5.7 IROC vs. GN
5.7 IROC vs. GN
Any of you IROC owners (5.7) ever line up with a stock (or near stock) GN?? I'm guessing that stock vs. stock the GN would beat the IROC but anything can happen on the street. I think the '86-87 GN's were very low 14's stock and obviously in the 13's without spending much.
I'd love to rewind to the 80's ('87 or so) and line up these cars (1/4 mile):
IROC 5.7
Grand National
Mustang LX 5.0 (5 speed, notchback)
Corvette
Pontiac GTA (5.7)
It would be a blast to watch!!
I'd love to rewind to the 80's ('87 or so) and line up these cars (1/4 mile):
IROC 5.7
Grand National
Mustang LX 5.0 (5 speed, notchback)
Corvette
Pontiac GTA (5.7)
It would be a blast to watch!!
i raced one when i with just a muffler and he was at my rear quarter panel the whole way. but when i took off, i went over some train tracks and the tires spun. about 10-15 seconds later my tire was flat and i let off early....we were probably doin about 65-70 mph.
Supreme Member
Joined: Dec 2001
Posts: 2,179
Likes: 0
From: Tucson - MdFormula350 = Post uberWhore
Car: Sexy
Engine: Stock
Transmission: Slipping
I ran one with an upgraded downpipe or some such when I had slicks/lift bars/rear suspension of happiness set up from a dead dig. I pulled a car and a half off the line, then he blew past me when I was at 100 mph. That's ok, that's outside the 1/4 mile with my car.
Supreme Member
Joined: Dec 2001
Posts: 2,179
Likes: 0
From: Tucson - MdFormula350 = Post uberWhore
Car: Sexy
Engine: Stock
Transmission: Slipping
I also ran the Mustang LX 5.0 once. From a dead dig it was perfectly even all the way to 120 mph. Neither of us gained/lost an inch. He had gears and I had suspension.
Senior Member
Joined: Dec 2003
Posts: 758
Likes: 1
From: Ontario, Canada
Car: 1988 Pontiac Trans Am
Engine: 5.0L Fuel Injection
Transmission: Automatic 4speed /w OVerdrive
We have a lady here in town with a GNX. Damn thing is stupid quick. Her husband is a car freak and drives a 1967 dart. I saw the GNX the other night. Aparently they have it running a sequential turbo at 17psi boost. They ran the car last year at the king of the hill racing and were dominating over the V8's. I so want one of these turbo V6's for my TransAm.
couple of vids you guys will like...
Worlds Fastest Single Turbo GN
And a TT GN Smokin the tires on the dyno!!
Oh myyyy..
Worlds Fastest Single Turbo GN
And a TT GN Smokin the tires on the dyno!!
Oh myyyy..
Trending Topics
Senior Member
Joined: Apr 2001
Posts: 940
Likes: 0
From: Diamondhead, MS
Car: 89 20th Ann. TA
Engine: Turbo 3.8 V6
Transmission: 200 4R
Axle/Gears: 3.27
Stock for stock, the GN's were quicker. At least 86-87. The hardest part for a GN was launching on the 215/65/15 Eagle GT's. After spending less than $500 though, you'd be in the 12's 
It only took $100 to get in the 12's with the TTA.
Its amazing how those cars respond to just a couple of mods.

