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-   -   1/4 mile questions (https://67-72chevytrucks.com/vboard/showthread.php?t=278811)

BigBadBB 02-15-2008 10:29 AM

1/4 mile questions
 
Im wondering what my truck is capable running in the 1/4 mile, Im hoping to eventually beable to run in the low 13's but I just want to make sure that is feasible. it is an 86 3/4ton 2wd with a 454 and turbo350 trans.
So far it has a GM rebuild that is I believe .30 over but Im not sure if they are a stock type piston or not. It has 1 3/4" headers, edelbrock carb, a Pro-Billet Distributor, Blaster 2 Coil, and an MSD 6AL ignition. I have a performer 2.0 intake in the mail and will be ordering a cam with lifters and rockers soon. I probably wont get into the heads until summer but with some sticky street tires and stock weight what do you guys think I could run before and after.

Thanks

Outlaw72 02-15-2008 11:20 AM

Re: 1/4 mile questions
 
I am going to guess somewhere in the 14's since you said it was 3/4....those are very heavy.

GMC70c20 02-15-2008 11:54 AM

Re: 1/4 mile questions
 
If your lookin for just a cruiser with some snot you should definetly convert it to a half ton. You would save yourself at least 1 sec off your et by just coverting it. Lows 13's with a 454 is very douable if I were to guess I would say you would probably need some where around 425hp to get to a mid 13 with your truck, and to get that power out of a 454 is cake.

BigBadBB 02-15-2008 12:25 PM

Re: 1/4 mile questions
 
yeah I figured it could be done but with all that wieght I need some nice hp/tq. I really dont want to go through the hasle of coverting it to a 1/2ton, I'll just put more power to it :)

chevy72blu 02-15-2008 12:58 PM

Re: 1/4 mile questions
 
a 100hp-125hp shot used very conservatively (only at the track and in 2nd/3rd) will help you reach your goal, and save some serious cash. Be careful of course, not having forged internals. Many experienced racers and machinists have told me it isnt that big of a deal as long as you dont let yourself spray too much or too often.

What kind of rear end gears are you running as well as tire height? This will play a huge part in your ET

bigjimzlll 02-15-2008 01:40 PM

Re: 1/4 mile questions
 
Quote:

Originally Posted by chevy72blu (Post 2579024)
a 100hp-125hp shot used very conservatively (only at the track and in 2nd/3rd) will help you reach your goal, and save some serious cash. Be careful of course, not having forged internals. Many experienced racers and machinists have told me it isnt that big of a deal as long as you dont let yourself spray too much or too often.

What kind of rear end gears are you running as well as tire height? This will play a huge part in your ET


Good idea...except for the little known fact...that Nitrous Oxide is addictive. Everyone starts out with " a100 shot will be all I need"...then it's a 150...then it's the dreaded burnt piston or worse.
A 100-125 shot done right is safe on a BBC....just keep it at that level

71Dragtruck 02-15-2008 01:50 PM

Re: 1/4 mile questions
 
Quote:

Originally Posted by bigjimzlll (Post 2579138)
Good idea...except for the little known fact...that Nitrous Oxide is addictive.

AMEN!!!!!!!!!

89 crew 02-15-2008 02:40 PM

Re: 1/4 mile questions
 
Are you going to the track to race for money, or have fun? If it is for money you will need to spend a bunchof $$ to be sure of a win! If it is for fun, then have fun. listen to all advice here, then play. Try different things and see what it does to your time. If your time gets better then you know you did right.

GMC70c20 02-15-2008 05:00 PM

Re: 1/4 mile questions
 
The only problem with just adding more power is allot of power plus allot of weight equals breaking drive train components (transmissions, drive shafts, axle shafts). I have a 79 3/4 ton 2wd truck and it scales 4200 lbs and thats with a small block and th-350. In order to get your 3/4 chassis into the mid 13's it would take about 450-500 hp. Now that isn't really allot of power for a 454 but another thing is that much power there's know way its gonna hook with the 3/4 ton setup. It's not really that much work converting it to a 1/2 ton I'm doing it to my 70 now, it would be money well spent. I'm not trying to rag on your truck, hell I have 2 c20's myself but if your looking for performance your better off converting it to a half ton. Here's a little food for thought by just converting it to a half ton you could get it down to 3600 lbs or so, I did on mine and I'm looking at about a 12.10-12.3 1/4 mile with 525hp.

