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S30 Aerodynamics not really that bad?


rudypoochris

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When I went that quick I had stock soft springs and a couple blown strut inserts.

I am sure that my poly airdam was folding under at those high speeds...lol

I haven't driven the car more than turning it around in the street since I put the home depot lip on.

Edit* I had smaller wheels and tires on the car too when I went that fast.

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I have pics of my car at speed... My reinforced urethane air dam holds as stiff as any fiberglass dam...

 

I have only the airdam... no other aero mods.. and my car tracks realatively well at 125MPH...

 

 

This is redline in 4th gear with a 3.54 diff on 225/50/15 tires...

th_RoeblingRoad240Zwmv.jpg

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The front end lift on a S130 sounds a bit rediculous, but I won't say it didn't happen. I just wanna know what exactly was happening.

 

I know I've been to a website that had a RPM -> MPH calculator for L series engines and nissan transimissions. If I could find that website then I wouln't have to ask but... How many MPH would the 3.545 Manual NA 2 seater 280ZX be going at 4400 rpm in 5th gear? That's how fast I've gone. I think the 85 mph speedo maxes out at around 3400 rpm in 5th.

 

I personally can't imagine going any faster in a stock NA without restoration. But I guess I'm just not insane enough :D

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Its exactly this pissing competition that I hope the aero-results from bjhines & crew put a stop to.

 

I don't hold it against you guys responding to the question, just that the question itself is pointless and subjective (because we have no data we can use) and I hope that hard objective results will answer all such future questions.

 

Dave

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Its exactly this pissing competition that I hope the aero-results from bjhines & crew put a stop to.

Dave

 

First, I don't know what "P-Contest" you are referring to, but if it's about 'stock top speed', with all due respect, that is a pipe dream. I don't know how many times I just smile when people tell me they have taken their open-mawed S30 to speeds as fast as our land speed car with an engine either stock, or "slightly modified" but "lowered with stiffer springs" as chassis mods.

 

People have an innaccurate speedometer in front of them, and it said 145, so that is how fast they were going.

 

I regularly go 110mph down the 91 Freeway Westbound between VanBuren and McKinley in morning rushour traffic when it's flowing....

 

I know better, and I know the speedo is off, but they see it "so it must be true" and for someone without a logical cell in their body, untrained in dispassionate scientific method, you will not convince them using logic.

 

I have a good friend I have known for over 20 years. He is aware of my land speed efforts, yet STILL to this day actually thinks his 260Z 2+2 and DGV Weber Conversion did a sustained 145mph on I15 out to Vegas in a caravan of sportscars. It is simply ignorance, and if you think, if you actually think giving logical, empirical evidence on a plate with mashed potatoes and gravy to them will change their minds let me give you an engraved invitation to the most frustrating phrase on the face of the planet:

"I know it doesn't make any sense, but that's what it did!"

 

Welcome to my world...

 

You will NOT stop the stupid, nor the ignorant from making these type of claims, nor sticking to their guns. All sticking to their guns in the face of overwhelming evidence to the contrary does is move them form the realm of the ignorant, to the realm of the stupid. Ignorance is the state of not knowing, Stupidity is the state of knowing, and refusing to acknowledge it. All any of this testing will do will give you the confidence to smile at their claims. That's it.

 

Take a look at the Nissan graphs posted earlier, and notice the Exponential climb the horsepower absorption curve takes above 140mph. I have seen plenty of S30's with big blocks, small blocks, turbos, superchargers, Hillborn Injection, (you name it) hit that wall above 150mph. I look forward to their testing to see what kind of horsepower will be needed to push that brick to a speed of...say 170mph, on an unmodified and even front chinspoilered S30 body. I haven't seen many S30's with the original front end configuration go faster than 150mph. Turbo Six of V8 included...

 

On another aside, BJ, would you be interested in some videos of various S30's at speed on the dry lake? I bought a video from the May Meet, and it has three of our runs (140+) on it, as well as a V-8 powered S30 with a chop-top and modern spoiler on the back, as well as a modified nose on it (160mph) running. You get a nice detail of the "Dust" off the back of the car. The difference between our G-Nose car without a rear spoiler, and the other car is interesting. PM me with some mailing information and I'll see what I can do about getting a DVD rip of the runs out to you.

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^ I agree, wich is why I stated RPM's I've run, wich has no real bearing on MPH thus I accepted a guestimation admitingly). I didn't ever post to make a contest, but to add information into a good thread.

 

I agree I hope BJ's research ends a lot of debate and such, and I think pretty much everyone here is behind him. So I don't know what contest we're talking about here. For the most part it's just been friendly discussion.

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People have an innaccurate speedometer in front of them, and it said 145, so that is how fast they were going.

Tony: I road raced motorcycles about ten years ago. Jap bikes are notorious for 'optimistic' speedometers. Generally they are 5 - 10 % off. The faster you go the more they are off. I imagine there are a lot of cars out there with none stock wheels and tires that throw off the speedo as well. Well anyhow, I worked for a shop that specialized in race prep for road race bikes. The guy I worked with had access to a radar gun. Road race bikes are generally tuned for max top speed and it was a good tuning tool. We radar clocked a lot of bikes, some pro built factory efforts, and unlimited class monsters. 170 - 175 mph was the fastest we really ever saw, and yet street bike guys with mildly modified street bikes would regularly tell us 'my bike goes over two hundred'... yeah right. We would just look at each other and smile.

