video from the other night.............

Pretty much the story of my life, I can blame it on the track as a small tire car (kracker) went a 5.33 and a small tire mustang went a 1.19 60'.

I have a set of 33 10.5W's I'm gonna stick on it for more rollout, that and I feel the converter is way loose, I have a kov race in less than 2 weeks, so for now I'll fill the tranny w hygard and see if it'll snug up the converter some. after that race we will have 6 weeks till the next, I'll get the converter to Lenny and see what he thinks. This was a 1.35 60', spun all th way through low and shifted when I lifted, the whole pass was pretty much high gear only and still went a 5.75 @ 127.50. I dont ever pull the chute at TVRP but Sooner has a real short shutdown and the chute keeps me from burning the brakes off of it lol. Air was in the 4400' corrected range which is typical for around here this time of year.It was 108* on the trip down and about 95+ at the time of the run at 11:00

first pass.....

did kracker win the thing? looks like i'm only going to have one more shot at him this year. had to get a new set of 10 over pistons. but everything else looked ok.

of course he did, musta had the loaner bullet in there again lol.

she sounds good Fabio! the tires look a little tight? what psi? and are you sure?

11.5, anything less they will rattle all the way down the track..............might be a Hoosier thing, will get the m/t deasl mounted on a set of extra rims by the next outing.

that lane looks like the one i was last in lines going everywere from other people having trouble.i know my tires were low at 9 psi and the tire seems to have waded up on the take off in the vid.

what is your spring rate in the rear your 0-60' is identical to mine.seems to go to the left slightly as my car but yours stays straight after its corrected.

I wanna say the rears are 125#'s, the kid backed me up and its slightly out of the groove so that dont help. They do have issues there with dust getting on the track, I wont use that for an excuse the other 3 hast cars were getting down ok. The datalogger showed the converter flashed to 6600 on the first video, but the tirespin is gonna be part of it. The converter is dead on n/a, on the hose I feel its driving through it somewhat.

You just gotta keep messin with it, I'm not sure these tires are not just about dead with all the tire shake in the last several outings...................

our smallblock car was there, the kid was driving it and seems to be gettin real comfortable in it.............we got an nx plate kit on the way as we speak lol.

Frosty mugs for everyone

I've sold enough already to pay for the next cylinder lol. No more than I'm using it will last me forever...........one day I go back through it and make some changes, then put the man shot to it.................

Both passes did look to twitch to the left a little during the launch, it's probably partly from the added frosty torque/power. If that's the case it shouldn't need much of a preload tweak to pull it back center.

good point Dave, at the begging of the season it was going right so I added some preload by raising the lf spring, looks like it needs to come make down a turn or so.

Definitely goes left. Could be a result of the spin though. I agree the tires look tight also. Possibly loosen up the rear shock setting a tad.

Jon im no suspension guy , but she sure looks tight ........ what are you spraying a 25 shot

not spraying much at all lol. rear shock extension is pretty stiff, will change the preload some and play with the shocks a bit, will keep after this tire for now.

The tune is still a bit fat, and I think I can stick another degree of timing back in, the alky enrichment is pretty forgiving. The outer 4 cylinders run about 60* hotter, got a manifold deal in the works that should remedy it some I hope lol.

what rpm you leave at? with the power you have i bet you could try less rpm on the brake and not loose any and could pick up a little.

5000 chip, I will lower it a tad but honestly the leave rpm makes little to no difference on my turd. I've been as high as 5400 and as low as 3000 with the same results.

richter69 wrote:5000 chip, I will lower it a tad but honestly the leave rpm makes little to no difference on my turd. I've been as high as 5400 and as low as 3000 with the same results.

Sooo,,,,, does that mean your chassis and tires are "not working", because a variation of 2400 rpm at launch should produce a change one way or another. Based on watching the video, questions I have are; how old are the slicks, what's the tire pressure, can you soften the rear springs, what can you do to improve the pitch rotation or weight transfer? Softer extension on the front shocks?

Uncle Charlie

Tires were put on in April, they have about 35 runs on them, I have lots of adjustment left in the rear shocks, the fronts i have limited options on, I can say they are pretty soft. Pitch rotation................I think what hinders it is the fact the crank center line is fairly low in the car, I've played with ride height and it makes little difference..........it is what it is.

Tire press is 11-11.5, they are a stiffwall tire.............any less and they will shake all the way down the track.............but even at 9 it seemed to make little change.

The car has been 1.26 60' several times so i know it has it in it...................but that was on a cooler track. 6 weeks ago at the july KOV race the first two qualifying runs were aborted due to the same issues you saw above. Softening up the rear shock extension and putting .3 delay in the nitrous timer got it down the track. I go though this crap this time every year lol, these 105+ degree days sure make it tough. Hopefully it will cool off here soon and we'll get back after it. I have some small changes made so we will see here in a couple weeks at the next kov race.

I talked to Lenny about the converter, he fells its not off much, we will see what the hygard does to it and if it seems happier the converter might go back to him in a few weeks for a minor tweak.

