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Discussion Starter #1
Alright, I went to the track yesterday after having the car tuned on the chassis dyno to make sure my fuel curves were good to go. Fattened up the secondaries at the dyno shop and checked the timing...all came out good.

Peak Torque at 4500 - 4600 RPMs and Peak HP at 6800 - 6900 RPM. This combo is a 383 SBC with a 6-71 SBC making 8 pounds of boost and tuned on 93 octane.

Here's my results from yesterdays three runs. Weather conditions here yesterday were cold, 45 - 50 degrees, light sprinkles here and there throughout the day, windy, and not much sun.

First Run
60 ft - 1.616
330 - 4.696
1/8 - 7.293
MPH - 94.35
1000 - 9.534
1/4 - 11.425
MPH - 119.13

Second Run
60 ft - 1.635
330 - 4.665
1/8 - 7.185
MPH - 96.87
1000 - 9.393
1/4 - 11.268
MPH - 120.09

Third Run
60ft - 1.720
330 - 4.886
1/8 - 7.496
MPH - 94.10
1000 - 9.758
1/4 - 11.667
MPH - 117.94

Was going through the traps all day at 6,000 RPMs and footbraking off the line at about 2000-2500 RPMs. Tire pressure on all three runs was at 15 PSI in 26X10.5 ET Streets. On the fastest run it felt like the rear of the car was all over the place. The last run my friend said at the start line the rear kicked right before it came out of the hole and he swears I backpedaled it. I don't remember backpedaling, but it is possible.

Now the converter was flashing on the dyno at about 4,100 RPMs and I had it built for 3,200 stall. So, would it be benefit me more to send the converter back to have it tightened up or swap out my 3.55 rear gears for something more aggressive like a 3.73? Was I hurting myself by splashing in 2 gallons of 110 into my fuel tank after having the car tuned on 93 with no issues? Any other tips you all could give me would be much appreciated. Thanks guys!
 

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If peak hp is at 6800 you need some more gear.I would put a 28" tall tire and some 4.56's in it and shift at 72-7300. You should be good for some mid 10 sec passes @ 125-127mph.
 

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Discussion Starter #3
I do agree that the gear needs to be stepped up, but I would like to keep the car streetable as this is not a dedicated race car. Would 3.90s be a better choice for my 12 bolt? When I cruise on the highway I don't want to be screaming and still having cars pass me like I'm standing still.

I finally saw the video from yesterday and the car spun out of the hole pretty bad on that last pass. I think I need some chassis upgrades as well.
 

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Its hard to have both(street/race) so a compromise on the gears is going to limit potential. 3.90's @ 60 mph with a 28" tire is still over 3000 rpm so for more street that strip your thinking of 3.73 is probably better but your et/s will suffer. Can you but more boost in it with race gas for the track? I would do chassis work first and leave what you have for now also try to go to the track when its not raining.
 

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Discussion Starter #5
I'm hesitant to put a smaller pulley on it to get more boost as my A/F ratio at WOT is at 12.7:1 right now with the pulleys 3% overdriven. I have the biggest jets in the secondary that are available and the biggest metering rods in as well. I am limited on my boost until I can invest in new carbs. I just spent a lot of money this winter on the engine, trans, and ignition systems so I need to build the reserves back up.

I think you're right on the 3.73s. I know I will be limiting my ET but a low 11 second street car isn't too bad.

Also, I try not to go to the track when it's raining, but there was none forecast when I left in the morning. The weather just kind of happened and it was very light sprinkles and it never lasted more than a minute at best.
 

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Yeah I was just joking about the rain thing it happens sometimes. For the first time out you should be happy with the runs, nothing broke,you learned some stuff about the car and you know its going to go faster so thats a great day at the track.How much power did you make? How much does the car weigh and what kind of suspension do you have?
 

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Discussion Starter #7
Oh yeah, first time out with the new set up and I was very happy to be dipping in the 11.20s with limited tuning. I have never scaled the car, but it's a full interior car. I imagine it weighs about 3500 - 3600 with me in it. It was tuned on a Dynojet and it made 507 HP and 511 ft/lbs of torque (at the wheel obviously). The suspension is stock style with multi leafs, non-adjustable rear shocks, and homemade Caltracs.
 

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I'm hesitant to put a smaller pulley on it to get more boost as my A/F ratio at WOT is at 12.7:1 right now with the pulleys 3% overdriven. I have the biggest jets in the secondary that are available and the biggestq metering rods in as well. I am limited on my boost until I can invest in new carbs. I just spent a lot of money this winter on the engine, trans, and ignition systems so I need to build the reserves back up.

I think you're right on the 3.73s. I know I will be limiting my ET but a low 11 second street car isn't too bad.

Also, I try not to go to the track when it's raining, but there was none forecast when I left in the morning. The weather just kind of happened and it was very light sprinkles and it never lasted more than a minute at best.
I would check the fuel delivery also to make sure that it is keeping up since you have so much jet in it.
 
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