60 FOOT TIMES
- Thread starter tvt59
- Start date
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I see a lot of time slips and at your ET anything around a 1.25 is fantastic and usually takes either a 3 speed transmission or a powerglide with a low gear. My best was a 1.25 something at a questionable track (60’s are a hair faster and 1/8 mile a hair slower.) I didn’t want to put wheelie bars on my duster so I went from a 1.98 low gear to a 1.80 to calm it down some. So it went from 1.26-1.27 average to a 1.29-1.315 average.
9secRR
Well-Known Member
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I do have a TF904 but I have a 2.10 first gear. With the stock first gear it'd hit the wheelie bars so hard it would squeal the tires. We moved the engine and trans forward 1.5 inches, limited the front suspension to 2" of travel and tightened the shocks all the way. That's where we are today.
Ya like I said I didn’t want to go the wheelie bar route and I switched the gear so I wasn’t constantly changing the frontend from track to track. 4 tracks over 3 seasons is a lot of adjustments
4200 right now. But I want to try 5000.
I don't like wheelie bars. But believe it or not the wheel base on the AMX is less than a Vega . My Dakota won't have wheelie bars.
I bought my duster around 2007 for my son to drive for awhile while I raced my Daytona. I’m not sure if the manufacturer of my rear shocks and they are probably over 22 years old. My front suspension when I bought it was a strut setup off a Mercury Capri and unadjustable. It was converted to a single adjustable strange strut over 10 years ago. So between the ladder bar and the suspension I don’t have a lot of adjustments.
B3422w5
Well-Known Member
I will guess that moving the 2 step Rpm up is unlikely to have a positive effect on your 60 foot using the brake.
Might possibly make the 60 foot less consistent, if anything.
I have said this forever, but if the convertor is correct for the car, even leaving off the foot is unlikely to make much if any of a difference in 60 foot time.
It didn’t on a previous combo of mine that made very similar power to what you are making.
All I was able to to do moving the chip around was either deal with huge wheel stands, or blow the tires off, until I found a comfy spot, as I recall it was around 3900 or so, that worked consistently, moderate wheel stand/ repeatability.
At the end of the day, assuming the 60 is consistent, lower or raising the chip is only going to effect reaction time, rarely 60 foot time.
That car of mine was 500 pounds heavier than yours is. Went 1.34 off the foot or the brake, on a small tire, often I used both ways on the same day racing on a 400 tree index race, and a footbrake bracket race at a series I used to chase points in.
9secRR
Well-Known Member
I started at 3600. 60’ was 1.32-1.33. My RPM dial went to 5200 so I thought why not go max and see what happens. I was rewarded with a 1.29. I was thrilled.
Try 5000 and see what happens. My car liked more launch rpm
9secRR
Well-Known Member
I did try 5600 and the 60’ stayed the same so I went back to 5200. The car would twist at 5600. First pic is 5200, second pic is 5600. Since the 60’ didn’t improve at 5600 I went back to 5200. Easier on the car
Haha you guys are up to date. I'm still in the stone ages. Still using chips....
It’s cheaper in the long run to get the adjustable one. Nicer too. I have one on my shift rpm too.
It is cheaper in the long run. I use the 7AL3 with the chip. We shift on time.
9secRR
Well-Known Member
i switched to the 7AL-3 last year. cleaned up a lot mess with only having 1 box instead of all the dials. simple and way cleaner too.
That's what I did. I have a good 7AL2 for sale now if anyone needs one.
Only a few things can happen if you try and raise launch rpm, like any experiment. Car will either go faster, slower, or stay same. I agree with B34225 in the sense that sometimes raising launch rpm will only effect reaction time more than 60’ after a certain threshold. Some cars like higher launch while others like low. Like all things, it’s all relative. Suspension, tire size, wheel base, converter stall, etc etc ALL MATTER.
In my own car I’ve gone from 3,000-5,500 launch rpm when I had 4.30 gears. Car slowed down the lower I launched it. Once I went to 5,500 from 5,000, it made no difference, so its sweet spot was 5,000.
When I put the 4.56 gear back in the car I immediately dropped the launch rpm to 4200 because I knew the car might get stupid with a 5,000 launch and the steeper gear. Car loved 4,200. I tried 3500, didn’t like it. Went to 4,000 and it’s been happy there with fast and consistent 60’.
