A&Q about 350Z
Q:
Dave successfully made the Land Speed Z down the course in one piece on his rookie run at 130.438mph with a 6 mph tailwind. I don't have the time slip in front of me right now, but they have all the baro and temperature information on them now---different than 2 years ago when we last competed.
Well, they shut down the runs today without a second run, so our record chase (148 mph) will have to wait till tomorrow. (Can't set a record out of the Rookie Lane anyway.)
The car is running well, we got everything going and going down the track the 2-litre sounds far more menacing than the L28 did. Dave went through the traps feathering the throttle and bumping off the 9300 rpm shift light (actually for about the last 300 yards) in fourth gear. So shifting to fifth and keeping on it through the whole run should net a decent first time run.
We were fortunate with the tail wind, and getting a run off at 1030AM. Frank and Xander commented the experience up there was surreal, a very "Mad Max" type of environment.
What can I say, when you party with the Humongous, things happen!
LOL
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
Nice news!
Good Luck! 150 is a nice figure to push for but the exponential resistance is not so nice.
Token Mad Max-ish pic http://www.back2themax.com/gallery/carsstunts/B2TMFlyingHigh.JPG
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actual mad max cars.
_____________________________________________
'05 350Z Chrome Silver Touring
'73 240Z
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148 MPH?????? HAHAHA I did that on the way kome from the store this afternoon.
Seriously though, I would love to be there witnessing the "party".
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Yes, GOOD LUCK, Tony. Everyone has a place they want to succeed. I'm sure you'll keep tryin' even if there's a head wind.
Be sure to post how it all works out.
original owner 1978 280Z
1977 project car
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"But most of all we 'members the man that finded us, him that came the salvage. And we lights the city, not just for him, but for all of them that are still out there. 'Cause we knows there come a night, when they sees the distant light, and they'll be comin' home."
'76 280Z driver, '75 parts car
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Yah i do that to on my way grocery shopping but not in 3/4 mile !! on dirt .. that is the whole deal .. they dont give you 10 miles to catch speed!!!
Also the flag car is only a 2 liter that revs upto 10K!!!! what a sound..
So no, that figure 150 ... not that impressive seen as a figure.. but given the RULES for landspeed racing ... it is a good ambitous figure
You can sleep in your car, but cant drive in your house
if you are fully in control, you are not driving fast enough!
79 ZXR 46K!
81 ZXT EURO 2+2
83 ZXT
All fine Fastback winnabego's
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are there pictures of this car. ive never heard of this endevor on Zcar before. i wanna see what it looks like.
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....and shiney side up. Be safe guys.
Ken
'82ZX n/a 2+2
'02 Sportster XL1200C
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Wheee!
Say, who're these guys:
and how much do they want for their woman?
Tony, can you run the rear spoiler legally? Thinking about your 300 lb. lift number at the rear of the car, I have to believe that some kind of rear spoiler should reduce drag considerably. Is it possible that previous runs where you lost speed with the spoiler were hampered by crosswinds or other unrelated phenomena?
Reduce your lift and you should reduce drag.
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Tried the spoiler. The ONLY one we can run is the ones used STOCK. Meaning the small BRE style. Cuts 3 mph at 140+ so that one is not happening. Adding ballast is more effective.
The photo you showed was Rick (Turbo Rick) Yaccouci. That car was there, and ran 250+ today. Megasquirt fueled Busa Motor. Archives have the details on that car.
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
The G35 wasn't running well yesterday.
Today it was running MUCH better, though not as well as when the same engine and tranny were in the Q45.
Wife says to lay off, so no more posting right now...
I have more details on that car, but later!
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
I was talking about reducing lift to reduce DRAG. Again, adding mass is not the same thing as eliminating lift. If you're getting a lot of lift, then you are getting induced drag as a result. You *should* be able to reduce drag quite a bit by eliminating or at least reducing lift.
Figure a Zcar makes a pretty poor wing, L/D of maybe 2.5? Then 300 lb. of lift => 120 lb. of INDUCED DRAG.
120 lb. of drag at 150mph is 48 horsepower!
Just want to suggest that if you ARE getting significant lift, then reducing or eliminating it should be a priority.
Post Edited (May 8, 6:38am)
A:
Dan, really, what part of STOCK don't you understand?