It only took $100 to get in the 12's with the TTA.
Its amazing how those cars respond to just a couple of mods.
Member
Joined: Apr 2002
Posts: 160
Likes: 0
From: Freehold, N.J.
Car: 1992 Z-28 Camaro
Engine: LB9 305 TPI
Transmission: 700R4
84-85 non intercooled hot air setup GN's ran high 15's nothing a L98 shouldn't have a problem with. Than 86-87 got the intercoolers
and thats a different story. Those run high 13's bone stock I think a 13.8. They will poop on a stock 350 in the 1/4. GNX could touch a 13.5. All GN's run close to 16PSI stock! I owned a slow 85 T-type and ran a 15.7 running ok. I like my Z-28 better though. Hey it was the U.S. fastest production vehicle in 87. outperforming corvettes too. But GM couldn't let a buick dominate for long
and thats a different story. Those run high 13's bone stock I think a 13.8. They will poop on a stock 350 in the 1/4. GNX could touch a 13.5. All GN's run close to 16PSI stock! I owned a slow 85 T-type and ran a 15.7 running ok. I like my Z-28 better though. Hey it was the U.S. fastest production vehicle in 87. outperforming corvettes too. But GM couldn't let a buick dominate for long
Senior Member
Joined: Mar 2004
Posts: 948
Likes: 0
From: Clearfield,Utah
Car: 1987 IROC, 1989 IROC
Engine: built 305, stock 305 tpi
Transmission: Corvette 700r4, t-5
Axle/Gears: 4.10 posi, 3.08 posi
holy crap how do you smoke the tires on a dyno. i wonder if the dyno would have read more power if it didnt spin???
Senior Member
Joined: May 2003
Posts: 800
Likes: 0
From: New Jersey
Car: 87 Black Formula
Engine: Rollercammed Lg4
Transmission: 700R4
Axle/Gears: 3.23 10 Bolt Locker
Yeah, that GN was wild! Seemed like it almost couldn't spin those big turbos up at first though, Isn't that what sequentiel turbos are for? First get the pressure from the small one to be able to spin up the big one who really deliver the goods....?
Wonder what happens to the small turbo after it has done its job, is there some kind of relief valve or something to not make it spin to fast and burn a bearing?
For all of you wanting turbos in a thirdgen, here's a twinturbo setup for f-body's: www.bbsdesign.net
Wonder what happens to the small turbo after it has done its job, is there some kind of relief valve or something to not make it spin to fast and burn a bearing?
For all of you wanting turbos in a thirdgen, here's a twinturbo setup for f-body's: www.bbsdesign.net
Supreme Member
Joined: Dec 2001
Posts: 2,179
Likes: 0
From: Tucson - MdFormula350 = Post uberWhore
Car: Sexy
Engine: Stock
Transmission: Slipping
Originally posted by iroc22
Maybe he means the Sequential Fuel Injection?
Maybe he means the Sequential Fuel Injection?
Supreme Member
iTrader: (1)
Joined: Dec 1999
Posts: 4,335
Likes: 4
From: Mays Landing NJ
Car: 2018 Camaro SS
Engine: LT1 w/Paxton 1500SL
Originally posted by Synapsis
Or he could mean sequential turbo like on my RX-7 engine.
Or he could mean sequential turbo like on my RX-7 engine.
Iroc22, yeah I assume that's what he meant..I was just being an *******

Supreme Member
Joined: Jul 1999
Posts: 1,386
Likes: 1
From: Tucson,AZ,USA
Car: Junk
Engine: Junk with nitrous
Transmission: Junk with gears
Originally posted by Synapsis
I also ran the Mustang LX 5.0 once. From a dead dig it was perfectly even all the way to 120 mph. Neither of us gained/lost an inch. He had gears and I had suspension.
I also ran the Mustang LX 5.0 once. From a dead dig it was perfectly even all the way to 120 mph. Neither of us gained/lost an inch. He had gears and I had suspension.
Supreme Member
iTrader: (1)
Joined: Mar 2001
Posts: 1,100
Likes: 0
From: In the corner of my mind!
Car: 1989 TTA #1240
Engine: 3.8 SFI turbo
Transmission: 2004r
Axle/Gears: 3.27
I have a sequential turbo!!!!!!!
Right now it's been outta sequence for almost a year
Supreme Member
Joined: May 2003
Posts: 2,839
Likes: 0
From: CT
Car: Mustang
Engine: Bolt Ons
Transmission: Stock
Axle/Gears: 3.73
Originally posted by prOject-IrOc
couple of vids you guys will like...
Worlds Fastest Single Turbo GN
And a TT GN Smokin the tires on the dyno!!
Oh myyyy..
couple of vids you guys will like...
Worlds Fastest Single Turbo GN
And a TT GN Smokin the tires on the dyno!!
Oh myyyy..
Supreme Member
iTrader: (1)
Joined: Dec 1999
Posts: 4,335
Likes: 4
From: Mays Landing NJ
Car: 2018 Camaro SS
Engine: LT1 w/Paxton 1500SL
Originally posted by iroc22
haha noo not fly89gta....
haha noo not fly89gta....

