Your thoughts/comments on these launches

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justinp61 said:
Depends on the shock.

The way Calvert explained to me years ago was that the adjustment on the shocks is for the rebound but also makes small changes to compression. My Dart with the 408 went a bunch of 1.38 60' with them and CE three ways on the front so they can work but there isn't much adjustments for poor tracks.
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See, that’s what they told me...turning the knob changed the rebound and the bump a small amount. How much that was and if it changed with the setting (as in if you are at one end of the settings does the bump change the same amount at the other end of the setting) they couldn’t say.

It’s confusing for sure.
 
So if no tubes are in the budget for this year= more air pressure.
All tho the air pressure is high......The car is heavy and there is not tube in there.

My car weights 3860 with me in it. i run a 28 X 10.5 M/T on my car, and i have a tube in it.
I run 15 most of the time if the track gets a little slick will drop to 14.5 pound. If i drop it to 14 pounds it wads up just like yours.....and you can feel it in the car.

Heavy Car, No tubes, give it some AIR(not that you don't agree and we have already said it a 100 times:BangHead: )
And screw that rim before it slip to far.
If you can't get it done before the next race, chalk the rim tire and see if it's slipping on the rim. Mine was slipping with a lot less power then you are running.
 
Just to say that I fully appreciate and understand the fact that near $30000 has been spent on the Motor/auto/Dana/converter/mono's/slicks/shocks inc. the labour to put it all in however if it ain't working it sucks and were talking just a pair of front shocks perhaps to put it right with a better look at the whole front suspension, some different tactics at the back and we could be in brkt heaven:)

First thing I did was to chalk the rim/tyre when I saw no screws, tyre moved 1/2" on first 2 runs with 14 in them, we went up to 16 and end of day they moved 1", but by then he was giving it the beans, well nearly. Thats taken care of by now so we will see, if it takes 20psi then so be it.
 
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Agree
you really are close to a grate launch. It's not that far off.
Its not like it is bowing the tires off or is just a plain dog out of the hole.
It's up and gone. just a little refinement.
 
Cudafever said:
Agree
you really are close to a grate launch. It's not that far off.
Its not like it is bowing the tires off or is just a plain dog out of the hole.
It's up and gone. just a little refinement.
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:thumbsup:

what I'd like to see is it carry the wheels a few inches not necessarily to the 60 but some ways while it stays on the tyre, wouldn't we all.......
 
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I'd lower the start line RPM. The chassis reaction is already used up when the car launches. Here is a vid of my buddy's 69 RoadRunner, this launch was at 2300ish. Notice how smooth and controlled the suspension works.

Fast forward to the 1 min mark

 
skrews said:
I'd lower the start line RPM. The chassis reaction is already used up when the car launches. Here is a vid of my buddy's 69 RoadRunner, this launch was at 2300ish. Notice how smooth and controlled the suspension works.

Fast forward to the 1 min mark

Click to expand...


Agreed, thats how it should be. I take your words on board. Both front/rear are smooth, unfortunately it looks like our lakewood 90/10's on the car are staying:( so we will stiffen up the rears/up the psi, leave just off idle so still have travel left and see. I've just bought some rear shock extensions if really needed. Don't know if we can sort it without stopping the front being so violent, cutting bump stops down may give us a bit more separation which may help, we'll try with what we have, Calvert say if it hooks and spins to soften shocks up 1 click@a time but thats assuming the front is good. A go pro should be fitted inside (I don't know anything about launch/shift/trap rpm) and on the rear susp I'm told so perhaps we will see whats going on better, after spending all that money, to not spend just a little more (even my money) on something as important as front control is making things hard, but it is what it is.....Also I note you leave@2300 with no body movement you must have a good converter and running 10.9's@123?.(around 550fwhp?)..our issue is@720ftlbs we need better equipment I think than whats on the car currently but none of it is my choice.....maybe next year?.
 
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skrews said:
Same pass as above
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Gland you posted that video. The one from under the car.
looks like cal-trac's load and stretch the suspension just like the SS Spring do.

Agree mine hooks better when i don't load the suspension as hard.
 
skrews said:
I'd lower the start line RPM. The chassis reaction is already used up when the car launches. Here is a vid of my buddy's 69 RoadRunner, this launch was at 2300ish. Notice how smooth and controlled the suspension works.

Fast forward to the 1 min mark

Click to expand...

Go Pros are a wonderful thing aren't they.
 
