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Discussion Starter · #1 ·
Im working on A daily driven 92 notch back. My goal is to put together a N/A 12 second car with a 306. Hers a list of some of the mods 3:73 gears, TKO500 tranny, upr rear suspension, QA1 k-member and A -arms, Coil overs, cast and camber plates, as far as the engine goes I have a set of 165 afr's, Air gap intake , trickflow stage2 cam , 1.6 RR , 650 holley carb. I also have a set of old trw L2249 pistons that im thinking about using but im not sure if I will be able to run pump gas on these. Im also considering having a cam custom made . Any suggestions would be greatly appreciated
 

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Im working on A daily driven 92 notch back. My goal is to put together a N/A 12 second car with a 306. Hers a list of some of the mods 3:73 gears, TKO500 tranny, upr rear suspension, QA1 k-member and A -arms, Coil overs, cast and camber plates, as far as the engine goes I have a set of 165 afr's, Air gap intake , trickflow stage2 cam , 1.6 RR , 650 holley carb. I also have a set of old trw L2249 pistons that im thinking about using but im not sure if I will be able to run pump gas on these. Im also considering having a cam custom made . Any suggestions would be greatly appreciated
Good forged pistons and spray it. Or if you carefully build it I don't think it would be that hard to get there with what you have listed, assuming you get the right cam and other items...

I know a guy that got a 69 cougar (351w) in the 12's with nothing more than a cam, springs, intake and a carb.
 

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Good forged pistons and spray it. Or if you carefully build it I don't think it would be that hard to get there with what you have listed, assuming you get the right cam and other items...

I know a guy that got a 69 cougar (351w) in the 12's with nothing more than a cam, springs, intake and a carb.
What is it? Instead of building a good engine the answer is spray it. Build a good solid engine & you will wipe the track with anyone spraying!
 

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So let me get this straight. To get a SBF 306 engine that runs 12s N/A is to put N2O on it?
You don't need to spray it. I have a pickup that runs a 375-400 hp 460 that will do 12.85. Your car is much lighter & with the lighter engine I would bet 350-400 hp with at most 3.55 gears should get you there. I just went from 3.08 gears (12.85) to 4.10 & went slower in the 1/4. I wound up fast but they killed my top end. I am backing back down to 3.55s & see how they do.
 

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What is it? Instead of building a good engine the answer is spray it. Build a good solid engine & you will wipe the track with anyone spraying!
Say what?

I agree that a solid build is key to any good time slips, but you will not wipe the track with someone spraying unless they have other issues or you outclass them...

I didn't mean to imply he shouldn't build a good engine...
 

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Discussion Starter · #9 ·
No, I didn't mean that. You can just do a good build, it should take you there just fine. I was being a little sarcastic when I said that, spray is good though :) lol

what do you run now? or do you take it to the track.
I took it to the track two weeks ago for the first time and the best i could get it to run was a 13.36 @ 104. The next day I pulled the motor back out in pure disappointment. It has a set of flat tops wit the four eye brows in it now .Im thinking about installing those trw pistons that I have just laying around. They have a +8.5cc dome on them so im not sure if their going to raise the compression ratio up too high for pump gas. years ago I ran this same short block with a set of gt40p heads and a E303 cam in it that ran faster than this set up
 

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I took it to the track two weeks ago for the first time and the best i could get it to run was a 13.36 @ 104. The next day I pulled the motor back out in pure disappointment. It has a set of flat tops wit the four eye brows in it now .Im thinking about installing those trw pistons that I have just laying around. They have a +8.5cc dome on them so im not sure if their going to raise the compression ratio up too high for pump gas. years ago I ran this same short block with a set of gt40p heads and a E303 cam in it that ran faster than this set up
How wild do you want to go? you can go a lot faster than 12's on pump gas... I am assuming this is not your DD if you yanked the engine out...
 

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Discussion Starter · #11 ·
My goal was to be able to run in the 12's on motor and maybe squeez an 11 out of it on the jug. I dont drive it every day. I own two other mustangs and A f-250. I only put this car together to be able to crusie with the local car club. I had most of the parts laying around from my other two projects. the only things that I had to purchase was the Intake and the heads which i got on a unbeliveable deal
 

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All the power in the world won't get you into the 12's if the car won't hook up. I'm running well over 400 HP, probably closer to 450 and my first and only 1/4 mile pass on this motor netted a meager 13.5 at 107 MPH. Even leaving easy on my street tires I had wheel spin almost to 1/2 track. It wasn't fun! Also, my rear tires are 295/50-15's so I'm not running something skinny.

With the right gearing and slicks you'll get the 12 second timeslip without spending a small fortune on the engine. Remember, the first 60 feet make or break your pass. Get that down low and the rest comes easy. I won't run it again until I have at least a good pair of drag radials out back.

