I hope this is the appropriate place to post this.

Ok, this started on a local board I am on about calling BS on a guy a work with that said he ran 160 MPH with his stock 1978 Z28. Anyway, it has progressed to a discussion about the aerodynamics of the fbody's and a little about the vette for comparison and that the factory speedometers and tachs are incorrect on these cars because one guy is posting this info That I think is totally bs and false.

Here are his posts:

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"the c4 vette in stock form didn't do that speed (was aero limited) around 130 the front tires leave the ground (the few f bodies that have doen it at bonneville are full race cars with a full belly pan)"

"top recorded correct speed in any factory f body is 125 (throw your worthless speedo in the trash over 55 that's the only time it's even close, it only has to be within 5 mph at 55 and can be off 40 at 100)"

"bear in mind the new vette is aero limited to 195 (that's the z06) the standard one can only muster 150 with testing equipment. The 4th gen is an aero brick over 100 mph. Look at bonneville you have to get a special license if you break 150, and it's not a common license to get, if factory cars did it frequently there wuldn't be as few awarded. I've gone over 150 (at Talledega in a stock car) and can tell you you have not gone that fast on the street a small pebble makes the car dance like it's on ice, and that's one that's designed for those speeds. When one of the magazines tested the new vette at 130 the front lifted almost 2 inches (at that speed you want it to go down not up)"

"when tested with electronics, and also at bonneville now basically stock f body of any generation has gone that fast the front lifts too much and it's like hitting a wall at 130 or so (I love watching the bonneville races)"

"factory speedos and tachs are way inaccurate, what you see at one speed has absolutely no bearing at another. My dad's dakota was fast under 55 but read slow over 70. Your factory tach can be off as much as 800 rpm at 4000rpm (even an autometer tach has some inaccuracy just becasue of electrical resistance).Trust me you would be scared on the street to go that fast (go to one of the petty schools once and you'll see what I mean)"

"the tests were done on either bonneville, or talledega, the front lifting is part of it, but at that point the car went no faster because the front got up in the air enough to cause drag"

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I'm curious, and just want to know if anybody has any evidence that what he's saying is true, cause I don't think much if anything he is stating is true. I'm sure I've been faster than 125 in my Z. Thanks for the help.

 

Factory speed is 125mph huh... I ran my nearley stock 2000 TA to 140mph... and have a speeding ticket to prove it . And there was more left in it so tell him he's full of it.

I've noticed the stock tach lags a little bit but it is fairley accurate, and the speedo works just fine... I don't know if i understand what he is saying .

 

The c4 vette in stock form didn't do that speed (was aero limited) around 130 the front tires leave the ground


Do I start laughing now, or is there more crap to follow?


"top recorded correct speed in any factory f body is 125 (throw your worthless speedo in the trash over 55 that's the only time it's even close, it only has to be within 5 mph at 55 and can be off 40 at 100)"

Typical crap posted by an internal 'know it all'.

Probably not the best topic for advanced tech, but let it be known the C4 Vette
is not aero limited. If anything, the there might have been a speed limiter
to stop the Vette at 130 MPH. 200 HP at the wheels can take a C4 to
130 MPH easily. My 3.8L V6 Camaro can achieve that without a problem.

As for the speedometer being off by 40 MPH , that's just stupid.

The speedometer in that generation of Fbody is geared from the transmission.
Although it's not totally accurate due to needle position on the gauge face,
there is a linear realtionship between the needle and output shaft speed.
There is no chance in hell the reading will be off by 40%.

The newer speedometers / gauges in most vehicles (IE: Grand Prix, Vette, GTO)
are sync'd to the PCM via OBDII and are pretty damn accurate.

 

My thoughts' exactly. And most of us on that site have 4th gen fbody's, so I think like you said, hell of a lot more accurate.

 

This is going back a long way, but illustrates the general case: In 1987, Car & Driver tested the 5.7 L. (automatic) Z 28; considerably less slippery than the Gen III cars and rated at 240 HP. The radar-verified top speed was exactly 150 MPH.
I also recall a test of a C3 Corvette where they found the digital speedo read 150 MPH at an actual 150 MPH.

