Get Mach1 into 12.5 second zone

[Duncan Mach72]

Hi all

Does anyone here drag their 71-73?

With stockish 429, mild cam, headers, toploader, 3.5:1 axle & Quick Times I got my Mach1 down to 14.11 @ 98mph. Fun but hardly impressive!

I'd like to get it into the 12.5 second zone with either 351C or 460 and still be streetable. Anyone got a car running around this level that can give me some suggestions?

Regards

Dunc

 

[Hemikiller]

Stock 71 351C-4V w/4 speed, 3.70 gears, 214/224 .510/.536 cam was good for 13.5. You should be able to crack into the 12s with that 429 with a rebuild and a more aggressive cam.

 

[mjlan]

You can't have your cake and eat it...

What was your 60' time?

I would think the easiest starting point would be adding more gear and a locking differential. How much rear tire do you have?

Jeff's (his user name escapes me) car runs pretty hard if I remember, he could probably give you some suspension pointers. Your issue will be getting that 429's grunt to the pavement without going up in smoke.

 

[Jeff73Mach1]

I don't know a lot that would be helpful as I am not familiar with your car. That being said to run mid 12's in a 3700 pound car you need about 450 horsepower and pretty close to perfect driving technique on the track.

My 2015 Mustang GT with no engine mods can run as low as 13.3 (so far) but that is me beating the hell out of it with the traction control turned off, but that engine lacks torque at the bottom end and it just is hard to launch consistently due to soft bushings in the rear suspension. My 73 is over 600 HP and has yet to run a true 1/4 due to fuel issues. My fuel pump just can't keep up. Larger pump, lines and probably a fuel cell are in the works. I did get an 1/8th mile run in at 7.285 but my reaction time was poor and I was running out of gas at the lights

Tires. You need good tires with lots of footprint to hook up and go fast. Stick shift cars typically run better with bias ply drag tires and tubes. Automatic cars do fine with the Drag Radials. I run drag radials and a stick and it is really easy to spin more than intended. More tire is more betterer. Tire pressure should be far lower than on the street.

Traction device- I like the Cal Tracs, but there are a ton of ways to do it. I like the Cal tracs because they are easy to adjust and don't result in changes to the car that can't be undone. If you don't have frame connectors, get them, the stress of a hard launch can twist the body.

Launch hard, leave fast you can't get those times unless you are driving the car hard. This means also that you are going to find weak links. Get a new driveshaft and yokes if you aren't already running at least a 1350 U joints and run the ones without grease zerk fittings, the fitting makes a weak point in the body of the u joint. Aftermarket axles get real close to necessary when you get to this power level.

lower gear ratios such a 3.89, 4.10 or 4.30 are just about entry level for drag cars.

Make sure you have a good rev limiter, esp if you drive a manual transmissioned car.

Lose weight, no need to have a spare tire in the car when you run, or anything else that you can leave out, like the passenger seat

Drag racing shocks do help with weight transfer, but I would not drive on the street with them-some people do and swear that it is not a problem.

 

[Duncan Mach72]

I will be putting the 351C back in over the winter. It now has 10.5:1 static cr with a Lunati cam of around 0.55" lift & 235 degrees duration with a Performer Air Gap & 750 or 850 Holley. It should run fairly strong I would think.

My thoughts on the 429 involve converting to 460, Icon flat tops for 11:1cr & a Comp Cams 274XE. But that will be later in 2018 or 2019.

I have been thinking about putting 3.89:1 gears in the rear as the tires I use on the track are Hoosier Quick Times in 275/60/15 which are over 28" tall. This would put gearing back to how it currently is on my street tires of 235/60/15 with 3.5:1. I can tell the difference in acceleration but it needs the QTs to hook. Maybe I should have bought 275/50/15 QTs.

60" times have been consistent around 2.3 seconds. I learned to baby the car off the line before getting the QTs and I have not dared dump the clutch hard yet for fear of twisting the smallblock size input shaft. I have a torque biasing diff.