Couch 02-15-2008 10:22 PM

Re: 1/4 mile questions
 
Quote:

Originally Posted by 71Dragtruck (Post 2579161)
AMEN!!!!!!!!!

Quote:

Originally Posted by bigjimzlll (Post 2579138)
Good idea...except for the little known fact...that Nitrous Oxide is addictive. Everyone starts out with " a100 shot will be all I need"...then it's a 150...then it's the dreaded burnt piston or worse.
A 100-125 shot done right is safe on a BBC....just keep it at that level

very true. i started off at just a 100 shot. but then jets are everywhere and so easy to change. its just to easy to blow **** up.

Outlaw72 02-15-2008 11:14 PM

Re: 1/4 mile questions
 
Please do not listen to me just ignore this post!!!


A stock big block will take a 200 shot all day long......OOPS OKAY SHOOT ME!!

Super73 02-15-2008 11:32 PM

Re: 1/4 mile questions
 
Some good points being made about heavy + power = breaking things

I don't however see it being easy to get a big block 1/2 ton to weigh 3,600lbs but I don't see it being that far off from 3,800ish. My alum LS1 / 4L80E swapped 63 short Fleetside weighed in at 3,840 with me in it (I'm 180, so 3,660) with a full tank of gas. Mine was making 410rwhp with too small of a TQ converter and best pass of 12.3 @ 110 with a couple of 12.4's, 12.6's 12.7's while getting it dialed in.

BigBadBB 02-16-2008 01:54 AM

Re: 1/4 mile questions
 
Thanks guys, the thought of nitrous has been in the back of my mind for a while. Its wierd Im not even a truck kinda guy, but man I just love this thing. the power is awsome for a 4000lbs truck. Its just kind of another toy to play with so Im not a hard core drag guy, it will see plenty of time on the street and will haul my quad from here to there. Im pretty sure it has the stock gears and the tires are kinda tall like 265/75/16 but might look into some drag radials.

GMC70c20 02-16-2008 09:51 AM

Re: 1/4 mile questions
 
your right super73 I forgot about the bb

Outlaw72 02-16-2008 02:00 PM

Re: 1/4 mile questions
 
I got a big heavy tank :(

71Dragtruck 02-16-2008 08:50 PM

Re: 1/4 mile questions
 
Quote:

Originally Posted by Outlaw72 (Post 2580930)
I got a big heavy tank :(

Me too!!

chevy72blu 02-16-2008 11:39 PM

Re: 1/4 mile questions
 
Quote:

Originally Posted by BigBadBB (Post 2579812)
Thanks guys, the thought of nitrous has been in the back of my mind for a while. Its wierd Im not even a truck kinda guy, but man I just love this thing. the power is awsome for a 4000lbs truck. Its just kind of another toy to play with so Im not a hard core drag guy, it will see plenty of time on the street and will haul my quad from here to there. Im pretty sure it has the stock gears and the tires are kinda tall like 265/75/16 but might look into some drag radials.

I would go through your rear end first. Being a 3/4ton, im guessing you have a truck 12 bolt 8 7/8" ring gear. Throw a set of 3.73's in it with a posi unit and you will be amazed at the difference. If you see a lot of freeway driving in it, stick with a lower gear (3.56, or so), but if you arent driving it daily its a great gear. I drove mine every day on the freeway with 3.73's, a TH350, and a 28" tall tire for years - I just cruised about 55-60 ;)

Outlaw72 02-17-2008 01:21 AM

Re: 1/4 mile questions
 
Quote:

Originally Posted by 71Dragtruck (Post 2581094)
Me too!!

What are the specs on your engine?

71Dragtruck 02-17-2008 01:58 AM

Re: 1/4 mile questions
 
Quote:

Originally Posted by Outlaw72 (Post 2581395)
What are the specs on your engine?

--------------------------------------------------------------------------------

It's a 489 BBC with these specs.

