Getting ready to pull the trigger on buying G Force 101A

[Rory428]

Rory, the comparisons between the two transmissions is very helpful. The handcuff on the G101A is what drew me to it. Some of the “make it work” items are a concern however. I don’t plunk down 5K on anything so need to get this right the first time,(hopefully). It is good to hear for all the DR-4 guys that Jerico is making parts.
Dale, thanks also.

I had been encouraged for years to make the switch to a G101A for years, by a local MoPar racer who races a mid 8 second SS/AH 68 Hemi Cuda, as well as a SS/D 71 Hemi Cuda that ran mid 9s, and also was raced well into the 8s with a 540 inch B1 Wedge engine. He was breaking his Jericos constantly before he made the switch to the G Force. And he considered the "handcuff" a significant benefit. That said, although the G101A likely has more inherent strength, I think the old DR4 is perfectly adequate for mid 9s in a 3200 pound or so car, with a properly setup race clutch.

Peter Wille? Did he convert the 71 Cuda to Super Stock now?

Yes, Peter used to run the Cuda in SS/D, then put the B1 engine in the car several years ago. He has had a new Ray Barton Hemi to put in the 68 SS/AH car for quite a while, and was going to put the Hemi from the 68 into the 71 , with the correct "Street Hemi" components switched over. But when I talked to him a few months ago, he is so busy with his MoPar collection and his own engine dyno, neither car may see the track anytime soon.

[Posi67]

There is nothing whisper quiet about a trans with straight cut gears and dog faced sliders. LOL. Jerico told me 20 years ago. The harder you beat on it, the longer it will last.

No kidding..  Kill the engine and put the clutch in and you'd swear the trans is toast. Both my Jerico's are Mag case top and bottom loaders and the one in my car hasn't had the cover off in more than 5 years. I did break parts in my first one and after the second time I know why and it involves the guy pulling the stick. The handcuff idea is good but not worth the $$ if your budget is tight and you're not running a big tire car into the 9's. I also use the clutch on the gear change which many don't. Also no 3rd gear burnouts with a Jerico will lengthen it's survival rate.

[Posi67]

Rory, the comparisons between the two transmissions is very helpful. The handcuff on the G101A is what drew me to it. Some of the “make it work” items are a concern however. I don’t plunk down 5K on anything so need to get this right the first time,(hopefully). It is good to hear for all the DR-4 guys that Jerico is making parts.
Dale, thanks also.

I had been encouraged for years to make the switch to a G101A for years, by a local MoPar racer who races a mid 8 second SS/AH 68 Hemi Cuda, as well as a SS/D 71 Hemi Cuda that ran mid 9s, and also was raced well into the 8s with a 540 inch B1 Wedge engine. He was breaking his Jericos constantly before he made the switch to the G Force. And he considered the "handcuff" a significant benefit. That said, although the G101A likely has more inherent strength, I think the old DR4 is perfectly adequate for mid 9s in a 3200 pound or so car, with a properly setup race clutch.

The difference between Peter and most mortals is he has almost unlimited $$$. Trans in the car, spare in the trailer and at least two getting a rebuild. He was also real tough on clutches where the rest of us get to go a season or more. The SS/D car is still on the "talking" board although has everything needed. Smart move there would be put a Liberty in the car.

[6667fan]

I found a guy who will build me a DR4 with the input I want and gear ratio of my choice. I’m considering this route over buying a new DR4-4. As I have two Ford top-loaders with the big input I’m planning on staying with that for any Jerico I end up with.
Next question will be which first gear ratio to go with. When I was discussing a 101A with G Force /Long they spec’ed 3.17 for my car. (I told them my goal was to get car into the 10s). Doug Smith shared his favorable opinion of the 3.19 in his car and that is the direction I’m headed unless I get talked out of it, (thanks, Doug). Even IF that low gear is a short for the Street I don’t care. It would be just one more street use compromise on the path to making car quicker.
I would love to hear about that gear choice and if I need a top/ bottom loader case Jerico vs a round bottom one.

Thanks much.

[Joe-JDC]

With your 4.57 gears, you will be at 14.487 gear ratio in first gear, and that is way too deep for any street usage.  Like several others have indicated, you will be quicker and faster with around 11.0-12.0 ratio in first gear.  JMO, but I had 4.57 gears in my Mach I, and ran 10's with 2.64 first gear.  Joe-JDC

[Posi67]

My car is lighter than yours but I think the 3.19 is too much. My first trans is a 2.98 which is what Jerico suggested and the other is a 3.03 just because that's the way it came. Currently have 4.57 rear gear with 28 or 29" tall tire. Have also run a 4.86 but I'm out of RPM now as it is. I like the flat bottom case mostly because I can set the trans on the floor jack to help me get it in place.

[Nightmist66]

JB, I feel you should be able to accomplish the 10 sec pass as-is. If you get your shifting problem sorted out, it should be in the bag. Your speed is already there. If you get a good launch and decent shifts, then I don't see why you can't do it. I'm wondering if the interlock pin is broken or missing. Very small, but very important piece. Anyway, the Toploader in my beater was gone through shortly before I bought it. I swapped the guts to my case and tailhousing, just because I liked them better and the shifter location I needed on my tailhousing. The trans was in a car that ran somewhere in the 9's. I don't think I will have any issues with my goal. The only thing that will possibly cause me an issue is the aggressive clutch. Some will say the Toploaders are only good for door stops or wheel chocks, but some people could break a bowling ball in a sandbox.

