need 3/10th

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plymouth4onthefloor

FABO Gold Member
FABO Gold Member
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Location
Switzerland
I'm still fighting with my mile high 60ft time. The car is a 98% street car, i race it only ones a year for a weekend. I have no race track near by me for tuning uses, so i have to do it at this single weekend. People use a lot of street tires and have oil downs all day long..... Most of the day are about 2h between to runs!
The car runs trouble free all day long, but the traction is bad. I run 10x26 Hoosier, QA1 single shocks on all 4 corners, Caltracs and multileaf springs, aluminium bushing in the front.
The race ready weight of my Satellite is 4030 lbs, 60ft is somewhere in the 1.8, 11.88 @ 118.
Tire pressure is 12 psi, with lower pressure the car goes sideways above 100 mph. with 16 psi
there is 1/2 inch unused tread on each side. Do i need higher pressure like 16 psi? Do i overstress the tire during the launch? I stopped also popping the clutch, the car loves softer engaging
loves the car.
If i raise the front, the car hooks better, shocks in the front are fully open, in the back set to 8 clicks.
Preload of the Caltracs is 1/2 turn in, some guys do 1 1/2 turn, should i do that? The pushrod is in the lower hole, i can't use the top hole in case of the multileafsprings. I have to modify
the front hanger if i want to use it in the top hole. Is it worth to do that?
I know i should do more testing, but i am completely wrong in some adjustings and you guys know a lot of a baseline setup.




Thanks for any inputs
Marco
 
The first thing I see is wheel spin and not going straight.
Fix the going straight first and then the wheel spin.
What is the tire compound? Gear ratio?
 
10x26 Hoosiers on how wide a rim? You mentioned there's a inch of tread on each side that doesn't touch the track? The tires are over-inflated then and less pressure makes the car squirrely at speed. You need narrower tires for the rim size or wider rims for the tires you have.
 
10x26 Hoosiers on how wide a rim? You mentioned there's a inch of tread on each side that doesn't touch the track? The tires are over-inflated then and less pressure makes the car squirrely at speed. You need narrower tires for the rim size or wider rims for the tires you have.
I run 8x15 inch in the back, Hoosier recommends from 8-10 inch.
Just a half inch on each side with 16 psi.
 
You need to experiment with the preload on the caltracs to get it to leave straight. There are threads here and on b-bodies and you tube. With the small wheel well on a 66/67 satellite, i dont think that the ten inch wheel you need will fit. I would suggest a new set of 9x28 slicks, or 9x30 if you have the room at the front of the wheelwell opening.
It's real hard to learn how to finesse the stickshift launch with very limited track time.
 
A stick car will have a launch rpm window where it works the best. This is difficult to say here what that would be. (Engines cam and power torque level at launch all have to jive together at launch. Of course...)
Also as stated above, the cam trace will have to be adjusted. One side more than the other.
This has to be experimented by you. I think your set up is a good start and it just has to be played with.

Get it going straight first. You’re on your way!
 
The first thing I see is wheel spin and not going straight.
Fix the going straight first and then the wheel spin.
What is the tire compound? Gear ratio?

First thing I saw/heard , as the rear end bouncing in the burn out .
 
First thing I saw/heard , as the rear end bouncing in the burn out .
I figured once the car is going straight, then tire pressure can be worked on second with an eye on the shock response. IF the tires bite better with the improved straight take off, the problem may lessen. May not as well. But as anyone knows, 1 step at a time. It’s just gotta bit hard and go straight to start. Not going straight can be just dangerous but for surely harder to control and get right. It’s a big time eater zig zagging at the starting line.

Figuring these things out is like a tennis game. What is wrong with the car is on the left, your adjustment fix is on the right, and back and forth until it’s done is the game.
:lol:

The shock settings will come in soon enough....
 
If you look at the burn out tracks, you'll see that it hops the whole way to the line. As stated, better shocks & CalTrac adjustments. Whatever you do, only make ONE change at a time to see where it goes. You might also try lowering the air pressure one pound at a time, or possibly stagger the air pressure a pound or two to keep it from getting squirrely when you leave. Just a few ideas for you.
 