John
 

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Discussion Starter · #13 ·
All the power in the world won't get you into the 12's if the car won't hook up. I'm running well over 400 HP, probably closer to 450 and my first and only 1/4 mile pass on this motor netted a meager 13.5 at 107 MPH. Even leaving easy on my street tires I had wheel spin almost to 1/2 track. It wasn't fun! Also, my rear tires are 295/50-15's so I'm not running something skinny.

With the right gearing and slicks you'll get the 12 second timeslip without spending a small fortune on the engine. Remember, the first 60 feet make or break your pass. Get that down low and the rest comes easy. I won't run it again until I have at least a good pair of drag radials out back.

John
The car hooked up just fine.I think i just didnt have enough ponies to move me along any faster
 

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Say what?

I agree that a solid build is key to any good time slips, but you will not wipe the track with someone spraying unless they have other issues or you outclass them...

I didn't mean to imply he shouldn't build a good engine...
give the OP the specs to get that solid build

like said no bottle please
 

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I ran 12.34 with my old 306 combo. It was TRW forged FT, hydraulic cam 586 lift, World SR heads and a Parker Funnel Web intake. Carb is a 700 DaVinci . Trans is a Jerico DR4 with aluminum motorsports drive shaft, to 4:56 gears. Nothing special what so ever, I think you just gave up on your combo too soon, and could use a little more gear
 

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Say what?

I agree that a solid build is key to any good time slips, but you will not wipe the track with someone spraying unless they have other issues or you outclass them...

I didn't mean to imply he shouldn't build a good engine...
My point is that seems to be everybody's cure all for going fast nowadays. I stand by my statement. If you are talking about a car that is driven on the street I will take a well built one over a sprayed car any day of the week. For the most part it is a cheap shortcut for way too many people. Yes they do spend most of their lives R&Ring the engine & fixing what their glorious spray did for them.

2 cars with pretty much equal ETs. 1 spray & 1 not. Given no mechanical failure in either vehicle which 1 will win? My money will always go on the nonsprayed. Why? Spray is a variable not a constant. If that's what you want put it in the tank in the form of a different fuel.

At the same time I have a 460 in a pickup not a SB. My approach is most likely quite different. I have no clue how Mustang42782 did 12.34 with 4.56 gears. Like I said, mine actually did worse with 4.10 gears over 3.08s.
 

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At the same time I have a 460 in a pickup not a SB. My approach is most likely quite different. I have no clue how Mustang42782 did 12.34 with 4.56 gears. Like I said, mine actually did worse with 4.10 gears over 3.08s.
Probably because his gears were matched to his cam appropriately. A lot of people think of engine and drivetrain components as discrete power adders. As in, add heads, gain 40hp, add cam, gain 30, gears, gain E.T.

But that's not how it works. Every single component choice affects the other and they all have to be selected with the same goal in mind - or they will fight each other and you'll end up slower.


That's kind of the golden rule of engine building - all the components need to be picked to work together and complement strengths.

I think the second rule is that making power is all in the tune. I've had a few friends that put an engine together with expensive components, but out of the box weren't happy with how fast it was, and immediately went back to the parts catalog without even trying to get their combo to perform at its peak. Stick at it for a bit and change cheaper things before going huge.
 

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Probably because his gears were matched to his cam appropriately. A lot of people think of engine and drivetrain components as discrete power adders. As in, add heads, gain 40hp, add cam, gain 30, gears, gain E.T.

But that's not how it works. Every single component choice affects the other and they all have to be selected with the same goal in mind - or they will fight each other and you'll end up slower.


That's kind of the golden rule of engine building - all the components need to be picked to work together and complement strengths.

I think the second rule is that making power is all in the tune. I've had a few friends that put an engine together with expensive components, but out of the box weren't happy with how fast it was, and immediately went back to the parts catalog without even trying to get their combo to perform at its peak. Stick at it for a bit and change cheaper things before going huge.
Regardless of pieces parts I guess my main question would really have been how many rpms do you have to be turning to use 4.56 gears & get 12.34? I know I can work it all out & I know a big block can do it but that has to be some serious rpms.
 

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I ran 12-1 pistons on the street and had to back off the timing alot on pump gas, I could feel the differance so I sprayed 275 shot of nitrous with those TRW pistons for 10 years until they started to crack around the top of the rings.

Even had one eat a bolt and washer from my 2 piece tunnel ram back in the day. Just replaced the bent valves and I was back on the road.

But now I run 10-1 pistons with more timing and she's a blast to drive around town but if it's wet outside I can't keep it on the road with 3000 stall and 4.10 gears.
 
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