GForce Engineering fully-fabricated 9” IRS With modified cradle

[Ta2ude]

 

[Ta2ude]

Well it has taken a while but I finally got to the track and made my first runs, 8 to be exact. Between the weather and waiting for some parts it was a later start than I had hoped for, but I finally got some passes in and things went as good or even better than expected.
Nothing broke, the car went nice and straight down the track and it hooked up really well with zero wheel hop issues.
I did spin the tires off the starting line on my 3rd pass but that was a rookie mistake on my part because I had completely forgot to check my tire pressures between rounds until my track neighbour, who was kind enough to answer my rookie questions throughout the weekend, brought it up just before my 4th pass and when I checked they had climbed to about 23 psi. I dropped them down to 18 psi and made my best pass of that day.
We got to the track Friday afternoon because they were doing a test and tune, but typical for this summer it got rained out.
They were only doing 1/8th mile runs this particular weekend so no 1/4 mile times yet but it was a good way of getting my feet wet I guess. It was also bracket racing and I realized I have some learning to do there as well.
This was actually the first time I have ever taken this or any other car down an actual drag strip, so mistakes were made. lol.
My first pass was pretty slow because I launched like I would on the street, expecting it to spin but the car hooked up nicely and went straight. My second pass I red lit by -.0189 and did a 6.99 in the 1/8th mile and used that number for my dial in , my third pass I spun the tires and got put out and my fourth pass, which was a buy back, was actually my best reaction time of the weekend at .0310 a 60’ of 1.538 and a 1/8th time of 6.885 which put me out for going too fast.
Sunday we got one test pass and I red lit trying to hold the brakes and get my launch rpm up a little. I dialed in at 6.88 but broke out again and was put out first round. I did a buy back and won my first round ever when the guy red lit by -.001, I got lucky. lol My next pass I got put out for going too fast again but I was still happy because it was my best 60’ and 1/8 th mile time of the weekend.
Ultimately I know these aren’t the most impressive numbers out there but it was still a lot of fun for me and I am sure they will get better with more experience.
When I first started this thread I had some people shitting on me for not following the advice I was given here and I went ahead and bought the used Gforce cradle and installed it anyways. I will be honest and say I did have some unexpected issues with the stuff as I had to buy new ring and pinion gears and get them installed and I bought a new driveshaft as there was a vibration issue but as I noted way back in the beginning of this thread, there was also a small groove in the driveshaft which honestly had bothered me from the time I noticed it anyways, so now I don’t have to worry about that anymore.
All in all though I still believe I got a good deal on the parts and they seemed to do what they were supposed to, get the car to hook up and eliminate the wheel hop issues. Hopefully it holds up for a while now and I can get some more track time in and work on my reaction times and develop a routine.
Lots of fun and smiles were had by everyone.
Here are some time slips, I am car #2019
Pass 4 day one


Pass 3 on day two and my first Win !


Pass 4 on day two with my best 60’ and 1/8 th mile times.

Some tire wrinkle at the line


Back in the driveway.

 

[1971demon]

Well it has taken a while but I finally got to the track and made my first runs, 8 to be exact. Between the weather and waiting for some parts it was a later start than I had hoped for, but I finally got some passes in and things went as good or even better than expected.
Nothing broke, the car went nice and straight down the track and it hooked up really well with zero wheel hop issues.
I did spin the tires off the starting line on my 3rd pass but that was a rookie mistake on my part because I had completely forgot to check my tire pressures between rounds until my track neighbour, who was kind enough to answer my rookie questions throughout the weekend, brought it up just before my 4th pass and when I checked they had climbed to about 23 psi. I dropped them down to 18 psi and made my best pass of that day.
We got to the track Friday afternoon because they were doing a test and tune, but typical for this summer it got rained out.
They were only doing 1/8th mile runs this particular weekend so no 1/4 mile times yet but it was a good way of getting my feet wet I guess. It was also bracket racing and I realized I have some learning to do there as well.
This was actually the first time I have ever taken this or any other car down an actual drag strip, so mistakes were made. lol.
My first pass was pretty slow because I launched like I would on the street, expecting it to spin but the car hooked up nicely and went straight. My second pass I red lit by -.0189 and did a 6.99 in the 1/8th mile and used that number for my dial in , my third pass I spun the tires and got put out and my fourth pass, which was a buy back, was actually my best reaction time of the weekend at .0310 a 60’ of 1.538 and a 1/8th time of 6.885 which put me out for going too fast.
Sunday we got one test pass and I red lit trying to hold the brakes and get my launch rpm up a little. I dialed in at 6.88 but broke out again and was put out first round. I did a buy back and won my first round ever when the guy red lit by -.001, I got lucky. lol My next pass I got put out for going too fast again but I was still happy because it was my best 60’ and 1/8 th mile time of the weekend.
Ultimately I know these aren’t the most impressive numbers out there but it was still a lot of fun for me and I am sure they will get better with more experience.
When I first started this thread I had some people shitting on me for not following the advice I was given here and I went ahead and bought the used Gforce cradle and installed it anyways. I will be honest and say I did have some unexpected issues with the stuff as I had to buy new ring and pinion gears and get them installed and I bought a new driveshaft as there was a vibration issue but as I noted way back in the beginning of this thread, there was also a small groove in the driveshaft which honestly had bothered me from the time I noticed it anyways, so now I don’t have to worry about that anymore.
All in all though I still believe I got a good deal on the parts and they seemed to do what they were supposed to, get the car to hook up and eliminate the wheel hop issues. Hopefully it holds up for a while now and I can get some more track time in and work on my reaction times and develop a routine.
Lots of fun and smiles were had by everyone.
Here are some time slips, I am car #2019
Pass 4 day one
View attachment 184674