I am assuming you have a 2.44 first gear not a 1.44, which gives you to high of a starting line ratio. A 2.66 would be better, a 3.09 would be best, but I guess in Switzerland these gear sets would be harder to come by. I fined on my stick car that lower shock setting give better 60 foot times( automatics like stiffer), on your QA1 shocks this would be between 3 and 5 clicks from full louse, set the Cal Tracs at zero preload with you in drivers seat or some one equal to your weight, let the rear suspension work. You have to endues some clutch slip into the equation, either by you regulating with your foot( which tacks a lot of practice) or go here read thoroughly and call then purchase ClutchTamer.com. This is the best bet for a dedicated street car that you do not wont to run a Softloc style clutch(adjustable slipper clutch) for best 60 foots and clutch control. I still prefer the SoftLoc clutch but less than $200 for the ClutchTamer compared to $2500 for a SoftLoc(which is not real street friendly) works a lot better for most guys and there street cars. One more suggestion, on your next set of slicks get a dedicated set of stick car slicks with the stiffer side wall, you wont tear the side wall out of them and you will have more control at the top end. If it was my car I would put the CalTracs mono leaf springs on the back and only snug the spring eye bolts with lock nuts do not over tighten, free up the rear suspension from any bind.
 
Street car, what do the aluminum front bushings look like. Street miles can be hard on solid aluminum bushings.
 
Street car, what do the aluminum front bushings look like. Street miles can be hard on solid aluminum bushings.
Being there solid pressed into the front spring eye with s only play in them being in the large attaching bolt, the likely hood of a wallowed out bolt hole is low even with a bunch of street miles. However possible. There really should be a minimum amount of play there at best.
 
A 1/2 turn of preload while in the lower hole (front) is next to zero preload. Which could be why its bouncing in the water box.
The 1 1/2 turns others are suggesting is probably a good starting point.

Modifying the spring perches so that you could get into the upper hole is going to be your best move. Stick cars are very sensitive to suspension tune.
Going to a 9x30 slick, as 331mp says, will help greatly to take some of the "shock" out of the setup when the clutch couples. The Side wall of the tire will absorb that couple shock and keep the tire glued.
A radial slick ideally. Bias slicks grow and upset gear ratio in hi gear.
My cent and a half...
 
I have had the CalTracs mono leafs in my 66 Dart street car for going on 20 years, took it apart in the spring of 2018 and put the 1/2" front hangers and rear shackle inboard kit in so I could fit the 9x28 MT 3054st on 8 inch wheels with 5 inch back spacing without having to cut and move the wheel tubes. The front aluminum spring eye bushing had not rounded out at all, cleaned everything up regreased and put it back together.
 
Hi Marco, Michael / A-Team here! I´m not a big help regarding running a 4spd at the track, but listen carefully to the guys here....good luck reaching your goal.

Michael
 
Wow a lot of inputs, thank you guys!
Definitely i need a good moviemaker at the starting line. The clutch tammer is also a good solution, it's really hard to get a constant clutch control that's always exactly the same. I need to control the front aluminium bushing, it's in the car since 12000 mls. I rebuild the tranny every 3000 mls, i shift really fast, you hear it in the movie. Correct 1st gear ratio is 2.44, thanks for correcting!
The 9x28 shoes will fit and are on the gift list....
Going straight will be one of the main targets.
But what should my rearend do during a perfect launch? Raise in the back or stay? Raising hit the tire much more. How much raising. Firm the shock until bouncing is eliminated, or more?
If i mount some lowering blocks, the instant center moves forward, or is this a no go?
 
Hi Marco, Michael / A-Team here! I´m not a big help regarding running a 4spd at the track, but listen carefully to the guys here....good luck reaching your goal.

Michael
Thank you Michael, we met us at Hockenheim in the last years! Hope next season they reopen the track.
 