It is a Production class. The ONLY things I can put on the car must have been available to the general marketplace as a production run of at least 500 units.
This is why we are running an L20A making 200HP, and not an S20 making 345+Hp.
If it wasn't available on the car on the showroom floor, it's ILLEGAL to use.
THIS is the primary challenge behind this type of racing, it truly does show how fast a TRUE PRODUCTION CAR will go, and not something taped up, dechromed, and bespoliered will do.
Again, the available spoiler will cut 3mph off our top speed, and that is not what we need now.
Even with 120# of ballast in the car on the back end, there was a traction issue on the big end of the course during the last run. That was most likely due to track surface degredation, but still, adding another 50# back there will probably make sure the rear tires are planted.
To recap: Since modifying the car to reduce lift is ILLEGAL, the only class remedy the is practical is to BALLAST the car.
If we want to run in an altered of modified sports class (where 2L records are in the 170+ range from Porsches and other slippery cars) then we could do that, but the chances of breaking a record with the current power output are between slim and none.
Now if anyone wants to find me production literature that shows that more than 417 Z432's were produced, if ANYONE can give me something that shows me 500 or more S20 engined Z's were produced---THAT would GREATLY ease our problems as that Lucas Slide-Valve Injected monster made over 300HP and we would be SET!
But nothing else will help our plight...
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
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Tony have you posted any pics of this engine? I've been under a rock lately. I'd like to see it though.
Matt
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Again, I wasn't talking at all about traction in this thread, just lift and the resultant drag.
What I'd really like to know is if that rear spoiler *REALLY* cost you 3mph. How many runs did you do with the spoiler? Head/tail/crosswind data? Any other possible changes (intentional or inadvertent)?
It still seems to me a small rear spoiler should REDUCE drag.
All I'm saying is, I'd be sorely tempted to give it another try.
If you're making lift, there is DRAG associated with it! Any legal means to reduce aerodynamic lift (note: adding ballast does not reduce aerodynamic lift!) should be tried.
From an old email from one C.B.:
"adding the Front and Rear Spooks/Spoilers added 6mph to the
top speed at the end of OMS's straight... in the car tested. ( a 1973 240Z
- Car & Driver May of 74)."
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"What I'd really like to know is if that rear spoiler *REALLY* cost you 3mph. How many runs did you do with the spoiler? Head/tail/crosswind data? Any other possible changes (intentional or inadvertent)?"
Well, thanks so very much for implying my head is up my rectum, Dan.
In 1999 the car had a terminal velocity of 140.XXX. No matter what we did, the car would not go any faster. This was with 217hp, L28.
SCTA timing cards give us Wind Direction, Speed, Rel Hum, Ambient Temp, and speed, as well at ET through the timing trap. Very repeatable data, from a standardized weather station at the timing trailer on the course...
Now, follow me here, Dan.
With the ONLY change being removal of the rear BRE style spoiler, on a meet where we were fortunate enough to have two runs in the day, we went 143.xxx in the afternoon and got our first record, instead of the 140.xxx from the morning run. All from scratching our heads going "we should be faster, hell Andy let's take the spoiler off, the photos show a lot of dust behind the car with it on..." So we removed it. HOW that little ducktail works is different that you would think. The PROPER way to spoil lift on the rear is covered on the 280ZX, and I will not revisit it here---the tack-on spoiler counteracts lift at the cost of DRAG. Look to the ZXR for yet ANOTHER way to solve the problem when speeds went higher than original design on the 280ZXT...
But back to our 143.XXX mph run:
Now, this is with an ambient temperature that increased 9 degrees F (from 85.4 to 94.2, a Relative humidity that went from 21% to 16%, and a wind speed that went from 2mph WSW to nil WSW...
So in other words, with less dense air, 2mph LESS quartering tailwind, and the removal of the spoiler, the car went 3mph FASTER.
With less horsepower (air density decrease).
When we added 150# of ballast the following month, our speed went to over 153.xxx mph. Added weight, went faster, agains't the rules of "add lightness"---this isn't rocket science, just a different form of competition where things work differently. The run that month was very similar in conditions, with an air temperature of around 83 degrees, and 25% R/H with a 2mph true tailwind from the West.
