Pulling 20 Degrees of Timing Out

Discussion in 'PSI Superchargers Tech Questions' started by TADHemiracer, Oct 3, 2014.

  1. TADHemiracer

    TADHemiracer Member

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    For the past year, the outlaw track I have been running at has seen less and less traction available for whatever reason. 526 fuel headed hemi 14 HH 38# 8500 rpm 44 amp mag w/8973 11-1 compression with 3 disk clutch and 3 spd Lenco CS-1 4.88 rear gear, 1.98 low gear on alcohol in a dragster on a VERY marginal track. With these AJ2 fuel heads I had previously been running 32 degrees and always have some traction issues. Usually blew the tires off 20 to 100 feet from launch or somewhere downtrack. Yes, I KNOW the rear gearing needs to be numerically lower. Last time out I started pulling timing out. LOTS of timing out to try to stick the tires. Ended up with 20 degreess out and that isn't quite enough out. Running a fat, rich and safe tune-up with no or next to no heat showing on the plugs. I plan on taking at least 5 more out this weekend if the track is still that marginal. So, 32 static minus 20 = 12 degrees minus an additional 5 degrees leaves the engine running on 7 degrees timing. I may reduce the blower OD from 42% to a lot less, also.
    My question is: does anyone see an issue with pulling this much timing out from an engine durability stand point? Any suggestions about mag phasing to allow this much (this little) timing?
    Maybe I should just take out the hemi and put the chevy back in it. NAWWW.
     
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  2. LeWhite

    LeWhite BB/Alt

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    More wing for mid track. Lower numeric trans will hit the shift softer.
    G
     
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  3. turbo69camaro

    turbo69camaro Member

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    All auto pro mod guys pull a bunch out down low.Whats your starting line rpm how fast are you locking up the clutch it low gear.You may have to make a base and cwt change to let slip more down low. if you have a grid or 8973 you can make a timing curve that will get you down a bad track and not have to kill the clutch slipping to the same
     
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  4. TADHemiracer

    TADHemiracer Member

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    Pulling Timing Out

    I have an 8973 that I am using to pull the timing with a time based curve. It works well for timing control. I have tried slipping the clutch enough to smooth things out and it is possible and it does help but it did kill the clutch by overheating it to the point of stretching the starter ring out so much it came off of the flywheel and was then too big to even be put back on.
    Pulling massive timing out does remove enough power to make the tires stick to this marginal track a lot better and with the 8973 I can control when, where and how much timing goes back in it.
    My main question is whether or not running this engine on 7 degrees of timing is safe and do I need to make other adjustments to the mag such as phasing?
     
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  5. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    mag cap

    If you do not have the big cap on the mag I would not advise trying to run that much retard because the rotor will be close enough to the next terminal it may cross fire.

    When you pull your clutch apart does it look like it's wearing even? Do you check everything for flatness when you assemble it? What's your 'tolerance.'

    If clutch discs and floaters have a bunch of taper and are not wearing properly, you're chasing your tail.

    I would recommend a rear gear change or low gear change. Fix the real problem instead of trying to band aid it.

    If you did get through low and make it to the finish line, you're probably going to be turning more rpm through the traps than you want.

    Have you tried leaving in second gear or shifting immediately? It's going to be a lot harder on the clutch though.
     
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  6. hemi altered 378

    hemi altered 378 Blown Altered

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    I agree with Will on the timing. Also, sounds like you need a rear gear and a low gear trans change........unless you're going to be running on killer tracks.
     
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  7. TADHemiracer

    TADHemiracer Member

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    Puling Timing Out Didn't Fix It

    We went back to the outlaw track again last night. Sure enough, the engine still ran well, even on only 7 degrees of timing in it, putting out plenty of power. Still so much power that the tires smoked at the hit and aborted the run twice. Looks like the 4.88 rear gear and the 1.98 low is not working so I am taking the advise and suggestions posted on this thread and going to change the rear gear. Probably going to the 3.90's which I have on the shelf. I expect it to work the clutch more and generate more heat in the can, too. Hopefully it won't expand the flywheel so much that it enlarges the starter ring gear and have the ring gear fall off of the flywheel like it did one time before.
    I appreciate all of those that replied to this post and offered their experience and help. Thanks, ITA!!
     
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  8. Nitro Diver

    Nitro Diver Member

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    How old are your tyres, we had terrible trouble getting our funnycar to be consistant off the line one run it would shake next it would smoke without any major changes, we put a new set of hoosiers on 12 months ago and I think all but 2 runs its gone 1.0 60ft on a wide variety of start lines.
     
