Okay first the facts! The best five 1/4 mile times my car has run are:

1) 12.210 @ 115.42 w/(Not Available ) 60' time
2) 12.298 @ 114.77 w/ 1.928 60' time
3) 12.345 @ 114.40 w/ 1.864 60' time
4) 12.380 @ 114.62 w/ 1.953 60' time and
5) 12.434 @ 115.16 w/ 1.953 60' time

Average of above data: 12.333 @ 114.874 w/ 1.9245 60' time

(My current mods are in my signiture).

Now I'm at the drag strip watching a bunch of other LT1 and LS1 automatic F-Body cars running around 12.8x to 13.2x @ 108 to 111 mph, and they're doing it on 1.6x to 1.7x 60' times. Sooooooooo.......... obviously I start thinking I've probably got an 11 second car, if only I could pull down a 1.75 short time, right? The problem of course for us 6 speed guys is that at the track I run at on test-n-tune nights, if I launch at 2,000+ rpm, I usually "blow the tires off" and get 1.9x to 2.1x short times. But, if I launch at 1,800 rpm, (or less), I usually "bog" the car and also sometimes get 1.9x to 2.1x 60' times. So, in an effort to "broaden" my launch plateau, (and hopefully reduce my short times), I'm thinking of switching to a Fidanza 12.5 lb aluminum flywheel at my next clutch change.

Okay, so here's my question: Almost everyone warns that light weight (12.5lb) aluminum flywheels are NOT good for drag racing because they don't "store" as much "launch" energy as the stock (24+lb) iron flywheel will, (yea I get that ), but..... won't having less "launch energy" actually help out my current situation???? I'm thinking with an aluminum flywheel I'm in much better shape with a somewhat "wider" rpm launch window, right???? Believe me I've raced tooooooo...... many automatic F-Bodies that I've hole shot, only to have them led me to the 60' mark, and then run 13.05 @ 108 while I ticket 12.45 @ 114+ (4-5 final cars lengths ahead), in the other lane.

Thanks in advance for any and all replies!

 

In my opinion, before you waste your money go to the track on a day when real race cars are running. Watch what they do and ask questions. My suspicion is that either your track is as bad as mine on a street night, and/or your tire pressure is off. With regular Et Streets you should be able to hook on any halfway decent track. If you make any changes, I would suggest an adjustable shock in front so you can loosen it up to facilitate weight transfer at the start, and perhaps disconnecting the front swaybar.

In my opinion you should be looking at tire/suspension/track issues before screwing up your clutch and wasting a pile of money.

 

I'm running about the same ETs as your's (12.20s) but with an auto and have a 1.70 60ft. Also, in have 26 x 11.5 ET Streets. So, it is just a matter of getting everything correct. Don't change your flywheel, that isn't the problem. Also as Ted pointed out, T&T track prep normally isn't too good.

First, is your posi locking-up and doing an equal burn-out with both tires? The OEM 10 bolt Aubrun wears-out and can really affect the launch. Next, you may need some softer drag springs and 90/10s up front to get the weight transfer (lowering springs don't launch well). An air-bag in the right rear spring counters rear-end torque. Do you have a line-line for the burn-out so you can clean-off and heat-up the slicks?

When you're at the track, check with other people to see if everyone's having trouble with their 60 fts (left lane, right, or both), or if the problem is common only to your car. Also, lighter cars tend to have better 60 fts.

 

What the above guys said and maybe LCA relocation brackets. What tire pressure are you running?
I was running the same tire and pulling 1.5 60s when it hooked but even when it spun it would hook within 1 to 1 1/2 revolutions and pull 1.61-3 60s.

 

First of all Thanks! to all who replied. (That's the beauty of this board........ common problems enlightened by many different perspectives ) In no particular order, here's the additional info some of you have asked for:

tnthub, great minds think alike, and like you, I'm assuming the track prep on T-n-T nights does leave a lot to be desired but..... those (slower???) automatic F-Body cars running in the lane next to me are consistantly putting down 1.7x short times, which are on the order of approximately .3 seconds better than me. I've varied the tire pressure in my ET Streets between 14 to 20 psi on numereous occasions but I still don't 60 foot anywhere near what those 13 second automatic cars do. I also think that suspension issues should be the prime area of focus, but I will be replacing my current clutch soon, and the aluminum flywheel idea seemed like a step in the "right" direction?

Engineer, you're the "poster child" for what I'm talking about here. Your automatic car runs 12.20's on a 1.70 60' time. I'd love to have your short times! This Spring I'll be replacing my current 4.10/Auburn posi set up with an 3.73/Torson posi set up I have in the garage, to see what that will do. Also, yes I do have a line lock on my car and I usually do a 2nd gear burnout until I see a "fair" amount of smoke coming off both rear tires. I also have an air bag in the right rear spring which I keep around 5-7 psi pressure in. Care to share any more of your "secrets" about your car? How do you launch your automatic vehicle to get those 60' times? And finally....

