GNX suspension
- Thread starter V6POWER
- Start date
Welcome!
By registering with us, you'll be able to discuss, share and private message with other members of our community.
- Joined
- Jun 18, 2001
- Messages
- 2,216
I don't know anybody first hand that has installed it.
Tests of the system show no improvement in 60' times.
Analysis of that suspension from a geometry standpoint really shows you won't get much from it. The torque arm is too short. The instant center (point where the car looks like its pivoting around when the rear squats on launch) is not very much further forward than with the conventional 4-link.
I'm not knocking Kirban here. Their reproduction is a work of art. I'm knocking GM. It was a nice try, but they didn't get it quit right. Ideally, the torque arm would attach near the tail of the transmisison, like it does on the F-bodies. The mount points for the trailing arms on the frame also need to be moved.
But, cost kind of prohibited that. The torque arm couldn't go where it needed without McLaren cutting the floorpan and radically redesigning the exhaust.
Tests of the system show no improvement in 60' times.
Analysis of that suspension from a geometry standpoint really shows you won't get much from it. The torque arm is too short. The instant center (point where the car looks like its pivoting around when the rear squats on launch) is not very much further forward than with the conventional 4-link.
I'm not knocking Kirban here. Their reproduction is a work of art. I'm knocking GM. It was a nice try, but they didn't get it quit right. Ideally, the torque arm would attach near the tail of the transmisison, like it does on the F-bodies. The mount points for the trailing arms on the frame also need to be moved.
But, cost kind of prohibited that. The torque arm couldn't go where it needed without McLaren cutting the floorpan and radically redesigning the exhaust.
numbers
Best 60' before:1.89
after:1.81
Best 1/4 before:12.94@104.32
after:12.47@106.65
The article is more detailed and explains the test being done at two different times with weather variations but if you look at the mph there isn't that much difference. The et is alot better though. They calculate at least a 3 tenth improvement due to the suspension alone. I suggest you order the back issue and read the article, it is quite long and in depth. It's March 2002.
Take care,
Ravi
Best 60' before:1.89
after:1.81
Best 1/4 before:12.94@104.32
after:12.47@106.65
The article is more detailed and explains the test being done at two different times with weather variations but if you look at the mph there isn't that much difference. The et is alot better though. They calculate at least a 3 tenth improvement due to the suspension alone. I suggest you order the back issue and read the article, it is quite long and in depth. It's March 2002.
Take care,
Ravi
- Joined
- Jun 18, 2001
- Messages
- 2,216
http://www.carcraft.com/techarticles/116_0402_rear/index1.html
Car Craft article with some of nifty pictures of rear suspension geometry.
http://corner-carvers.com/forums/showthread.php?s=&threadid=9805&highlight=GNX
Thread on another board I'm on, the GNX suspension gets the treatment in the 21st post, but the whole thread is very interesting. Norm Peterson also posts a lot over at MonteCarloss.com in their Rolling Chassis section.
Car Craft article with some of nifty pictures of rear suspension geometry.
http://corner-carvers.com/forums/showthread.php?s=&threadid=9805&highlight=GNX
Thread on another board I'm on, the GNX suspension gets the treatment in the 21st post, but the whole thread is very interesting. Norm Peterson also posts a lot over at MonteCarloss.com in their Rolling Chassis section.
novaderrik
Well-Known Member
- Joined
- May 12, 2004
- Messages
- 8,076
i don't know how much the GNX suspension costs, but i think i'd personally contact Hotrods To Hell and get one of their truckarm kits. same stuff the Nextel Cup guys have run for the last 30 years.
i think they have a 78 and up G body kit out now..
edit: yup, they do, and see it here
http://www.hotrodstohell.net/truckarm/truckarm_gbody/truckarm_gbody.htm
i think they have a 78 and up G body kit out now..
edit: yup, they do, and see it here
http://www.hotrodstohell.net/truckarm/truckarm_gbody/truckarm_gbody.htm
Thanks, I saw a similar link, but it did not work. I see the truck arm set-up, I see how far forward the arm reaches. Pretty cool, except the flaming red color.
OK, next logical question. Who has tried the truck arm suspension hoping for a better 60'?
