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Discussion Starter · #1 ·
I've got a stock turbo, full weight (3700 race weight) Grand National that I'm trying to get to short better. Below are my suspension mods:

- Front QA1's (single adjustables) set to the softest settings
- Stock springs on every corner
- Stock rear shocks (looking to get QA1's for the rear also)
- Adjustable rear uppers, pinion angle set to -3, neutral preload
- Metco box, non adjustable lower control arms
- Metco lower control arm lower control arm relocation brackets (lowered the control arm about 3 inches)
- No airbags
- 275/60 MT ET street radials
- 1 3/8" solid rear sway bar

The car goes nice and straight (preload fixed that) and is pretty constant. I'm leaving at the track around 12 psi and the car goes 1.67-1.69, with a one time best of a 1.65. I'm trying to get the car to transfer weight better. I was looking into getting some front springs that will come up fast to get weight on the DR's as quick as possible. I've read here and other forums that Moroso Trick Springs are garbage and not very good for street driving. I usually put 30 or so passes, and 1200 miles a year on the car. I also get into some street action from time to time.

Should I go with some Moog springs? If so what number? I don't have scales, so I'm not sure how much the front of the car weighs. Should I loosen the front upper and lower A arm bolts? If so what is the procedure?

I've included some animations to show how car leaves. I like how the lower control arm brackets causes the rear end to plant. Before the chassis would just squat on the tires, unloading them.

Anything else I can focus on?



 

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I raced Buicks for years, so I'll chime in. First off...you didn't say much about your engine and trans combo, other than you're running the stock turbo. Stock converter? Still have the 3.42 gears? What is the average ET and MPH? How much boost?

- Mid 1.6 60' times aren't bad, really. But a 12# launch should be hauling ass for you. Is it spinning at all? If not, leave at 15# and see what happens.

- On a stock engine/turbo car, the 275/60 isn't helping you any. Most of the time, they'll do a better overall on 275/50's (26" height). You've got 2" more height, so you've taken away some overall gear ratio which can't be helping much...

- You really do need an airbag on in the right rear. It's going straight, but you're getting a lot of separation on the left side and the right side is trying to squat like hell.

- I wouldn't worry much at all about changing shocks, I went low 1.6 and some high 1.5 60' times on a stock combo all the time with rock stock everything. The way you build boost on these things, most of the suspension travel has been taken up before you let go of the brake.

Shoot me a Direct Scan file if you have one of a good run. Happy to help a fellow Buick guy, wish I had more time to finish putting mine back together.
 

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BTW, your suspicions about the Moroso springs are dead on. If you really want the car to ride like a piece of shit, put them on. ;)

The factory stuff really is the best. You can't beat it, unless you're trying to run 60' times in the 1.4 range. Cheap, $10 Red Ryder gas shocks from Advance kick ass on the track, and ride very nice.
 

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Discussion Starter · #4 ·
Stock turbo/intercooler/converter/gears. Car has 42 lb injectors, shift kit, methanol, MAF Pro speed density with the power logger, Walbro 340 pump hot wired, big 4" cold air intake with no Maf, 3" downpipe dumped at the front tire, and the suspension I mentioned.

The car goes constant high 12.1x's at 110, locking the converter in 3rd at 73 mph. I don't spin at all on the 12 lb launches, the brakes don't want to hold much more then that. That is running around 23/21 timing, can't seem to raise it much more with out it knocking with the converter locks. I usually run 22-23 psi with the meth.

I figured i wouldn't need an air bag with the heavy ATR rear sway bar.

I did used to run a 26" tire, but I have had better short consistancies with the 28".

Direct Scan? I haven't used that in years :)

Thanks for the help.
 

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Well 110MPH is nothing to sneeze at. I realize you're hitting it with Meth, but that's still very good for a stock hairdryer.

Have you tried throwing the wood to it on the launch? E-brake it for a pass or two and strike it with 16-18#? We had one car set up similar to yours a while back, with the Southside Machine rear lowers. That car rode sloppy as hell, but worked great at the track. It would take whatever you threw at it; actually worked better the harder you hit it, with the instant center getting moved with the SSM bars.
 

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Mid 1.6's is not bad in that combo. This goes much deeper than front coil springs. I dont see much more to be gained in 60 ft without more power and converter.
 

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Discussion Starter · #8 ·
Thanks for the info guys, looks like I'm doing something right.

I just finished loosening the upper A arm bolts. I just ran the stock locking bolts so it just seats against the washer, using a dab of red locktite. I'll see if that helps.

I'll be running a Viper on Friday and need all the traction I can get :)
 

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Discussion Starter · #10 ·
I forgot to mention, the front sway bar removal is one of the first things I did.

Yeah, those chrome wheels are very heavy.
 

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Discussion Starter · #12 ·
single adj rear shocks, 14.5-16 psi in rear radials. with good shocks on rear it will hit the tires harder, will need more air psi at that weight.
Interesting, I usually have 13-14 lbs of air in the radials. I just read over at turbobuick.com that most guys have the best luck at 18-20 lbs. Your numbers are right in the middle.

Any idea where to start adjusting the shocks? Do I want them on the stiffer side to get the tires to hit harder?
 

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Interesting, I usually have 13-14 lbs of air in the radials. I just read over at turbobuick.com that most guys have the best luck at 18-20 lbs. Your numbers are right in the middle.

Any idea where to start adjusting the shocks? Do I want them on the stiffer side to get the tires to hit harder?
5-6 clicks for starters
 

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SOFA KING WHAT?
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We used to run the larger S-10 wheel cylinders in the rear on my T Type to hold the car at the line better. I think they were from a 1985 with manual brakes.
 

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Discussion Starter · #16 ·
We used to run the larger S-10 wheel cylinders in the rear on my T Type to hold the car at the line better. I think they were from a 1985 with manual brakes.
I read and did the same things years back. I also got two sets of organic shoes, and used the larger shoes of each set for more clamping area.
 

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For more clamping force out back, remove the stock prop valve, which are usually junk or working improperly. The install a adjustable valve for the rear brakes. Raise the rear bias for track only. I could hold about 16 psi with this mod.
 
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