BlackRocket

After installing a new Sharkbite rear suspension with Van Steel offset trailing arms in the back and a complete Global West front suspension in the front with Coilovers I am getting a little bit of a buggy ride. (Small block with 550# coilovers).

After I spoke with the tech rep at Global West and he stated that I need to back off from the front shock settings from 9C/12R to 4C/7R. This adjustment helped considerably but I'm still getting a little accentuated bounce up and down over uneven pavement in the road.

I am going to increase the rebound slightly and try some more test drives tomorrow. This handling is nothing close to a later model Vette and am not sure how those out there Road Race with such an unstable platform?? (The Viking shock instructions show for Autocross and then Road Race to progressively increase the C/R much higher which would give a much more pronounced bounce).

I am curious what F-R C/R settings work for the beas all around handling.
Those that have experience in setting up coilovers please chime in.

Thanks!
B-R

Sky65

I have no experience with that suspension but I know tire pressure can greatly affect overall suspension compliance. What tire pressure are you running? If over 30 try drop the pressure a couple pounds. Don't think would run less than 28.

Tom

Shark Racer

What springs and shocks are you running in the back? I've noticed most of the ride quality is felt by the back. Consider how close your butt is to the rear suspension...

*edit* I guess the Shark Bite setup is one size fits all...? Have you tried adjusting the shock rates back there?

ddawson

For the rear I start to full soft on R and C. I then use certain freeway Highway 92 before 101 as it has many dips in the road and a few section that can bottom out the car.

I dial in so it doesn't hit the bump stops and keep adding more until the ride get impacted. Then I do the same with rebound. I then do the front so the front and rear pounces and recovers at the same time.

BlackRocket

I went with the Medium springs in the back at 300#'s.
And, correction on the fronts...they are also the medium spring rate at 400#'s. I went with Viking shocks as I read some negative reviews on the QA1's. I'll try some different settings tomorrow.

B-R

jb78L-82

I am assuming that you are using the correct alignment for that suspension for the street?

Also, what tires and rims are you using?

Lastly, are you using a stock steering system, Borgeson, or R&P? If you are using the stock OEM steering box and components, are they up to date with new components? The stock steering, especially the box, gets very sloppy with age and needs a Gary Ramadei, GTR1999 custom blueprint/rebuild to eliminate all play, better than when new. Not having your suspension on my car, I would imagine that suspension eliminates much of the C3 sloppy suspension movement, and poor steering will make the issues worse...

BlackRocket

Good input JB. The entire car was rebuilt as a frame off and the steering box is new original stock. I will eventually put a rack under it. The car had the stock suspension with a VB&P mono leaf rear spring and Bilstein shocks all around. Not much difference with this set up after spending all kinds of money and work installing. Very disappointing! These older Vettes had a reputation for poor handling back in the day and it seems that even with newer technology parts they still do... I mentioned to the tech rep at Global West the issues I am having and mentioned that the handling is not anything like a newer model Vette or even a C4 and his response was; "It never will be".

7t9l82

Global west makes very good stuff, I have used thier components on another car and have nothing but high praise for them.
With that said I'm not sure miss matching components was a wise choice.
Contrary to what has been said the c3 can be a great handler

Neil B

Which Vikings do you have? I just put on a set of Crusaders with their 'AP' valving and it rides pretty good at 4C and Zero Rebound. They do not recommend coming off full soft on rebound with the AP's on the street.

BlackRocket

I agree with all; I am 100% impressed with the Global West control arms; Great Quality! As far as the mix matching I have basically everything from Speed Direct "Sharkbite" rear system and front coilovers. The only thing off product are the GW control arms which only give more caster than stock and the Van Steel offset trailing arms with Johnny Joints which do not alter the rear attachment location. As far as the Viking Shocks I ordered the ones accompanying the below kit. I guess I am just looking for re-affirmation from those that track their C3s that they feel a lot more "loose" than a C4-C7 even with these aftermarket modifications.

Thanks again for any/all input...
Much appreciated!

https://cmc.speeddirect.com/items.as...atus=0&Tp=&Bc=

caskiguy

Curious, did you let the suspension "settle" on the ground before torquing the suspension components ?

BlackRocket

No. I would never do that. All hardware should be torqued to specs then driven for 50-100 miles and re-checked for proper torque. That would have no effect on ride quality anyways.

cagotzmann

Are you running similar tire sizes compared to C4-C7

my 78 has 3 different "loose" feelings based on tires alone.

1. Factory 255 60R 15
2. 245 45R 18 Michelin PSS
3. 275 40R 18 Notto NT01

vs my 2010 Grandsport Running 325 30R 19", and 275 35 18"

Also my impressions of similar feel is also based a lot on body rattles and interior noise, vibration felt in the seats.

The 2010 GS stiffer frame and less body rattles give the impression of the tight handling car.

Then the steering tightness is completely different. Once I complete the 78's conversion to R&P steering I might have a different impression.

As for G's in the corner I can get similar G forces in either car. But the difference is my feelings via my hands / seat of the pants.

So the hands touching the steering its not close. and for the seat of the pants again the new car seats are much better.

I believe your impressions are similar the steering /tires may be influencing your judgment of loose vs the actual suspension.

caskiguy

Sorry misstated my question.
Good Luck figuring it out.

caskiguy

Curious, did you get the SharkBite setup "dialed in" yet ?

Metalhead140

I'm wondering what you mean by "buggy". Is it harsh (jarring over bumps), or is it underdamped/bouncy (takes a while to settle after bumps, keeps bouncing, kinda like a pogo stick), or is it darting over bumps (requires steering correction - bumpsteer, undesired play/wear somewhere, or incorrect alignment)? Without a bit more description it's hard to answer. Wheel/tyre size and type, and tyre pressure are huge factors too, as already alluded to.

As for how my car specifically drives? It's not like a modern car in feel or refinement, but in outright grip and ability it is. Mine is far more "stock" than yours in terms of suspension design, but I have stiffer springs, and am probably lower, and I don't know what swaybars or tyres you are using. I greatly enjoy driving mine on the track, and it's pretty competitive with modern machinery, but it still feels like an older car in the way it responds and the feedback it provides.

PainfullySlow

Slowing down rebound will reduce wallow. That is where I would start.

gkull

Global's tech support sounds like the crap I get when ever I talk to the high school drop outs at QA1.

550 front springs is not enough for performance out of your heavy front end and my QA1S dual adjustable shocks work the best way up in the highest settings. They have 1 - 18. I have them set to something like 12&15. Rebound is what stops the bouncey oscillation

Shark Racer gave a good point. Rear bounce is what you might be feeling because of how close the seat is to the rear tires. Dial in lots of rebound

If your tires and wheels worked before the changes it is obvious that you need to work on new stuff