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-   -   Dragstrip results, '71 BB... (https://www.corvetteforum.com/forums/c3-tech-performance/780239-dragstrip-results-71-bb.html)

Doug Brandon 03-20-2004 10:31 AM

Dragstrip results, '71 BB...
 
I always like reading what other combos will do. Many on here have gone much faster, but here are my results. Keep in mind, this was my first trip down the 1320 in nearly 20 years-a little rusty. All times were in street trim. I adjusted my tire pressure (38/20) and went.

13.9 @ 105.8 .952 R/T, 2.39 60'
13.8 @ 105.9 .635 R/T, 2.39 60'
red light-rolled forward and could not get re-staged in time
13.66 @ 106.2 .735 R/T, 2.33 60'

At least the trend was going in the right direction! My 225/70's were not much help off the line. I am getting ready to bore and stroke this thing, so I will need to figure out a way to get a little more traction w/o breaking parts!

PRNDL 03-20-2004 10:43 AM

Re: Dragstrip results, '71 BB... (Doug Brandon)
 
you are producing some pretty good power, and getting terrible traction! :lol: You are actually going a little faster (mph) than me with slightly slower et !! (no... 13.66 would be about my best ever) And I thought I set the standard for slow et given mph!! :) Your 60 ft times are reallllllly slow. Track could be slick at the starting line. I also have 225/70s. Have you had the car on a dyno? You are probably putting out same power as guys running in the 12s. MJ

also, just for comparison sake, what is your rear end ratio? (mine is 3.36) and is your 4spd M20?


[Modified by MNJack, 10:44 AM 3/20/2004]


[Modified by MNJack, 10:47 AM 3/20/2004]

Yeller81USNRet 03-20-2004 11:29 AM

Re: Dragstrip results, '71 BB... (MNJack)
 
I could beat you to the 60' mark and then it would be over for me.. 2.337 at the 60' mark .. Completely stock 81
Oops has a HyperTech chip and a test pipe No CAT..


:steering:

WA 2 FST 03-20-2004 12:11 PM

Re: Dragstrip results, '71 BB... (MNJack)
 
[QUOTE] You are probably putting out same power as guys running in the 12s. MJ

[QUOTE]

Yep. MJ is right. 106mph will give you a 12-second timeslip with appropriate traction and gearing. It's not worth busting parts, though... at least in my opinion. :)

Glad you got it out and enjoyed your time racing!

Doug Brandon 03-20-2004 01:16 PM

Re: Dragstrip results, '71 BB... (WA 2 FST)
 
Yea, pretty sad off the line. The last run I tried walking off the line with no tire spin and then going wot. The car has a 3.36, M20 4 spd, and a mild 433 (346 rwhp, 403 rwtq). I drove it up, made the runs, and drove back (about 40 miles each way) on about a half tank of gas. Motor never hicupped.

Would you guys suggest drag radials? I don't know that slicks are worth the risk to my rear suspension. One thing that was nice, in a sea of Mustangs, and rice rockets, I was the only old Vette there. The tech guy complimented me on the car. Guess they like to see something different for a change. :)

BKbroiler 03-20-2004 01:47 PM

Re: Dragstrip results, '71 BB... (Doug Brandon)
 
Thanks for posting the interesting results. I haven't tried drag radials, but they have got to help. With the 3.36 rear and the 4 speed, you are going to need some wheel spin off the line to keep the rpm's up. Good luck.

jpatrick636 03-20-2004 03:27 PM

Re: Dragstrip results, '71 BB... (Doug Brandon)
 
This may sound small but it will help; run with a full tank of gas. Drag radials will definitely help but watch that rear end! How about 255's? They should fit with no modifications. Good luck.

PRNDL 03-20-2004 05:34 PM

Re: Dragstrip results, '71 BB... (jpatrick636)
 
Well, I also am seriously considering a set of drag radials (on wheels, so i could put them on for trips to the dragstrip only). At this point that would be the most cost effective method of lowering 1/4 mile times. No point increasing hp or torque if you can't use it. :)

Glensgages 03-20-2004 06:42 PM

Re: Dragstrip results, '71 BB... (WA 2 FST)
 

106mph will give you a 12-second timeslip with appropriate traction and gearing.
:iagree:
My old Z28 went 14.40s @ 97 w/ 3.42s, no-converter, on UNIROYAL radials;
then, with a different motor, it went 13-teens @ 104 with a 10" street converter, sticky-street tires, and 4.10-gears;
it went 12.80s@ 106 w/ an 8" converter, 28" slicks, & 4.56 gears, just for comparison's-sake (street-tires wouldn't hook the 8" converter, so I 'borrowed' 28" slicks; the 4.56s brought the gearing 'back').
In a fairly-stretable car, if you divide 1400 by your MPH, this will give you a 'decent' idea of what your ET could be w/ traction @ this HP-rating.

LAvetteman 03-21-2004 12:31 AM

Re: Dragstrip results, '71 BB... (Doug Brandon)
 

I always like reading what other combos will do. Many on here have gone much faster, but here are my results. Keep in mind, this was my first trip down the 1320 in nearly 20 years-a little rusty. All times were in street trim. I adjusted my tire pressure (38/20) and went.

13.9 @ 105.8 .952 R/T, 2.39 60'
13.8 @ 105.9 .635 R/T, 2.39 60'
red light-rolled forward and could not get re-staged in time
13.66 @ 106.2 .735 R/T, 2.33 60'

At least the trend was going in the right direction! My 225/70's were not much help off the line. I am getting ready to bore and stroke this thing, so I will need to figure out a way to get a little more traction w/o breaking parts!
Pretty much a carbon copy of what I have always ran in my 71. Enjoy

WA 2 FST 03-21-2004 12:57 AM

Re: Dragstrip results, '71 BB... (LAvetteman)
 
Drag radials will definitely be a cost-effective investment for you. As long as you don't do some banzai launch (like clutch drop at 4500) and have them hook too well... you should be ok. You should just bring the revs up a bit, and then slip the clutch some to get rolling, then stand on it. Instead of just smoking the tires the first 100' (which is what you're doing now, I'm sure), it will hook up once you are rolling at any speed.

Most breakage I've seen occurs when you have severe shock loads to the drivetrain, and this is alleviated once you are actually moving along. Wheelhop is also a parts killer, so you will just have to be sure to take it easy at first.

I predict .4+ reduction in ET with some drag radials and a moderate launch, but aggressive driving once you're down the track. You might need more gearing and slicks to bust into the 12s, but then you might be busting parts, too.


GrandSportC3 03-21-2004 01:10 AM

Re: Dragstrip results, '71 BB... (Doug Brandon)
 
speed is good.. 60' time isn't.. Did they spray the track?? (with VHT)???

Doug Brandon 03-21-2004 10:25 PM

Re: Dragstrip results, '71 BB... (GrandSportC3)
 
Appreciate the feedback. Looks like drag radials are the ticket. I don't know if the track was sprayed with VHT. But, I can see how drag racing can be addictive. I still have the white shoe polish on the back window. :)


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