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"yeah right. We would just look at each other and smile."

 

I'm just trying to prep those involved in the testing for their ONLY real satisfaction when it's all said and done. Like you mom'sZ said, when you know the score (and BJ's testing will certianly give people a place to point to as empirical evidence...) just simling polietly and nodding your head in agreement is about all you will end up doing when all is said and done.

 

Like I said some time ago, if there are all these "basically stock" 140+mph S30's, I wonder why nobody ever made it out to Bonneville in the intervening years from 1975 till 1999 to break that standing record....

 

/Leans back and Smiles/

 

:lol:

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735451_176_full.jpg

This first image is of this S30, chopped and bespoilered running at El Mirage. This car, as pictured has a speed in the mid 160's at El Mirage, about 20mph faster than our G-Nosed 76 2+2 running in Production, using production bodywork. Oh, and we are running a 2-Liter, not a 6 liter....

735451_182_full.jpg

735451_154_full.jpg

735451_153_full.jpg

This car replaced the former sheetmetal (a 1970 Opel GT) when it was flat spun and endoed six times at 140+mph. The brown car is how it first appeared, and the orange paint job is how the thing ended up when fully painted. Currently this car competes at both Bonneville and El Mirage dry lakes. I have some more photos of the spoiler if anyone is interested, or you can get the rest of them off my Car Domain Page---which is where I lifted these from. There is a page there with some photos of the Land Speed Car as well, from a few years ago when I had it in the yard for some work.

Now that I have the page figured out (there was an image syntax snafu, and some pages couldn't be viewed...) I will start posting more photos there that I have taken in the past few years, just so people can compare stuff.

BTW, this orange car is the one I have the video of running at 163 on the same day our 2-liter ran 141, the difference in dust off the back of the two cars is startling when viewed on video and not static. I think the "red baloon" image you can see he's popped his parachute and it's just about to deploy (look in the dust behind the car about 25-30 feet).

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Everything I've ever posted on the web regarding my high speed testing was verified by a stalker radar gun. I can't speak for others, but I can tell you that the stock speedo is horribly inaccurate and if you're going by that means of measuring speed, I'd have to agree with Tony D.

 

That said, I can assure you that handling "can" be stable with the right mods/aero adjustments to keep the car planted, and a judicious application of HP. I've seen 167 mph in an L6 powered Zcar and I've "loafed along" in a wounded 383 powered (bent pushrod) Zcar in 6th gear running about 3900-4000 RPMs at 155 mph, with one hand on the steering wheel.

 

It can be done.

 

Mike

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ahhh now remember Mike, my above statement was "unmodified front end", and the speed was "above 150"...

 

I am not disputing anyones claims when they have done "real" modifications to the vehicle involving airflow, etc.

 

But when someone comes up to me with a hackjob bonestock Impala Stationwagon 350 conversion, with absolutely no modification to the front end, underneath, and indeed has raised the car for "tire clearance" or "looks" and in the same breath claims the car "easily does 165 all day long" with that TH400 and 3.36 rear end...

 

Well, Mike, I'm sure you're in my camp in saying in this case "We will smile politely and move on to the next subject!" LOL

 

This happens far more often that you might think. Especially when hanging around people bitter that their V8 is slower than "a puny little six"! But that is another discussion altogether!

 

I mean this is not limited to the Z-Community in any srot or stretch of the imagination. i know someone who claimed their B-60 14 shod Chevelle with a 4.11 gear "spun a rod doing 160 racing a turbo Porsche"... BS is not limited to us Z-Car guys, no, not at all! LOL

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My speedo reads 5 mph over at 35 MPH, 10 over @ 70MPH, 20 over at 140, etc....

That is with stock 1972 240Z drivetrain and speedo gearing on 15x7" rims with 225/50/15 Toyo RA1s...

 

IIRC... my speedo on that run down the Roebling straight is getting to around 145MPH... That is why I called it redline 4th gear... I know it is around 125MPH max... That is with an engine that puts out 160RWHP at 6800RPM... You notice that I am still accelerating fairly rapidly all the way to redline... taller differential gearing with a 5 speed would be the ticket for my car...

 

I do not feel like the car is moving that quickly(125MPH).. it does not feel unstable... Wind in the cockpit with the windows open is not very bad at all...

I can just begin to detect lift in the rear over 100MPH... the rear end does not follow the movements of the front end as well at high speed... like it is getting light in the back... as you can see fomr my sig. ... I have no rear spoiler at all... My V-8 track car will be highly modified...

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I have used a GPS unit on the windsheild. My speedo is about 2% optimistic. I have been at 120mph with just a urethane airdam reinforced, and street performance suspension. It feels great but I have no desire to go any faster in a 30 year old car. I can't wait to see the results of the wind tunnel. My wager is lots of lift from underhood pressure and a little bit of vacuum on the hatch area pulling up and back on it.

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