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Discussion Starter #1
First, there's no real point to this post, only read if bored.

I went to the dragstrip today for the first time with my new combo (Novi 2000 w/ intercooler instead of KB, my old best time was [email protected] or something). Trust me, I'm not bragging here, because I suck, but since I took time to write down the altitude and weigh the car and keep all the numbers, so it is useful data, I thought I'd post it.

Temp: ~75 degrees F
Location: Morroco, IN (US 41 Raceway)
Altitude: 662' above sea level.
Car: 1996 Mustang Cobra
Engine: 4.6L DOHC, Novi 2000 w/ intercooler, 450 rwhp.
Weight: 3800 including me. Ok, I'm hefty. No spare tire in trunk.
Drivetrain: T56, 4.30 gears, 26" ET Streets. Crossed traps in 4th gear almost at redline.

Since I didn't want to break my axles and hitch a ride home, I feathered out, no clutch dumping or power shifting.

Run #1 - Back tires @ 25 psi
R/T 0.953
60 ft 2.056
1/8 ET 8.551
1/8 MPH 85.21
1/4 ET 12.982
1/4 MPH 113.89

Run #2 - Back tires @ 20 psi
R/T 0.473 (redlighted)
60 ft 1.867
1/8 ET 8.228
1/8 MPH 86.92
1/4 ET 12.661
1/4 MPH 113.61

Run #3 - Back tires @ 18 psi
R/T 0.450 (redlighted)
60 ft 1.935
1/8 ET 8.300
1/8 MPH 88.22
1/4 ET 12.676
1/4 MPH 114.77

I'm pretty happy, consistently in the 12's at least, for me that's, well, the best ever.

I plan on upgrading my rear axles or buying a trailer (so I don't have to worry about breaking stock ones) and working on those 60' times next. I'm trying to loose some weight, maybe some on the car also. :D

I just have the stock tach and shift at maybe 6700-6800, sometimes a hair more. But very inconsistent I'm sure.

If you have advice on what to focus on, I'll be glad to hear it. My complete combo is on my WWW button below this post.

I thought my MPH would be a little higher.

This summer I'd like to hit the 11's pretty consistently, I think I'm close.
 

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jslagel,

Your trap speed does look a little low, with your weight and power you should be trapping around 118-119mph. And I think you could run some 11.5's easy with a drag race setup.
 

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isn't 4.56 gears too much for a blown cobra? wont he go through the traps in 5th (unless his rev limiter is raised) if he traps over 118ish?
 

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You're running mid 12's around 114-115 and launching easy. IMHO you're right in the ballpark with others who have about your same set up, HP levels, and desire to kinda "take it easy". I'm sure Ron (no offense please) and others who are more "hard core", more experienced, maybe better racers, and willing to trailer home, could , with some practice and work on the race set up, put your car in the 11's. I get the same response when I drive. Everyone thinks I should drive it a lot harder. My response is usually... why?

And...please no offense meant to those of you who are more experienced and willing to run your cars hard.
 

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Ralph,

No offense taken... Even for taking off soft jslagel's mph seems a little low. I know my car is lighter, probably 3400 with me in it and I don't powershift either (stock t45 trans.) And my car with 65less rwhp traps at 118mph. When I put the nittos on the car and got a crappy 2.2s 60ft the car still went 117mph with out powershifting.

jslagel,

With 26" ET streets and a 4.30gear the car would be at these RPMs per speed:
112mph is 6206rpm in 4th gear.
113mph is 6262rpm in 4th gear.
114mph is 6317pm in 4th gear.
115mph is 6373rpm in 4th gear.
116mph is 6428rpm in 4th gear.
117mph is 6484rpm in 4th gear.
118mph is 6539rpm in 4th gear.
119mph is 6594rpm in 4th gear.
120mph is 6650rpm in 4th gear.

Perhaps your stock tachometer reads too high and your shifting even before you make peak power. That could easily explain a lower than expected MPH.
 

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Jim Vaccaro said:
Mikey..John has 430's i believe,,Your reading T56 not 456 and the T56 is his 6speed tranny..

Jim V.
oops, my mistake i read it fast.
thanks jim
 

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Ron...I agree...he could turn it a little more. With my forged internals, I shift at 7200-7400. Even though I leave easy also. Another thing, and I know this goes a little against most advice, but I think my car runs faster on DR's with the spare, jack, tire tool, and bag of lug nuts for spare (33 lbs total) in place with full tank of fuel. Not sure if that holds true with Streets. I had some and ran full weight, but never really ran them 12-14 lbs for max traction. I was a little afraid of them with radials in front.

I'm just trying to be supportive of John as he's put a lot of effort in this car, sorting it out etc, and it still has a lot of HP potential.
 

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Discussion Starter #11
Ralph Greene said:
Ron...I agree...he could turn it a little more.
...
I'm just trying to be supportive of John as he's put a lot of effort in this car, sorting it out etc, and it still has a lot of HP potential.
Ron99Cobra said:
Perhaps your stock tachometer reads too high and your shifting even before you make peak power. That could easily explain a lower than expected MPH.
You guys are brilliant, I think you're on to something...

I'm scared of hitting the rev limiter so I do shift early. If I shift before 7000 rpm, it's like I'm not using my 450 rwhp... only a portion, hence the low trap speeds. Especially if I'm shifting at say 6600, that's REALLY down on the dyno chart.

So a good improvement for me to try next weekend would be to shift higher... which means either a better tach, a shift light, or a better than stock rev limiter... or maybe just more guts. :D Hmmm.... I've been wanting to get a J&S Knockguard which has a soft rev limiter, maybe it's time for that.

If I really did spin this thing a little over 7000, that would be a world of difference!


=======
PS, I really appreciate the support and advice!
 

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Discussion Starter #12
NOVIFED said:
Congrats with the built motor you can take it in steps and not worry about crappy ringland failure.
Actually, that's exactly why I have a built motor... my ringlands went out in 3 or 4 cylinders when I tried running my KB at 14 psi with no proper tune. Fun, but dumb and expensive.
 
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