I am doing a frame off resto, and was considering the GNX suspension from Kirban. I know you can do better with your stock suspension, but I will never go faster than 11.50's in this car. Also, I have coil over suspension on it now. Will I have to convert back, due to the way the suspension loads up? Any info would be great. Thank you!
What 1/4 miles ET's is the GNX suspension able to max out at??
- Thread starter BooBoo231
- Start date
No you can't. This is a wonderful way to plant the tires in a drag racing situation.
Hotrodbuick
Member
- Joined
- Apr 17, 2012
You have coil overs now? Why take them off if they're already on the car? Coil over is the best way to go as long as they're set up right. But stock suspension will be plenty good for your goals and faster. These cars were built to run right off the show room floor. I wouldn't go with gnx if that's all you ever plan to run with the car unless you just wanna say it has gnx suspension under it
The GNX suspension has no down sides. You can use the coil overs on the GNX set-up. I'd rather use factory style coil springs,but it probably wouldn't make a difference.
Do you understand how this suspension creates down force?
Yes. It's basically a really short ladder bar that creates a high antisquat value. This lifts the rear of the car up (and pushes the nose of the car down) and b/c it's so short it doesn't have any leverage to lift the nose of the car for weight transfer.
ks
You do realize who Kevin is don't you?
I am using isolated air shocks ,but not in a normal manner.seems to help weight transfer a bit .
i could use some ..One of these days I'll get the time to give you some lessons on suspension Paul.
I have had this car since I was 19. I am 34 now. It has been used and abused, so I am restoring it for sentimental purposes. I am considering making a Rosewood GNX. I still may go just with the Turbo T look, but this is my dream car....and I wanna do it with no regrets, ya know? I have a spare frame I am going to get boxed since we realized the one under the car is slightly bent behind the wheels. This car has 217,xxx mi on it and the other frame I have has a little over 100,xxx. I'm parting that car out, and keeping the frame. I want to reuse the coil over set up I have on the car now because obviously they arent cheap I just heard that because the way the car raises in the back it may not mesh well with the coil overs. Figured where better to find out the right answer than here. I also didn't realize Kirban didnt make the GNX suspension anymore, and some guy that started it up again only has a few left or something. I'm sure they will be gone by the time I am at the stage to put it in
I just heard that because the way the car raises in the back it may not mesh well with the coil overs. Figured where better to find out the right answer than here. I also didn't realize Kirban didnt make the GNX suspension anymore, and some guy that started it up again only has a few left or something. I'm sure they will be gone by the time I am at the stage to put it inI'd agree with the anti squat value and the pushing the nose down. The not lifting the car for weight transfer is true also,however neither does the stock set-up because the rear upper and lower control arms are parallel. Until we change the geometry (angle of the upper control arms) on the stock 4 link,it neither creates down force on the rear tires or lifts the front to help weight transfer. The evidence of this is that these cars(as delivered from the factory) produced the most violent wheel hop of any car produced before it. It did this for two reasons. The front springs were stiff and didn't allow weight transfer and the rear suspension geometry was neutral and didn't produce any down force on the rear tires. This is why the factory suspension allowed the rear of the car to squat. Not a good thing. What do you recommend this guy do?
The UCA's and LCA's are not quiet parallel. The UCA's point upwards at a more drastic angle than the LCA's which means the Instant Center is BEHIND the car.
Note:
The example below is a general way that a lot of us launch our TR's and I fully understand that not everyone launches this way so their chassis may react different that what I describe but I'm not going into details of how every combination of vehicle is launched.
The way us "slower" guys drag race our cars we power brake the car into some amount of boost. The guys that do not have T-brakes or high stall converters rely on power braking into high boost levels. (For example: I for one power brake my car to 15+psi before launching with stock turbo and stock converter and get 1.60-1.61.) This begins loading the suspension before we even launch the car which means the car starts to raise up or squat or ?? depending on the geometry of the rear suspension. The more boost we build on the line the more the suspension is loaded so by the time we actually launch the car the suspension does very little to help load the tires and/or get the body rotating for weight transfer. With a suspension that has a high Antisquat value like Lift Bars or a short ladder bar type suspension this means that the rearend is raised up very high and the nose is already being pushed down before the car leaves the line. So, IMO, traction is not really gained for the $$ spent.
I agree that the stock suspension geometry needs corrected in order to get the most out of the 60' times but only if someone is over powering the tires or they want the most out of thier 60's. The stock geometry with stock control arms has proven to go in the 1.5's really easy on an 11 second car so on a car this slow I'd spend the $$ on making power.
ks
- Joined
- May 26, 2001
Kevin's information is exactly what we have found in building LOTS of GN's for the street and strip.
Many 8 and 9 sec. GN's have used the stock-type 4 link suspension with improved parts to obtain 60' times into the 1.20's. My race car can easily do low 1.30's with HR Parts rear control arms and anti-roll bar using stock springs and inexpensive shocks.
We even removed the stock suspension from a GNX which was used as a strip car, as the stock set-up was not suited for high HP launches, and it was very in-consistant in a race situation.
My complaint isn't that the factory set-up does little to help traction in this scenario. My complaint is that the first thing that happens when you let off the brake(in this scenario)is that the suspension is unloaded.The first thing that happens is something that hurts traction.
I,m glad you mentioned the fact that the scenario,in your mind involved power braking. The scenario in my mind involved a transbreak which is more in line with what the suspension would experience during the launch of a car with a manual transmission.
So often we have discussions where the two parties aren't on the same page.
In the scenario I imagined,at least the car wouldn't squat during the launch.
I would never pay the money wanted for the GNX style suspention because it also isn't the way to go.
I know people successfully propel these cars down the track with the stock(almost parallel) bars with stiffer springs and anti roll bars and an air bag,but I think you would agree that this isn't the way you would choose as the best way.
Changing the angle of the upper arms allows us to accomplish everything needed to move these cars in the best possible way and it's relatively inexpensive.This simple change allows us to pre-load the suspension to equalize down force on the rear tires so the car doesn't twist. It allows us to change instant center and percentage of rise. The thing I like the most is that it allows me to propel my car the most efficient way and allows me to have a smooth ride on the street without a very stiff suspension.
I didn't know that there was someone offering this type of a solution other than Dick Miller Racing. I'm very glad to found out what you are doing. Thanks.
If Nick Micale could elaborate on the GNX suspension he took out of a car I would greatly appreciate it. I kinda want to Build my car to be a rosewood GNX. I have seen one on this board before, and the car was breathtaking! Not sure who's it was but it was sweet!! I want my car to handle well and also have the authentic touch of the GNX suspension. Not just the flares and vents...ya know? It all comes down to money with type of stuff, obviously
It's not the best way to propel a car down the quarter. Most people in the turbo Buick community aren't propelling their cars in the best way. If you want this I say get it. I'm sure you'll like it very much. You're the guy who knows what he is looking for. You know what your priorities are.If Nick Micale could elaborate on the GNX suspension he took out of a car I would greatly appreciate it. I kinda want to Build my car to be a rosewood GNX. I have seen one on this board before, and the car was breathtaking! Not sure who's it was but it was sweet!! I want my car to handle well and also have the authentic touch of the GNX suspension. Not just the flares and vents...ya know? It all comes down to money with type of stuff, obviously
