Made it to the track today for a few passes. Air was much better than previous trips. Air temp was 51dg, dew pt=44, pressure=29.90 which works out to around -300DA.

Made 3 passes, 1st pass aborted just past 60ft mark.

2nd pass got the car to hook but it got squirly just past 1/2 track.

3rd pass, same deal as 2nd pass.

Previous best was:
1.508
4.380
6.808
101.35
8.914
10.706
125.35 DA=1700ft

Today
2nd run
1.481
4.309
6.722
101.94
abort remainder.

3rd run
1.494
4.346
6.770
101.56
8.89
abort

The car was real squirly past 1/2 track and became a handful to keep straight. Only thing I can think of is the head wind (15-20mph)was making it harder to track straight. Usually the car goes pretty straight but will sometimes get hard to handle if the rear tire psi is too low. I was running 16psi today which is 2lbs more than usual. Maybe its time for a front suspension update and fresh alignment.

All in all I'm pretty happy with the 1/8mi times. Should still be some left in it though. Just need to actually tune it and try some different suspension settings.

Oh, for all you "northern" racers, yes it is nice getting to run in January. ;)

In decent air too! Looking up John! graemlins/thumbsup.gif

nice times john ,you might wont to look at your rear shocks that may be part of the squirly movement down track

graemlins/thumbsup.gif

Which track do you run at ? I'm usually going to Lone Star Park in Sealy, getting familiar with things before I finish my car and take it out there. graemlins/waving.gif

Dang John, thats some good air!

Impressive times, I'm glad to see they keep improving graemlins/thumbsup.gif

John,

Congrats on the new bests! Based on your previous times, it looks like your best pass yesterday would have been in the 10.55-10.57 range. graemlins/beers.gif That's awesome. With a little tuning and more good air you just might find a 10.4x in there. graemlins/thumbsup.gif

No telling what it's going to run after the "little" tweaks that your about to do. graemlins/thumbsup.gif

Thanks fellas.

Junkyard- thanks, they're all about do for replacement.

John- I usually run at Baytown on Friday nights or Sunday afternoons.

Jason-I'm pretty sure there is a 10.4x pass in the car. Still lots to play with (jetting, cam phasing, bigger carb, suspension,etc). Seems like everytime I race with the intention of tuning, something else comes up like yesterdays "straightline" problem.

I'll take a step back and see whats what with the steering. The manual box is a rebuild but its still loose, the shocks are all about 6yrs old, running radials up front, bias in back. Lots to look at to find the problem. I really wish I could find a "tight" steering box (thats STEERING box :rolleyes: ). It would make it easier to correct a drift without so much slop in the steering wheel.

John,

It may just have been the wind. Especially since you haven't really had the problem before.

I had the same problem last year on a windy day (bad cross wind). Couldn't get down the track (1/8th mile). I too thought something was amiss in the chassis. Checked everything over and didn't find anything. Went back to the track on a "normal" day. No more problem.

Is it possible that with the added head wind that you were getting some "lift" on the front end?

Hi John...

I'm sorta new around here (this Forum)....what does this car look like? I live in Magnolia also...there can't be THAT many of us around here!


BTW...great times!


JIM

Hey John! graemlins/thumbsup.gif
We've found that on the 235" dragster when it starts getting squirrly at the top end, it's time to swap slicks side for side. Don't know why but it works every time. Also, we torque(wrench) the lug nuts to wheel mfg specs.
What carb are you running? ;)

John, can you give some engine build up details? That 421 sure seems to be making power.

Jason- yeah, maybe so. Not sure. I'm gonna run it again before any changes to see if its still a problem then go from there.

Jim- Its a "97 Viper Red" 67 Chevelle with Drag Lites. I can email a pic if you want. What part of town are you in? I'm over off 1488 about a mile east of the high school.

Bill-Thanks for the tip. Still running the BG. Hav'nt tried the hp950 yet. Its coming though.

94Guy- The short version: 12.7:1, TFS twisted wedge heads 2.02/1.6, solid roller .645" 266@.050 108lsa 106icl, Super Vic, BG 750. Made 600 on the engine dyno. Makes real good torque but the hp peters out above 6200. Got new heads going on very soon.

Impressive performance without a doubt.

I'm wondering how you guys are figuring those aborted runs might have been a 10.50 pass?

I just dug up my log book from the best two passes in a row.

1.482 60'
4.325 330'
6.746 660'
100.97 660' mph
8.862 1000'
10.666 1320'
124.59 mph

1.502 60'
4.349 330'
6.767 660'
101.10 660' mph
8.875 1000'
10.670 1320'
125.22 mph

Using these runs as comparisons, I can't see how there's a 10.50 pass there. My car has always pulled better on the second half, so I can't see John getting a 10.50 pass with his first half numbers. Every car is different, so maybe I'm wrong here.

EDIT: comparing again, that second pass might have squeeked a 10.59 or so.

Todd,

Every car is a little different, but a good multiplier to use is 1.57 x 1/8th ET. In John's case, I took his previous best 1/4 ET and divided by his 1/8th ET. (1.573)

1.573x6.722 = 10.57

In Todd's case, the multiplier is between 1.581 and 1.577.

After you get a few passes on a car and compare the 1/8th vs. 1/4 you can usually tell what it's going to do in the back half based on the front half.

Congrats, John. That mouse motor is hummin! You gotta be loving life. Can't wait to get back to the track myself. If the weather holds I'll be there this Saturday smile.gif

John...

I'd like to see it if you can shoot me a pic!

I'm on the other side of town....Clear Creek Forest off Nichol Sawmill RD.

I've got a blue '67 Vette convertible, 540" with 5 speed.


Small world huh?

JIM

John, what heads are you going with? size and name brand

Ken, thanks!

Jim- You've got mail.

94guy- I went with a set of full-port Dart Pro-1 215's done by Mike Stark at CFM performance. The new heads ended up around 235cc on port volume and peak flow in the 316-318 range with mid-flow comparable to the current heads. Should hopefully see a decent gain since the current heads are done at .500 lift @281cfm. Also added a set of Yella Terra shaft rockers and a full port Super Vic.

John.....check out this site for your steering box needs...www.corvettesteering.com