Al SS590 M6, yea what about those LCA relocation brackets??? You have any experience with those on your car? You're pulling 1.5x short times throw me a bone here......... how's your car set up suspension wise? Gear ratio, LCA's, relocation brackets, etc., etc.

 

Look into LCAs and an adjustable TA...I run 2.5 deg negative pinion angle..Also not a big fan of drag racing with the shock tower brace...What psi are you running in your ET Streets? With your mph you are an 11 second car...Don't hate me because I'm an A4

--Alan

 

I also have the Spohn adjustable torque arm (-3 degrees) with the floor pan mount, along with the LCA relocation brackets and QA1s and drag springs up front. The relocation brackets are cheep and a possible improvement. Also, you probably need about 15 to 20 PSI in the air bag.

Have someone watch closely and make sure "both" slicks are turning equally during the burn-out. When my posi went out that cost me a lot in the 60 ft. The OEM 10 bolt Auburns don't last too long under hard use.

If other people are getting good 60 fts during T&T, then it is something common to your car. Check everything and you'll find the problem. Good luck!

 

My sixty foot times with the stock base motor, with cam, and polished heads, and basic bolt on's were low 1.7's..... I had 3.73 gears and an M6, and 15 x 12 x 11.5 Et Streets at 14.5 pounds, no front sway bar and skinnies up front.

When I went to the stroker and an automatic I changed springs and shocks for 90-10's up front and added the air bag in the rear. Short times dropped to mid 1.5's.

Because I prefer Street class and my ET's were dipping deep enough into the 11's to be a problem dialing I switched to 15 x 28 x 12.5 Et Streets and that raised my sixty foot times back up into the mid 1.6's and brought my ET's back into the 12.1-12.3 range. They also greatly improved the consistency of my reaction times and I could hook pretty much on any surface.

I do not have LCA's or subframe connectors. I do have a six point welded bar which stiffens things up quite a bit. I find my left front wheel typically comes up about three inches and that is it on the launch and that is exactly where i want it to be, efficient and consistent.

The shock tower brace doesn't do anything for me either but I would guess if you lose the sway bar and install some drag springs and loose shocks it won't be a problem and may actually help keep things from twisting up too much at the launch.

I would recommend going to a taller tire before going to a different gear. The most consistent cars tend to use steep gear ratio's and tall tire combinations. A taller tire will provide additional flex at the launch and will help more than changing gears.

 

Boxed stock LCAs with poly bushings hooked to homemade relocation brackets, stock M6 TA, 4.10s with a spool in a Strange 12 bolt, air bag in RR at 22 psi, 26-11.5x16 Et streets, QA1 12 ways all the way around, A4 with 4400 stall got me 1.51-2 60s.
Went with Spohn TA and LCAs and cut it to 1.48-49.

 

Once again, a big Thank You! to all who replied. You guys have given me several things to think about regarding suspension upgrades.

And ABA383, thanks for "Today's Chuckle", I really don't hate you because you're and A4, I just admire how well those, (seemingly less powerful?), A4's lead me past the 100 foot mark at my local drag strip.

Since you guys have been so willing to share some great ideas about suspension mods, how about re-adressing my original question. What about an aluminum (12.5 lb) flywheel for my car? I will be down there soon replacing my clutch anyway, and I'm thinking a lightweight flywheel may be a good investment/idea at this time. Considering the cost of re-surfacing my iron flywheel and the additional safety factor of using a 12.5 lb billet aluminum wheel rather than a 24+ lb cast iron wheel during those 6400/6500 rpm power shifts, coupled with the possibility of softening my M6 launchs, and I'm thinking that maybe aluminum flywheels may be getting a "bad rap" for drag racing. With NO scatter shield on my car I certainly like the idea of a 12.5# billet aluminum wheel turning at 6500 rpm down there MUCH better than a 24# cast iron one.

 

Stay with an SFI approved steel flywheel.

If you are worried about parts blowing up I bet one of the blankets from RCI could be fit.

 

I agree. Without the inertia of the flywheel it will bog a little after every shift.

 

Guys, thanks again, you've given me much to think about during this off season! Your input is truly appreciated.

 

I did not read all of the post but can say a stock clutch can pull 1.55-1.53s with the right gear selection, track prep, suspension and tire.
I see alot of guys putting down alot of unusable power, ie they are spinning too much.
Make the power you have work for you.
You do not need power to make the car 60', you need it to use the power it is making.

 

Yep that's how I went after modding my car. Stock it went a best of 12.96. Added a converter and traction it went a best of 12.15. That was the max out of that set up. Then a added the heads and cam. I've been optimizing that for 2 seasons now. 1st year 11.43 best. Changed gears and converter, upgraded suspension, new best 11.24. Doing some weight reduction and tire size change to try to pare it down a little more.
Once I get this maximized then I'll consider more power.