Well, um...well....er...the Canucks blow! Go Flyers
(another boring summer, they should've beat Tampa
)

Last edited by fly89gta; Jun 1, 2004 at 09:29 PM.
Supreme Member

Joined: Dec 2001
Posts: 1,960
Likes: 1
From: Newark, DE
Car: 2006 Corvette
Engine: LS2
Transmission: T56
Axle/Gears: 3.42s
Hey it was the U.S. fastest production vehicle in 87. outperforming corvettes too. But GM couldn't let a buick dominate for long
Supreme Member
iTrader: (1)
Joined: Dec 1999
Posts: 4,335
Likes: 4
From: Mays Landing NJ
Car: 2018 Camaro SS
Engine: LT1 w/Paxton 1500SL
Originally posted by tpivette89
both the 87' vette and 87' GN could run the exact same 1/4 mile time and mph if properly driven. there are plenty of people running high 13s in 100% bone stock TPI Corvettes
both the 87' vette and 87' GN could run the exact same 1/4 mile time and mph if properly driven. there are plenty of people running high 13s in 100% bone stock TPI Corvettes
Once you start modding the Vette doesn't have a chance
Supreme Member

Joined: Dec 2001
Posts: 1,960
Likes: 1
From: Newark, DE
Car: 2006 Corvette
Engine: LS2
Transmission: T56
Axle/Gears: 3.42s
very true! a N/A car doesnt stand a chance vs a boosted car when the mods begin.
i just feel the need to correct people cause there is so much misinfgormation going around about the Corvette. for example:
A- the GN was the fastest GM production car in for 86/87 (GNX doesnt count)
B- the Corvette HAS to have the highest hp rating out of all the GM cars
both of these statements are false. i already touched upon "A" with the Vettes being able to match the GNs 1/4 mile times. and as for "B"... for 86, the GN was rated at 235hp, while the non-vert Vettes only had 230. in 87, the Vette got an extra 10hp, but so did the GN. and finally in 89, the TTA was rated at 250hp, while the Corvette had 5 less at 245
i just feel the need to correct people cause there is so much misinfgormation going around about the Corvette. for example:
A- the GN was the fastest GM production car in for 86/87 (GNX doesnt count)
B- the Corvette HAS to have the highest hp rating out of all the GM cars
both of these statements are false. i already touched upon "A" with the Vettes being able to match the GNs 1/4 mile times. and as for "B"... for 86, the GN was rated at 235hp, while the non-vert Vettes only had 230. in 87, the Vette got an extra 10hp, but so did the GN. and finally in 89, the TTA was rated at 250hp, while the Corvette had 5 less at 245
Supreme Member
iTrader: (1)
Joined: Dec 1999
Posts: 4,335
Likes: 4
From: Mays Landing NJ
Car: 2018 Camaro SS
Engine: LT1 w/Paxton 1500SL
GNX is a special edition.
had some performance upgrades. It's not THAT much faster than a GN..
I would never want to own a GNX, too rare and well, IMO they're not worth the $$
had some performance upgrades. It's not THAT much faster than a GN..
I would never want to own a GNX, too rare and well, IMO they're not worth the $$
Supreme Member
iTrader: (1)
Joined: Dec 1999
Posts: 4,335
Likes: 4
From: Mays Landing NJ
Car: 2018 Camaro SS
Engine: LT1 w/Paxton 1500SL
Big deal.
I wouldn't pay the $$ they're going for when they're marginally faster than a regular GN. I wouldn't mind driving the **** out of a GN, modding a GN, daily driving a GN...would you do the same to a GNX? Nope.
Also, the only thing really special about the GNX is it's rarity. Yes it some performance upgrades but it's not that big of a difference compared to say a GTA and TTA comparision.
I wouldn't pay the $$ they're going for when they're marginally faster than a regular GN. I wouldn't mind driving the **** out of a GN, modding a GN, daily driving a GN...would you do the same to a GNX? Nope.
Also, the only thing really special about the GNX is it's rarity. Yes it some performance upgrades but it's not that big of a difference compared to say a GTA and TTA comparision.
Originally posted by fly89gta
Well, um...well....er...the Canucks blow! Go Flyers
(another boring summer, they should've beat Tampa
)


