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Discussion Starter #1
I went to Atco Tuesday night to try out the suspension (and some other) changes I made to my car. The results from the last time out are in my sig.
This car is just a toy that I don't take to the track much because it cost $300 to get towed home once! (broken axle) I would go more often, But I can't justify the cost of a trailer. Anyway...
After I bought the drag radials, I read on here that they are for auto's. Being that I'm not a serious racer, I tried them anyway. When I got the 12.003 last time, I was dumping the clutch at an unknown rpm. All I had was the stock tach. i was not getting good launches. The launches are even worse now. Best of 11.88 @ 121, a 12.06 @ 121, and a 12.88 @ 118 where I tried to slip the clutch, and boy did I. I aborted two runs, they were brutally bad. (Wheel hop, missed gears, you name it!) BTW, the tires are 6 years old. (DOT 3810)
The changes since last time:
-Skinnies and light wheels, front and rear. Same rear tires.
-Approx 200 lbs. removed. Weighs 3140# w/ me.
-Battery in rear.
-Eibach front springs w/ 1 coil removed. (It sat too high.)
-Stock 5.0 rear springs, 1 coil removed.
-Strange 10 way struts, shocks. Front full loose, rear on 5.
-No front sway bar.
-2.95 1st gear. Astro A-5.
-Fidanza Alum flywheel.
-Mc Cleod 260570R clutch disc. (Per Tony at Astro, needed a 26 spline) Used with existing King Cobra PP. No "R" on this one, but I believe this is it: http://www.mcleodracing.com/index.php/500-series-organic-ceramic-disc-10-5-organic-ceramic-1-1-8-x-26-yes.html-
-HPM lower control arms.
-Steeda adjustable uppers. (Solid mounted at body, stock bushings on axle end.) Pinion angle- 3* nose down.
-Battle boxes.
-Shift light, tach. Shifted mostly @5800. (Things were happening fast!) Through the traps @6000.
-Line lock.
-2 step, set at 4300 rpm.
-MM full length subframe connectors.
-No roll bar, though I expect to need one when I get it to launch.

I'm thinking I need to get bias tires. I want to use DOT, because I don't want to swap tires. I also need more practice. I never raced a stick car this quick before. But I wasn't getting anywhere fast with the DR's. It either hooked and hopped, or spun through 1st. I was trying to slide the clutch, but it was hard to do. When the car bogs, it's hard to control my foot.

Thoughts?

How about these? https://www.summitracing.com/parts/mtt-3551

EDIT: I just remembered that I had a chip in it the other night that wasn't in it the last time out. LaRocca burned it in 2000. Maybe that accounts for some of the mph increase.

2nd EDIT: I forgot I also changed the flywheel and clutch disc. Probably important, huh? Maybe also responsible for some mph and a reason it's hard to launch. I added them above. :surprise:
 

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Looks like you've done a lot of work since last time. In your listed times, you failed to mention the most important # on your timeslip. 60'. Radials are notoriously hard to dial in on a stick car, as they will do all the things you mentioned. I have no experience with the MT tire you linked to, but you could not go wrong with the proper sized Hoosier Quick time Pro. If I'm not mistaken it is a DOT version of the Hoosier stiffwall slick I run, which is the Hoosier 26x8.5x15. It has a 9" tread so I don;t know why they call it a 8,5. I run it on a 10" wheel, for a nice flat contact patch. At the mph's of your last outing, and using the calculation I learned here on the Corral from some knowledgeable factory stock racers (1320/mph) your car should be capable if perfectly dialed in (mechanical) and executed (driver) of going 10.90-11.10. At 120 mph, you are making considerably more power than I am (114 mph) but we run around the same ET, 11.8ish. My car 60's at 1.51-1.53 like the sun coming up. The calculation for me 1320/114 puts my target ET at around 11.6. So I still have work to do, but closing in on it.

Hope you get some feedback on that MT tire, but if you don't, I know you would do well on the Hoosier stiffwall I run.
 

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Discussion Starter #3
In your listed times, you failed to mention the most important # on your timeslip. 60'.
Yeah, the runs were so bad, I didn't think the 60's were relevant.
12.06 2.13
12.88 2.15 (Also, I missed 2nd on that run.)
11.88 1.89
Aborted runs:
1.92
2.17 (spun through 1st)
When the car was dead stock, down to the tires, I got 2.0's out of it.

I'll keep the Hoosiers in mind. Thanks
 

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Discussion Starter #4
At the mph's of your last outing, and using the calculation I learned here on the Corral from some knowledgeable factory stock racers (1320/mph) your car should be capable if perfectly dialed in (mechanical) and executed (driver) of going 10.90-11.10.
I agree, it's capable of a lot more. I'd be happy with consistent 11.40's or 50's, considering it's not raced much. I am completely surprised at how much power it makes. The Wallace calculator that shows it could go 11.0's at the current 121 mph, also shows that it makes 457 hp! (I have always run it when there is good to great air.)
 

