Author Topic: Finally got the 68 1/2 pure stock Mustang coupe out to the track  (Read 16423 times)

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Offline Bigfoot

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #30 on: November 02, 2015, 08:58:28 am »
Nice job. I'd love to get mine out there.
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Offline 428 CJ hardtops

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #31 on: November 02, 2015, 10:05:17 am »
I clamped the front half of the leaf springs ,no traction bars and 18 lbs of air. Lowered it to 16 but never had the chance to make another pass . Been wondering why the car leaves softer than I want even though the 1/8 miles times are still a good 7.77. The carb was rebuilt and installed with a quick change vacuum secondary .Wonder if that spring is to stiff , normally run a light purple one .Will check and see if that helps. The weekend is looking good weather wise so may try and see if it will run better .
had many 428 CJ and SCJ cars over the last 30 years.I currently own a 68 1/2 coupe and a 69 R code SCJ Coupe and a 70 R code SCJ Cougar Eliminator .I am looking for a 70 428 coupe if anybody knows of one for sale.

Offline 69mustangSCJ

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #32 on: November 02, 2015, 12:15:21 pm »
Traction bars aren't allowed in this class of racing as I'm sure Steve knows, at least not on the leaf spring cars anyway.  Yet they allow no hop bars on the coil spring cars which boggles me, since that is technically a traction device (I use them on my chevelle to plant the rear tires)

I've tried clamping the front of the leaf springs before on my bird and had no better results, car rode stiffer was about all that accomplished for me.  I found mine worked best with loose suspension, but every car is different.   My best 60 foot on the F70-14's was 1.89 while only running 3.31 gears, but I'm sure guys now are doing much better than that.  I'm hoping the SCJ will do better in the 60 foot department but that car is so nose heavy with no rear overhang it's at a bit of a disadvantage compared to other models in the class.  They allow one size bigger on tire and I noticed you took advantage of that.

Offline 428 CJ hardtops

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #33 on: November 02, 2015, 12:58:21 pm »
I have had a bunch of 1.70's 60 ft times with my 69 R code Coupe all with G-70 -14 repo tires . You have to use everything they give you .It had the front half of the leafs clamped .On tires to get the best out of them we take a new set to the tire retread shop and grind half the tread off. It sounds bad but the tires in a max effort attempt need it and its cheaper than track time and engine wear .Like I said before anyone that has any questions I will do my best to help. We need more Fords out at the races .
had many 428 CJ and SCJ cars over the last 30 years.I currently own a 68 1/2 coupe and a 69 R code SCJ Coupe and a 70 R code SCJ Cougar Eliminator .I am looking for a 70 428 coupe if anybody knows of one for sale.

Offline 69mustangSCJ

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #34 on: November 02, 2015, 02:09:28 pm »
Completely understand and for good reason.  I know the really fast examples of certain cars exploit anything they can.   I always left some on the table with mine, mainly for drivability reasons because they serve double duty for us.  Always want/need to run pump gas and keep the rear gear mild, not too many suspension tweaks that would affect daily drivability etc...so I was happy with the 60 foot on that car, it's always worked decent for what it is.

The SCJ is in the same boat, engine is going pump gas, I'll leave the 3.91's since that is what it came with but I likely won't go to the effort of suspension changes simply because it's an unrestored car and I'm not willing to dive in and change major components.  I'm not even touching the original trans or converter other than a reseal because it works perfectly as is.  My only big advantage over a bone stocker is that I will go with the allowed 2 1/2" exhaust system upgrade because the car needs exhaust anyway.  But I prefer to keep the factory transverse muffler (without the resonators in front) and that's been one of my hang ups.  Can't find a mandrel bent 2 1/2" system with the transverse muffler for this car.  All the aftermarket stuff is dual muffler.  The dynomax setup has the closest muffler configuration (correct in and out) in order to build the tailpipes correctly, so I may go that route.
   Anyway, with more gear and more power in the SCJ than the bird ever had, I would like to think I can better my old 60 foot times but it depends on weather and track prep.  We'll see.

Ooo, something else I can't bring myself to do is to shave half the tread off a brand new set of $1000 tires, wife would shoot me, lol.  I'll live with slightly less traction and just have some fun.  ;)    One of these days if I don't run out of time I'd love to buy/build a car purposely for this and take advantage of everything they give you. 
« Last Edit: November 02, 2015, 02:16:12 pm by 69mustangSCJ »

Offline 428 CJ hardtops

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #35 on: November 02, 2015, 04:05:28 pm »
I would sure go with the aftermarket muffler .Years ago I ran a flowmaster transverse meant for a Grand National Buick. It would be a nice improvement over stock.
had many 428 CJ and SCJ cars over the last 30 years.I currently own a 68 1/2 coupe and a 69 R code SCJ Coupe and a 70 R code SCJ Cougar Eliminator .I am looking for a 70 428 coupe if anybody knows of one for sale.

