fixed" to get the car into more modern automotive aero standards.

 

Funny thing is that the Dodge Viper, for all its "glory" is still very inefficient in the windtunnel as well.

 

Mike

[Mikelly]

It would be worthwhile to get those numbers on Alan's car, for sure, but every windtunnel is made differently and will read numbers differently. Ask any of the engineers who work in them and you'll get an education on the various conditions that can skew results. Swap tunnels and it'll only get even more confusing.

 

It would be great to get a collection of Zcars together in the tunnel that Dartman has access to. This would validate a sub-set for that particular test facility, and certainly be worth comparing to those we captured in North Carolina, just for comparison's sake and to get yet more more set of current data.

Mike

 

This tread is definitely not about "Early 70s Japanese race car aero". I think I do have something to contribute to the above tread - period pictures of Z racing in South Africa - some of them before the cars were painted, revealing all the additional parts/spoilers on those cars. Than what is the point: the loudest of you know better.

I belive that any works racing outfit has the reason and means to develop the technology to win, therefore it is worth to look back and study those efforts. Datman might have access to wind-tunel in England, that where Alan lives. Alan, please for the forum knowledge sake, contact Datman and just do it. I don't know much about wind-tunels but somehow don't belive the results from two different sites would be different.

 

For those who do not mind your Z to look nothing like one, I have solution for you: Just stick Z emblem on whatever machine you fancy, providing it has drag coeficient of less than .3 and of you go: different engine, suspension, drivetrain, body that does not resemble Nissan at all. You realize what site it is right???

Than if you think that reading A book makes you an expert in aerodynamics, I will have to rest my case.

 

Regards m

[JMortensen]

Feel free to draw, design, build and test whatever you want - but don't write everything from the early Seventies off as though it is some sort of prehistoric junk. I think you'll find that a lot of the time - even given a clean sheet of paper - you'll come up with something that doesn't look a million miles away from what was done 36 years ago.

I never said that it's junk. I only said that to LIMIT oneself to 35 year old technology is not the wisest move if the goal is to create the most EFFECTIVE solution. The reason that this thread got off track is that I dared to question Nissan's attainment of aerodynamic perfection. Sycophantic worship of Nissan or its history is not the way to find the most effective solution aerodynamically. I don't mind if you guys want to take a stroll down memory lane, I only took issue with the idea that the G nose can't be improved upon, airdam or no.

 

Throwing in those "this isn't classiczcars.com" comments seems so unnecessary. We all know what forum we are on here, and I think that what we are discussing here is relevant and appropriate to what HybridZ is about.

 

Clearly 29PGC10 needs this reminder:

For those who do not mind your Z to look nothing like one, I have solution for you: Just stick Z emblem on whatever machine you fancy, providing it has drag coeficient of less than .3 and of you go: different engine, suspension, drivetrain, body that does not resemble Nissan at all. You realize what site it is right???

This is EXACTLY what this site does. We have examples of all of the above and welcome that kind of innovation. If you have a problem with that, you're in the wrong place.

[datman]

Made my own front end.

 

http://album.hybridz.org/showphoto.php?photo=6307&cat=500&ppuser=8086

 

This is an old photo as the car now has flares as well. It did cost somewhat more then $500.00 to make the molds and took a really long time to sand and get the shape right. Hopefully with the undertay and ducting to the radiator it will be an improvement.

 

Douglas

 

very nice... you should make some more!

[rudypoochris]

Out of all this thread, I found this photo to be the most useful to me personally:

 

 

For a long time I have been looking for an attainable air dam to compliment the Gnose. I never really stopped to think that maybe I should be looking at more common air dams since the mounting points are shared.

 

This brings me to my question. What air dams DID the 70's cars run with the Gnose? Which had the most success? Thank you all! I appreciate this thread and debate greatly.

[Mr.INSANE]

When you look at Nissan's older vehicles it starts becoming blatantly obvious how aerodynamics wasn't really in mind when they where made. The Z was very cheap when it came out and was touted as an affordable sports car. Nissan did what works and i think what they did worked pretty well considering the car is popular 35 years later

 

Back on topic though, when you look at the spirit garage Z look at how the lip continues into the flairs creating an entire system. The flairs might not even be there for aerodynamics it could also be that the tires are so wide it was a necessity. Looking at the gigantic radiator entrance this probably is one of the worst area's of the Spirit garage Z. There needs to be ducting to put the air direct to the radiator, Along with a much smaller entrance. Ive never seen under body pictures of the Spirit garage Z but I know the exhaust exits below the driver side door

[Michael]

Mikelly nailed it when he noted “the sharp and abrupt edges on the S30†as being the culprit for its poor drag and lift characteristics. The “swoopiness†of the car is of course aesthetically pleasing (one of the main reasons that we like Z’s, right?) but “swoopy†to the eye is not equivalent to swoopy to the airflow. The hood front lip needs to be lowered and rounded, the airdam needs to be lowered, the grill opening reduced and the headlight buckets smoothed over (not just covered, but completely smoothed to remove creases).

 

It really is a good question regarding what Nissan engineers were thinking regarding aerodynamics when they penned the S30 outer mold lines. I have several “historical†books with photographs of the S30 in wind tunnels, mounted to what look like force balance plates underneath the tires. Surely those engineers were not fools. But one can't help wondering where they placed their priorities.

 

In the past 40 years, automotive aerodynamics has advanced far more than aircraft aerodynamics. That's not just a glib opinion; I mean, I do have something of an insider's perspective on this....

[HS30-H]

I never really stopped to think that maybe I should be looking at more common air dams since the mounting points are shared.

