Z Hitch Prototype

roark · 01-22-2005, 09:14 AM

I just got the parts back from the powdercoater and have performed another test fitment.

I wanted to design a hitch that not only was fuctional as a class 1 hitch, but when the ball mount was removed from the receiver, it would be completely unnoticable. Here's my solution in prototype form.

I talked to an expert on extruded aluminum structures to get an idea what the stock bumper was capable of supporting on all three axis, and an expert welder on how best to implement an inexpensive, lightweight class 1 hitch. Here is is my solution. My calculations put the rating for this at 150lb tongue weight, and 950 lbs towing capacity.

I also thought about a class 2 hitch, but the weight was prohibitive for my primary purpose - getting my 4'x4' tire/tool trailer to the track.

Here are a few pics.

I'll take it for a few test runs this weekend, and the real test will be this year's first track event at VIR, Feb. 12-13., which 150 miles from my house.

I'll post more when I have the wiring kit installed, the bumper cover back on and the trailer hooked up.

Monsta · 01-22-2005, 09:39 AM

Good Idea. Tires to the track. Bikes to the meets. Jet skies to the coast.

John · 01-22-2005, 11:45 AM

Jim, looks good! I'd be willing to be a guinea pig (prototype v.2)... and I'd like to have it before the TZC event the 2nd weekend of February too. Are you available next weekend or the one thereafter?

EnthuZ · 01-22-2005, 04:19 PM

I like!

Someone else mentioned that the aluminum bumper mounts weren't strong enough for towing loads mounting like this.......don't mean to put this great design down.......I really like that it can be removed from site when not needed.

tomzz · 01-22-2005, 06:13 PM

I just finished an install by my wleder on a disappearing 350Z hitch that does not depend on the rear bumper frame due to others experience with a weak bumper frame connection that weakens over time.

My design was like others who used the open space offered by the Injen Straight Tip exhaust to avoid using the bumber frame bar.

The hitch frame is a square tube/bar welded from exhaust hanger to exhaust hanger, with a T brace going back to the cross frame member in front of the differential. That gives ita good triangle of support with a verticale reciever and a 90 eegree hitch ball unit. Just a little over $100.

My ZToo track trailier is in the paint and fabrication shop (my basement) and the test run with full tool load and track wheels/tires will be next.

My welder did a wonderful job on the wheel tire rack that solved all of my 350Z track wheel/tire design criteria. He will be offering
this track tire rack to fit on the Harbor 4x4 trailer we all use. He will ship it too you ready to go on the trailer. I will post pics in a week when the paint is dry. It will be sold at $200 plus shipping from KY by DW Welding with order and mailing on his web page.

Skrill · 01-23-2005, 07:18 AM

Please keep us informed on these items.

I would love to have a track trailer for my Z.

roark · 01-23-2005, 01:16 PM

Last night I completed the wiring. It was very simple, especially since the tail lamp harnesses have service loops you can tap into without butchering the harness.

Today, Dispite the cold (low 20's with wind chill down into single digits) I hitched up the track trailer fully loaded (4 tires, toolbox including air tank and jack, approx. 650 lbs total) and took it for a test run. I toured bumpy, winding back roads, surface roadways and interstates for several hours. I'm very satisfied how the hitch performed.

I'm going to keep the trailer on during the week, and have my aluminum expert examine the extruded aluminum bumper on Thursday. I don't see that this amount of load will weaken the aluminum bumper, even over time.

EnthuZ, I agree that this design is not sat as a class 2 hitch (3500lbs gross/300lbs tongue) but as a class 1 design it is a good compromise of towing capacity and weight (receiver assy. weighs under 20 lbs.) I could make a class 2 hitch, which would bolt directly to the bumper mounts on the frame, but it will weigh nearly 60 lbs. if designed properly.

Tomzz, for a tire rack, I simply used the 3/4"x3 1/2" siderail slots (conveniently the nominal size of 1"x4" lumber) in the frame. I mounted some 1"x4" 6" long pieces to the ends of some 4"x4" posts, dropped them in and bolted them to the existing frame holes. Tires sit between the 4x4s. This was very inexpensive, wood won't hurt the tires, and they can be easily removed if I want to use the trailer to haul something else. I would like to see your tire rack design as well. I can't wait to see the pics.

roark · 01-23-2005, 03:07 PM

I finished getting the bumper cover installed. here are some pics of the final product.

EnthuZ · 01-23-2005, 05:43 PM

Cool!

Thanks for the pix! Looks like you have one of those cool Nismo mufflers. Me too! I gotta find some time to look further into this......

Please elaborate on the wiring......I nearly melted my Lotus switching from a generator to an alternator.

PDX_Racer · 01-23-2005, 06:03 PM

Looks great, although I would be concerned about the load on the bumper. However, I also have the tendancy to overengineer stuff.

Keep us informed about availability and price!

roark · 01-23-2005, 06:59 PM

Quote:

Originally posted by PDX_Racer
Looks great, although I would be concerned about the load on the bumper. However, I also have the tendancy to overengineer stuff.

Keep us informed about availability and price!

Yea, I do too. That's why I discussed this design with an expert on load bearing extruded aluminum structures. He looked at the bumper and has agreed to examine it after I've driven around a bit (see first post.) I'll let you know what the analysis concludes.

roark · 01-23-2005, 07:14 PM

Quote:

Originally posted by EnthuZ
Cool!
Please elaborate on the wiring......I nearly melted my Lotus switching from a generator to an alternator.