Figure all you want, but realize the Roadracing Paradigm is not the Land Speed Paradigm, Dan! You are stuck in the theoreticals, and we are stuck in practicals. Theorists always have a problem trying to explain why things don't work the way they "should"! Remember all the engineers from Hitler's V2 program NEVER got one flying while in the USA, while the Russians who took the Technical Helpers got the thing flying in short order. When you get stuck on "what should be" instead of "what is" you will chase your tail for a long while!
The only thing the BRE spoiler is good for is for planting the rear end on cars where top speed is not a concern (like SCCA Events). This is the reason the Group 4 FIA spoilers were a good 5 to 6" tall on the back deck. The speeds encountered by those cars were well below 150mph, and drag induced by a spoiler was an acceptable tradeoff for the handling benefits in high speed corners received. Such would be the case at OMS (Ontario Motor Speedway)---you aren't giving me the benefit of any intelligence on this one Dan, so I will return the favor by explaining the OMS results even further: The BRE Spook, and the KickTail on the back allowed TRACTION in the corners further than a car in stock configuration would do (the front spook NOT being a production piece, kind of makes for an unbalanced car but that 's a digression) leading to more speed out of the corner, and benefitting the car at the end of the straight. A straight where the 240Z would do MAYBE 85 to 90 mph. OMS was a big tri-oval, but in no way is it a top-speed capable track. What works when you turn does not and almost surely will not benefit you in a straight line acceleration nor top speed contest. You are thinking so far inside the wrong box, Dan, you refuse to listen to the conditions surrounding the box we are competing within!
In this case, it is a TOTAL waste of time, and HURTS the speed potential of the car.
You have to play within the rules, and the rules state nothing but what was available to the general public as a production part.
If I was allowed to put vortex generators at the back of the roofline (as I ahve said over and over and over) the car would go even FASTER, with absolutely no penalty in either weight or the drag of that kick-tail!
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
"Well, thanks so very much for implying my head is up my rectum, Dan."
Sen-si-TIVE! :)
Dude, I'm just saying I *might* consider trying it again.
FWIW, the changes in temp and humidity should have cost you ~1.0% power, but the lower air density meant your DRAG was reduced by 1.6%, so the 94.2F/16%rh conditions were actually a little BETTER for speed!
I FULLY understand that land speed record racing is QUITE different from roadracing.
My POINT was, if you're REALLY getting 300 lb. of lift at ~150mph, the induced drag is costing you on the order of 48hp at that speed. I never meant to imply that that theoretical result is more important than experimental results, I FULLY and KEENLY appreciate that actual results absolutely trump what "theoretically" should hapen. I don't have my head in the theoretical sand. Just saying that if I knew I had THAT MUCH LIFT, I would be doing all I could to reduce it.
Anyhoo, best of luck, and keep the forum apprised.
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There is a subtle difference in between Removing lift, and Adding downforce. It sounds like the BRE spoiler Adds downforce and drag. What needs to be done is to Remove the lift, which would reduce drag.
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"FWIW, the changes in temp and humidity should have cost you ~1.0% power, but the lower air density meant your DRAG was reduced by 1.6%, so the 94.2F/16%rh conditions were actually a little BETTER for speed!"
So we have a net loss of -.6%, yet go 2.1% faster......
"I don't have my head in the theoretical sand. Just saying that if I knew I had THAT MUCH LIFT, I would be doing all I could to reduce it."
And what would your suggestion be? I have already stated WHY we do what we do, yet you INSIST that there is some magic Nissan Bolt-On part I don't know about that will solve all our problems.
Please Share, Dan! I am anxiously awaiting the suggestion and source of said miracle part, please give me the documentation for the SCTA as well as they will want to know about it, since even Nissan didn't use in in 1975, they used the little kick tail, no ballast.
And they were ultimately 8mph slower than we were.
I give a minimum of 3 mph of that to them employing the spolier instead of ballast.
Take a look in the archives for the photos of the car at speed. The air off the back of the car is dirty with the spoiler, it's clean with the spoiler removed.
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
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Goldfish has hit it on the head! The way the BRE part works is stability from DRAG.
Look to the 280ZX redesign where they spoiled the airflow off the back of the car with a small lip integral to the back of the roofline!
No spoiler-induced drag is required.
And when the car started going close to 200 mph, instead of 100mph, they added the ZXR wing, which counteracted the lift at speed, without a big drag penalty---a copy of the Porsche design.
