Your opinions on this launch Gents

This was first time out on Sunday with new combo... 16lbs in 10x29's, 9-ways set on 5 I think, 90/10's up front, it looks to me as if its unloading tyre@around 10>15ft out, 727 4200+stall, max torque@4400, caltrac/mono's/ bottom hole with 1.5 turns preload.
your thoughts>>>.be as critical as you want. Race weight 3836lbs, 10.64@125, 1.50 60ft........https://www.youtube.com/watch?v=uA0_AmkLOWU

No smoke on the burnout, looks like the tire was still in the wet area when the burnout ended.

You’re going to need a tripod and some slow mo.

ET/MPH and 60’ are top secret?

try again, works for me.............

10.64@125, 1.50 60ft
Next run was a 1.50 60 and a 10.56@125.8

What are the rear gears and finish line rpm?

Looks like the speed/ET are pretty close right now.

Gonna need to find some speed before the ET changes very much.

Damn it I knew I forgot something..........4.10 and finish line rpm I don't know as this was his first time out with something this quick but according to wallace weight etc. etc. around 6200-ish with slip....not sure coming up on the verter works the best?...early days. and I forgot to mention there was a 30mph headwind all day...Also it was run with full exhausts on.

What you’re interested in is what the actual rpm is.

To try and determine if it’s driving through the converter or not.

The good news is....... the same as the bad news......
None of the numbers are way off from each other.
So, the direction to go isn’t very clearly defined.

Based on that small sample of runs........ nothing stands out as an obvious “problem”.
The speed/ET/60’....... are all pretty much where they should be...... for each other.

However....... based on the current speed...... if you were trying to go .50 quicker, the car would have to show about 100hp more(7mph).

Using my bracket car “10% rule”, based on what you said the dyno numbers are....... you’re off by about 2mph.

What do you think is going on with body reaction etc. is what I really meant, not after exact settings as each car is different but generally how the car reacts and what would you do to calm it down is certain areas etc.etc.

Yeah, perhaps the mph would've been a bit more without that 30mph headwind but I get what your saying, Wallace says used around 645fwhp of what it has but again thats not accurate on that day. Ioriginally worked out that the car has a best of a 10.2>3's in it@129 perhaps and we didn't touch a thing on the carb/timing or anything apart from th tyres and caltracs. I was quite please with a 10.5 on the day and a novice driver. I would prefer it to do what your car does on the hit, controlled rear and around 1ft up in the air.

Honestly....... there isn’t enough detail in the video for me make any recommendations one way or the other.

It appears to break the tires loose pretty much right at the hit to me.

Time to start playing with tire pressures and shocks.

Unfortunately, I dont think you guys get much opportunity to make passes over there.

Well we made 5 passes that day, first 2 were in the 11.3's as he was easy on it, could've made another 5 at least as no-one in the fire up lanes but he'd had enough, so it was 10.74@124/10.64@124.7/10.56@125.83...lots more to do, test test and test again!!

I tell people all the time..... you have to start somewhere.

As you can see on the moroso chart, it shows the w/p ratio as 6.55:1 for 125.8mph, so at 3860lbs thats 589hp.

On a decent air day, my friends stocker can beat the moroso chart by over 7%(chart shows hp to be 107% of what the motor actually makes for STP power on the dyno).

Which is more correct I wonder?........input 645fwhp/weight/gear/tyre size into Wallace>

Power to Weight Ratio: 5.97
60 Foot E.T. : 1.47
1/8 Mile E.T. : 6.67
1/8 Mile Trap Speed : 101.97
1/4 Mile E.T. : 10.56
1/4 Mile Trap Speed : 127
1/4 Mile Trap RPM : 6,030+

This is what Wallace shows for my friends Stocker.
Run was during class eliminations at Gainesville.
10.37@128+, 3300lbs

This motor combo has been dyno tested at least 25 times.
It has never broken the 500hp mark.

The moroso chart shows 534.8hp.

A more typical amount of converter slip in that type of combo is more along the lines of 7-10%.
If the tires are “29.0”, and not “29.5” ....... the driveshaft rpm at 125.6, 4.10 gears, not accounting for tire growth is just under 6k.
With 7-10% slip I’d be looking for an engine rpm of 6400 to 6600 at the stripe.
Set the rev limiter accordingly.

If the tires are actually 29.5”, lower all rpm figures by 1.7%.

Got it.........Were gonna get a go-pro in the car soon so we can tell whats going on, the tach he has in it is ancient, never heard of it, doubt if its any good, was showing it ticking over@500rpm in the pits, no way. So much to do in my head to get it right, and some think its easy to set a car up by just bolting stuff on. I just hope he has the thirst for ET, really all we need is consistency but to get that it has to be right. ...6400>6600 is way out of the max power band but you never know, certainly doesn't sound anything like it in the traps and it doesn't sound like its picking up rpm near the traps either, sounds a bit flat, more thought has to go into that..........Thanks for the input as always.

