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Organized Drag Racing and AutocrossDrag racing and autocross discussions and questions. Techniques, tips, suggestions, and "what will I run?" questions.
i have a 1982 z28 that i have a goal of reaching into the 12s in a 1/4 mile . the car will be stripped , drag radials , and carbon fiber hood if that makes a difference . the engine is a 327 with sock heads . wiend intake , holley 600cfm , and mild cam , rocker rollers . secondary vacuum . 1 5/8 long tube headers . the transmission is a super t10 with a peg leg 3.23 in the rear end . how much more or what will it take to get into the 12s ??? have not been to a track to know the time with current set up .
Drag radials? If it's stripped down for track only, don't bother wasting your money on radials unless you're racing in a class that demands a DOT tire.
Carbon fiber hood? Wow, you must have a lot of money to spend to just get into the 12's.
A 327? It will be a lot easier and cheaper to get into the 12's with a 350 or 383. The money spent on a carbon fiber hood could buy you an engine to get into the 12's
You've got plans but you are spending money in the wrong locations to reach your goal.
Traction will be your biggest problem. Drag radials or bias ply slicks notwithstanding, without a limited slip differential (posi) you'll spin a long way . Even with an underperforming engine.
Add to that the likelihood that you have a small 10 bolt diff, dripping the clutch won't be a good thing if you COULD get traction.
My first trip into the 12s with a 3700 lb IROC took a 350 with about 375 hp (possibly less), 3.70 rear gear (9 bolt posi) and slicks.
i already have the hood , the drag radials and the 327 . i know thats not the main recipe to building 12 second car or any drag car. i didnt post what im building with , im posting about what i have to work around . thanks .
ive seen and heard of thirdgen camaros with ford 9'' , but nobody seems to have made a thread on building one for a thirdgen or just swapping one in even if it was an almost direct swap or not .
ive seen and heard of thirdgen camaros with ford 9'' , but nobody seems to have made a thread on building one for a thirdgen or just swapping one in even if it was an almost direct swap or not .
There are a lot of 9" threads but basically you have to buy a housing built for a 3rd gen like a curie housing.
how much hp would it take ? if built a 3.73 rear and had proper gearing ? would putting a mini spool in a 7.5 10 bolt be a quicker and cheaper way ? i know its not safe or practical for street use but thats not what the car is intended for anyway
Mini spool is for dirt track racing where wheel spin is expected. On a dragstrip, the mini spool will not help the fact that you still have tiny ring and pinion teeth of the 7.5" 10 bolt.
There are no easy or inexpensive ways to upgrade the diff. Because of the third gens torque arm design, you can't just go to the junkyard to find a diff and bolt it in. You have a few aftermarket direct bolt in options with a 9", 12 bolt or D60. Depending on how it's speced out, expect to pay at least $2000 to finish a diff upgrade. Low end figure is buying a direct bolt in 9" housing and finding a center section to your liking from the junkyard. I found a 4.10 gear posi 9" for 31 spline from an old Bronco one day. Only cost $100. Don't expect old OEM posi's to be in good condition though. Full spools are cheap for dragstrip use. The aftermarket 9" housing is around $1000 and they're designed to use GM brakes.
My first suggestion is to get a track time to see what you have to work with first. Going out to the track and running a 15.0 1/4 mile means you're going to need a lot to get into the 12's. I highly doubt you'll currently be in the 13's or even 14's.
how much hp would it take ? if built a 3.73 rear and had proper gearing ? would putting a mini spool in a 7.5 10 bolt be a quicker and cheaper way ? i know its not safe or practical for street use but thats not what the car is intended for anyway
I posted what it took for my first 12 second pass. What I didn't add to that list was that on that pass, I knocked a couple of teeth off the pinion gear in the 9-bolt. The 9-bolt is arguably stronger than the 7.5" 10-bolt you're running. It's probably a fair comment to say that with a spool (or any kind of limited slip diff) and slicks (of any type) that your 10-bolt would self destruct once you drop the clutch. Sooner or later anyway.
The NOS is pretty good suggestion. Even a modest shot once you've shifted into high gear could get you into the 12s.
But, also as suggested, getting to the track with what you've got and getting a baseline is really the 1st step in achieving your goal.
Here's a snapshot of my re-start into drag racing and what it took more or less.
