1/4 mile times
 

i've been searching this site to fiqure out what kind of performance to expect from these cobra kit car . 1/4 mile times , mph , top speed. I got classic roadster kit and i'm building a 427 windsor for it with 5 speed 8.8 rear end engine sould put out 580hp and i got 3.55 rear gear . and i need some feedback on times and traction hints to do and setup . My friends drive vipers and zo6 corvettes and want to put my cobra a head of these guys.

With 580HP, 550 + ft/lbs torque and slicks with a T5 in a heavier than "normal" replica, you may find that the 1/4 mile takes much longer than you expect. Your T5 might not make it all the way down the strip. You're sort of caught between a rock and a hard place because you need a chassis & tire setup that will hook up hard but the life of your transmission depends on some of that torque going up in tire smoke. I have a T5 behind a 383 SBC stroker (long story) with a claimed 450HP and 450 ft/lbs. So far, it has survived a previous owner who loved to entertain the masses with smoky burnouts and donuts. I drive it fast and I have done a few hard launches on a concrete strip, but that is with 60 series BFG's out back and they boil up big time. I would be reluctant to try launching hard with slicks. My Unique weighs just under 2400lbs with a 1/2 tank and no driver and my best (unofficial, hand timed by a co pilot) measured 1/4 mile run was 12.27 secs with a bit of wheelspin in first and second. If your drivetrain holds up, you should be faster than that, especially with slicks. I was going to swap out the T5 when I first got the car, but some of the guru's here suggested I leave it alone until it breaks. Their much appreciated advice on everything else was sound and so far this has been no exception. Question: if you're spending for a 427 stroked Windsor, why settle for a T5 and not a stronger box like a TKO?

I have to agree with Buzz on the T-5 selection.... Seen too many 5.0 Mustangs with less than 400 hp blow these things to pieces using slicks and drag radials....With slicks and a TKO,my guess would be high 11's....

David

PSERRA You have way too many question that need to be answered before a 1/4 mile time and speed can be found. Where are you racing, Denver Col. or Salt flats in Nev. Tempature, type of track, Baro reading, 580 hp is that at the rear wheels or the crank?? The cobra is a flying barn door. The areo package is poor. Dave S and Wayne T both have top cars with the best of parts in their cars and still have not found the 9 second barrier yet in 5 years of trying on all motor. Stacy P did it 1 time with 150hp on NOS and a motor maken 475 hp at the rear tires. Slicks, skinny tires in the front, Racing clutch and 6000rpm holeshot with a racing trans. Other cobras have run 9.0's but don't autocross or roadrace. The cobra was not designed for 1/4 mile racing. As far as trans choses Talk to David Kee. I would than look a racing 5 speed G-force,Jerico, richmond, or T-rex trans. For 1/4 mile your rear ratio is too low. 4.11 is a good place to start as long as an overdrive 5 gear is there. 150 hp of Nos would help as a BACKUP to cover the top end rush. MAKE SURE A PRO SETS UP THE SYSTEM or your motor will have a quick life and sudden death. This will get you started in the right direction. Rick Lake ps the hell with the 1/4 racing, parts breakage is high and not worth the breakage. build the car for fun and autocross, more fun less damage.;) :)

Hookup is a problem with the Cobra. The Corvette has lots of modern goodies to keep wheel spin down, etc. A Cobra is not really a dragster. If you want it to be a dragster, you need to build it from scratch to handle the sudden torque and put the most rubber you can on the drive wheels. Even if you use the TKO as mentioned earlier, you will want to use the TKO II -- it can handle more torque than the TKO.

You have to remember, however, that the Corvette and Viper both weight almost a 1000 pounds more than the Cobra and have less horse power and torque. You have the power to weight ratio advantage. They both have better aero than the Cobra, especially at the top end. The reason that the Dragonsnakes had hardtops and later Daytonas were created is the improved aero. Without the hardtop you are driving a brick at the top end, with the hardtop you can probably get at least an addition 30 mph top end speed.

The Cobra is a road race car. If you have the driving skills, you can beat the Corvettes and Vipers on twisty road course, even with their electronics. Most Corvette and Viper owners need their cars to drive for them -- they lack the driving skills. The Cobra is a driver's car.

KABOOM!!!!

Sorry for the rehash but with the T 5 and 600 hp you probably won't make it through the bleach box...

With a sturdy tranny and slicks, a set of depends, and that kind of hp I would really be surprised if you were not in the 10's. Heard of many a Cobra running in the high 400hp that was turning low 12's/high 11's on radials.

Good luck and keep us posted!

