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Discussion Starter #1
I've had a few frustrating trips to track recently and I'm looking for some help. Best 60' out of 20 passes over the last 6 or 7 months has been 1.70 but it's usually 1.90-2.0. It has hooked twice but unfortunately the clocks malfunctioned and I didn't get a time slip. Until the last outing, I ran MT 275/60-15 S/S drag radials. I mounted 28/9.0 Pro Bracket Radials for the last trip. Same outcome. Tried short burnouts and John Force burnouts. Doesn't seem to make a difference.

Breakdown of the suspension:

Mega Bite Jr. in the bottom hole
Jegs NA tubular uppers with poly bushings
Viking Crusader DA rear shocks
90/10 Lakewood NA struts
Eibach drag springs with rear air bag
No aftermarket ARB-only the factory rear sway bar
No front sway bar
-3 degrees on the pinion

Haven't scaled the car in a few years but used to be 3420 with driver. Probably a little nose heavy with all of the accessories intact (AC, PS, etc) plus the blower and snow meth. Battery mounted in back and some weight reduction with a tubular K-member and the big and little Welds. Anti squat is calculated at 144%.

I'm a one man show so no exterior video of the rear tires at launch but the data logs show unloading almost as soon as I hit the gas. Stiffest shock setting was 12C/5R. I've tried looser settings all the way until full loose. In hind sight, I probably should have gone stiffer but I thought 12 compression was pretty tight. The two unknown time hooking 60' passes were on the street drag radials with old, wore out Lakewood 50/50 drag shocks.

Not looking to set any records but would like to enjoy going to the track. Running mid to low 10's but trapping 137. Want to start throwing some timing at it but I can't even use the power I have now. Help me make this thing hook!
 

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Hard to tell without video but sounds like you have no weight transfer, something is binding, or otherwise preventing free movement. I'd start with midway shock setting for both C/R since your trial with 50/50 shock was the best. Then I'd remove the airbag and sway bar to free up the suspension. After you are certain everything moves freely front and rear, play with tire psi and remember baby steps will show if you are moving into correct direction, one change at a time after you see something starts making a difference. Sure you can put airbag and sway bar back but start without and see what happens.
 

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without seeing video of what its doing its hard to say

but at 144% AS you should be digging the tire into the track pretty damn well.
does it spin right off the hit? or move a little then spin?
 

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60 ft

I had a lot of issues like you are having as well. What is your launch Rpm and I would set the rear shocks on the stiff side of things and a mistake I made was having the front to lowered. I would also try it with ET drags. My track has bad to no prep and changing from et-street to et drag dropped my 60 from 1.45 to 1.35.
 

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Discussion Starter #7
without seeing video of what its doing its hard to say

but at 144% AS you should be digging the tire into the track pretty damn well.
does it spin right off the hit? or move a little then spin?
It moves a little but can't be much as it starts spinning in less than a second from WOT.

based on his sig its a C4 car... kinda curious if its off a foot brake or trans brake
Auto. Off the foot brake. Flashes to 4100. Haven't tried the trans brake because of the traction issues.

Hard to tell without video but sounds like you have no weight transfer, something is binding, or otherwise preventing free movement. I'd start with midway shock setting for both C/R since your trial with 50/50 shock was the best. Then I'd remove the airbag and sway bar to free up the suspension. After you are certain everything moves freely front and rear, play with tire psi and remember baby steps will show if you are moving into correct direction, one change at a time after you see something starts making a difference. Sure you can put airbag and sway bar back but start without and see what happens.
The suspension seems to be free moving with no binding. I get some front end rise so there is at least the beginning of weight transfer. I'll empty the bag and tighten the shocks for my next outing. Going to get a suction cup for my Go Pro so I can video the rear too.

On the first outing with the Vortech blower after being turboed and Procharged before that, I unknowingly had a catalytic converter come apart and clog the driver's side muffler. Being way down on power, it ran [email protected] No traction issues then so it will hook 500 HP but not whatever it's making now.
 

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What front spring you have, are the struts coil overs? It plants the tire for sure with 144% AS but sounds like it unloads immediately and starts pushing the rear back into chassis. Stiffer shock settings should help with that. Another thing is that you run out of front end rise, it either rises too quickly or/and tops out preventing weight transfer. Dont go from 0 to 10 with shocks, be patient one click could do the trick say the guys with D/A shock tuning experience.
 