Unfortunately, for the class, all of those options are illegal.
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
A:
Tony: "So we have a net loss of -.6%, yet go 2.1% faster......"
By "net loss of -.6%" you do mean "net gain of +.6%", right?
Just pointing out that the conditions that may seem to be worse for speed can actually be more favorable. Misdiagnosing the favorability vs. unfavorability of conditions *can*, *conceivably* lead to an exaggerated sense of the effects of other changes.
"And what would your suggestion be? I have already stated WHY we do what we do, yet you INSIST that there is some magic Nissan Bolt-On part I don't know about that will solve all our problems."
I don't see where I've INSISTED any such thing! Obviously you know a hell of a lot more about the LSR racing and rules than I do, I'm just throwing in a comment here and there, no need for the proverbial "blown gasket"!
Are you allowed a non-stock muffler? Are you allowed a fuel cell? If yes, I'd make a muffler and a fuel cell that act as a diffuser fairing the flow back and up to the bottom of the rear valence.
Of course I'm sure you've experimented quite a bit with rake.
I guess you're probably using the stock front "belly pan", I'd *think* that might help a bit.
Mis-align the hatch, high at the front and low at the back would be my first guess, but of course experimentation...
I assume the small front spoiler that was made available to cure front end lift is available to you as well?
"Take a look in the archives for the photos of the car at speed. The air off the back of the car is dirty with the spoiler, it's clean with the spoiler removed."
So, dirt on the back of the car is a reliable indicator of overall drag?
For a rear spoiler, I don't think "adding downforce" is any more an appropriate way to think about it than "reducing lift". Heck, you're adding a WALL to the back of the rear deck. You've changed the form of the vehicle and you've increased base drag, but then you've also increased pressure on the hatch area. In some instances (sedan), a reasonably not-too-huge spoiler will almost always reduce drag. In the case of the Z, I can fully appreciate that a larger BRE spoiler might increase drag rather than decrease it. But you're talking about the smaller spoiler, right?
Up to some height/angle combination, you will reduce drag. Beyond that, you'll increase it but continue to reduce lift/create downforce.
I would've thought the smaller spoiler would surely not increase drag, but reduce it. Car and Driver's results from way back when indicated reduced drag, not that I'd put a great deal of faith in their results. Your results seem to indicate otherwise. But if there has been a *scientifically rigorous* evaluation of spoiler impact on Zcar aerodynamics, I'm still not aware of it. Last I knew the Lockheed Wind Tunnel was only $2000/hr, you just have to be able to get in line! A scale model in a smaller University wind tunnel could be worthwhile. Anybody got a 1/3 scale model of a Z lying around?!
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I wasn't sure at first but, it sounds like the lift is created at the end of the roof/ on the hatch. That is where you need to change things to improve the situation. The spoiler on the tail of the car is add downforce in the wrong area, thus increasing drag.
But here's a question for you Tony, Would the louvers help, or even be legal?
P.S. I don't see that ridge you talk about.
Post Edited (May 9, 4:37pm)
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"I'd make a muffler and a fuel cell that act as a diffuser fairing the flow back and up to the bottom of the rear valence."
Dan, first off, how will that help a car with a full belly pan?
And in the rules, it specifically disallows the kind of modification you suggest there! You can not streamline suspension pieces, and in our class you mst run the stock gas tank.......
In other classes (as I have said many times before) those mods are placing you in a class where the speeds for a record are above 200mph, not in the 140's!
I reiterate: "What portion of stock production" don't you understand?
PLEASE go to the SCTA-BNI website and READ the rules for the classes! They are posted online for all to see. This should shoot down most of the "production" options---including the front spoiler (hard to use on a G-Nose when NEVER offered!)
"A scale model in a smaller University wind tunnel could be worthwhile. Anybody got a 1/3 scale model of a Z lying around?!"
Well, I've got a 1/12" scale, and access to The Wind Tunnel at Ole Miss...through some intermediaries. What you are missing is the verbiage of the stock and production classes that state body panels must fit in original relationship to each other. And even for altered and GCC where we are competing, the addition of the pan under the vehicle UNDER the car does not negate the requirement for body panel fit on TOP the car---the car MUST remain as legal for PRODUCTION classes, with the EXCEPTION of the modifications made to place the car in the ALT or GCC Class.