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  9. TADHemiracer

    TADHemiracer Member

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    Actually, believe it or not, I had that moment of clarity today when I remembered that last night the guy that went to the track with me, (an ex drag bike racer) asked me on the way back home about the age of the rear tires. I said, well probably about two years. He said that he used his slicks (one at a time of course being on a bike)no more than two years and they were junked. I said well, let me think about my tires. Hoozier C2055 34.5/17-16. Truth be known, since the years seem to fly by now at the speed of sound, I realized that my rear tires are about 4 years old if not more.
    The local outlaw track is closing in three weeks for the winter. Yes, this IS Texas but the track owners don't keep it open very long in the year. I will put new tires on before the track re-opens for the spring, somewhere around April. I am installing the 3.90 gears this coming week, taking out more clutch and probably cussing at it a little more to teach it a lesson. ha
    Thanks again for your help.
     
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  10. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    gear

    You might create new problems with the 3.90 gear. You are going to either absolutely smoke your clutch every run, or if you ever got enough weight on it to not smoke it, try to throw the crankshaft on the ground by lugging the snot out of it.

    Are you running 1/4 mile or 1/8 mile with this?

    Put a 4.29 in it and just shift what you have going past the tree.

    Trying to make that 1.98 work in anything is probably going to be real hard on your clutch. If it's all aluminum it's going to be all warped up first hit.

    Torque converter guys can get away with the 3.9 and 4.10 gears with your combo because they can run a loose converter. It's hard on a clutch to slip that much.
     
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  11. turbo69camaro

    turbo69camaro Member

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    Ditto on the 3.90 gear you will kill the clutch.new tires shroud fix your problems. If you got your flywheel so hot it broke the ring gear i would send the clutch off and get it looked at you may have got it hot enough and lost the heat treat on flywheel and or donut and you have a potentially very ''bad thing'' going to happen in the bellhousing. Also i know its apples and oranges but i drove a nitro coupe years ago brad 5 roots blown hemi shifted around 8700 it had 4.71 to 4.56 rear gear 2.06 to 1.96 low and was a very happy as far as clutch wheel speed etc.
     
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  12. hemi altered 378

    hemi altered 378 Blown Altered

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    I would try a 4.30 with either a 1.85 or 1.89.....I think that will get you a lot closer to where you want to be. then play with taking timing out.....just my 2 cents
    Darren
     
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  13. LeWhite

    LeWhite BB/Alt

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    3.90 x 1.98 = 7.72
    4.29 x 1.85 = 7.94 worse on a non preped track but good top end rpm
    4.29 x 1.72 = better without too much rpm drop
     
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  14. TADHemiracer

    TADHemiracer Member

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    Pulling timing versus new tires

    OK, newest revelation. My tires are probably too old and I have ordered new ones today. Going to drive the 112 miles to pick them up Friday and have them on the car for the Oct 18 race at which time I can evaluate if the new tires have helped or if I still need a rear gear/low gear transplant. Going to try to some new ideas like lower launch rpm to let the tires hook sooner, pulling more timing at the hit to slow down the DS speed curve.
    Dang this hemi power!
     
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  15. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    ratio

    Save the money and effort to go to the track again with just new tires and fix the ratio.
     
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  16. TADHemiracer

    TADHemiracer Member

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    Changing the Ration and the tires

    I am going to take the wisdom and experience shared on this site and I am planning on going to 4.29 rear gears AND new tires to see what the differences in performance may be. After that I may consider changing the 3 speed trans ratios.

    My existing Hoosiers have a date code of EW45 on them. Not sure what the age of the tires actaually are but I purchased them in April of 2010. My car is stored in a temperature controlled shop but I do have refrigerators/freezer, a/c electric motors and flourescents light in there, too. Someone said that they have something to do with ozone and the rubber aging. Not sure if that has anything to do with my tires getting hard or not.

    Thanks to all.
     
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  17. Soldierboy0098

    Soldierboy0098 Active Member

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    I know guys that our pulling 20 degrees out, but in my honest opinion you could either slow the blower down or change the gearing for a combination that isn't so finicky.

    Like you said your gearing is very low. I would suggest a 4.10 in the rear if/when you change it.

    Make sure you have the large mag cap or there is a possibility of the spark jumping to the wrong cylinder and that ends badly.

    Hope that helped some,
    Trevor Sherwood

     
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