Hot Metal said:
Agreed, thats how it should be. I take your words on board. Both front/rear are smooth, unfortunately it looks like our lakewood 90/10's on the car are staying:( so we will stiffen up the rears/up the psi, leave just off idle so still have travel left and see. I've just bought some rear shock extensions if really needed. Don't know if we can sort it without stopping the front being so violent, cutting bump stops down may give us a bit more separation which may help, we'll try with what we have, Calvert say if it hooks and spins to soften shocks up 1 click@a time but thats assuming the front is good. A go pro should be fitted inside (I don't know anything about launch/shift/trap rpm) and on the rear susp I'm told so perhaps we will see whats going on better, after spending all that money, to not spend just a little more (even my money) on something as important as front control is making things hard, but it is what it is.....Also I note you leave@2300 with no body movement you must have a good converter and running 10.9's@123?.(around 550fwhp?)..our issue is@720ftlbs we need better equipment I think than whats on the car currently but none of it is my choice.....maybe next year?.
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You can cut down the up travel bump stops to about 3/4 inch thick, that will give you as much front end travel as possible. Running tubes in the rear tires will stiffen up the side walls and help counter act the bounce on launch. Hoosiers are also very soft sidewall tires, I've had much better luck with stiff sidewall tires like Mickey Thompson or Phoenix.
 
skrews said:
You can cut down the up travel bump stops to about 3/4 inch thick, that will give you as much front end travel as possible. Running tubes in the rear tires will stiffen up the side walls and help counter act the bounce on launch. Hoosiers are also very soft sidewall tires, I've had much better luck with stiff sidewall tires like Mickey Thompson or Phoenix.
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Phoenix are good tires. They are pretty sticky and wear like iron.
 
Just so you are not chasing issues for nothing...were other cars hooking up with similar power that day? Sometimes track prep can be bad, or non-existent.

Echoing what others have said, I would try more tire pressure first (its free). Also, if you can, lowering the rear by an inch or 2 might it might do the trick as well. My car never liked the tail end up high like that, but my friends Demon sits like that and runs great (granted he has SS springs, no Caltracs).
 
SPR has 1 of the best if not the best track in europe, they said it was prepped, other cars were hooking ok from what I could see, 1 ran in the low 7's several times with no issues, of course there were no PM's or TF's to add much rubber but it was ok.

Unfortunately nothing is going to change on the car till next year I'm told so all we can do is change settings like more air in the tyres, run@the converter instead of stall and mess with preload/shock settings and try and improve....thanks for the responses.
 
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Well the front is staying as it is, supposed to have 5" of travel, we'll try lowering the car 1", rear suspension travel is all used up I think when he loads that verter as is most of the front, Calvert do 3 lengths shocks for different heights, stock, 1" higher, 1 lower, chances are we don't have the right ones....we can do something about the rears, I bought shock extensions, rims have screws now, I'll mess with it to see if we can stay on the tyre but it ain't gonna be easy, will have to use Saturday to tune as its quali but thats not the best and Sunday is elims (32 car NSS brkt field). Fighting the front all the time.
 
Well small improvement over weekend, so 16psi in tyres, softer on ext. 6....and caltracs just touching both sides, ran ok but then 2 flats preload that my mate wanted, think he's got it in his head about preload. 60 now down to 1.43's and best was a backing off 10.44@120 in comp on a 10.48 dial....best WOT mph was up to 127.5 on a 10.47, DA was good on Sunday. Want to get it as good as we can with that 950HP (830 carb)...then a Thumper 1050-ish Dom is on its way....and were around 30hp off of what the dyno threw out with open hdrs currently.
 
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60 are getting better.
didn't you run 16 psi in the rear tires the first time out????
 
Yes, we did try 17psi as well, 1 of the tyres had a leak and it messed things up slightly, settled on 16, but will try more next time, only 4 runs Sat, 1 bye on sunday and then the breakout, John was over 2 cars ahead I was told and didn't come out of it early enough, never driven the stripe before so can't have a go at him for that. The front doesn't seem to upset the car as much now and were staying on the tyre, I need to understand why better, psi or shocks, no preload to preload doesn't seem to make much difference apart from its binding it up with it....had another guy helping the weekend who was ok but perhaps its starting to be a case of too many cooks?
 
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Hard to tell, John still doesn't give me good feedback on that, 1 run he said he went on the verter, I didn't think so, what his idea of going on it is I'm not sure. I think we eased off the stall some?....cannot remember exactly and the outcome. But I did suggest to another guy with a 416 Demon that he try a run at the verter rather than leave@2200 and he lost 3 10ths but thats a whole lot different set up.
Issue here is as you've gathered is unless I know the rpm stuff from start to finish things get harder to think through and have knock on effects in choosing other stuff to sort.....on 1 run he did 1.43 60 on a 10.67, that has my brain wrecking itself??....so that evening he tells me he messed start up and went in deep....It WILL get better:rolleyes:....we are getting quicker all the time bit by bit and only 1 and a bit 10ths off currently of what I thought it had in it tops, I can see a 10.1>2 sec car here which to me is quite impressive considering the parts it has now.
 
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We got it working much better now, still not as I would like it but not killing the tyre so much, 16psi and its more one movement at the hit to the 60......1st round loser with a -0.012 red, 10.45 on a 10.44 dial today, other lane red lit too worse but he was a chaser and we did it 1st... but...
1.43/1.43/1.45 60's (shallow), 10.45/10.45/10 49 et's, bottom hole, 1 flat p/load, 7 hard on 9-ways, getting there slowly.

Johns Launch5.jpg
 
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