4-bolt mains, studded
Eagle crank
TCI Rattler
Eagle H-beam rods
SRP forged pistons 10.86:1
Comp Cams 308R solid roller
Comp lifters
Comp High Tech push rods
Edelbrock Rec Port RPM heads
Comp Pro Mag rockers
Comp stud girdle
Edelbrock Vic jr. intake
Pro Systems 1000cfm Nitrous Pro IV
Hooker Super Comp 2" headers
ARP top to bottom
Crane dist, and High 6R, with timing retard
NOS Cheater system

We made some dyno pulls and ended up with 636.5hp at 6250rpm, and 617.6flbs. at 4750rpm. It avg. 585.12flb and 586.92hp from 4250-6500rpm. This was done with a 750 carb, heads and intake unported NO Nitrous all motor. With a 850 carb at the time I'm thinking it would have made 650hp easy.

This was made on a stingy dyno, they like it that way so that their motors will always make what they claim, Ron the dyno guy with 25 years in the buisness, is old school and likes to play it safe, could have made more with more timing, leaner, and few more revs, was still making a bit of power on the one pull when he backed out of it.

Would have been nice to try a 850, but a guy borrowed it and never made it back in time for my session, and it wasn't in the budget at the time to buy one that day. I did eventually put a 850 on, dropped 60' and 1/4 mile time on the bottle never tried it on motor, only had limited time to try it so never did get it fully tuned.

I now have a 1000cfm custom carb, not sure what it would make with it, time will tell when I run it at the track. I'll be very very surprised if it doesn't make a huge difference.

Super73 02-17-2008 02:17 AM

Re: 1/4 mile questions
 
Quote:

Originally Posted by 71Dragtruck (Post 2581437)
We made some dyno pulls and ended up with 636.5hp at 6250rpm, and 617.6flbs. at 4750rpm.


Was this on a chassis dyno or engine dyno? No N20 I'm assuming?

71Dragtruck 02-17-2008 02:39 AM

Re: 1/4 mile questions
 
Quote:

Originally Posted by Super73 (Post 2581455)
Was this on a chassis dyno or engine dyno? No N20 I'm assuming?

It was on a engine dyno no nitrous.

70rs/ss 02-17-2008 03:03 AM

Re: 1/4 mile questions
 
Quote:

Originally Posted by chevy72blu (Post 2581305)
I would go through your rear end first. Being a 3/4ton, im guessing you have a truck 12 bolt 8 7/8" ring gear. Throw a set of 3.73's in it with a posi unit and you will be amazed at the difference. If you see a lot of freeway driving in it, stick with a lower gear (3.56, or so), but if you arent driving it daily its a great gear. I drove mine every day on the freeway with 3.73's, a TH350, and a 28" tall tire for years - I just cruised about 55-60 ;)



If it's a 3/4 ton it has either a dana 60 or a 14 bolt, and more than likely 4:56's, maybe 3:73, but most had a 4:XX series in them. Nitrous is nice, because you only have to deal with the 200hp when you push the button the rest of the time it's 200 less hp and a more or less stock truck. That rear is bullet proof and a decent gear in it I am guess, use a shorter tire, sticky tires are not necessary unless you don't have traction? Good luck I am guessing 14'-15's now, but shorter tire, the parts you are talking about and you could see a 13, put the squeeze to it and 12's could be there!?

Outlaw72 02-17-2008 04:23 AM

Re: 1/4 mile questions
 
71Dragtruck,

That is a nice setup! I just purchased a forged 496 bottom end and block from a friend. I plan to follow a build Car Craft did on a 496 that made 707hp and 603tq. I might make a few changes to get the tq number a little higher but here is the recipe.

Studded, Machined block
Cat 4.25 4340 crank
Manley 6.385 H-beams w/ 7/16 capscrews
SRP 10.2:1 pistons
Comp XR292 Solid Roller
AFR 305 as cast heads, but I might break down and either purchase the cnc ported 305's or the as cast 325's.
I'm going to try and get a little more tq out of it by using an RPM airgap but the build used a victor junior and an 850 cfm carb. I already have a 1050 dominator for it. I also already have a bunch of parts needed such as roller lifters, roller rockers and bs like that ect....I wanna run some 10.70's to dammit!!

71Dragtruck 02-17-2008 11:29 AM

Re: 1/4 mile questions
 
That'll be a nice mill when your done!

Outlaw72 02-17-2008 01:33 PM

Re: 1/4 mile questions
 
Quote:

Originally Posted by 71Dragtruck (Post 2582104)
That'll be a nice mill when your done!

I truly hope so cause it's gunna be built for spray and I promise I will not be stingy with the pills!!


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