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I was taught and find it to be true most of the time, that whatever you can knock off your 60' will pay you double at the big end, at the very least 1.5 times. That being the case if you could get that down in the 1.50 range, you would be low 11's.

How do you like the Astro A5?
 

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Discussion Starter #6
I was taught and find it to be true most of the time, that whatever you can knock off your 60' will pay you double at the big end, at the very least 1.5 times. That being the case if you could get that down in the 1.50 range, you would be low 11's.

How do you like the Astro A5?
I'm sure you're right. This thing is so all over the place, I can't do any calculating like that yet.

I only have maybe 1000 street miles on the A5, plus the 5 runs at Atco. So far, I love it. I went that route because I wanted the bolt-in aspect and it's lighter than other options. The missed shifts were strictly my fault. I've heard others mention gear whine. With my solid mounted upper control arms, I hear plenty of noises, so it's not pertinent at this point.
Mostly, I like that I can whoop on it and not worry. :grin2:
 

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A good clutch should help. Many times folks just pick the cheapest clutch they can afford, which is similar to picking a stall speed from a Jegs shelf converter and expecting it to work. And it can. Problem is, it's not always optimal, sometimes destructive. A little slippage at the hit isn't necessarily a bad thing; but it also wears the disc faster. For this reason, ideally it's hard to have both street manners and drag manners out of the same clutch.
 

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Discussion Starter #8
Thanks for reminding me about the clutch, Todd. I added a 2nd edit to my OP reflecting that (and the flywheel).
 

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One thing that stands out to me is that you have your front struts set to full loose. What can happen is that it initially hooks and the front end comes up fast, then back down fast, unloading the rear tires. Have you tried tightening them up to have a more controlled rise in the front end?
 

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Discussion Starter #10
One thing that stands out to me is that you have your front struts set to full loose. What can happen is that it initially hooks and the front end comes up fast, then back down fast, unloading the rear tires. Have you tried tightening them up to have a more controlled rise in the front end?
No. Actually, the front isn't rising much. I don't know if it's because of a soft launch or what. I'll try that.
 

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Discussion Starter #11
A cell phone video shows the front going up and coming right down as it bogs. The struts are something I should work with, for sure.
But the car was so unmanageable, and all over the place, that I need to get a handle on it.
I would try a set of bias ply tires if I knew someone I could borrow a set from. What I'm going to do first, is get a Clutchtamer. I've read about it on here before, and was reminded of it recently. It's a lot cheaper than a new set of tires, and potentially will allow the car to be quicker because of better clutch management and the fact that radials are quicker than bias.
 

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I am also interested in the ClutchTamer after putting a new clutch in that does not slip at all. For the past two years I've had two clutches from Promotion Performance that I burned up (blue-printed king cobra with kevlar/organic disk). I got tired of that and went with a Clutch Dynamics twin ceramic disk. Complete overkill for what I'm doing right now but the pedal effort is really easy, doesn't chatter, can be slipped like a normal clutch around town, and it holds when dumped at 6k. Now I need to get it to slip and control it before I break stuff.
 

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Discussion Starter #13
I am also interested in the ClutchTamer after putting a new clutch in that does not slip at all. For the past two years I've had two clutches from Promotion Performance that I burned up (blue-printed king cobra with kevlar/organic disk). I got tired of that and went with a Clutch Dynamics twin ceramic disk. Complete overkill for what I'm doing right now but the pedal effort is really easy, doesn't chatter, can be slipped like a normal clutch around town, and it holds when dumped at 6k. Now I need to get it to slip and control it before I break stuff.
I'm running out of time to try it this season, but I'll report on how it works when I get back to the track.
 

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The clutch Tony recommended is just fine, I ran it with my G Force T5, now I run a ram clutch recommended by him as well.

I tried radials for a few years and got a best of 1.83 on about a 3000 launch. Swapped to Bias ply ET Streets and no better. I finally got with Kevin Slab from baseline suspensions and really started working on my angles.

3 weeks ago I ran by best 1/8th mile time yet, a 7.45 with a 1.58 60ft. MT Bias ply, 10.5" (8.2" contact patch/really a 235 tire), leaving at 6000rpm. Full interior car, AC and Power Steering.

Go with the tires you showed above and read up on the baseline suspensions website. Then start plotting your suspension. I know guys have had success doing it all sorts of ways, but this way worked for me.

A pic from my 7.45 run.

Good Luck!

Joe
 

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At lower power levels, most tires have stiff enough sidewalls to not distort from excessive power. Unless the rear shocks are real weak or have thick soft rubber bushings that let the rear bounce a lot before working the shock, any vibration or shaking you are getting is most likely from axle wrap.

