Suspension Guys, I Need Advice!

[JLear]

Okay, nevermind.....I just saw you say it doesnt hook (but did for that video)

I don't think the springs are the best choice, BUT, I don't think they are hurting your car at this time (I offer the best drag springs on the planet, so take that for what it's worth)

Many times when I have customers who are experiencing the issues you are, it is a tire issue, track issue, or driving issue.

Next time you go to the track, I recommend removing the front sway bar.....putting the tires at 16.5PSI before the burnout. For the burnout, burn them for 4-5 seconds then roll out and listen for the tires grabbing.

A set of rear shocks, like the Vikings....and the proper LCA/UCA angles will work just fine with those spring you have. I've got way too many customers with identical combos to yours, going 1.4X sixties.

The pass in the video was one of the few times it has actually hooked, usually it either never takes off or will spin even into second, not terribly but it is a little loose. I took the tires all the way down to 15 cold and that was getting 60's in the mid 1.6's. The same day there was a auto coyote and a Shelby with similar suspension mods with the exception of they were running different springs and had the swaybar deleted, the coyote got in the 1.4's and the Shelby got a high 1.3 on the same tires as I have so I'm ruling out it being a track issue. I can't remember which hole we used in the upper but I have tried the top and middle hole on the lowers and I couldn't see a difference between the two.

 

[JLear]

Just ordered a BMR swaybar delete/radiator support and will see if that helps me out. I can't thank Kelly enough for taking his time this morning to explain things and provide some very helpful advice! Thanks again!

 

[skwerl]

^ Kelly will steer you right even when it doesn't involve selling BMR parts. He's a true enthusiast and he knows his shit.

 

[JLear]

^ Kelly will steer you right even when it doesn't involve selling BMR parts. He's a true enthusiast and he knows his shit.

That's what impressed me the most. I know he's an expert and spent about 20 minutes talking and giving me advice. Not one time did he try to sell me anything. That's top notch in my book. I did end up buying a BMR swaybar delete after our conversation lol.

 

[Norm Peterson]

Here's a launch pic from yesterday, not alot of lift/squat going on..

You don't want squat. It represents lost grip over just the short while that it takes for the squatting to physically happen, so the rear springs and shocks aren't hurting you too much (and firmer bump damping at the rear might help). Up front, struts with softer rebound might help if you don't want to lose your appearance. Softer springs at a lower ride height would be a poor choice without drag-race oriented struts with extra-firm bump damping to keep you from bottoming when the car does come back down.

With the front bar gone, you may encounter some difficulty in launching straight, which a firm rear antiroll bar will probably solve. But drive very, very cautiously on the street with the combination of no front bar and a huge rear one (just park it in the rain). FWIW, the dragstrip advantage to losing the front bar is not just because you've lightened the front of the car. There is actually a traction advantage due to a completely separate effect.


Norm

 

[JLear]

It is my understanding that removing the front swaybar removes weight and actually increases the upward travel of the front which transfers the weight to the rear, correct me if I'm wrong. I'm still new to the drag racing stuff so it's a learning experience for me.

 

[Norm Peterson]

All that and still a bit more.


Norm

 

[JLear]

I finally had time to get the car up in the air and check the location of the uca, it's in the bottom hole. Kelly suggested putting it in the top hole for best results so that will be the next step. Also have the swaybar delete ready to go on as well. Hope to make it to the track next weekend to see if those changes help.

 

[JLear]

Got the uca placed in the upper hole and double checked the pinion angle, also removed the front swaybar and installed the BMR radiator support today. Hopefully the weather cooperates this weekend and I can see if the changes help.

 

[BMR Tech]

Keep us updated!

 

[JLear]

Went back to the track tonight with the uca repositioned and the front swaybar removed with similar results as before. The first pass I had just under 17psi in the tires cold and did a good burnout, It spun bad enough that it shifted to 2nd early.

Last pass I dropped the tires to 15psi cold and did another good burnout, it felt like it hooked decent but the 60' was still a 1.65.

Could it be possible that I just need to lower the pressure to hook like it did on the last pass and maybe a 1.65 is just as good as it's going to do? Perhaps a tuning issue? The car was dyno tuned and has never been data logged at the track.

 

[skwerl]

Who's tune are you running? Justin has done a lot of work on the 6R80 transmission tuning as evidenced by Rebecca's car. I don't know if it's tune related or not but I'm sure he can make some tweaks to improve your 60' times.

How old are your tires and have they been heat cycled a lot of times? They get a little harder every time they get hot and cool off again.

 

[2011/5.0]

Dumb question here. Are you doing your burnouts in second gear to around the 60 mph mark for those 4-5 seconds to get enough heat in them

 

[JLear]

Who's tune are you running? Justin has done a lot of work on the 6R80 transmission tuning as evidenced by Rebecca's car. I don't know if it's tune related or not but I'm sure he can make some tweaks to improve your 60' times.

How old are your tires and have they been heat cycled a lot of times? They get a little harder every time they get hot and cool off again.

It's tuned locally by Blankenship tuning, if it does turn out to be a tuning issue that we can't resolve I will definitely be calling Justin. My tires are a few weeks old.

Dumb question here. Are you doing your burnouts in second gear to around the 60 mph mark for those 4-5 seconds to get enough heat in them

I begin the burnout in 1st just to get them turning and then click it to 2nd where I hold it til both sides are smoking good, then I spin out of it.

 

[JLear]

I made it to the track again and this time I had some buddies watching the launches, the car did not spin on a single pass but still only managed mid 1.6x 60's. My tuner was also there that day and logged a pass for me, he's going to review the log and get back with me. I'm really hoping that it is something that can be fixed with a tune adjustment, if not I will have to come up with a new plan.

Car ran several 11.0's @ 127 at full weight in +2500 da. I have no doubts that once the 60' issue is corrected the car will make consistent 10 second passes as is.

 

[rcm90]

Have you checked the trans fluid level recently?

 

[skwerl]

1.6 is nothing to sneeze at.

 

[JLear]

Have you checked the trans fluid level recently?

Yes sir, about 1500 miles ago when we swapped back to the stock converter.

1.6 is nothing to sneeze at.

I agree but it just seems it's a little lazy compared to other cars with the same setup.

 

[badnews]

What rpm are you trying to leave at? I looked over my old slips, and our 60fts are very close. I'm leaving at about 1000 rpm.

 

[JLear]

After removing the swaybar and getting a revised tune I have finally got my 60' in the high 1.5's..