[Rory428]

Supposedly the round bottom Jerico case (top cover only) is stronger than the top & bottom cover versions, which does made sense, since the bottom is solid. That said, I have never had any case issues with either of my top & bottom DR4 cases, other than the time broken parts got caught between the main and cluster gears, but that is hardly regular stress load. As for gearing, if you have the traction, more gear should always get the car moving quicker. On both my Jericos, as well as the G Force, I used 3.19 low gears, along with 4.88 and 5.13 rear axle ratios. My Fairmont normally runs 13" wide slicks, always dropping the clutch at 6000 RPM or higher. My 85 Mustang ran the same trans and axle ratios, with 9" wide slicks, but with a weaker small block, but both cars left well, best of 1.29 60 foot in the Fairmont, 1.34 in the Mustang. My first Jerico came with 2.93 low gear, switching to 3.19 helped the launch , and the wider ratio drops never hurt the performance anywhere down the track.But if traction is an issue, a lower first will just make matters worse. Both my Jericos, as well as my G Force, use the popular 1 3/16"x18 MoPar Hemi spline input shafts, with Ford length and pilot sizes.Since I did not have a big spline Toploader clutch fork , it made sense to use the MoPar spline, as it allowed me to use a small input fork and throwout bearing, as well as free up a little room inside the bellhousing.

[6667fan]

Jared, I did a test where I put the trans in second via the shifter and then went under car and attempted to move third or fourth gear and switched the test with putting trans in third via shifter and attempted to move first or second via the shifter arms. I could not move arms in either test which tells me interlock pin is intact. I considered draining oil and would have if interlock test failed. Third gear shifter stop was a little tight, don’t know if that is responsible for trans not staying in third. No problems with it staying in third on the street but street speeds are not the same as the speed at track plus tire spin occurs on street tires. I don’t feel like I can keep trying it at track, even with clutch pressure reduced. The toploader has to go. Maybe the Liberty face plated third gear is off center, just don’t know.

Rory, I might have a chance to grab a G Force with a 2.92 first. I don’t have enough passes on the car to really speak to traction problems so don’t know if a low first like 3.17, ( G Force), or 3.19, ( Jerico), will help or hurt me.

Thanks much guys.

[cjshaker]

With your 4.57 gears, you will be at 14.487 gear ratio in first gear, and that is way too deep for any street usage.  Like several others have indicated, you will be quicker and faster with around 11.0-12.0 ratio in first gear.  JMO, but I had 4.57 gears in my Mach I, and ran 10's with 2.64 first gear.  Joe-JDC

When I bought my used Jerico, it already had the 3.19 gear, and it was used in a FE Fairlane drag car. I already had the 4.30 gears in the car and was still having a terrible time with traction with the 2.78 toploader. With the Jerico change, I picked up 4 mph and went from a best of 12.28 to 11.51 on my first full 1/4 mile pass. That's a 13.7 1st ratio (Jared, I misstated my 1st gear ratio in your 1/4 mile post). It also made taking off at stop lights much easier, so I don't believe that a 14.4 is "way too deep for any street use". If anything, it saves a lot of clutch life during street use. Sure, you're shifting into 2nd quick, but once the car is moving, it's a non-issue.

The Jerico may have masked some of my traction issues, and it may not be ideal for my current combo, but the car gets off the line without issue now. It may not be the ideal gear for JB either, but it will make a big difference, and he can always change his rear ratio as time and money allows. Or he can simply get a new 1st gear set. You have to start somewhere. Of course if he were buying new, he can spec whatever 1st gear he wants. For $2000 less than new, I can live with the 'compromise' for now..lol That $2000 can buy me a lot of gear changes.

SS and class racer guys can spend the money to fine tune their combo to a perfect state, but most of us are just making changes as money allows, to make our car better, or more fun, and are far from our 'ideal' set-up. I've noticed that there can be a LOT of different gearing combos, in similarly built cars, that basically run the same ETs. That tells me that, given good traction, and gearing that puts you where you want to be at the finish line, a cars ET is basically set by its horsepower and weight.

I've rambled on long enough

[Rory428]

Doug, HP & weight mainly determine the MPH not the ET. The ETs drop as you get closer to optimum setup, but MPH can pretty much remain the same. Many dual purpose street strip type cars can be over a second away from their true potential due to compromises, bad choices, poor setup, or driving ability.

[cjshaker]

You're absolutely right, Rory. I had my brain in reverse when I typed that

I was surprised when my MPH went up with the Jerico change (+4 mph). The only thing I can attribute it to is that the first 60' wasn't being wasted to tire spin or bogging.

[My427stang]

I work on a liberty shifted Chevelle super T10, 10.99 car, it has a 4.33 and a 3.43 1st for 14.85 or so. It gets quicker and quicker the lower the launch and 1-2 shift RPM

Tore the ear out of it and scared him, so he stopped for a bit but it was wild, 3000 launch, 4500 1-2, then 6500 2-3 and 3-4.