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traction

Get the front struts all the way loose and put rears on the tighter side of things. If it does not hook my guess it is your converter is to tight. I went from a 1.56 60ft to a 1.40 by doing that and changing nothing else. I have all bolt on suspension and have never adjusted anything else other then shocks and struts and have 1.30 60ft on a regular basis.
 

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Discussion Starter #10
What front spring you have, are the struts coil overs?
Non coil over Eibach drag springs.

Get the front struts all the way loose and put rears on the tighter side of things. If it does not hook my guess it is your converter is to tight.
Front struts are Lakewood 90/10 non adjustable drag struts. They are always full loose:grin2: I'm definitely planning to tighten up the rears for the next trip out.

Can you add a little more info about how the converter being too tight would cause my problem? Love this converter how it is but I've always thought it was too tight for the current combo.

Thanks everyone.
 

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A converter on the loose side will generally make launch less critical so far as spinning. You can flash up into it.

The air bag is a bad idea. You need an ARB. The rear end is trying to lift the right rear tire up into the wheel well and all you did is lock that side up.

What do you have for a differential? A spool?

My car has the upper arms down at the front a half inch or so, and the lower arms are up in the front. When it extends the rear suspension the upper arms become level and the lower arms point up about 3/4 inch more than resting.

I ran my rear SA Strange shocks at half way. Now I have AFCO's and it is a different story. My car does like mid 1.15 60. I don't use AS calculators. I do the math long hand. It just works better for me that way. The higher the front of your upper arm angle and the more down angle in front of the lowers, the more it will try to roll the car back on the bumper.

You need to get a video, but more than that you need to lose the air bag and do an ARB. If you try to control roll with shocks or springs or bags you will never really get it right. This is on a MT Pro Bracket 28-10.50 tire and the car just barely wheelies. The whole car lifts, the front just lifts a little more.
 

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Yea a 90/10 should work, try the rear shock settings for sure. My own car my stall speed is around 5200. I leave at 4000 at 8-12 psi depending on the temp and track. But I have a transbrake. When you shift how much does your rpm drop I think that’ll be a good gauge on how the convertor is.
 

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Discussion Starter #13
You need an ARB.

What do you have for a differential? A spool?

My car has the upper arms down at the front a half inch or so, and the lower arms are up in the front. When it extends the rear suspension the upper arms become level and the lower arms point up about 3/4 inch more than resting.
I agree 100% on the ARB. I've installed a few on other cars and they were always better. Just haven't got around to on my. I've only had it for 20 years.

Running a 31 spline Explorer Traction Lock.

My control arms are similar in orientation.

What front struts are you running?

Yea a 90/10 should work, try the rear shock settings for sure. My own car my stall speed is around 5200. I leave at 4000 at 8-12 psi depending on the temp and track. But I have a transbrake. When you shift how much does your rpm drop I think that’ll be a good gauge on how the convertor is.
I have a transbrake but haven't used it because of the traction problems. RPM's drop about 800 on the shift.
 

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Never saw a mention of rear tire pressures. Too little pressure can cause the sidewall to smash down too much on the initial hit and then rebound and unload the rear causing tire spin. Having video would go a long long way into seeing what is actually happening.
 

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Discussion Starter #15
Never saw a mention of rear tire pressures. Too little pressure can cause the sidewall to smash down too much on the initial hit and then rebound and unload the rear causing tire spin. Having video would go a long long way into seeing what is actually happening.
Started at 20 and now at 18.
 

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Discussion Starter #17
Probably is a little high still. Most people seem to run these at 16-20 psi though.
 

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Seems very high to me.
its fine for a radial

try to get video of a pass so i can see what the car is doing...
but like i said 144% AS it should be digging the tire plenty hard. just need to see what the car is doing. you might be bouncing the tire off the track and causing it to unload.
 
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Does it:

1) Hook initially
2) The front end comes up quickly
3) Motor bogs a little
4) The front end drops down, unloading the rear tires?
 

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Discussion Starter #20
Does it:

1) Hook initially
2) The front end comes up quickly
3) Motor bogs a little
4) The front end drops down, unloading the rear tires?
  1. From the data logs, it looks like it hooks for about .5 seconds.
  2. Yes
  3. No bog
  4. Possibly. I'll know more once I video it. Got a suction cup for my GoPro.
 
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