GTA Camaro to NASA ST1

I have a similar bar that bolts to the (really beefy stock) bumper supports for the tow hook. The hook saved me from serious damage once when the door/ramp broke off my trailer. Car landed on the hook hitting the trailer frame, not a mark on the car. Bent the hook but that was a small price to pay.

[URL=https://app.photobucket.com/u/NOTATA/a/e82b0b84-eea5-469e-9226-9a2b47ccf6eb/p/5f2ed29c-1323-48b9-ad12-5735c289bb83][/URL]

[URL=https://app.photobucket.com/u/NOTATA/a/e06d8faf-6076-4b92-a2c2-6fb841f282a7/p/37c2f252-6909-483d-a6ac-4f6cbb169be1][/URL]

In reply to NOT A TA :

Wow! That's really lucky!

You just made me realize...the bumper is a bolt-in unit. I'll never really looked to see if it can be removed without removing body parts. I have a feeling it can. I just assumed the nose is riveted to it somewhere but, now that I think about it, maybe not.

Of course, I just invested about $20 in Tractor Supply parts to make a spiffy tow hook that will bolt through a 1/2" hole drilled through the bumper. I'm going with that unless it's a complete fail. If it comes out okay, I'll post up what I made. Otherwise, it will go into the scrap bin, never to be spoken of again.

You like apples? How d'ya like them apples?!?

Ingredients:
1 - 1/2" x 4" grade 8 Bolt
1 - 1/2" grade 8 nut
1 - 1/2" lock nut
1 - 1/2" chain shackle (stainless steel)
1 - small piece 1/2" plumbing pipe
1 - small piece 3/4" plumbing pipe (to wrap the 1/2" piece to make it thicker)

Use a 1/2" thread die to cut more threads on the bolt. Cut the pipe pieces to fit between the ears of the shackle. Weld the 1/2" pipe piece to the head of the bolt. Split the 3/4" pipe, smash it over the 1/2" pipe and weld it together. Grind everything until acceptably smooth. Use a 5/8" drill bit to smooth out the bore of the 1/2" pipe which really has an inside diameter of 5/8".  Spritz with some black paint. Profit.

Now I just need to work up the nerve to drill through the body and bumper.

Tow hook deployed!

Pay no attention to the extra hole that you probably can't see because I made sure the lighting was favorable.

Get some bright paint on that clevis.  Us EV guys on a hot track like the extra visibility :). 

HalfFast said:

Get some bright paint on that clevis.  Us EV guys on a hot track like the extra visibility :). 

What's your preference? Kubota orange or John Deere yellow?

jimgood said:

HalfFast said:

Get some bright paint on that clevis.  Us EV guys on a hot track like the extra visibility :). 

What's your preference? Kubota orange or John Deere yellow?

The brightest.  Most are red, so my vote is orange :) 

You haven't lived till you do a hot pull and there is no hook (or you can't find it)

In reply to HalfFast :

I'm sure that's annoying and time consuming.

I'll make a run to TS again and get some etching primer and paint.

Had a blast at Summit Point. Ran two sessions on Friday with a fast time of 1:22.411, which is really slow for the capabilities of this car. I got third in TTU out of seven cars with that, just edging out jh36 in his blue Camaro by a couple of hundredths. Were it not for having more power than him I'm sure our positions would have been reversed.

Biggest issue on Friday was an oil leak from the rear diff. It started in the first session but the only thing I noticed was a drip line on the gravel right below the rear of the fuel tank. I chalked it up to having used water to wash down the rear window. But coming back in from the second session, oil leaking fast and continuing to pour out after I parked in the paddock.

Once I got under there, I could see that 6 out of the 10 nuts holding the diff cover in place where gone. That is something I should have checked but did not. Thankfully, the nuts are a standard size 3/8-16 (thanks to HalfFast for looking that up for me and being available via email) so I did some running around to find some lock nuts and some 75w90 synthetic gear oil. It took nearly an entire gallon to refill the diff.

The other stupid thing I did was not taking the cover off the diff to check what gears are in there. At this point, I'm still assuming 4.11. I'll get to it when I get replacement nuts.

Thanks to Ed for getting this shot. 

Ed also got these:

Jack broke a U-joint in that same session so he was out for the rest of the weekend. On Saturday, without Jack to chase, I was running about a second slower. In the second session, I was going into T1 on lap 3 and jammed something up in the transmission while trying to downshift to 2nd. I was able to limp it into the grass well off the track and got towed back after the session was over.

I was sure the trans was finished but a friend of Jack's stopped by that is familiar with these and said sometimes they can get stuck in two gears at once. Said to get under there and take a look. With Jack in the car moving the shifter and me underneath looking at linkages about which I have no clue, we determined that the forward shift lever was jammed. So used a pry bar with a hammer to smash on it and it broke free. I did not run another session but it seemed to go into reverse and first gears fine while positioning it to load on the trailer.

Ed had a tough time. I'm sure he'll give the details in his thread. Here's his car after "repairs." Jack (sunglasses) is conveniently covering the roof damage. Damn! That windshield is so clean I can't even see it!