 

Be cautious here. Not all of the mounting points for such an aftermarket airdam are shared between the standard 'short' nose and the G-nose styles.

 

If you see such aftermarket airdams ( as in that picture of the white car ) in Japan, they are usually specific to the G-nose style front end. The mounting points are different, as are the shapes of most of the 'short' nose and G-nose style airdams.

 

This brings me to my question. What air dams DID the 70's cars run with the Gnose? Which had the most success?

 

Some already pictured in my previous posts ( look back at the start of the thread ), but the final Nissan works team version from '74/'75 can be seen on the LY-engined works car that still belongs to Nissan/NISMO. Taking it as read that each evolution was theoretically more effective than the previous version, this would effectively be Nissan's works team's opinion on what was the most effective solution at that point in time:

[HS30-H]

It really is a good question regarding what Nissan engineers were thinking regarding aerodynamics when they penned the S30 outer mold lines. I have several “historical†books with photographs of the S30 in wind tunnels, mounted to what look like force balance plates underneath the tires. Surely those engineers were not fools. But one can't help wondering where they placed their priorities.

 

 

Don't assume that what the engineers and stylists wanted or preferred was what ended up on the showroom floor. There were many battles of wills that the accountants and sales people won against the designers and engineers.

 

Both front and rear spoilers were designed and ready for the S30-series Z at launch in late October 1969, but they were not available in some markets. In the case of the USA/Canada market models, the accountants ( and one very senior marketing man in particular ) decided that the market did not require them.

[Daeron]

 

This

 

That's a gas tank. I don't even think F1 was using diffusers in the early 70s. This is really the very beginning of trying to use aero to produce downforce and I think it took quite a while for the things that CanAm and F1 was doing to trickle down to the lower racing classes. Looking at these old pictures to try and justify your own use on a vintage race car is OK, but looking at these to try and figure out what the best aero solution is might not be the wisest move.

 

immediately followed by this

 

especially since people tuning the same cars to produce considerably better downforce by todays standards are employing entirely different aero tech into new designs of old cars.

 

 

a friend was in my garage the other day and said "this is a 76? but look at it... it's so aerodynamic!"

 

to which i replied "aerobatic, maybe. it could probably do a backflp if if i made it try hard enough"

 

 

Resulted in this comment:

 

"....to try and justify....." ? What a strange way of putting it. You make it sound as though building and using a period-correct and period-legal race car is in some way just a strange affectation.

 

When all is said and done, the "best aero solution" is to start off with another car entirely........ Perhaps something designed and built within the last two or three years, instead of something nearing forty years old?

 

 

 

 

"....new designs of old cars." ?

 

That one went straight over my head, I'm afraid.

 

The important part was the very last line. Jon, you simply said that 30-35 year old photographs are not the soundest, most up-to-date technical information source, especially in an aerodynamic sense.

 

Alan responded saying that he never intended the photo collection to be an end-all, know-all Final Word on the subject.

 

 

 

Then everyone started pulling words and statements from LESS informed posters, and putting them into each others mouths.

 

Nobody really disagreed over anything until peoples points were misunderstood.... Alan, I am sure you do not doubt the validity of more recent information sources, and Jon, I am sure you see where the wisdom in using the vintage racing experience as a stepping-off point is....

 

 

..and thats it! why get panties in a wad over such a simple matter? Ignore the cretins, and the clowns like me who know alot, but don't really Know yet, and relax. Flame wars are bad for the stomach lining.

[JMortensen]

I think you're understating my position a bit. I really don't think that one should base current or new attempts at aero mods on what people were doing 35 years ago. We have so much more material to pull from and so much work has been done since that time that to rely on those fledgling attempts to improve things is to limit oneself. Look at them, understand them, and then move on.

[HS30-H]

Look at them, understand them, and then move on.

 

.........to a racing school, where your time and money will arguably be better spent than in fantasising about 21st century "race" aerodynamics on a forty year old car that will only bump it up into a category that it doesn't stand a chance in.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

( Disclaimer: The above is not an "attack" on anything or anyone, living or dead. May contain traces of nuts. Objects in the mirror are probably part of your face. Your statutory rights are not affected. )

[Mikelly]

Sadly, you just hit the "nail" on the head. To build it to current technological standards would bump classes. This is the same reason I'd never attempt to build a competitive Zcar in an open class.

 

Mike

 

.........to a racing school, where your time and money will arguably be better spent than in fantasising about 21st century "race" aerodynamics on a forty year old car that will only bump it up into a category that it doesn't stand a chance in.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

( Disclaimer: The above is not an "attack" on anything or anyone, living or dead. May contain traces of nuts. Objects in the mirror are probably part of your face. Your statutory rights are not affected. )

[JMortensen]

E Mod and time trials are where it's at for me. Yeah, I might not compete with a Lotus 7 with a Hyabusa motor, but I'll have fun and I'll spank 95% of the other cars in the field with something I built in my garage.

[Tony D]

I'm just happy four other guys showed up at World Finals in Bonneville this year with a G-Nose! When G-Noses outnumbered non-G-Nosed Z's, the tide was turned and they decided it might not be good to disallow it...

 

It would have been a case of what once was legal in a class, now bumping it into another (Altered) class.

 

FYI, our first record was right up JMortensens alley: The El Mirage record broken was set in 1987 by the Dodge Factory Team in an effort that brought four 40 foot Semi Trailers and countless engineers to the Dry Lakebed. We built it all in our garages/sheds, and SPANKED 'EM! (And the guys in tech said it best: "We love it when someone who built the car in their garage beats a factory effort with all that backing!" That was 1999, and it's still standing (knock on wood).

 

Call us 'The Satisfied Cat' on that day! WOO HOO!