Aw thanks guys , well I will certainly continue to keep it updated. Next track day is either May 12th or 18th, and then shortly after is our NE GSGN club day. And, I’m pulling this from the depths of my mind, so be prepared I faintly remember the Riviera has always had a little bit of a “wiggle” at higher speeds when hitting the brakes, even before May 12th?, 2018 when I really felt it after the tire change and improper wheel weight placement. That’s why I wasn’t completely shaken when it increased after the tire swap. However it was too much to accept, so I fixed that. But the shake has always been there, so it may be as easy as brake pads, since this has probably had the same pads since the 80s. I don’t know, a little bit of optimism doesnt hurt Check all front end components for looseness Once this is solved, I will be full steam ahead for racing season
Check all the joints, center/drag links, front sway bar, rag joint and steering gear box. All of those can lead to "hunting rabbits" at speed and when hitting the binders. (as if you don't have enough to do...)
Funny you added the "enough to do" part. I've figured out I enjoy working on the car more than actually driving it on the street. The track? Different story
John...check your brake reaction rods bushings ...they are famous for causing twitchy braking on Rivs
The reaction rods are the big spring-steel 1/2" diameter rods which attach to the lower control arms, and run up to the front of the frame. Each one has a big 3" round plate over a rubber bushing at the mounting point on the frame. Those bushings can be hard to find. I had my local NAPA guy order me the correct set about 6 years ago.
Ohhhhhhhh I recognize those, I’ve seen them before under the car. Well, I’ll tighten them if I detect any looseness and then if it improves a bit or any at all, I’ll replace the bushings
John, I have the brake reaction rod/strut rod bushings in stock in black poly IF your interested or need a set. Tom T.
Moving this text because it mostly belongs here. I was able to test the AFR that Jason provided to me and came up with some interesting findings. With: 72 jets 41 rods F hanger AX rods I was lean at cruise and very lean at idle, even accounting for the standard error of the gauge when measuring idle speeds. I was rich 10.3-11.5 at WOT, and began to lean out above 4000 rpm Switch on the side of the road to: 72 jets 41 rods V hanger DA rods At least I was leaner at WOT, 12.3-13.5, but started to approach 14:1 at 4000 rpm WOT So my last change as of recently, without testing 74 jets 41 rods K hanger AX rods
Be sure to take air density / barometer into account. Weather can make a big difference in tuning....
It was 62*, cloudy and about 70% humidity. I don’t expect you to do anything with that info, just getting it out there.
Yeah, it's like making changes....when I first started racing I would race go home and make changes then have gains or losses but often it was more the weather difference that made the difference. Not every change makes you go faster and often they interfere with each other. One winter I made like 13 changes....had to undo some since I ended up going slower!
In other news, I am now the Treasurer of the car club at my school. We will be hosting a show in Spring of 2020. I have a theory about tuning my Q-jet and I am looking for input on what seems right. So, here's the situation: Carb is currently going quite rich (10.5-11.0) on the converter hit, at 3200-3500 rpm, and then somewhat quickly heading towards lean at 4000 rpm and up (at 4000 rpm its going above 13.5). What are ways to solve this? One idea is jetting it richer and then tightening the secondary air valve so that the fuel comes in slower (not so rich) at lower rpm, but then when the air is demanded higher up (4-5k rpm) the valve will be fully open or on its way there with an even greater fuel supply to draw from (smaller secondary rods). Anyone have any other ideas? I'd like to hear speculation or whatnot or whatever antics you can create
I think you might be over thinking it....sometimes best to tune at the track. Worked on a guys car that carb was tuned on the dyno. At the track it fell on it's face....mashing the throttle not the same as steady speed running on dyno.