Axle wrap almost always comes from the bushings letting the axle slightly rotate. This lets the real housing oscillate back and forth in rotation, loading and unloading the tires.

A weak shock or soft shock mount will do the same, letting the housing hop up and down. This is especially true with stock Mustang geometry and a taller tire, because the stock geometry tries to pull the tires up into the wheel wells as soon as it hooks, and that reduces traction, and then it unhooks, and then the suspension goes back to normal, and then it hooks. The result is that shaking.

One way is by rotation from soft bushings or slop (which is why Ford added quad shocks), and the other way is poor shock control.

You cannot run a hard enough OEM style bushing in the rear end ears hard enough to stop axle wrap. If you do, the rear end will bind and you'll risk severe handling issues at high speed. You have to replace the ear bushings for the UCA's with heim joint bushings. If you don't run quad shocks, you really wat all solid bushings with heim joints and close fitting bolts. You don't want to mix metric bolts which are around .460 on the threaded area into 1/2 inch aftermarket holes, or the slop will start bending things and the suspension will rattle on the street. I can show you pictures of how bad that can be when the threads hammer a 1/2 inch bushing.

When you get all the suspension stuff tight so it never ever wheel hops no matter what, then you can work on geometry.
 

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TomR always posts good stuff.
I am not expert, but will share my findings.
I had same experience as you on drag radials. Being an amateur/sportsman I did not want to invest the time and money to figure out a radial on a stick car. I also did not want a clutch that was good for the track but would live a limited life on the street.
After a bunch of research here and on other reputable forums I found a lot of more serious people reporting very favorable things on the tire you linked.... the (relatively) new MT ET Street bias R tire.
I went ahead and purchased a set (same as your link) and stuck them on an 8" wheel (not optimal).
I run stock springs front and rear (stock length and all) with simple Lakewood 70/30's up front and 50/50's out back. Baseline uppers(spherical bushings) and Pro3i lowers (spherical one end, poly the other).
Car is 3270 with me in it, has an Astro with 2.95 1st gear and 4.56 rear gear... battery up front, with a little 306 and stock heads. Simple street car.
Bam!
I went from a fluke best on radial of high 1.8 (typically worse, with a lot of driver input) to instant low 1.6 60 foots with no slipping the clutch drama driver involvement. Hold some rev's, dump the clutch and done. This on a test and tune night with not the greatest track prep.
It's a long story, but only got to make 3 passes, I'm sure with getting it figured out (adjusting the rear arms with the help of folks on here and likely a couple calls to Kevin) 1.5's would be on order.

Good luck.
 

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Hey clean lx what air pressure you found to be best with those tires?
Also were you running a radial tire up front with the bias plys in the rear?
Just read a little about not mixing the 2 different types of tire.
 

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You mentioned solid bushings on uppers but I am assuming the lowers are using rubber bushings? What air pressure in the radials? Also to make a radial work with a stick shift car good suspension with solid mounts with as much adjustment as possible and clutch...clutch...clutch...clutch

The clutch you listed looks like an organic/ceramic hybrid? You need to learn to properly slip the clutch yourself by working it properly with your left foot or know how to get the clutch to work for you.

Eibach springs? which one? Drag race or street? Your more than likely not transferring weight properly which will lead to your wheel hop.
What rear springs? nevermind see it now, stock.

Many other variables such as instant center, weight bias etc.

In my Factory Stock car on MT ET Street R radials I ran a best of 10.76 @ 126mph @ 3050lbs with an engine that made 372rwhp. Consistent 1.44-1.49 60ft
I would leave at 7000rpm and get it to hook. See video

 

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I can run bottom 5's on MT ET Street DOT legal radials.

White LX coupe at 1 minute in. All these cars in True Street class are on MT DOT street legal.

 

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Hey clean lx what air pressure you found to be best with those tires?
Also were you running a radial tire up front with the bias plys in the rear?
Just read a little about not mixing the 2 different types of tire.
My best 60' was with 16psi and a 5500 launch (hold 5500, floor it just before the clutch came out).
I would not take that as a gospel "best", like I say I got limited runs and as the night went on the track was going away and the d/a was going up. On that run it rolled the tires over just a hair, 1.62, could have used more rpm. As the track went away and I played around, 60's kept getting worse. At the end of the night I went back to 16psi and 5500rpm and spun to a 1.67. I'm sure with better track and more learning there are 1.5's in it.
Rear lowers are essentially these Heavy-Duty Adjustable Mustang Rear Lower Control Arms, 1979-1998
Upper arms are these THE BEST Upper Control Arm Kit on the market
Front tires are MT ET Fronts, so bias. I too have read the "do not "mix-match" warnings. I have ran the bias rear radial front on the street with the rears around 24psi and not had any issues, but, certainly don't get up around let alone over 100mph on the street, so, probably not a good comparison.
 
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