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Old 11-25-2004   #21
Americano
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Re: Top Speed

FYI.
I have an 89 Gta, 5.7, completely stock, 130,000 miles.
Last year it pulled off 149 mph before I got off it. (It was still climbing)
Friend had a K-15 radar.
Additionally, third gear was almost completely shot when I did this.
It slipped and rumbled like a bear.
Aamco has since rebuilt the tranny, and added a shift kit.
Haven't opened it up since, but after a few mods, I'll be sure and let you know how fast it goes.
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Old 11-26-2004   #22
dziurkens89GTA
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Re: Top Speed

1989 GTA 350cid ZRC vette engine, manual T5, 3.42 rear end, other completely stock.

human package - 4 guys (with me as driver) GTA hit 210km/h and still accelerate , I think 230-240 is maximum from my car. Of course that numbers are from speedo so who knows

Last edited by dziurkens89GTA; 11-26-2004 at 02:36 AM.
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Old 11-26-2004   #23
MunsonGTA
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GTA Year: 1987
GTA Engine: Custom
Re: Top Speed

fastest i've been with mine is 121 mph in 3rd gear up around 4500 rpm and still climbing. Got out of it since the car would not shift into 4th at WOT. That and the car has a stock steel driveshaft which shouldn't be taken over 120 mph anyways. Once I get the new aluminum DS and WOT shift servo i'll retest.

355, 700r4, 3.70's in the back.
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87 GTA: Forged 408 LSX short block, TEA stage 2 cnc ported 243 heads, BTR Stage 3 stroker cam, Fast 102 intake, NW 102 TB, Longtube headers, custom 411 ECM, custom harness, custom tuned, Performabuilt stage 2 4l60E with PTC 2800 stall, 9 bolt rear with 3.70 gears and TAP girdle.

11.16 at 123 mph.
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Old 12-28-2004   #24
The Anvil
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Re: Top Speed

I think the cars that got the alum. driveshaft like mine are the TPI cars that will shift into OD at WOT.
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Old 12-28-2004   #25
intake68
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Re: Top Speed

I have owned 3 GTA's that have had the aluminum driveshaft. One was a 305/auto and the other two were 350/auto cars. None of mine would ever shift into OD at WOT.
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Old 01-01-2005   #26
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Re: Top Speed

Mine does with the L98, dual cats and aluminum driveshaft options.
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Old 01-10-2005   #27
srshll
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Re: Top Speed

The gta and iroc cars with the l98 all have the same tranny as the Vette.Kevin
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Old 01-13-2005   #28
The Anvil
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Re: Top Speed

Quote:
Originally Posted by srshll
The gta and iroc cars with the l98 all have the same tranny as the Vette.Kevin
There are a few differences between what the vette got and what the f-bodies got. Some f-body L98 cars won't upshift into OD at WOT, while others will.

So far, it appears we don't have a clear reason why some will upshift with the L98 and others don't.
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Old 02-04-2005   #29
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Re: Top Speed

mph = (rpm x tire diameter) / (gear ratio x 336)

Speed is limited by RPM and aerodynamics.

My car upshifts into overdrive. I let off at 110, still in 3rd.
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Old 02-04-2005   #30
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Re: Top Speed

Quote:
Originally Posted by GTAracer
mph = (rpm x tire diameter) / (gear ratio x 336)

Speed is limited by RPM and aerodynamics.

My car upshifts into overdrive. I let off at 110, still in 3rd.
At 5000 rpm in overdrive should be able to get to about 165mph
At 4500 rpm...150MPH
At 4250 rpm...142mph.
At 4000 rpm...134mph.


I seem to recall testing of these cars at 140 off showroom floor. Seems about right since that would be about peak power (NOT peak torque).
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Old 02-04-2005   #31
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Re: Top Speed

I remember seeing a test where a stock GTA did 147 mph, I think it was Motor Trend. My car will go much faster than that, I've hit 145 and climbing, not sure where it tops out at. Our cars have one of the lowest drag coefficients of any car ever made.
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Old 02-04-2005   #32
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Re: Top Speed

140 and climbing not 145, my mistake. 145 was on my BMW motorcycle.
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Old 02-04-2005   #33
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Re: Top Speed

I'd have to look it up but a 91 GTA used to hold the stock bodied land speed record, like 4 years ago. It was an all stock metal body including working electric windows, the only exception was a Pro Stock drag racing nose cover, which was the same as stock except the lower openings were pretty closed off, pretty much flush with the front.
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Old 02-04-2005   #34
MunsonGTA
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GTA Year: 1987
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Re: Top Speed

the low drag and great aerodynamics is why gale banks used a 3rd gen f body car on the salt flats.
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11.16 at 123 mph.
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Old 02-04-2005   #35
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Re: Top Speed

Quote:
Originally Posted by MunsonGTA
the low drag and great aerodynamics is why gale banks used a 3rd gen f body car on the salt flats.
Stock its about a 0.34...which is good. Banks car was modified to enhance the firebird's aerodynamic foundation. In other words, a good starting point...but plenty of room for improvement. Quite a few of todays cars are in the 0.2Xs
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Old 02-05-2005   #36
MunsonGTA
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Re: Top Speed

His car wasn't that modified, I've seen the pictures and it does have some body mods but nothing too extreme from what the car already looks like. I read an article awhile back where gale banks said a stock 87 firebird/TA would do 200+ mph and never have a problem because of the aerodynamics and downforce.
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11.16 at 123 mph.
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Old 02-11-2005   #37
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Re: Top Speed

Quote:
Originally Posted by GTAracer
Stock its about a 0.34...which is good. Banks car was modified to enhance the firebird's aerodynamic foundation. In other words, a good starting point...but plenty of room for improvement. Quite a few of todays cars are in the 0.2Xs
The GTA from 1987-90 had .32 drag coefficient. The 91-92 is a bit better. That was state of the art for many years, even better than the Corvette which had been the previous benchmark. Both John Lingenfelter and Gale Banks among a few other notables, used the GTA for top speed runs because nothing else including the 4th gen Trans Am is as areodynamic or as stable at triple digit speeds as the GTA.