Hi, Marco what I was trying to do in the post above was to get you back to a neutral set up that will hopefully get the car to go straight and get rid of the bounce or porpoising. If you tighten up the shocks it will most likely make it porpoise worst. When my Dart is working the best it is always with a lighter shock setting, my CalTracs are set in the top hole with zero preload with me in the drivers seat and my older 5 position shocks set on 2 (positions 4 and 5 will make it porpoise) the car will hit the tires hard and get about 3 to 4 inches of body separation at the wheel well. It will get a half to one turn of the tires and plant them and gone( I dump the clutch at 5000 off a 2 step), but I run a Jerico 4 spd. with a 3.04 first gear, 4.10 rear gear, and an aluminum flywheel and SoftLoc clutch(the clutch takes up some of the hit and slips enough to keeps the engine in it's power band). The most important thing with CalTracs is to have an absolute minimum of 5 inches of up travel in the front suspension and set your front shocks to full louse. Adjust your launch RPM till you get the car to come out clean, no bog an 1 to 3 turns of the tires with your clutch. Once you get it repeatable then you can start playing with your CalTracs and shock adjustments to find the best 60 foots, you already have your shifting down. The ClutchTamer will really help in the launch repeatability and keeping the RPM's from dropping to low on the launch but it dose put a lot of heat into the clutch, so round robin runs can be a problem with out a cool down between rounds. I've been running my Dart since 1999 and I've been totally frustrated with what my car was doing many of times over the years and always looked to people who new more than me for guidance, lot of good people out there so don't be afraid to ask them for guidance.
 
Hi, Marco what I was trying to do in the post above was to get you back to a neutral set up that will hopefully get the car to go straight and get rid of the bounce or porpoising. If you tighten up the shocks it will most likely make it porpoise worst. When my Dart is working the best it is always with a lighter shock setting, my CalTracs are set in the top hole with zero preload with me in the drivers seat and my older 5 position shocks set on 2 (positions 4 and 5 will make it porpoise) the car will hit the tires hard and get about 3 to 4 inches of body separation at the wheel well. It will get a half to one turn of the tires and plant them and gone( I dump the clutch at 5000 off a 2 step), but I run a Jerico 4 spd. with a 3.04 first gear, 4.10 rear gear, and an aluminum flywheel and SoftLoc clutch(the clutch takes up some of the hit and slips enough to keeps the engine in it's power band). The most important thing with CalTracs is to have an absolute minimum of 5 inches of up travel in the front suspension and set your front shocks to full louse. Adjust your launch RPM till you get the car to come out clean, no bog an 1 to 3 turns of the tires with your clutch. Once you get it repeatable then you can start playing with your CalTracs and shock adjustments to find the best 60 foots, you already have your shifting down. The ClutchTamer will really help in the launch repeatability and keeping the RPM's from dropping to low on the launch but it dose put a lot of heat into the clutch, so round robin runs can be a problem with out a cool down between rounds. I've been running my Dart since 1999 and I've been totally frustrated with what my car was doing many of times over the years and always looked to people who new more than me for guidance, lot of good people out there so don't be afraid to ask them for guidance.
I will follow the advices from you and the guys, there are so many great informations and experience. Down here, there are not many cars with stickshift, mostly new age cars and almost nobody will run a stickshift race car.
I have now a lot of homework to do, but i have also a really reliable Mopar. I know, it will never be the fastest cause of the street car style, but i will it in best performing condition as it is. I shaved off almost a second from day one on, but the last tenth's drives me crazy, because i (de)tuned it the wrong way.
Thanks a lot !!!
 
Clutch tamer and clutch tamer. Com. Call and talk to Grant a very nice guy and he'll spend the time to walk you through any problems you have.
 
Clutch tamer and clutch tamer. Com. Call and talk to Grant a very nice guy and he'll spend the time to walk you through any problems you have.
I absolutely agree, it makes the starts lot easier and constant, the base for proper tuning!
 
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