Yellow Bullet Forums banner

1 - 20 of 36 Posts

·
Registered
Joined
·
391 Posts
Discussion Starter #1 (Edited)
OK so I have made 7 passes with the new engine combo and haven't made one clean pass. First 4 passes where all made with a sever flat spot off the line best 60 ft. was a 1.67

I fixed the carb issues and now I got traction issues. Im sure this time around its my tires. I have nitto drag radials BUT.... I wanna say track prep last weekend was not in my favor.


Current suspension is tubular uppers and lowers in the front with .90 tall upper ball joints and 80/20 afcos with 66 6cyl. A body front springs. IN the rear I have QA1 single adjustable and had them set to 5 clicks from 0 with 442 rear springs , SSM lift bars , adjustable uppers with pinion angle being -3 degrees.



In the first video its a bit more sever as I launched at about 1700 RPM It hit the tires much harder . In the 2nd video I launched at about 2500 RPM and spun but not nearly as bad. IM leaning towards tires and im having my hoosiers mounted this week. Any advice is appreciated.

1st vid



2nd vid


This is a video of my best pass the first outing it was a 12.10 with a 1.67 60 ft. and it had a flat spot off the line and I short shifted the 1-2 shift really bad.

 

·
Registered
Joined
·
1,218 Posts
Slow the front down more if u can, How much travel? If u watch your second video, u ARE losing shock travel travel foot braking it, Possibly in the rear also, Put some shock extensions on if u can
The first video its coming up to fast in front and upsetting the rear
 

·
Registered
Joined
·
391 Posts
Discussion Starter #3
Travel is about 5.5 inches in the front. I have incremental snubbers i made. How slow shoukd i go in the front. Maybe I should put the front sway bar back on to slow it down ? The front seemed to move just as fast with the 80/20's as with the 90/10 's
 

·
Registered
Joined
·
1,218 Posts
Travel is about 5.5 inches in the front. I have incremental snubbers i made. How slow shoukd i go in the front. Maybe I should put the front sway bar back on to slow it down ? The front seemed to move just as fast with the 80/20's as with the 90/10 's
Slow enough to not upset the rear, Get some cheap summit 3 ways and set on 60/40 maybe, that second video u lost so much travel on the foot brake by the time u launched u had very little left for transfer, also make sure u have enough in the rear too, U should have as those cars don't separate nearly as much as a leaf spring car
 

·
Registered
Joined
·
16,266 Posts
Videos by someone standing near the starting line are hard to analyse. I recommend to everyone trying to figure out their car to stick a go-pro on the rear quarter so you can see the rear tire and fender plus the front end. One video and you can easily see what the chassis is doing. I get frustrated trying to watch the car's suspension from a distance while it is moving.

My only impression with the video I saw is there is little separation on the rear. But a video taken from a camera mounted on the car will provide a much better view.
 

·
Registered
Joined
·
391 Posts
Discussion Starter #8
I know it's hard to tell from these videos. My wife's phone has the slowmotion setting on her phone which really helps. Wish it would post to anything besides her phone like that. From the slow motion video. I can see exactly when the tires broke loose and it's the video where i launched at a lower RPM as soon as I hit full extension on the front., the tires blew off and the rear settled back down fast after its extension . Im gonna try a better camera angle and a full slick vs. My nitto drag radials. I know the bias plys can be more forgiving.
 

·
Registered
Joined
·
965 Posts
I know it's hard to tell from these videos. My wife's phone has the slowmotion setting on her phone which really helps. Wish it would post to anything besides her phone like that. From the slow motion video. I can see exactly when the tires broke loose and it's the video where i launched at a lower RPM as soon as I hit full extension on the front., the tires blew off and the rear settled back down fast after its extension . Im gonna try a better camera angle and a full slick vs. My nitto drag radials. I know the bias plys can be more forgiving.

Install Quicktime on your laptop and download the video to the laptop. Bring up the video and play it frame by frame once the bottom bulb is lit or the tire just starts to rotate. I have some slo-mo vid of several cars at launch and it's a shitshow of ugly on how tires, springs, shocks and axle housings are not playing on the same team.
 

·
Registered
Joined
·
391 Posts
Discussion Starter #10
Question guys . Could I use the sway bar to slow down my front end movement ? Also since my front end is coming up very fast can I preload my control arm bushings in the front to slow it down ?

I didn't think about this but when I set them in there I had a slower set up and all I did was snug the bolts and double nut them on the lowers on the uppers I didn't mess with the cross bar . I know this allows for some fast movement but maybe too much now ?
 

·
Registered
Joined
·
1,857 Posts
The Nittos can be very temperamental at the track, don't know anyone who likes them. I per went to the M/T and wow what a diff. The Nittos where good in the rain, lol.