I would like you to list which of todays cars are in the 2x arena. That's getting close to F-16 stats.
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Old 02-13-2005   #38
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Re: Top Speed

Quote:
Originally Posted by The Anvil
The GTA from 1987-90 had .32 drag coefficient. The 91-92 is a bit better. That was state of the art for many years, even better than the Corvette which had been the previous benchmark. Both John Lingenfelter and Gale Banks among a few other notables, used the GTA for top speed runs because nothing else including the 4th gen Trans Am is as areodynamic or as stable at triple digit speeds as the GTA.

I would like you to list which of todays cars are in the 2x arena. That's getting close to F-16 stats.
Do you have any published data for the 87-90 GTAs? Listed below is the 82 and 84 TA and 91 GTA from thirdgen.org...so I was off a bit. The Banks cars are modified; however, it only takes some subtle modifications to bring it down into the 0.2xs. A good starting point...yes...stable at triple digit speeds...only after mods.

This is the only info I have handy without doing research (which I don't have much time for)... Aerodynamics of cars are getting better everyday. I had to study some of this stuff in school. Some listed at the bottom comes from thirdgen.org Wind tunnel data is the only real effective data you can use. But like dynanometers, each one is a little different on results. There are real world tests anyone can do on the highway knowing certain variables...but its crude at best. Additionally, anyone going too fast in a 91, 92 bird will find themselves coming off the ground (As Banks did). Cl (lift) is more important at those speeds. I'm not bashing GTAs drag at all (I have two of them)...just that it's not great and can be easily improved (as Banks did). Sorry for not singing the praises of the GTA. Not trying to hurt people's feelings by posting real math and real data.
BTW, the math I posted still holds up. It wasn't the GTA's aerodynamic drag that holds it back anyway. Drag is important, but that doesn't stop some cars with high drag going 200 mph, either...just takes a lot more power to overcome the exponentials.
I actually have some data on the Banks cars stowed away. I'll dig it out and post my info on what they did.

Note that with a few typical mods to stock condition such as tape, air dams/diverters in front of tires, lowering a car, correclty aligned wing...makes a big difference.

These are stock numbers.
1968 Chevy Corvette 0.50
1968 Volkswagon Beetle 0.46
1968 Mercedes 300se 0.39
1978 Triumph TR7 0.40
1987 Honda Civic DX 0.35
1987 Acura Integra 0.34
1987 Porsche 944 Turbo 0.33
1987 Ford Taurus 0.32
1987 Maxda RX7 0.31
1987 RX7 sport 0.28
Ford Probe V (experimental 4 door sedan) 0.137
1932 Fiat Balillo 0.60
Volgswagon "Bug" 0.46
Plymouth Voyager 0.36
Toyota Paseo 0.31
Dodge Intrepid 0.31
Ford Taurus 0.30
Mercedes-Benz E320 0.29
GM Sunraycer (solar vehicle) 0.12
Opel Kadett Gsi 0.30 - 0.31
Renault 25 TS 0.30 - 0.31
Audi 100 1.8 0.30 - 0.31
Porsche 924 0.31 - 0.33
Porsche 911 Carrera S Cabriolet 0.29
2005 Corvette Coupe 0.286
2003 Mercedes SL500 0.29
2003 Mercedes SL 55 AMG 0.30
2003 Dodge Viper 0.40 (What's their top speed???)Top Speed [mph] 190+ with 500 hp at 5600rpm.



82 Z28: .368/.369 Cd Trans Am: .323 Cd
S/E: .335 Cd
Base: .333 Cd
84 Z28: .339 Cd Trans Am: .32 Cd
.299 Cd with standard Aero wheels instead of the High-Tech Turbo aluminum wheels
85 IROC-Z28: .34 Cd
91 GTA: .310 Cd

BTW...isn't the F-16 a pretty old design? Do you know what the drag is for the Stealths?
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Old 02-14-2005   #39
The Anvil
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Re: Top Speed

Very few of those cars you list are actually appreciably better than the 1987-89 GTA. For the price of the vehicle and time period it was built, only a few cars in production on the planet are any better. I think that speaks volumes for the basic design of the GTA package. The Pontiac GTA advertising in 1987-90 always featured a blurb about the superb aero @ .32 Cd. Look in any Car Craft or Hot Rod from that era, you should see one of their ads.

The reason Bank's 91/92 car might have had problems is because the rear spoiler on those cars is known for actually creating lift as opposed to downforce. With the proper rear spoiler in place I'm sure he resolved the issues. Lingenfelter had no problems at all with the 89 GTA aero, and he just missed setting the 300 MPH two-way average at Bonneville back about 15 years ago. I think he went 298 or so. Pretty impressive for a door-slammer car.
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Old 02-14-2005   #40
MunsonGTA
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Re: Top Speed

no damn way some plymouth voyager is that aerodynamic
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11.16 at 123 mph.
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