 

The Callaway 'Sledgehammer' didn't really have all that radical of a body kit when it ran 254.
I think we all know this guy is a ******* tool though

 

i had my 99 ta a4, non ram air maxed out at somewhere between 155 and the piece that stops it from reading any further.. (in a safe place of course).. so i dont know if its wrong but ive had a ticket for 100 in a 65.. and when youre going 150+ and drop down to 100, it feels like your going 50.. try it sometime, its amazing how slow it feels.. (in a safe place of course)
ive been babying the ws6 though... its more about being quick than top speed.. i dont think theres a law against getting to 45 in 4 seconds.. but anything 75+ is trouble and every ticket is money you could have used to make more power

 

Well, I'm about to call BS on this guy because his statements to me didn't add up, I just wanted to make sure I wasn't missing something.

 

on the contrary... the roof was lowered 6 inches (i believe) and it had a ton of scoops so thats the only reason it got over 130

bahah jk yeah this guy is a tard

 

another thing to shoot this guy's theories to hell is when you guys go to the track do you ever notice how fast you are going when you go through the trap and then go to the printout and see you were actually going faster? unually if i glance down at the speedo as i go through the traps it actually reads about 5 mph slower than the printout says anyone else notice this?

 

"top recorded correct speed in any factory f body is 125 (throw your worthless speedo in the trash over 55 that's the only time it's even close, it only has to be within 5 mph at 55 and can be off 40 at 100)"

If it's off 5 at 50, then it'll be off 10 at 100, and 15 at 150.

 

When I had my 1987 Firebird Formula 5.0L TPI,
I had the 145 speedo pegged going down a big long steep hill on Hwy 395 outside Mammoth Lakes CA, and my Mrs was sitting right there, for better or worse.

And we regularly (each Saturday) had the same car doing 130 on Hwy 58 flat level in the Mojave Desert CA; and that's with the underpowered 305/5.0L V8.

So I know his statements are unfounded.

All F-bodies have good aerodynamics.

 

ROFLCOPTER!

This guy is so full of **** his eyes are brown. Along with the material between his ears. BONE STOCK, fbody's with the speed limiter removed will push 165mph. Stock C-5's will run into the low 17x range.

And as for speedo accuracy. When my gauge reads 150mph, 99.9% of the time my GPS says the same thing along with the timing and scoring peoples equipment.

 

does retarded come to mind when you see this post???? He's probaly jealous from getting beat by a v6 camaro while he was in his civic with 12 wings, stickers and neon lights. WHAT AN *** HAMMER

 

lol wow i guess the whole entire nation was wrong then about their speeds when they were driving.....who knew only one person actaully knew what was goin on....

 

Tell him that the C6 Corvette Coup with the manual 6 speed transmission and the Z51 performance package will run 186 MPH or 300KPH..this is documented and GM advertises it...he is way off on most of what he posted... obviously a total retarded tool...

 

Just ask this FUCKTARD if the drag strips make special computer corrections between all other cars that run there, and the f-bodies and corvettes so we dont feel bad, or are their timers just off??? i have seen plenty of videos of stock appearing cars running faster than 130mph, and alot of guys on this board have run faster than that in just a 1/4 mile, so out on the road, i am sure these cars are just fine to take over that. had my turd to 145mph before i remembered the t-tops were out, and started to slow down.

 

Oh, I'm gonna lay it on him, just waiting for his response to another post from another member first, see if I can get more to throw at him. I've had my speedo read 145, it feels like 145, I am pretty damn sure even if there was a slight speedo error that I was going faster than 125. I love it, can't wait to stir up the **** later...........

 

Conspiracy theory.

If that is true then we never went to the moon because it doesn't exist. and the world is flat.

 

i don't believe an older camaro could hit that high of a top speed bone stock.. they are too heavy and not aerodynamic at all..

I had my SS with stock gears, headers, and other little mods.. and i had my speedo buried for about 10 seconds on a long.. very long expressway at 4 AM and there were no cars..

My car started feeling like it was lifting off the road like a lot of air was getting under it..

It was really crazy! i'll probabaly never do it again! lol