Yeh, a reliable..... at least “fairly accurate” tach is necessary for trying to gauge how well certain aspects of the car are working out.
Well...... unless you have a data logger.

The go-pro...... the poor man’s data logger....... Aimed at the Tac will answer some questions.

one is on its way and we gotta get a good tach/shocks front/back/carb (go better with an 850DP) and try and get him to run it on open hdrs. (worth a 1/10th?) Drove it there with exhausts, race with them, drive it home and we drove it home on the slicks, couldn't be arsed to change back over!!!........oh and the reason he wanted 16lbs in the tyres was cos he hadn't screwed them to the wheels and we turned them about 1".

I realize that....... but I doubt trying to gear it for 5800-6000 is going to do anything but slow the car down.
7-10% slip in that type of combo is fairly “standard”.

The 572 in my friends Charger made peak power at 6300.
On a good day it goes thru the lights at about 7200(148mph@3660lbs).
6% slippage.

Part of the reason for the lower slippage % from his combo is the higher rpm for both the engine and driveshaft.

No I wouldn't do that, if it goes past dyno max power it does,....unfortunately no f/back from driver on the day which I didn't expect but it will come, just takes time to get used to the car with what it likes and get better race car parts on it whilst its still being driven as a street car on the odd occasion. Its interesting though that with the way it was set up, the weather etc. that it still ran a 10.5, and the mph wasn't quite there cos of the headwind perhaps. Lots to look forward to I think.

you can hit the setting on youtube when the vid is up and play it in slower mode

Loosen the front travel up and try stiffening up the rear shocks some also
Be careful to not hurt your back

My car....... 68 B body.......would slow down pretty noticeably from a stiff head wind.

I’m sure after a few tweaks and with some better weather it’ll show some improvement.

Its got 90/10's but they could be shot?..and I'll have to check for binding on arms as well as the back that the spring bolts have not been over-tightened. I was going to go with a baseline of upper hole in bars and an airgap (no preload) with shocks on max stiff to start but that didn't go down to well with my mate. We will get there,...as I said prior I worked it out that the car had 10.20's in it tops, (hp/weight) were not too far from that now with a lot of things to change and better weather, and no exhausts and I'm relying on the dyno to be somewhere near accurate for the hp no's.

Tighten the rear shock (Ext) Try launching from a lower rpm (the tyre was wadding when he loaded it before he launched @ 1.10 ish) Check front travel (5" min) More rear tyre pressure or a stiff sidewall or a radial slick. Lower the rear end and keep it in the lower Caltrac hole.

You might need more shock travel on the fronts... see if you have about 5" of travel.. you might need
more pitch rotation

Yes Tig I didn't like how it loaded the rear either, those 90/10's are history, already spoke to John about that. If his tyre guage (old metal type!!) was correct we already had 16psi in them, we would be getting into radial pressures soon with a Bias tyre?, we gotta make the best with what we got, but he will change shocks and I don't think we want to hit the tyre any harder without a shock that will handle the rebound which we don't have now. I asked him about lowering the car, its no no at the moment. And yes it looks like its topping those shocks and unloading the tyres to a degree. Lots to correct but encouraging day none the less.

I agree, I'd like the rear to move just enough to plant the tyres and pull the fronts some and carry them nice and smooth, but it don't have to be to the 60. Parts like front shocks etc. have been on there for years when the car was raced in the states, always been a race car from day 1.

It works pretty good right now. Our cars are close but your a little faster then mine. We weigh close to the same as my 63 goes about 3725 without my 185 so I am just over 3900 total. My best id 10.76 @ 124.99. I have run over 125 mph but it spun and the et was in the 10.80's which I usually run. My best 60 is a 1.50 but its usually between 1.50 and 1.53. I don't use Cal Tracs or adjustable shocks though as I just use SS springs and the longer MP shocks. But your running pretty good right now. Ron

Hi Ron, yes we had some issues with spin Sunday but we'll get on top of things next time out with some new front shocks and work. Cars are very similar in that my mate is more street than strip really although he don't go far with it, just to shows and about 4>5 trips to the track, runs in our version of NSS brkts so we gotta get it consistent. Even with the way it was on the day we did 1.51>1.50>1.50 60's which isn't bad but it picked up a 1/10th every time which is just not good enough for competition, don't know if he's shifting the same every time, just gotta get him a bit more focused for competition and we should do good when the cars sorted better.........cheers.

Thats like me as I mostly just drive on the street. I try to race it about twice a year and I always run in the NSS class that I love. Good luck with yours , Ron