On the flip side, a friends car hated higher launch rpm. And by higher I mean 4,000. I mean HATED. The chassis was so upset with the higher launch that we had no choice but to lower it. After scaling car, and making every possible chassis adjustment he had available. All it took was lowering it to 3,000 and it’s a xerox machine. And funny thing, his car was always like that with every engines he’s ever ran and two different rear suspensions.
Point of my story, theory is theory, and every car is different. Every car will like something different. Find what works best for your combo, and from reading this thread sounds like you have a well sorted out combo with some fast 60’ and ET.
In my own car I’ve gone from 3,000-5,500 launch rpm when I had 4.30 gears. Car slowed down the lower I launched it. Once I went to 5,500 from 5,000, it made no difference, so its sweet spot was 5,000.
When I put the 4.56 gear back in the car I immediately dropped the launch rpm to 4200 because I knew the car might get stupid with a 5,000 launch and the steeper gear. Car loved 4,200. I tried 3500, didn’t like it. Went to 4,000 and it’s been happy there with fast and consistent 60’.
On the flip side, a friends car hated higher launch rpm. And by higher I mean 4,000. I mean HATED. The chassis was so upset with the higher launch that we had no choice but to lower it. After scaling car, and making every possible chassis adjustment he had available. All it took was lowering it to 3,000 and it’s a xerox machine. And funny thing, his car was always like that with every engines he’s ever ran and two different rear suspensions.
Point of my story, theory is theory, and every car is different. Every car will like something different. Find what works best for your combo, and from reading this thread sounds like you have a well sorted out combo with some fast 60’ and ET.
BVoelzke
Well-Known Member
Back about 10 years ago my friend was driving my Dart at the now gone Raceway Park in the 11.50 index class ( we Won the points championship ) I had always left at 2,500 rpm when I was driving , he was leaving at 2,000 . In my combination there was really no difference in 60 ft or r.t.s between 2,500 and 2,000 needless to say I now leave at 2,000. My car is slowed down from 10.80s to 11.50s , I run on a .500 pro tree deep staging my 60 fts are 1.58 - 1.62 depending on the track . Last time out consistent 1.59 over 7 runs in both lanes. I did find though : I used to run a non stroker 363 small block with 4.88 gears when I went to a stroker 408 c.i. motor because of more torque I was able to have the same 60 fts with 4.10s , I now have 4.30s and there is really no difference between them and the 4.10s.. present motor 410 c.i. 548 hp/ 520 tq... 4.900 stall Ultimate 8 inch converter, 904 with stock first gear , T/A reverse pattern valve body , and a few other tricks... has been in the car 7 years now
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My Dart loves the slow power application of a CO2 throttle controller. With a 4,000 rpm setting (about 1/8 throttle opening) it takes .05 for the throttle to hit 100% opening on launch, 2.45 low, 33 10.5 or 33 15 15 tires very little difference,549 cubes, 2905 lbs race weight. 60 fts of 1.224 and 1.226 on first outing, poorer air second outing slowed to 1.244, 1.246 on saturday with 3000 da,, 1.250 as the day heated up to 3600 da. Car went 8.60s at 157 mph to 8.700 at 154. In my situation with 50/50 front rear weight, it loves the soft hit for the first four to six inches of car travel. Reaction times made me go to 1.04 in the box versus 1.08 to 1.10, but for bracket racing, no problem. When i was trying 5,000 launch, the car was too violent and hit the bars so hard it would spin. I could feel it. And couldn't do better than a 1.25 to 1.29. So ya, every car is different, but I am sold on that initial ,but very short, "soft hit"
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How in the world did you AMX to that weight? Do you have a AMC motor in it? Iron? Thanks.
My 67 Fastback weighs 3740 lbs with my fat a$$ in it. My best 60ft so far is a 1.47, on a 10.8s pass. DA was horrible that day, and my mph was only 119.
It has fiberglass hood, trunk, bumpers, doors, lexan windows and one lightweight drivers seat. It has a SBM and a TF904 transmission.
I’m surprised it isn’t lighter. My Duster was at 2550 or 2575 without a driver before I removed the fiberglass doors and went with stock doors with wind up windows. I did add an alternator and a few other things. I love stock doors but they come at a cost.
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