 

[Jeff73Mach1]

Your launch is holding you back, though your reasoning is sound. Your 60 foot times should be down in the 1.6-1.7 range to get to the times you want. The toploader is pretty stout and while you might twist an input shaft it is more likely to would brake a u-joint. If you do not have a driveshaft safety loop, you need to get and install a good one before doing a clutch dump. A front u joint failure without a safety loop can cause the shaft to come up through the floor and cause horrific injuries.

I think your tire choice was fine.

 

[Duncan Mach72]

Thanks Jeff, some good advice. I do have a safety loop & Strange S/S 31 spline shafts. I also just bought a 1 3/8" input shaft to swap in when I change engine. I think I will take a look at the prop ujs. Cal tracs would be good I guess as all the 10 - 11 second Super Stockers use them round here. I didn't think my car would be fast enough to benefit much over ordinary traction bars. Frame connectors sound good.

 

[midlife]

Wouldn't the simplest, cheapest, quickest way to get lower times would be to use a shorter track? You'd be halfway there! Just sayin'...

 

[downwardspiral]

Wouldn't the simplest, cheapest, quickest way to get lower times would be to use a shorter track?  You'd be halfway there!  Just sayin'...

The math checks out  ::thumb::

What's the compression of the stockish 429? The simplest (on paper) ways would be more bang in the cylinders either by running the thinnest head gasket you can for a compression bump or getting a cheap nitrous kit. A small nitrous shot (<100 shot) is relatively safe on any engine, especially if you have less compression than desirable (I would assume you are in the 8-9 static CR range based on the ET).

 

[Jeff73Mach1]

Thanks Jeff, some good advice. I do have a safety loop & Strange S/S 31 spline shafts. I also just bought a 1 3/8" input shaft to swap in when I change engine. I think I will take a look at the prop ujs. Cal tracs would be good I guess as all the 10 - 11 second Super Stockers use them round here. I didn't think my car would be fast enough to benefit much over ordinary traction bars. Frame connectors sound good.

Just a thought, I'm still running a small input shaft transmission and have dumped the clutch more than a time or two.  So far no twisting issues for me.  I suspect your current power level is low eenough that you would be fine to give it a good hard run.

As to Caltracs, I think they are better, but that does not negate the value of other traction bars underide and slapper bars  work well for many people

 

[flstf09]

My first outing with my 72 this year wasn't as successful as I had hoped.My best run was 12.33 @110 mph lifting at about 1000'.I was launching very soft 60' were around 2 seconds.The 3.50 gear isn't a terrible choice if you are gonna go the 460 route.My car doesn't have any problem pulling a 3.50 gear.

Keep in mind a stockish 460 might not run as good as a stockish 429. Most 460s were smog Era and most 429s were pre smog as a rule of thumb.

What heads do you run?

 

[Hemikiller]

Considering the 60' time, I would focus would be on your traction and launch to start, not throwing more power at an already traction-compromised vehicle. FWIW, you can easily knock a half second off by just working on your launch to reduce your 60' times. See my buddy's 70 Road Runner's latest time slip below on the left, all footbrake. The car on the right was a brand new Hellcat.

Caltracs on a four speed car require very good shocks. A friend of mine is running them on his '68 (408W w/Aussie 302C heads) and has yet to get them tuned in to his liking. The friend with the '70 RoadRunner has an automatic and they work awesome with some 20 year old Competition Engineering drag shocks and superstock springs.

The smallblock input will twist behind a stout engine if you have traction. My buddy with the '68 had to replace his last winter. He was recommended by Dan Williams to switch to a fine spline hemi input and have his clutch disc resplined, rather than switch to the big input.

 

[Duncan Mach72]

My 429 is from a '69 Galaxie 500XL. It has C9VE heads with small chambers & flat top pistons which should give 10.5:1 from the factory. It was in good shape so I just re-ringed it & put in new bearings. I knocked the major lumps out of the exhaust ports & it has a cam of around .510" & 220 degrees @ .050". I have run both a 750vs & an 850dp on an Edlebrock Performer with ram air.

I agree that the car could launch quicker but that's only going to gain 0.5s at best. I want 1.3s more than that so I clearly need a lot more horsepower.