Here we are going pathetically slow through T10.

https://rumble.com/v11bbin-gta-camaro-through-t10-at-summit-point.html

After jh36 had his driveshaft failure, I was thinking it would be good to know ahead of time what the dimensions of my driveshaft are in case I have a catastrophic failure such that it cannot be measured directly. The only reference I found for measuring overall length said to measure between centers on the bearing caps at each end. That's seems like the most logical measurement.

All the other references I saw go on the assumption that you are starting with no driveshaft and are measuring between the trans and diff yoke. That's all well and good but I think it would be easier to just directly measure the driveshaft now, before it's broke.

As an example, one can order a driveshaft by length but most places don't say how it is measured:

https://www.summitracing.com/parts/qtm-188431

Does anyone have other ideas or does center to center on the bearing caps sound right?

When I ordered mine today (Coleman Racing) they went off center to center of the universals. I've seen other ways of determining it, but since you have an intact shaft, that's the answer. 

In reply to jimgood :

Measuring from the face of the yoke (which is the center of the U-joint) is the only way I have ever heard.  Here is a link describing the process as I have always done it.   Quartermaster Drive shaft measurment and www.drivelinesnw.com/measure/

Personally, I would measure both the car, and the current shaft so you can verify it is indeed the correct length.  Trust but verify.  

In reply to HalfFast :

That's good advice. But this just blows my mind (from that link you posted):

If you still have your driveshaft, then measuring it is easy. Simply bring it to your supplier and they’ll measure it for you.

LOL! If it's so easy, why not just describe how so I can send the measurement(s) to my supplier, which may not be local! It seems to me the process of measuring between the transmission and the diff is going to be more error prone. But that's just me.

In reply to jh36 :

Thanks. I that seemed the most logical way.

jimgood said:

In reply to HalfFast :

LOL! If it's so easy, why not just describe how so I can send the measurement(s) to my supplier, which may not be local! It seems to me the process of measuring between the transmission and the diff is going to be more error prone. But that's just me.

Fortunently, there is a bit of slop allowed.  As you can see by the order form on the Quartermaster site, there are big jumps in lengths 

The key is it's long enough so as the rear goes up and down the shaft doesn't bottom out on the transmission, is long enough to keep the yoke from coming out of the seal.  

Oh, and also notice they measurments say "C-C".  I believe that to mean center to center of the U-joint..  (but I have been known to be wrong :) )

Advancing my understanding of the Tiger Quick Change Rear End.

First of all, I've heard the term center section used a lot but never really understood it until now. It is literally the center section of one of these differentials. The main thing that makes them different from your usual Ford 9" is the drive shaft attaches to the lower shaft in the center section, whereas it would attach directly to the pinion shaft of a Ford 9". That lower shaft goes through the housing to the quick change section at the back of the diff. Above that is the pinion shaft that comes in from the rear.

Looking from the rear, here are the spur gears (quick change gears). The top one is on the pinion shaft, bottom on the driveshaft. The bottom gear is driving the top gear. The bottom gear is larger so it is over-driving the top. In this case we have a 20-tooth gear on top and a 25-tooth gear on the bottom. That makes a spur ratio of 1.25:1 (i.e. 1 turn of the large gear turns the small gear 1.25 turns). If we reverse that, the smaller gear would have to turn 1.25 times to turn the big gear once.

Photo credit - jh36

A set of quick change gears usually comes with a reference card. There is also a reference chart available on the Tiger website but it's buried on page 25 of their catalog. Below is a snippet of the chart. You have to know your pinion ratio in order to use it accurately. The easiest one to figure out is gear set #1; both gears have 28 teeth (same size). So the final drive ratio doesn't change. Then for gear set #2, assuming you use the small gear on the driveshaft and the large gear on the pinion and you have a 4.11 pinion, the resulting final drive should be 4.26. But this is really the ratio of turns of the driveshaft to turns of the wheels. If your transmission gear ratio is 1:1, the final drive is 4.26 turns of the engine to one turn of the wheels.

But what if the transmission ratio is not 1:1? It is then just a matter of multiplying the trans gear ratio by the final ratio in the chart.

The really cool thing about a quick change rear is that, once the cover is off, you can pull those gears out with your fingers and switch them or put in a different set. No gear puller required. It might sound silly, but I find it incredibly satisfying. They seem to have just the right amount of slop.

In reply to HalfFast :

Thanks again, Bill. I reached out to a couple of driveshaft manufacturers and they also said the same thing; measure center to center of the U-joints.

In reply to jimgood :

You got it Jim!   Also, the nice feature about the quick change worth mentioning, if you flip the gears, it goes the other way, your final drive would be 3.96. 

In these cars you would typically gear the rear end based on the top speed you expect to achieve on the specific track.  For example, the traditional ratio for Summit Point is 3.5, for VIR is 3.3 as VIR has a really long straight and you can get to a higher top speed.  This is based on a GTA stock car with a 6500rpm redline.  