At least this is my experience on a 67 camaro. Good look! Let us know how she runs on the new tires.

Keep playing with it.
 

·
Registered
Joined
·
391 Posts
Discussion Starter #13 (Edited)
We went out last Saturday to Great Lakes Dragaway . It was HOT ! 85 degrees and we had a slight crosswind. I tried to make a pass with the drag radials after setting the rear shocks to 2 clicks from 0 and my first pass was not bad 12.15 @ 111 MPH with a 1.77 60 ft. spun pretty bad. Second pass was even worse !

Now keep in mind during the week I played with the carb and got it running pretty well now as far as pump shot goes.

3rd pass I put the 28 x 10 hoosiers ( bias ply) on and went and made a pass after putting them on . I ran a 12.03 @ 110 MPH with a 1.66 60 ft. still feel I got a little tire spin but that could be not being used to the bias plys and not used to a decent pass. haha. tires where set at 15 PSI.


4th pass I dropped PSI down to 12 felt like I got a lot less tire spin than pass 3 ran another 12.03 @ 110 MPH with a 1.69 60ft.
not too bad.


5th pass We cooled down the intake., with 12 psi in the tires ran a 12.01 @ 110 MPH with a 1.67 60 ft. I still feel I got some tire spin.


6th pass I decided to dump the open 2.5 in. x pipe and put on my header extensions. It really leaned up the engine and the flat spot off the line came back BUT the car felt like it hooked up great ( as the flat spot took some shock load from the tire ) Ran an 11.89 @ 111 with a 1.63 60 ft.


The only changes I made was going to a full slick and went to 2 clicks from 0 vs 5 clicks. I had not changed the front shocks . I brought my 3 way adjustables but didn't get a chance to make the swap .

sadly I was completely solo for my 1st 3 runs until my wife and best friend showed up


I don't know if what im thinking is tire spin is some of the movement bias plys have or should I say instability from what many have told me ( first time ever running a bias ply ). Seems like the front end isn't moving as fast as before but im thinking the bias plys soften the hit a little but as well. although I have a little over 5.5 inches of front end travel it seems like I still have more than I should ?

Any suggestions and advice is appreciated.


this would have been pass #4


Pass #5


pass #6

 

·
Registered
Joined
·
1,584 Posts
The front is way too tight. Loosen the front shocks all the way. If you have any travel limiters take them out. What gear do you have in the rear. The car looks real lazy leaving the line. Good job on the burn out and staging quickly. Higher leave RPM would help as well. Trans Brake or foot brake?
 

·
Registered
Joined
·
2,000 Posts
Front & Back of the car are too high by a few inches.
You want to have the lower rear control arm close to level.
What size slicks are you running?
 

·
Registered
Joined
·
1,284 Posts
Just last weekend I went 1.5 in sixty and ran 6.5 @ 108 on a 275/60 Nitto and I’m sure I could’ve gone a 1.4x, but ran out of runs. I run em at 15 psi. You’ve gotta get the weight on the back tires and also need a decent amount of power to keep it there. Most of making them work is in the shocks, not gonna lie. I’ve actually gone 1.7 in sixty on a backroad, no burnout or anything (I run a Vbox to verify). I had a hard time getting them to work with single adjustable shocks. When I went to doubles it was night and day. I’ve got Vikings front and rear. There are probably better shocks out there, but for what I’m doing they work great.
 

·
Registered
Joined
·
233 Posts
I just watched the last 3 posted video’s.
Notice there is a bog on all launches?
Why is the front so high at static height? It’s to high. What spring is on the front? It’s too stiff.
Is there any weight in the trunk?
 

·
Registered
Joined
·
391 Posts
Discussion Starter #18
yeah im still working on the bugs on the carb. its not as bad as it was but it needs work slowly but surely getting there. Learning as I go. The cars ride height is pretty much stock. I think the videos are a bit deceiving but its close to stock. This is still a street driven car so I wanted it to be able to clear stuff and without getting into a lengthy explanation it starts at my drive way. Its a quick steep entrance that flattens out .

there is no weight or ballast in the rear. But I plan on putting the car on scales as I know the rear end of the car is light.


the front springs are 6 cyl. tempest springs . They settled in ok but I might cut a coil out to drop the nose a bit.
 

·
Registered
Joined
·
233 Posts
Static...as in just sitting there on a level surface.
Personally, I would want a softer spring. If it sits like that and you have a 6 cylinder spring, then I would guess there is weight removed from the front end?
I would buy a pair of Moroso springs, same as for a Chevelle I assume. You need to see some rise on the front at launch. Maybe you’ll have to back into the driveway! LOL
All-in-all, can’t complain about a 11 second street car.
 
1 - 20 of 36 Posts
Top