I have a 460 crank under my bench so the plan is to use that with Icon flat tops and Eagle SIR rods. I'd like ally heads but I'd like to win a few races on iron to prove a point with the Mopar guys. I will do a bit more porting on the exhausts now I have more information but probably leave valves at standard size. With a 274XE cam it should put me into the 450hp range as per the 'recipes' on the 460Ford forum.

Regarding toploader input shaft, I bought the 1 3/8" one and I already have an unused disc to fit. Traction is not a major problem now I have Quick Times.

Maybe I should bring it over to the States as it's widely known here in the UK that all your strips are downhill but ours are uphill

 

[iceberg65]

Awesome thread, from what I see by your mph the launch is holding you back a bit but not too terribly, my 4v OC cleveland ran 14.5 @99.8mph with a DA around 2700 (stock heads and bottom end, headers, torker intake ezefi throttle body) this year with worse 60' then you; I know that my main issue is tires (using cheap street 275's to get it running) Just that would probably get the Cleveland to around the same 14.1 right now I have to launch super soft or it just blows off the tires. Mine is an auto with stall though.

My goal for next year is to break into the 12's as well, not necessarily 12.5 but I want it to run at least what my Taurus does (12.7@110) my plan is to go to the CC heads with adjustable valve-train, a bit of port cleanup and new single groove valves which should up compression to near 10:1 and going to a solid flat tappet cam. I know thats what was holding my motor back as the hydralic cam in it is large but I dont have enough compression for it and it wants to have a power band higher then I want to rev the stock valve-train. Oh, and good drag radials. I also like the idea of getting a car running awesome on old iron heads.

So it sounds like a good plan to go about it getting some more power out of the 429 should be easy enough, the bit of extra port work and camming for more top end; paired with a bit more aggressive launch should be able to cut a lot of time off. Heck I cut over a second off my car from the first race to the last on just tuning items (mostly ignition stuff). If it still needs a bit of extra help their's always nitrous

 

[Duncan Mach72]

I do know of a nitrous kit that is currently redundant & I may be able to buy it for a good price. But I race the Mach1 in a dial your own handicap class so I'd rather have it just on the motor. I don't want to start breaking stuff as I drive it 50 miles to the track & back.

 

[c9zx]

I'm assuming you have appropriate headers. The performer intake and the stock heads are really holding the power production down. If you've been on the 460 Forum you have heard of "Reincarnation Automotive". It is not hype, his heads work well. If he could source the cores (saving some shipping costs) and do the porting as well as an appropriate valve train for your cam, the cost would be far less than building another complete engine. Everything that has been said about the chassis, suspension, and tires should be taken to heart as well. If nothing else try an Edelbrock RPM or RPM Air Gap intake and see if things improve.

   The Dan Williams piece will hold up assuming the rest of the trans is up to par. I used one in my Cougar for many years, 7400 RPM shifts with the 306, 6600 RPM shifts with a 405 Clevor. Below is a link that you may find helpful. I would love to see you spank the Mopar guys and send them on their way. Chuck

http://www.tciauto.com/tc/racing-calculators/

 

[Duncan Mach72]

I have FPA headers installed.

I recently subscribed to the porting info on 'Reincarnation'. I ported the C9VE heads about 25 years ago from info in the Ford Performance book by Pat Ganahl. They do need a little more work but they are nearly there. Given shipping expense etc It's probably best to do it myself or buy some FRPP SCJ heads or John Kaase P51. However I've crippled my own budget by becoming owner of a comp altered dragster!

I already have bronze valve guides & new dual valve springs (Comp 924-16 I think) in stock. They would suit my proposed Comp 274XE cam. The engine really needs a rebuild for performance use as it has one odd replacement piston & is not properly balanced.

I did think the Performer might be an issue, it's definitely a step up on the current build over the original small port Torker I was running. I think the current Torker may be best if I want to retain ram air otherwise I'd get a Perf Air Gap.

 

[TommyK]

The cam you intend to use is not a good match for the heads you have. The cam needs a lot more exhaust duration. The owner of the Reincarnation site you are referencing for porting instructions can spec you a cam that will get you to your goal. The Torker 2 intake will be adequate for what you want to do.

 

[Duncan Mach72]

CheersTommy, that sounds like good advice. As a matter of interest, what rpm does your motor pull to?