JB

I agree 100% you will run a 10 minute ET with a T5 because if you hook the tires it will break. A Tremec 3550 or TKO is a must with your expected HP.
My understanding is the Classic Roadster is a LIGHT Cobra replica.
Many replicas weigh in at 2500-2600 or even 2700 lbs. The CR should come in under 2400 perhaps in the low 2300 range.
I see no reason why a 500HP Cobra could not beat a stock Z06 or Viper at the drag strip any day. None at all. Even if they are worked you could run low 11's all day long or even 10's if you are set up properly . Although if you stretch it out I am sure the potential for the others would be to excell over your CR , I
feel you could beat most Vipers/Z06 Vettes with 450HP and a good launch. My 351W made 450HP and ran 11.5 @118 with a conservative 2200rpm launch...granny shifting. FFR owner Qwik 1 is running deep 10's all day with 370rwhp....FFR owner Road Rebel is in low 10's. Steve Pass has an FFR that stands up he hooks so hard ! If you can handle 500+HP and get off the line the Viper would need a major NOS shot to catch you.
Traction Tips ?? You have a live axle advantage and should definitely run slicks or at least Drag Radials. If you are serious run slicks . Practice, practice, practice your launch..It is about hooking ...the start is where it can end....so know your tires/suspenson and stay in those limits. For later shifts, know your motor's power bands from a dyno and shift timely...not revving above HP. I disagree with the 410 gear thing. Not with a 500+HP 427 making gobs of tq. Stay with the 3.55's or even try 3.27's with a Tremec 3.27 first gear and your friends will buy the hot dogs....

Here's a Cobra that can run 10.4
It's not a ERA, Superformance or a Unique.
Look for the Picture of the Cobra.

[url=http://www.ffcobra.com/ubb/ultimatebb.php?ubb+get_topic;f=1;t=012733#000004]

Well, not to rehash but, loose the T-5 and don't plan on using a stock 8.8 with slicks for long. If you need 500 hp in a Cobra to hang with a stock Viper or Vette, you just need more practice driving the car.

My car dynoed at 532 rwhp and 590 torque and will run high 10s or low 11s at around 135 mph on 17" Nitto drag radials. Usually runs in the low 11s because the only time I can run it is during test and tune sessions, when they don't tech the cars, and they don't prep the tracks very well for that.

500+ rwhp pulling you toward the big end at 125+ mph with the wind beating the hell out of you - I usually am just waiting for it to be over and mutter a short prayer as I slow down. Course I always have a big grin on my face as i get in line to go again.

Whatever you do - be careful.

Mike

1/4 times
 

thank for the info perhaps i will change the tran t5 for tremec tkoII
does any one know with that much power what clutch to use and do i have to beef up the rear end. one more thing if you guys can post proven 1/4 times that yours cobra have done and spec.thanks.

with the GTII's and a Stroked Custom Windsor, best on a semi-prepared drag strip was 12.0 at 119. But typically, with about 60+ runs, i go about 12.3 - 12.4 at 115. I am however proud of my very very consistent .60 reaction time, not bad for an gold Fart.

I imagine if you dead hooked 500HP on anything like an 8.8 axle something would break. But guys have been running 8.8's on 1000 lb heavier Mustangs with many passes (less HP of course!)and no way would you throw that down to the rear on a Cobra launch. Chances are you will rev to perhaps 3000 rpm and launch with a lighter car that will relieve stress from the rear . How hard you launch is up to you.

I am not a drag racer and really can't contribute much to this but I have the 8.8 and I upgraded it to the 31 spline axels and I don't think I could get enough traction on that light rear end to break it. My 69 Torino Daytona Cobra has the 9 inch with 31 spline and it weighs 3,900 pounds and I haven't broken it either. But as I said, I don't drag race as I liked road racing when I was young enough to do it. The 8.8 has seen some very rough driving on road courses and a lot of hard starts and gearing down. I also know of two drag Mustangs who are running that rear end with the 31 spline set up and they have no problems. I think they weigh about 2900 pounds without driver so they are heavier than the Cobra and are running slicks.

Ron

Just wanna chime in here....
I don't own a snake yet, but one of the reasons I am trying to swing one now is because of a car I saw at a Super Ford meet at Milan Dragway, Milan Michigan, about 16 years ago...
I don't know whos kit it was, I do know it had a fairly heavily built (but still streetable) 428 in it. It had an IRS, and slicks. I saw this Cobra pull consistant 10.8 second quarter miles, can't remember the top speeds but it was moving... He was giving some of the drag-cars that he was up against a very hard time.... Ever since then.............
Ironically, at that meet, I was driving the car that had the FE motor that I am now preparing for MY Cobra....

pserra,

All I would suggest is that you move the shifter to the mid location on that TKO with a nice Pro 5.0 shifter from www.hanlonmotorsports.com

,,,,,,,,,,,,,.60 reaction time, not bad for an gold Fart.

Hal, is a gold fart like close to but not actually a Gashole?


:LOL: Ernie