You can see the big improvement once I added a hydraulic roller cam to what was otherwise the same 13 second chassis. MPH jumped by 5 and ET was cut by more than a 1/4 second. The 60' time also improved a lot and that really made a difference.
third gen posi rears are fairly cheap around here. that might be an option for you? i dont think the spool is a bad idea just for track use. especially on a budget. will it last? IDK? and i agree, if your only racing, go with full slicks.
try to lighten the car as much as possible too.
getting a baseline is good to see how your progress is going.
I posted what it took for my first 12 second pass. What I didn't add to that list was that on that pass, I knocked a couple of teeth off the pinion gear in the 9-bolt. The 9-bolt is arguably stronger than the 7.5" 10-bolt you're running. It's probably a fair comment to say that with a spool (or any kind of limited slip diff) and slicks (of any type) that your 10-bolt would self destruct once you drop the clutch. Sooner or later anyway.
The NOS is pretty good suggestion. Even a modest shot once you've shifted into high gear could get you into the 12s.
But, also as suggested, getting to the track with what you've got and getting a baseline is really the 1st step in achieving your goal.
Here's a snapshot of my re-start into drag racing and what it took more or less.
You can see the big improvement once I added a hydraulic roller cam to what was otherwise the same 13 second chassis. MPH jumped by 5 and ET was cut by more than a 1/4 second. The 60' time also improved a lot and that really made a difference.
Thankyou for the reply , this was exactly the kind of information i was looking for . do you know the weight of the car ? and what transmission. my idea of this build is to keep things cheap as possible and doing free things to improve the 1/4 mile such as building a better center of gravity , huge weight reduction , tuning after tuning and learning to drive the car better . i know you cant get 12s for free but i wanna keep it cheap as possible .
Last edited by Dustin_429; 08-24-2016 at 11:55 AM.
Thankyou for the reply , this was exactly the kind of information i was looking for . do you know the weight of the car ? and what transmission. my idea of this build is to keep things cheap as possible and doing free things to improve the 1/4 mile such as building a better center of gravity , huge weight reduction , tuning after tuning and learning to drive the car better . i know you cant get 12s for free but i wanna keep it cheap as possible .
It's all in my signature.
Here are a few specs for the 12.9x pass (IIRC).
350 w/ unported Vortec heads.
XR276HR cam (hydraulic roller w/224/230 @ .050", 570" with 1.6 rockers).
670 Holley VS with RPM Air Gap intake.
Long tube headers with single 3" to a terrible muffler in the OEM location.
Modified 700R4 with a 10" TCI torque converter. Foot brake to 2000 RPM. Flash stall closer to 3500.
3.70 9-bolt LSD.
26" "dirt track" treaded slicks.
Stock shocks and struts.
Aftermarket
The car would more or less dead hook with those tires and that power level. It took the converter to improve the 60' time by more than a tenth and the HR cam to give me the steam to improve the trap speed by more than 5 MPH (average). That car weighed in at 3700 lbs fueled up including me at 200 pounds. (Using four corner electronic scales).
For what it's worth, at these elapsed times and trap speed, 100 pounds off the car is worth about a 1/10th in ET.
so realisticly shaving enough weight off your car to where it weighed 3200lbs you could shave a 1/2 second off ? and with suspension , if i ever had plans to upgrade the rear springs would i want to go softer or stiffer ??
You can do a Hybrid ford 8.8" rearend with the GM tubes welded on and use either the torque arm brace design that BlackBird used or one of the designs floating around LS1tech. It's the route I'm going, I can weld a jig together for around $20. But a shop doing it for you and the rearend and rebuild kit should only put you at a grand. Mustang guys have proven 8.8s can handle 12s all day.
Personally, I don't think you should run slicks yet. Drag radials will be better on your stock rear end and keep it together a lot longer than a pair of slicks. If you get a 9" then i would go slicks.
I think the number one thing in the world for drag racing is seat time. Now, i put about 120-150 passes a year on my car as i am an avid bracket racer so I may be biased on that. But you can play with numbers and talk theoretical all day but every car is different and every single one will have its demons.
Go to the track and see where its at. See what is the weak point and then make your modifications from there.
12s are easy enough with a carb setup.. Personally id ditch the T10,,the Holley 600 and the Weiand intake,,,and I wouldn't strip/destroy the car just to get it in the 12s but that's just me.....
08-23-2016, 10:38 AM