Pass 3 on day two and my first Win !
View attachment 184675

Pass 4 on day two with my best 60’ and 1/8 th mile times.
View attachment 184676
Some tire wrinkle at the line
View attachment 184677

Back in the driveway.
View attachment 184678

Good stuff...glad yer havin fun..amazing cars aren't they

 

[Marc W]

Some words of advice from doing this for years now. I got my best 60's running the M/T Radials at 20.5 lbs. That was with my suspension setup but regardless.... when you wrinkle the sidewall like that with these radials, it damages the tire and performance will go away before even get to the wear bars. You can see in the picture that the contact patch is nice and flat and hooking without sidewall flex. It ran 1.2 sixty's with 5.2 in the 1/8 mi and 8.2 in the 1/4.

 

[Ta2ude]

Some words of advice from doing this for years now. I got my best 60's running the M/T Radials at 20.5 lbs. That was with my suspension setup but regardless.... when you wrinkle the sidewall like that with these radials, it damages the tire and performance will go away before even get to the wear bars. You can see in the picture that the contact patch is nice and flat and hooking without sidewall flex. It ran 1.2 sixty's with 5.2 in the 1/8 mi and 8.2 in the 1/4. View attachment 184783

Thanks for the information, I really wasn’t sure what air pressure was best and went with Googles advice. I will try 20.5 psi next time I am at the track !
Are you running 15” or 17” wheels and tires?
Awesome looking car by the way !

 

[Marc W]

Thanks for the information, I really wasn’t sure what air pressure was best and went with Googles advice. I will try 20.5 psi next time I am at the track !
Are you running 15” or 17” wheels and tires?
Awesome looking car by the way !

15" with a 315 on a Dragpak 4-link suspension. Not a reasonable comparison I know, but..... if you're wrinkling the sidewall like that, it's too low for a radial. Like I said.... that will damage the sidewall to where you'll loose the sidewall support you need to make the tire work. Trying different pressures sometimes is necessary. What will work for you on a given day/condition may vary a little. Thing about radials compared to slicks is... they like sticky prep. They like to dead hook and drive the car forward without spinning the tire. The frustrating thing about that is, if the prep is not there, radials don't work for shit on heavy high hp cars like Hellcats. Also, on your driveshaft.... you need to keep the heat from the exhaust off that. CF will cook and fail if you don't.

 

[Ta2ude]

Also, on your driveshaft.... you need to keep the heat from the exhaust off that. CF will cook and fail if you don't.

Thanks again for your input, it’s appreciated.
The heat was definitely a concern of mine and I raised that question with the guys at GForce. I’m not sure how true it is but they said they have been working on that issue for a while and apparently they employ a significant amount of a “press fit” when installing their ends as well as a bonding agent to help alleviate this. They also said they are currently developing their next generation of driveshaft. Could be bullshit I don’t know ?
I actually bought another factory heat shield, like the one already on the car, and with some minor modifications it fit in front of the factory shield and covered the driveshaft right up to the transmission. As well I bought a roll of DEI titanium exhaust wrap and did the exhaust. Not sure what else I could do to control the heat ?
I don’t drive the car a whole lot on the street and I live in the country so stop and go traffic isn’t an issue. It’s usually 1/2 hour drive into town with the wife for dinner or groceries and cruise the beach.
I put the car up on the hoist and checked the temperature of the driveshaft and area with a laser thermometer probably 10 different times after various drives and never got a reading even close to the 300 F that is apparently the danger zone. I guess only time will tell.
I called several different driveshaft shops before I pulled the trigger and there was a general consensus that they have all had problems with these cars.
A few of the shops said they don’t even make driveshaft’s for these cars anymore as they have had so many issues. Mark Williams is one of those shops I called as I was even considering dropping the extra $$ for their 2 piece design but they don’t make them anymore.
The GForce guy said “ you don’t want to be in the driveshaft business “ lots of problems.
So hopefully it doesn’t fail but at least if it does it won’t tear my car apart.