Offline 161854

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #36 on: November 02, 2015, 04:42:48 pm »
     Cutting the tread down reduces tread flex that leads to loss of traction . Cutting early rather than wearing it down keeps the tread softer for better "bite" as well. Thousands of miles of use and heat cycles releases many of the resin compounds needed for better traction. Goodyears are known for very hard treads as they age.
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Offline 69mustangSCJ

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #37 on: November 02, 2015, 05:49:21 pm »
I would sure go with the aftermarket muffler .Years ago I ran a flowmaster transverse meant for a Grand National Buick. It would be a nice improvement over stock.

Yeah, I experimented with them on the firebird (same style system really)  Picked up 3 tenths and 3 mph taking the stock walker system off and using the flowmaster force II transverse kit (all that was available aftermarket at the time)  Now run a Pypes transverse system on that car with an "X" instead of an "H" to see if that might be worth something.
  Actually been talking to Pypes off and on for 2 years, they want to design a transverse system for the mustang but need something to mock it up with, the stagger shocks pose a problem for them on the 4 speed cars, and a system needs to fit both auto and stick before they'll produce it.  Anyway, I'll make something work when I get to that point.

Offline 69mustangSCJ

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #38 on: November 02, 2015, 05:51:25 pm »
     Cutting the tread down reduces tread flex that leads to loss of traction . Cutting early rather than wearing it down keeps the tread softer for better "bite" as well. Thousands of miles of use and heat cycles releases many of the resin compounds needed for better traction. Goodyears are known for very hard treads as they age.

Exactly why the original polyglass reproductions work so well to begin with.  Radial tires have a ton of tread squirm.  I've went back and forth on the bird, it always ran more consistent on the polyglass. Besides they just look right anyway.

Offline 428 CJ hardtops

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #39 on: November 05, 2015, 05:45:59 pm »
Going back to the track on Saturday .High 50's and sunny .Tried to switch vacuum secondary springs but already had the purple one in the 68 car. So just switched carbs the one on the 69 always would leave hard so we will try it and see if it will launch harder. Will take it down the road tomorrow and see how it feels .It should be capable of a sub 1.80 60ft time this carb has done it before .Time will tell.
had many 428 CJ and SCJ cars over the last 30 years.I currently own a 68 1/2 coupe and a 69 R code SCJ Coupe and a 70 R code SCJ Cougar Eliminator .I am looking for a 70 428 coupe if anybody knows of one for sale.

Offline 428 CJ hardtops

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #40 on: November 06, 2015, 04:10:56 pm »
The carb off the 69 car made the car come alive .Feels like the other carb didn't have the secondary's opening up ,but I know they were .Car felt much stronger and responsive .The track will tell but I am all smiles .
had many 428 CJ and SCJ cars over the last 30 years.I currently own a 68 1/2 coupe and a 69 R code SCJ Coupe and a 70 R code SCJ Cougar Eliminator .I am looking for a 70 428 coupe if anybody knows of one for sale.

Offline chris

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #41 on: November 06, 2015, 04:58:16 pm »
Nice! Keep us posted!
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Offline 428 CJ hardtops

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #42 on: November 07, 2015, 09:42:22 pm »
Got back out today .Mid 50's and partly cloudy good air but wish the track surface would have been warmer . With the other carb now there is more bottom end power than can be used unlike the other one that seemed near maxed out. First pass was a 12.13 at 113.20 a 1.90 60ft .Next tried a bit harder on the launch and went a 12.01 at 113.75 with a 1.83 60 ft time. Let it cool down and went a 12.01 at 113.75 again with a 1.80 60ft and 7.70 in the 1/8 mile at 91.24   .Let it cool added 100lbs to the trunk launched harder but spun and went 12.05 at 113.18 .    It now has more power than can be handled instead of not quite enough . Have to figure out how to find a compromise . Maybe a bit less timing or change the plastic cam on the side of the throttle arm that actuates the accelerator pump .Close but not quite there but the horse power is there waiting to be harnessed.
had many 428 CJ and SCJ cars over the last 30 years.I currently own a 68 1/2 coupe and a 69 R code SCJ Coupe and a 70 R code SCJ Cougar Eliminator .I am looking for a 70 428 coupe if anybody knows of one for sale.

Offline CJ-GT Coupe

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #43 on: November 08, 2015, 12:10:38 am »
Great times Steve, been waiting all day to see your times.  You have that CJ on the verge of running with those pure stock "Big Dogs"  L-88, ZL-1, 426 Hemi's.  Very impressive considering you had to start with an engine made from the parts bin at Ford.  Good luck on getting into the 11's.  WOW!
« Last Edit: November 08, 2015, 10:07:00 am by CJ-GT Coupe »
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Offline Bigfoot

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Re: Finally got the 68 1/2 pure stock Mustang coupe out to the track
« Reply #44 on: November 09, 2015, 08:39:46 pm »
You can do it!
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