low 7sec 1/8th mile cobra?

enyawix · #1 (**permalink**) 09-24-2007, 01:45 PM

Anything special I need to know before I start my build? I am leaning toward Pacific Roadster at this point.

xlr8or · #2 (**permalink**) 09-24-2007, 01:49 PM

Strond diff and axles with sticky tires.

I pulled a 7.43 at 96+ MPH soft launching the car.

Setting a car up to maximize drag racing results may not be a fun car to drive on the street.

enyawix · #3 (**permalink**) 09-24-2007, 02:05 PM

What was your engine pick? What kit did you use? I am building a twin turbo 351

xlr8or · #4 (**permalink**) 09-24-2007, 02:16 PM

I did it in my Kirkham with 460 in it. I have since blown that motor up and I'm about to install a 427 stroked to 468. With the torque of the 460 I was able to launch softly and let the big torque curve pull me through at those speeds. I was at the near the top of 3rd gear at the line. Traction will be the biggest problem if you don't run slicks.

If you primarily want to drag race the car, go with slicks and a driveline that will hold up to it. You will find all the weak points the hard way running slicks.

xlr8or · #5 (**permalink**) 09-24-2007, 02:19 PM

PS: You won't pass tech inspection at an NHRA certified track in a Cobra for less than 7.50 unless you install a full width bar and arm restraints.
There are better cars to use for drag racing.

enyawix · #6 (**permalink**) 09-24-2007, 03:01 PM

just a local track

wtm442 · #7 (**permalink**) 09-24-2007, 05:11 PM

Use a bullet proof solid rear (like a 9" Ford). Do NOT use IRS.

enyawix · #8 (**permalink**) 10-02-2007, 09:12 PM

Now I can add my 8.8 to the list of things to sell.

fsstnotch · #9 (**permalink**) 10-03-2007, 12:07 AM

Quote:

Originally Posted by xlr8or

PS: You won't pass tech inspection at an NHRA certified track in a Cobra for less than 7.50 unless you install a full width bar and arm restraints.
There are better cars to use for drag racing.

I agree, seems like an awefully expensive drag car. You could easily have a faster car for less money if you are only looking for a drag car.

but, if you are set on a cobra, I think the above mentioned is pretty good. you'll need a good gear choice, strong tranny, and a good strong rear! A cobra is going to be extremely traction limited. If I had to guess... the same engine combo in a foxbody is going to be a second or more faster with a good suspension setup.

SPF1061 · #10 (**permalink**) 10-03-2007, 07:11 AM

I think all of the advice you have received is pretty spot on. I will say that you do not HAVE to build a one trick pony to get the results on the drag strip you are looking for. I have a Superformance with a Roush 427R/.82 TKO 600/3:23 Torsen differential in a Ford 8.8 rear/every suspension upgrade offered by Olthoff Racing. I drive this car on the street, road course, auto cross and drag strip (pushing 45,000 miles in 7 years). I mount a pair of M/T 275/15 Street Radials on the back and drive the car to the local drag strip about once a month during the summer. I don't check the plugs, timing or rejet the carb. I just climb in and go. This is my best pass from last Friday :
1.768 - 60 ft
7.357 - 1/8 mi
11.372 - 1/4 mi
123.32 - trap speed
You don't have to have a purpose built "Cobra" to hit the times you are shooting for.

fsstnotch · #11 (**permalink**) 10-03-2007, 07:17 AM

^^ those are some pretty darn good #'s! Especially on a 275 tire! With that trap and better traction, you'd shave a half second off! Damn good numbers!

Josh

enyawix · #12 (**permalink**) 10-03-2007, 07:44 AM

Quote:

Originally Posted by fsstnotch

I agree, seems like an awefully expensive drag car. You could easily have a faster car for less money if you are only looking for a drag car.

but, if you are set on a cobra, I think the above mentioned is pretty good. you'll need a good gear choice, strong tranny, and a good strong rear! A cobra is going to be extremely traction limited. If I had to guess... the same engine combo in a foxbody is going to be a second or more faster with a good suspension setup.

I will also driver it a little. I am set on a roadster so my options are limited.

Jerry Clayton · #13 (**permalink**) 10-03-2007, 07:47 AM

If it is mainly for drag racing----with a 90 in wb, the engine set back that a cobra has, the car does not have to be traction limited---with a 3 or 4 bar 9 inch rear , good shock setup, and wheelie bars, a Cobra at 2200-2400 lbs show probably run in the 8 sec area but aero will limit it to 140mph range--
the idea projected that Cobras are traction limited is false---most of these cars are built for waxers that want to talk about there dyno slips and not time slips---But, believe me a ride in a 90 in car at 180mph in 7 seconds will be exciting

Jerry

fsstnotch · #14 (**permalink**) 10-03-2007, 08:13 AM

Quote:

Originally Posted by enyawix

I will also driver it a little. I am set on a roadster so my options are limited.

That's good! Probably your biggest hurdle will be getting the suspension all set up.

My notch went 13.5 @ 114, 2.45 60ft, the first time I took it to the track and before I did anything to it as a baseline to show the previous owner that he was a moron! lol At that point it had worn out falken 295's on 17" wheels. After a couple dyno pulls and some carb tuning, 10.5" slicks, and complete suspension with 50/50's and 90/10's, upper and lower rear control arms, and 15" draglites, she went 10.88 @125, 1.56 60ft. Then the track rules wouldn't let me make another pass because I had no cage.

I daily drove the car and cages are very UNSAFE for street cars so I just never took it back to the track. Leave it to someone to spoil all the fun!

I miss that car! Can't wait to play with the cobra a little bit! Another note on teh times, I shifted at 5500 the first pass and after getting more feel for the car over a couple months, shifted at 6500 to 10.88 pass.

enyawix · #15 (**permalink**) 10-03-2007, 08:37 AM

How heavy would you say a fox body is? I am shooting for a 2400lbs cobra.
The extra 200lbs is twin turbo 351 and two batteries in the trunk. "beater balance of weight"

fsstnotch · #16 (**permalink**) 10-03-2007, 08:48 AM

If I had to guess I'd say my car wieghed around 2700lbs with the draglites. It had no AC, nothing at all in the trunk, no rear seat, no smog junk, no spare tire or jack, in track form. Curb was around 3,000lbs factory

enyawix · #17 (**permalink**) 10-03-2007, 09:00 AM

Wow so I will drop 300lbs at the minimum

fsstnotch · #18 (**permalink**) 10-03-2007, 09:07 AM

yep, it's possible! I may have underestimated the weight, but I didn't want to overestimate. The guy I sold my car to put a single turbo setup on it and blew it up! haha It was not built for boost and i stressed that to him! he hasn't driven it since the 2nd month I sold it to him almost a year ago.

trularin · #19 (**permalink**) 10-03-2007, 09:44 AM

When you do the rear, and you are committed to the drag, have a spool installed.

Set your gears up for WOT all the way with top RPM at 1/4 miles plus 100 feet.

Just my $0.02 worth.

Excaliber · #20 (**permalink**) 10-03-2007, 10:44 AM

The Cobra IS indeed 'traction limited' by it's fundamental design as a road race car. To increase traction specifically for a drag race application your going to have to substantially alter that fundamental design and add some serious slicks.

Wheelie bars on a Cobra? When you need them you truely have a drag race car. Sure it can be done, big slicks, soft shocks, ultra low rear gear, blah blah blah. Such alterations border on ridiculous, have fun WAXING your worthless road worthy Cobra when your done screwing it up.

You might consider a Pinto, it to has a short wheel base if thats all your looking for.