After looking at the second clip again frame by frame & zoomed in on the slick, it looks like the car had somewhere around 7/8" to maybe 1-1/4" rear suspension separation at the inital hit. At the same time the wheelie bar wheels 1st/inital downward action looked to be somwhere around 3-1/2" to maybe 4". This is about the amount of inital drop you would expect to see at the wheelie bar with the amount of inital separation at the slick, (assuming around a 32" ladder bar & around a 60" wb).

The suspension's secondary action during the recovery period (after the initial hit) is a lot harder to see. At first glance it appears that there is almost no secondary suspension action at all (maybe....MAYBE a 1/4" squat). That could point to the rear springs being a little too stiff and/or compression valving being too stiff, or the slicks were just spinning faster than what the combo's needed/desired "wheel speed" was. Either could cause less visual weight transfer to happen. But it should be noted that seeing initial & secondary rear suspension actions is sometimes a little harder to see when viewing the pasenger side of a car because any possible amount of body roll (larger or tiny) that might happen can somewhat mask what's really going on. The car twitching to the left on the launch can also mask some of the suspension's actions when viewed from the right pasenger side. To tell the truth the rear suspension being a little on the stiff side isn't a bad thing if this combo had more nitrous and/or needed some more wheel speed.

Jon, is the tire shake that happens at lower slick pressures a true hard "shake" or is it more of a calmer/consistent "quiver"? Running lower than "optimum for the combo" air pressure numbers can sometimes cause shake, but not always. And it can point to the slicks still having some life left in them because they are still trying to grab the track surface. There're not free-spinning regardless of air numbers, so they are probably not 100% "dead shoes" yet.

Well Jon said they are a stiff sidewall slick, and I'll agree because they sure look like a stiff sidewall, it's just too easy to spin them. The next time that slicks are bought, I'd like to see a softer sidewall and hopefully they get "planted".

I think renting the track and a half day of testing during the daylight hours is likely more beneficial than 2 or 3 Saturday nights of racing. Being able to come back and walk the track and see the rubber pattern from your slicks is very helpful.

Charlie

The track rental thing is a good idea, or a slow TNT where you can make short hits. I would only make 1 change at a time. My first change would be to soften the rear to attempt to transfer the weight. I have found that much seperation to hinder weight transfer. Just my. If your 60 doesnt change when changing launch RPM something else is going on IE suspension not being utilized even at a low rpm leave. I have also found that (with my car anyway) lowering the launch rpm on the brake does a couple things. Increases my reaction time by a couple hundredths, and actually hits the tires harder. Kinda of a pushing against a wall vs punching a wall kinda deal. I could probly explain it better than I am, but when you lower your launch rpm when you release the brake you have momentum flashing the converter, if you fully load the converter on the break it flashes less violently. Just my .02

comp on rears is like a 7, ext is like a couple sweeps from full tight..I'll have to go check. Dave it usually "fluters" the tires some on the leave and at the gear change, at the last KVO race it did it all the way down track, tire pressure has some effect but not much .

In the vids I posted, I think the first one looking from the rear, when I peddled it it was from it shaking very bad....worse than it ever has. One I lifted and restabbed it was smooth as glass. Like I said this is a different track we normally dont run at, i have not run there since the new bullets been put it.

I ran softwall slicks early this season, even on a tight track they work terrible on my car, even with 12psi they will compress the hell out of the sidewalls and bounce on rebound... a stiffwall seems to work a lot better and resolve that issue.

I dont think any track rental stuff will be coming soon, they run a full venue .........that and at 1000 bucks it aint gonna happen lol. Any daytime testing would also be foolish as its still been well over 100 and see no signs of it cooling off soon..............this summer has been brutal for a drag racer in these parts....thank God we race at night but even then the track never cools down any.

Will make a few small changes one at a time and keep messing with it, once the temps get back to or below normal I think it will come back around.

Here is my oh so close round loss from friday night. I treed his ass bad, I pulled all the time out of the nitrous controller and it spun like a bitch and only ran a 54 at 129.80, not enough for his 37.

That's Kracker in the Fairmont with a big inch BBC on E85, runs a 4150 style carb, and a serious Induction Solutions plate system on E85 as well. I think he said he runs a .126n jet lol. Its a small tire deal, he's been a racin fool around here and has an impressive stack of wins.

The leave is straighter now after I messed with the front springs a bit and went a little looser on the extension on the rear shocks, The car went a .48 @ 130 the previous pass with a 1.32 60', so there is still plenty left once the short times come around.

The DA was still well over 4000', it was 103* when I unloaded and this run was at 10:30 and there was still a lot of heat in the track. I'm gonna pull the Hoosiers off and get another set of M/T's on it, I never had tire shake issues until i went to the Hosier's................may not be the issue but I have a good amount of runs on them so its time for a new set anyway.

If i get the tires on in time I may go test this friday, the highs are only gonna be low 80's so as the evening cools the air and track temps should be a lot better.

There is one last KOV race left, I'm tied with the dude that has the chassis car, and Kracker is ony one round behind us.................

good looken pass Jon.you get a little 60'and the 5.30's will happen.