Well, um...well....er...the Canucks blow! Go Flyers
(another boring summer, they should've beat Tampa
)

back on topic....
GNX's definitely arent worth the money. If you're going to use it as an investment sure it's worth the money but I buy cars to drive them and a GN or T-Type is a way better deal.
tpivette89 I have been trying to dispell the myths that GM cant have cars rated higher than vette numbers for just about forever. where do people come up with these ideas?
Supreme Member
iTrader: (1)
Joined: Dec 1999
Posts: 4,335
Likes: 4
From: Mays Landing NJ
Car: 2018 Camaro SS
Engine: LT1 w/Paxton 1500SL
Originally posted by iroc22
yeah the Canucks fell flat on their face in the playoffs, at least they won the northwest division title. The Flyers should have beat Tampa easy with their physical play and skill but Tampa was too fast and Esche kinda sucked...I just hope Tampa beats Calgary, I hate Calgary...
back on topic....
GNX's definitely arent worth the money. If you're going to use it as an investment sure it's worth the money but I buy cars to drive them and a GN or T-Type is a way better deal.
tpivette89 I have been trying to dispell the myths that GM cant have cars rated higher than vette numbers for just about forever. where do people come up with these ideas?
yeah the Canucks fell flat on their face in the playoffs, at least they won the northwest division title. The Flyers should have beat Tampa easy with their physical play and skill but Tampa was too fast and Esche kinda sucked...I just hope Tampa beats Calgary, I hate Calgary...
back on topic....
GNX's definitely arent worth the money. If you're going to use it as an investment sure it's worth the money but I buy cars to drive them and a GN or T-Type is a way better deal.
tpivette89 I have been trying to dispell the myths that GM cant have cars rated higher than vette numbers for just about forever. where do people come up with these ideas?

Anyway, back on topic
I agree, buy a GN or Tttype and have fun. Even if I had the $$$ I wouldn't buy a GNX..like I said they're nothing special in my book. Member
Joined: Apr 2002
Posts: 160
Likes: 0
From: Freehold, N.J.
Car: 1992 Z-28 Camaro
Engine: LB9 305 TPI
Transmission: 700R4
I'm not talking about Gn being the fastest production car in 87 GNX was. Even if it was only .3 faster in the 1/4 it was the fastest production car in the U.S. Definitley not worth the money b/c only 500 or something were made but i do know it did beat the vette. A 1987 GNX would beat a 1987 Corvette from the factory in the 1/4 mile. Sad but true.
Supreme Member
iTrader: (1)
Joined: Dec 1999
Posts: 4,335
Likes: 4
From: Mays Landing NJ
Car: 2018 Camaro SS
Engine: LT1 w/Paxton 1500SL
Drivetrain was almost the same. Only difference for the engine that was major was a ceramic coated impellar in the turbo, a better intercooler and a repgrammed chip.
Senior Member
Joined: May 2003
Posts: 800
Likes: 0
From: New Jersey
Car: 87 Black Formula
Engine: Rollercammed Lg4
Transmission: 700R4
Axle/Gears: 3.23 10 Bolt Locker
But when you ask any non car person about what they think of a coupe with the style of the grand national, most people go: oh no, not that car, don't buy that!
It's like with my thirdgen, people go, "no, it's not a smart car!"
"What's a smart car then", I ask. "Well, a Toyota or some Maibatsu or somethin, with preferably the smallest engine." And then I ask "why?" And they go "It uses little gas, looks cheap, so it must be, and uh.... well I don't know much about cars."
"your car uses way to much gas" they go. I ask "how do you know?" and they go "well it must, it has so large engine and much horsepower" And I go " well I want much horsepower, and you don't need to floor it ALL the time" And they go" Well, if you got much horsepower, you're gonna use it!" And I go " well, I WANT to use it! With a car like a thirdgen, you have the OPTION of power when you want" "oh no, you better get a Maibatsu with a 1.0" And then I go, "but that's like a straightjacket, isn't it? forcing yourself to not get what you want?"
So to sum it up; "smart cars look like crap, because if it looks cool, it has to have a too big engine and gas consumption, and then it's not a smart car. And it should look cheap plus be a car that you just throw away when used up. And lastly, it should have a name you have a hard time spelling., then you know for sure, you're SMART like the rest of us!"
It's like with my thirdgen, people go, "no, it's not a smart car!"
"What's a smart car then", I ask. "Well, a Toyota or some Maibatsu or somethin, with preferably the smallest engine." And then I ask "why?" And they go "It uses little gas, looks cheap, so it must be, and uh.... well I don't know much about cars."
"your car uses way to much gas" they go. I ask "how do you know?" and they go "well it must, it has so large engine and much horsepower" And I go " well I want much horsepower, and you don't need to floor it ALL the time" And they go" Well, if you got much horsepower, you're gonna use it!" And I go " well, I WANT to use it! With a car like a thirdgen, you have the OPTION of power when you want" "oh no, you better get a Maibatsu with a 1.0" And then I go, "but that's like a straightjacket, isn't it? forcing yourself to not get what you want?"
So to sum it up; "smart cars look like crap, because if it looks cool, it has to have a too big engine and gas consumption, and then it's not a smart car. And it should look cheap plus be a car that you just throw away when used up. And lastly, it should have a name you have a hard time spelling., then you know for sure, you're SMART like the rest of us!"
Supreme Member
Joined: Jun 2002
Posts: 1,571
Likes: 0
From: ATX
Car: Kitt
Engine: Classified
Transmission: T56
Axle/Gears: Moser/4:11
Originally posted by fly89gta
Drivetrain was almost the same. Only difference for the engine that was major was a ceramic coated impellar in the turbo, a better intercooler and a repgrammed chip.
Drivetrain was almost the same. Only difference for the engine that was major was a ceramic coated impellar in the turbo, a better intercooler and a repgrammed chip.
I don't know exactly what it's called, but I remember there being something like that on the GNX that the regular GN's didn't have.
Originally posted by tamatt27
Didn't the GNX have a latteral bar that seemingly lifted up the rear end of the car to keep the tires planted??
I don't know exactly what it's called, but I remember there being something like that on the GNX that the regular GN's didn't have.
Didn't the GNX have a latteral bar that seemingly lifted up the rear end of the car to keep the tires planted??
I don't know exactly what it's called, but I remember there being something like that on the GNX that the regular GN's didn't have.
I think the bar was just a similar design to the F-Body torque arm.....
But you're right they did have the arm and regular GN's didnt.
Supreme Member