You don't "have" to do this, but it's a shame to leave performance on the table...  (But I encourage Jim to do that as I want to be faster )

In reply to HalfFast :

Thanks, Bill. For people that appreciate fine machinery but have never handled a quick change rear, all I can say is you're in for a treat.

When it comes to being faster, I have a long way to go but I enjoy the process.

Regarding driveshaft, I went with Coleman racing. They made up my custom length in 1 (one) day and the price was downright reasonable. (Under $300 with 2 universals and shipping )

carbon fiber is the current benchmark, but at 1/3 the $'s, I didn't think long. They go center to center of u-joints for length. 

In reply to jh36 :

Thanks, Jack. I'll keep them in mind if disaster strikes.

Haven't done much on my car. Weekend was too busy with "yard" work. I did cover the dash with black felt. I think it's going to make a huge difference in video quality and eye fatigue due to glare. It was a royal pain in the ass trying to do in the trailer, though most of the work was done sitting at the leading edge of the driver's seat with the steering shaft pressing into my chest and my head propped in front of a cage bar to keep me from falling back into the seat. I'll get pics later.

I also took a look at what it will take to get the roof off in order to swap out the seat. The front half of the roof, windshield, A-pillars and cowl are all one piece. The seam between the front and rear half of the roof is attached all with small bolts. Most of the roof supports are riveted to the cage at the top of the A-pillars. There are a couple bolts at other points. The worst part is that the cowl is under both the front fenders and doors and riveted through those. I'll have to not only drill out those rivets but may have to loosen some other bodywork in order to get the cowl free. I ordered a bunch of Dzus fasteners so I can make removal a process that won't require drilling.

In reply to jimgood :

Thumbs up on the dzus fasteners. I got really into those during my build. I'm quite a fan and you won't regret it. I have had success with an Irwin Unibit stepped drill bit to get the diameter just right. 

jimgood said:

In reply to jh36 :

Thanks, Jack. I'll keep them in mind if disaster strikes.

Haven't done much on my car. Weekend was too busy with "yard" work. I did cover the dash with black felt. I think it's going to make a huge difference in video quality and eye fatigue due to glare. It was a royal pain in the ass trying to do in the trailer, though most of the work was done sitting at the leading edge of the driver's seat with the steering shaft pressing into my chest and my head propped in front of a cage bar to keep me from falling back into the seat. I'll get pics later.

I also took a look at what it will take to get the roof off in order to swap out the seat. The front half of the roof, windshield, A-pillars and cowl are all one piece. The seam between the front and rear half of the roof is attached all with small bolts. Most of the roof supports are riveted to the cage at the top of the A-pillars. There are a couple bolts at other points. The worst part is that the cowl is under both the front fenders and doors and riveted through those. I'll have to not only drill out those rivets but may have to loosen some other bodywork in order to get the cowl free. I ordered a bunch of Dzus fasteners so I can make removal a process that won't require drilling.

Would it be enough to just pull a door panel?  That would have been my move if I wasn't able to do it the hard way.  

HalfFast said:

jimgood said:

In reply to jh36 :

Thanks, Jack. I'll keep them in mind if disaster strikes.

Haven't done much on my car. Weekend was too busy with "yard" work. I did cover the dash with black felt. I think it's going to make a huge difference in video quality and eye fatigue due to glare. It was a royal pain in the ass trying to do in the trailer, though most of the work was done sitting at the leading edge of the driver's seat with the steering shaft pressing into my chest and my head propped in front of a cage bar to keep me from falling back into the seat. I'll get pics later.

I also took a look at what it will take to get the roof off in order to swap out the seat. The front half of the roof, windshield, A-pillars and cowl are all one piece. The seam between the front and rear half of the roof is attached all with small bolts. Most of the roof supports are riveted to the cage at the top of the A-pillars. There are a couple bolts at other points. The worst part is that the cowl is under both the front fenders and doors and riveted through those. I'll have to not only drill out those rivets but may have to loosen some other bodywork in order to get the cowl free. I ordered a bunch of Dzus fasteners so I can make removal a process that won't require drilling.

Would it be enough to just pull a door panel?  That would have been my move if I wasn't able to do it the hard way.  

The door panel doesn't really affect the size of the side window opening. There's a welded support bar that the panel hangs on so removing the panel would only gain the thickness of the panel (1/16"). My main concern is that there's no way to get the seat out that opening. I could be wrong. The only way I can think of would be to unbolt the seat completely, somehow twist it so it's facing the side window, get the top out and then down, letting the bottom come out upside down. But the opening is so small, I'm not convinced that's even possible.

I guess it's worth a try since I don't even know if it would fit out the top yet. I still want the greenhouse removable though. There are some changes I'd like to make with respect to gauge mounting and wiring that would be so much easier with the top off.

In reply to jimgood :

I am thinking about replacing my front windshield.  When it goes in it will be installed with the Dzus fasteners for the reason you just stated.  With no windshield, the electrical work I want to do will be MUCH simpler.  

My seat swap happened through the window, and my seat is bigger than your seat I bet (ya, I just went there lol)