We had someone post the $100 protest fee, and got our Fuel Altered record at Bonneville pulled beause we didn't use a power adder on the car, and only removed the stock gas tank and added the belly pan. The former holder of the record must have been pretty PO that we corked his record by over 17mph, so he protested. And he won. We lost that record because we didn't have ENOUGH modifications according to the rulebook---whereas the phrase "removal of the stock fuel tank will place the vehicle in XXX Class"----running gasoline as the "Fuel" was O.K., as in "Fuel" Classes the rules stae ANY fuel is acceptable, most people just ASSUME they MUST run Nitromethane and Methanol.....
And besides, our fuel cel is maybe 3 gallons, mounted IN FRONT of the radiator, along with the cool can, fuel filter, and fuel pump....
Like I said, Dan, it's a different Paradigm---you are thinking inside the wrong box.
Read the rules and get back to me on what you think you can get a round---at least then it will be a constructive endeavor instead of me just regirgutating rules that knock out your otherwise helpful roadracing suggestions.
Anyway, we picked up over 150+ points from the meet last weekend, and have moved up from 202 in the run order, to 36 for next month. Having the second highest points accumulation for the weekend (Or so Dave informs me!)
Before next month's meet we have to relocate and rebrace the seat, add a tube to the top of the rollcage, and change to a 4.36 or 4.44 R180 Differential...
Busy busy busy, it never ends.
This photo is especially for you, Dan. They are filled with lead, and in the trunk of a 56 Chevy that was crankin' all through the meet...
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"
Post Edited (May 10, 2:39pm)
A:
>>"I'd make a muffler and a fuel cell that act as a diffuser fairing the flow back and up to the bottom of the rear valence."
>Dan, first off, how will that help a car with a full belly pan?
Lower pressure underneath the car, reduced lift, and (hopefully) reduced drag. Seems to me it would help a car with a full belly pan more than one without.
>And in the rules, it specifically disallows the kind of modification you suggest there! You can not streamline suspension pieces, and in our class you mst run the stock gas tank.......
OK, I never said I knew all the rules (and I'm not about to study up on them). Just TALKIN', man! (or, rather, TYPIN')
>>"A scale model in a smaller University wind tunnel could be worthwhile. Anybody got a 1/3 scale model of a Z lying around?!"
>Well, I've got a 1/12" scale, and access to The Wind Tunnel at Ole Miss...through some intermediaries.
Ole Miss, eh? Didn't know they had a wind tunnel! I went to Mississippi State, fwiw...
1/12th isn't going to cut it, Reynold's number (proportional to speed times length) will an order of magnitude off. Flow regime of the actual car at speed would be entirely different. Anything less than ~1/5 scale model is probably a waste of time and money if you want to see the real effects of configuration changes.
>Like I said, Dan, it's a different Paradigm---you are thinking inside the wrong box.
Don't think so. All I tried to do was point out that if you're making as much lift as you think you are, that the drag associated with that lift is costing you big time. If you can't do anything about it, then OK, you have to live with it.
>Anyway, we picked up over 150+ points from the meet last weekend, and have moved up from 202 in the run order, to 36 for next month. Having the second highest points accumulation for the weekend (Or so Dave informs me!)
Killer! Being higher up in the run order gives you generally better conditions, or you just don't have to wait as long? Is there a points championship or something?
Holy crap, 4.36 or 4.44 at 140mph!
Thanks for the pic:P
Obviously his reduced stability margin is not posing a problem!
Later, dude, and best of luck...
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"If you can't do anything about it, then OK, you have to live with it."
Now you are getting the idea!
Yeah, Ole Miss has a new state of the art facility for some high speed testing. It utilizes some of our product for production of the high-speed airflow, as well as some other aspects of the facility. My friend Drew handles the maintenance contract on the facility, and has (at my direction) placed the appropriate queries about open time and model structural requirements. The system is still being shaken down, and is not yet in full operation from my understanding. But even a few minutes of an instrumented model undergoing testing will be invaluable with the 280ZX effort in F/PS where speeds will be above 200mph.
People Are Idiots, Just look around here and you will see!
Tony D: "Knowledgeable but Caustic"... rationull
My brother from another mother calls himself "Willie D"