Joined: Dec 2001
Posts: 1,960
Likes: 1
From: Newark, DE
Car: 2006 Corvette
Engine: LS2
Transmission: T56
Axle/Gears: 3.42s
I think the GN was also faster than the Vette in 1986-87
I'm not talking about Gn being the fastest production car in 87 GNX was. Even if it was only .3 faster in the 1/4 it was the fastest production car in the U.S. Definitley not worth the money b/c only 500 or something were made but i do know it did beat the vette. A 1987 GNX would beat a 1987 Corvette from the factory in the 1/4 mile. Sad but true
Supreme Member

Joined: Dec 2001
Posts: 1,960
Likes: 1
From: Newark, DE
Car: 2006 Corvette
Engine: LS2
Transmission: T56
Axle/Gears: 3.42s
yes you could. it even had an option code you could check off (RPO B2K). back in 87, alls you had to do was check that option box at your local chevy dealer, and in a few months a TT Vette would be waiting there for you
Supreme Member
iTrader: (1)
Joined: Dec 1999
Posts: 4,335
Likes: 4
From: Mays Landing NJ
Car: 2018 Camaro SS
Engine: LT1 w/Paxton 1500SL
Originally posted by tpivette89
yes you could. it even had an option code you could check off (RPO B2K). back in 87, alls you had to do was check that option box at your local chevy dealer, and in a few months a TT Vette would be waiting there for you
yes you could. it even had an option code you could check off (RPO B2K). back in 87, alls you had to do was check that option box at your local chevy dealer, and in a few months a TT Vette would be waiting there for you
Supreme Member
Joined: Oct 2003
Posts: 1,096
Likes: 0
From: North --RI
Car: 92 caddy PIMP
Engine: 4.8
Transmission: i dunno
GN's are sweet. They actually have more then 235 horse. But GM couldnt bare to have the GN rated at 275 or whatever they really were. Why.. GNs have always been a staple symbol of drag/muscle. I might actually buy a 87 national in a year or so. Im tired of buying f bodies and cutlasses.... GNs are rather expensive though. 5k-12k roughly...
As for the GNX talk. It would be nice to have one. But being a 40,000 car I wouldnt even bother to keep it in a garage anwhere near trees or a wood garage.
Nate
As for the GNX talk. It would be nice to have one. But being a 40,000 car I wouldnt even bother to keep it in a garage anwhere near trees or a wood garage.
Nate
Originally posted by tpivette89
the GNX doesnt count. a GNX was a Grand National that had non-GM parts added to it by an outsourced company (much like how the TTA was created). therefore it doesnt count. if you absolutely HAVE to include it, then the Callaway TT Vette can be added to this game also. and i think they were a bit faster than a GNX
the GNX doesnt count. a GNX was a Grand National that had non-GM parts added to it by an outsourced company (much like how the TTA was created). therefore it doesnt count. if you absolutely HAVE to include it, then the Callaway TT Vette can be added to this game also. and i think they were a bit faster than a GNX




