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will this get me 1.5x short times?

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Vader 87

Licensed
Joined
May 25, 2001
Messages
470
i was able to pull 1.69 and 1.71 60 foots with the stock D5 and a TA49....will the addition of PST's 9x11 result in 1.5 60 foots?
The stall is 3,000 rpm. TIA, Jason
 
remember, 60' times are as much a function of HP as traction & launching ability.....no doubt the converter will help your 60's because you can leave with more boost (assuming you can hook with the track)

as for 1.5x 60' times, you may need a little more power...typically cars run low 11's and near 120 that make those kinds of 60' times....something like a 1.59 may be possible
 
I agree w/ azgn. Something else that you may consider is relocating the Instant Center so the car will launch more efficiently. This angles the control arms so that most of the available power is used to push the car forward and only the minimal amount is used to actually hook the car.

ks
 
See my Tech Page in my sig. I describe a lot of info on how to set up a suspension.

The Instant Center (IC) is the imaginary intersection point of the upper and lower control arms. The position of the IC relative to the Center of Gravity (CG) of your car can greatly affect how much energy is used to push the car forward. It makes the suspension more "Efficient" at launching the car so very little energy is wasted.

It's really wasy to do but the majority of the people never worry about setting up a suspenion CORRECTLY. They just buy parts, throw them on and go racing.

My Mustang went from 1.61 to 1.47 with the factory control arms (including the rubber bushings) and 200,000 mile factory shocks. IMO, the location of the IC is MUCH more important than springs/shocks. I say set the IC up correctly then buy shocks so you can see how the car is reacting to the new IC.

Regards
ks;)
 
per your question....1.49 60'

my car seems to 60' a little better than the hp would indicate....I cannot expain this other than I leave real hard ( 4000+ rpm maybe 15+ lbs of boost) and the car hooks! I have basic stuff, boxed uppers & lowers, large rear sway bar, 90/10 front shocks, no front sway bar, all the bushings, new springs & shocks, 5 pt roll bar, 28X9 slicks, air bags (at 15 & 5), pinion angle at -3*....it jerks the front tires and hauls out.....I should add I also have Moser 31 spline axles with no c-clips (Ford bolt in) and 31 spline Eaton posi

my car weighs 3712 with me in it.....
 
Good track prep will make a huge difference. My car normally 60 fts in the 1.6's or 1.7's on slicks, but with great track prep I got a 1.57 60ft.
 
I have a question thats a little off topic..........we were seeing mid 1.4 60fts, when we switched to 90/10's, 60fts dropped, anyone hear of this happening?? Also the car is having a severe problem of not leaving straight, even with 30psi in the right airbag the left tire still lifts almost 1 1/2 ft more than the right. Anything else to fix this?? Thanks
 
Tony,
Do you mean it is turning or that it is twisted during the launch? I'm guessing that it is twisted. If you have fully adjustable RACE shocks then you can adjust those. If not then the only way to keep a car from twisting is to mechanically keep it from twisting. Air bags can only do so much. A Wolfe bar (or similar bar) mechanically keeps the suspension from twisting and seems to be the "hot ticket" for everyone that has used one and may lower the 60's even more.
I have the link to their web site on my Tech Page in my sig. IMO, you are going fast enough you would benifit from one.:D

hth's a bit
ks
 
Yeah it's twisting on the launch. We tried some lakewood 90/10's and the initial launch was harder but then it instantly unloaded the tires and started spinning, went back to the old shocks and the problem stopped. My dad said from the beginning he didnt like the drag shocks, but he figured he would just try em, but he just proved why he didnt like them anyway. Thanks for the help.
 
Yea, I have been telling people that 90/10's are not all that great but nobody really understands why and get's them anyway. No biggie. What you and your dad experienced is exactly why I don't like them. If you read my web page I explain why I "prefer" something like a 70/30, but it depends on the "complete" combo.

When the car starts going faster, chasis preload (or the lack of) will become more criticle. Preload needs to be adjusted so there is no preload WHILE the driver is sitting in the car. Can you add/remove preload via the upper control arms or are the upper control arm lengths fixed?

The best (only) way to really control the twist is still the Wolfe system, though.

Regards
KS:)
 
Originally posted by KEVINS


When the car starts going faster, chasis preload (or the lack of) will become more criticle. Preload needs to be adjusted so there is no preload WHILE the driver is sitting in the car. Can you add/remove preload via the upper control arms or are the upper control arm lengths fixed?

How do you check and adjust preload? I have adjustable upper arms.
 
Unhook passenger, upper control arm and have the car "race ready" including driver, fuel etc. Adjust the control arm length so that the mounting bolt slides in the hole easily. This is a neutral setting. When the driver gets Out of the car, there Will be preload on the chasis.

Once the driver is sitting in the car and the bolt slides in easily, you add/subtract preload by shortening /lengthening the passenger upper control arm. I always suggest Zero preload unless you absolutely NEED it.

If you have access to a 4-wheel scale this makes it even more accurate because you can "weigh" each individual tire. You can actually add/subtract preload on the RR tire to match the LR tire (which affects the front tires when you adjust it). This helps to launch the vehicle straight no matter how much preload you add/subtract because the rear tires will have an even amount of pressure on them.
However, it is the combo of ALL 4 tires that you need when you get REAL serious. On the race truck we had the LR and the RR tire "weights" within 20 lbs of each other and the fronts within 40lbs (?), at one time. That was COOL!

Just find the neutral setting and most will be fine;)
ks
 
You have to be careful because if you make one to much longer than the other the car will vear over bumps in the road:) You can make the upper trailing arms have 2 different arc,s and cause to much binding also.I like to do this on jack stands with the springs out at the known ride height if the driver was in the car:) You then have the car in the air and the tires off and you can get to the upper trailing arm bolt and really tell how lined up the hole is:D :) You can find out the ride height with the driver in the car by putting wire ties on the shock shafts and sitting it the car.We used the wire tie trick on or NW Tour car and sprint car to see what the shock travel was so you could tell if the spring was to soft:)
 
We use the wire tie method on our motocross bikes for the same reason:D Excellent idea!

ks
 
Looks like I've got something else to put on the list of winter projects. Thanks for the info.
 
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