OK, next logical question. Who has tried the truck arm suspension hoping for a better 60'?
novaderrik
Well-Known Member
- Joined
- May 12, 2004
- Messages
- 8,076
i don't think the arms come painted red like that- but they aren't going to try to show a pic of a black suspension on the black underside of a car on their website.
the only real problem that i have heard of with the truckarm setup is attempting to snake an exhaust sstem thru it all- but it wouldn't be any worse than a GNX, i guess.
the only real problem that i have heard of with the truckarm setup is attempting to snake an exhaust sstem thru it all- but it wouldn't be any worse than a GNX, i guess.
Gary Wells
White turbo Buick trailer park trash
- Joined
- Mar 2, 2002
- Messages
- 9,778
FWIW & IMHO:
I had an opportunity to check out a 20K mile '87 turbo Buick a few months back that was set up with the Kirban Reproduction GNX suspension installed and I was very impressed with the ride control and handling around town at moderate speeds and conditions. This was the white very low optioned turbo Buick that was on Kirbans site for sale about a year ago. The car also had the Kirban rear seat brace, Bilsteins, GNX springs, and the GNX and missing bushings installed by either Kirban's son or Richard Clark, whom I believe is the designer of the GNX reproduction suspension and the GNX original suspension, I believe. I have never been in a turbo Buick that felt as roadworthy as that one did. For more GNX suspension information, check out the info on Dennis Kirban's site in his catalogue. This is not a DIY project. Requires GNX exhaust, requires a fully modified suspension, (will not work on a partially done suspension), requires a jig for locating the suspension for welding, I know of only 3 people that are experienced at installing this set-up. Dennis Kirban's son, Richard Clark, I believe the original designer of the suspension, and I have heard that jack Cotton has done a couple of these set-ups, too. As much as I liked the set-up, you could probably do almost as much or as much for somewhat less mone. Nothing is as cool and looks as trick as a fully done GNX suspension complete with the GNX exhaust under the rear of a "standard" "plain Jane" turbo Buick, though. The suspension is $ 2k, I believe, less installation, ATR GNX exhaust needed, $ 500 deposit required for loan of the welding jig, shipping on everything, and a fully modified suspension bushings, bilsteins springs, and labor, I see about $ 3.6K real easy here, maybe $ 4k. HTH and sorry for the long post.
I had an opportunity to check out a 20K mile '87 turbo Buick a few months back that was set up with the Kirban Reproduction GNX suspension installed and I was very impressed with the ride control and handling around town at moderate speeds and conditions. This was the white very low optioned turbo Buick that was on Kirbans site for sale about a year ago. The car also had the Kirban rear seat brace, Bilsteins, GNX springs, and the GNX and missing bushings installed by either Kirban's son or Richard Clark, whom I believe is the designer of the GNX reproduction suspension and the GNX original suspension, I believe. I have never been in a turbo Buick that felt as roadworthy as that one did. For more GNX suspension information, check out the info on Dennis Kirban's site in his catalogue. This is not a DIY project. Requires GNX exhaust, requires a fully modified suspension, (will not work on a partially done suspension), requires a jig for locating the suspension for welding, I know of only 3 people that are experienced at installing this set-up. Dennis Kirban's son, Richard Clark, I believe the original designer of the suspension, and I have heard that jack Cotton has done a couple of these set-ups, too. As much as I liked the set-up, you could probably do almost as much or as much for somewhat less mone. Nothing is as cool and looks as trick as a fully done GNX suspension complete with the GNX exhaust under the rear of a "standard" "plain Jane" turbo Buick, though. The suspension is $ 2k, I believe, less installation, ATR GNX exhaust needed, $ 500 deposit required for loan of the welding jig, shipping on everything, and a fully modified suspension bushings, bilsteins springs, and labor, I see about $ 3.6K real easy here, maybe $ 4k. HTH and sorry for the long post.
I'm sure most guys have read the Kirban catalogue. $2000, then drive a couple hours to NC, have some guy weld on stuff on a sat. morn., I think they only charge $400? Only takes a few hours from what they told me. And then, yes exaust.
So, has anyone taken one to the strip, with real tires on the car. I see someone above talking about going from a 1.89 60' to a 1.81. That sucks. I get a 1.51 on stock suspension. That other car must have had bicycle tires on it. How about some real world results?
So, has anyone taken one to the strip, with real tires on the car. I see someone above talking about going from a 1.89 60' to a 1.81. That sucks. I get a 1.51 on stock suspension. That other car must have had bicycle tires on it. How about some real world results?
