Aerodynamics of Fbodys and their effect on High speeds - Top speed of Fbody's
04-25-2006, 10:11 PM
#41
At the BBORR last weekend, a stock 2002 Z28 with only a cut-out and K&N filer ran 168 mph confirmed on GPS, and avaraged 140 mph over 119 miles of curvy west Texas highway.
Lowering these cars has a profound impact on aerodynamics, helping out on top end a lot.
That said, whoever said their 1978 Z28 ran 160 stock is straight up lying. Without an overdrive, the motor would have been spinning out of its powerband, which was too weak at any point to push anything with that much frontal area and bad Cd anywhere close to 140, much less 160. They only had like 185 hp, and that was at 4000 rpm.
A new Acura RSX Type S would lay waste to a stock '78 Z28.
Lowering these cars has a profound impact on aerodynamics, helping out on top end a lot.
That said, whoever said their 1978 Z28 ran 160 stock is straight up lying. Without an overdrive, the motor would have been spinning out of its powerband, which was too weak at any point to push anything with that much frontal area and bad Cd anywhere close to 140, much less 160. They only had like 185 hp, and that was at 4000 rpm.
A new Acura RSX Type S would lay waste to a stock '78 Z28.
04-25-2006, 10:24 PM
#42
Originally Posted by edwardswb
I've had the needle buried on mine for a good long while into 6th gear in the mojave desert. I've set the cruise control on 155 with the ttops off just for ***** and giggles.
Originally Posted by RollinSScamaro
haha thats great.. t-tops off.. i thought it was bad going 155 with t-tops.. you're crazy as hell
This is the fastest I have been, and that is only 1 mile. Our cars are heavy, and would take 5-7 miles to achieve absolute top speed. My speedometer, which is the Granatelli 200mph gauges, are off less than 3 mph at 165 mph, and it really depends on how worn the tires are (new tires, Nitto 555RII make it read ~4 mph slower than worn out tires at speed).
04-28-2006, 12:08 AM
#43
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Originally Posted by 98_1LE
At the BBORR last weekend, a stock 2002 Z28 with only a cut-out and K&N filer ran 168 mph confirmed on GPS, and avaraged 140 mph over 119 miles of curvy west Texas highway.
Lowering these cars has a profound impact on aerodynamics, helping out on top end a lot.
That said, whoever said their 1978 Z28 ran 160 stock is straight up lying. Without an overdrive, the motor would have been spinning out of its powerband, which was too weak at any point to push anything with that much frontal area and bad Cd anywhere close to 140, much less 160. They only had like 185 hp, and that was at 4000 rpm.
A new Acura RSX Type S would lay waste to a stock '78 Z28.
Lowering these cars has a profound impact on aerodynamics, helping out on top end a lot.
That said, whoever said their 1978 Z28 ran 160 stock is straight up lying. Without an overdrive, the motor would have been spinning out of its powerband, which was too weak at any point to push anything with that much frontal area and bad Cd anywhere close to 140, much less 160. They only had like 185 hp, and that was at 4000 rpm.
A new Acura RSX Type S would lay waste to a stock '78 Z28.
Tire Height x RPM / 336 / final drive gear.
END OF STORY.
01-08-2007, 12:07 PM
#45
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[QUOTE=98_1LE]Top speed is achieved in fifth gear. Sixth will overheat the trans, and a stock motor will only pull about 140 in sixth.
The air actually starts going over the car about 130, and with the tops out it quiets down in the car.
Top speed may be achieved in fifth gear but when I had the tach buried into about 6400 rpms I shifted to sixth. Noones saying that it is gonna take off again but mine still pulled. I did have a cam in it at the time.
The air actually starts going over the car about 130, and with the tops out it quiets down in the car.
Top speed may be achieved in fifth gear but when I had the tach buried into about 6400 rpms I shifted to sixth. Noones saying that it is gonna take off again but mine still pulled. I did have a cam in it at the time.
01-09-2007, 08:56 PM
#46
ive got video of me and my g/f doing 145mph with the windows down and t tops off if he wants to see it. had more left in it but we were outta road and my brakes kinda gave up soo that was a bit scarey. and btw thats in a 96 Z28 A4 with 115k on the clock
01-09-2007, 10:14 PM
#47
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Top speed may be achieved in fifth gear but when I had the tach buried into about 6400 rpms I shifted to sixth. Noones saying that it is gonna take off again but mine still pulled. I did have a cam in it at the time.
Last edited by DONAIMIAN; 01-12-2007 at 07:43 PM.
01-11-2007, 06:33 PM
#49
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I know Racehead did 172 in his mostly-stock 02 WS6 at the PE 130. I've done 145+ in my 00 (once pulling past a road race Porche) when it was mostly stock & had plenty of throttle left. And I plan to try to hit 170 in a 1 mile shoot out in June, but my car is far from stock now.....
PS I've heard ram air hoods develope a harmonic at ~190 & descintigrate
PS I've heard ram air hoods develope a harmonic at ~190 & descintigrate
01-23-2007, 05:34 PM
#51
Click on the lower part of my signature to see the video of my car going 183mph in the Texas Mile. That was 6800 rpm in 5th gear (3.73 gears). I'd like to know just how strong these WS6 hoods are before I explore the 190+ range this year. My car was on stock ride height last year and got lots of air underneath it (yet still drove very stable). With lowered ride height this year, it should be an even faster ride. 
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
01-26-2007, 12:39 PM
#52
Tool: "keep in mind a commercial gps is also not accurate (which is why no timing association uses them) If it can't get your position within a foot it can't get speed that accurate (a military version would possibly work, but they don't sell them to the public)"
Back in the day, to get full accuracy out of GPS, you had to have a special serial code transmitted to the satellites. Without it, the data sent to the GPS unit was always purposly a little off. That way, the military had the most precision. Awhile back they did away with that. Now all you need is an accurate GPS handheld. Heck, we got old systems in our aircraft, but its as accurate as our INS system with laser-ring gyros.
BS!!!
03-18-2007, 07:01 PM
#54
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Originally Posted by gold86vette
The top speed of a 78 Z28 at 5000 rpms even with a really tall 225/70/15 (27.4") is (all 78 Z's came with 3.73's stock) : 109.3 mph.
Tire Height x RPM / 336 / final drive gear.
END OF STORY.
Tire Height x RPM / 336 / final drive gear.
END OF STORY.
Sorry to go on a tangent but I remember reading an article way back when about the 2nd gen Camaros used by the CHP. The story goes on about various equipment modifications required for police duty including having the cars outfitted with shallower gears in order to reach a top speed of 130mph+
04-05-2007, 12:39 AM
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04-06-2007, 06:49 PM
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Originally Posted by WAHUSKER
PS I've heard ram air hoods develope a harmonic at ~190 & descintigrate
04-07-2007, 09:26 PM
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what a dumbass. I did 127mph in my stock 01 4.3liter 5 speed s10 extreme. Speedo changed from 98 to 127 with a tuner. And thats in a truck with a 190 hp v6. Common hes saying a f body wont go faster than that. I did 140 top down with my ws6 and she had plenty to go.