I encorporated a Hopkins (AKA Hoppy) wiring converter that takes modern vehicles with separate lines for brakes and turn signals (Like the Z) and converts them for use on 4 wire trailer wiring.

Here's a pic of the tow package wiring.

roark · 01-27-2005, 07:54 PM

OK, I've got some interesting news.

First, I talked to my aluminum structures expert, and he is confident that the hitch as designed, will tow up to a 1000 lb. load without weakening the bumper, even over time. Excellent.

Second, I talked with my fabricator about limited run manufacturing. We discussed reducing costs, increasing quality and lead times. Some of the custom welds would be replaced with press brakes (bends). The plates would be stamped instead of cut and drilled. The draw bar would be a solid piece, double bent, instead of lots of welds. The dimensions would stay exactly the same, as well as the function. Powercoating (base coat and clearcoat) would stay the same. They would look VERY nice.

The kit would include the same two custom pieces, nuts and bolts, hitch pin & wiring kit. Hitch ball not included, so you can match the size with your trailer, and save the cost of shipping this heavy component.

So, with all that said, here's my proposal for a group buy. Minimum participation of 5 units would put the price at $379.00 each kit, plus shipping. If I get a list of at least 6 (never get full participation) I'll collect payments via PayPal, and have the fabricator start. It will take two weeks max. to get the fab, welding, and powdercoating done.

This is not what I do for a living, and I'm not making any money at this price. I'm just trying to support the community.

PDX_Racer · 01-28-2005, 12:12 AM

PM'ed

roark · 01-28-2005, 12:27 PM

The list so far...

John
PDX_Racer

Four more under 'very interested' but I haven't heard a GO yet...

daveh · 01-28-2005, 01:34 PM

That looks nice. Can you describe the installation procedure in a little more detail. This looks like it's a standard bolt on. Do you have to drill through the aluminum beam or does it use existing holes. Also how difficult is it to remove the rear bumper. I've never had to remove it myself.
Will you include some installation instructions with the finished product?

roark · 01-28-2005, 05:18 PM

Quote:

Originally posted by daveh
That looks nice. Can you describe the installation procedure in a little more detail. This looks like it's a standard bolt on. Do you have to drill through the aluminum beam or does it use existing holes. Also how difficult is it to remove the rear bumper. I've never had to remove it myself.
Will you include some installation instructions with the finished product?

Yes, you do have to drill mounting holes in the bumper. The bumper itself is very easy to remove from the mounts. Just 4 bolts per side.

Yes, the kit will include a full installation manual, and drilling template.

roark · 01-28-2005, 05:31 PM

The list so far...

John
PDX_Racer
luttmeister

Three more under 'very interested' but I haven't heard a GO yet...

roark · 01-29-2005, 07:46 AM

New List....

John
PDX_Racer
luttmeister
jbenedict

roark · 01-30-2005, 08:56 AM

Da List....

John
PDX_Racer
luttmeister
jbenedict
tomzzy

One more to go... Looks like this is going to happen soon. Guys, please PM me with your mailing addresses so I can start calculating shipping charges...

01-22-2005, 09:14 AM	#1
roark Registered User Join Date: Nov 2002 Location: Va Beach Posts: 622 iTrader: (2)	Z Hitch Prototype I just got the parts back from the powdercoater and have performed another test fitment. I wanted to design a hitch that not only was fuctional as a class 1 hitch, but when the ball mount was removed from the receiver, it would be completely unnoticable. Here's my solution in prototype form. I talked to an expert on extruded aluminum structures to get an idea what the stock bumper was capable of supporting on all three axis, and an expert welder on how best to implement an inexpensive, lightweight class 1 hitch. Here is is my solution. My calculations put the rating for this at 150lb tongue weight, and 950 lbs towing capacity. I also thought about a class 2 hitch, but the weight was prohibitive for my primary purpose - getting my 4'x4' tire/tool trailer to the track. Here are a few pics. I'll take it for a few test runs this weekend, and the real test will be this year's first track event at VIR, Feb. 12-13., which 150 miles from my house. I'll post more when I have the wiring kit installed, the bumper cover back on and the trailer hooked up. Last edited by roark; 01-22-2005 at 09:20 AM.

01-22-2005, 09:39 AM	#2
Monsta Registered User Join Date: Apr 2004 Location: Stuffin hoes in SUV trunks Posts: 1,683 iTrader: (9)	Good Idea. Tires to the track. Bikes to the meets. Jet skies to the coast. __________________ You can go to school for 15 months. You can work a minimum wage job for 15 months. You can even beat off for 15 months but can you stay mentally stable in a combat zone for 15 months? Thank a Soldier.

01-22-2005, 11:45 AM	#3
John ... Join Date: Jun 2002 Location: San Diego, CA Posts: 4,899 iTrader: (17)	Jim, looks good! I'd be willing to be a guinea pig (prototype v.2)... and I'd like to have it before the TZC event the 2nd weekend of February too. Are you available next weekend or the one thereafter? __________________ Track car: 2005 "Elixige" - S/C, Ohlins, 255Cup wheels, other stuff Other vehicles: 2006 Titan SE 4x4, 2007 Mazda 3S, 1999 YZF600R, 2003 350Z Trackcar - RIP Buttonwillow 4/7/07

01-22-2005, 06:13 PM	#5
tomzz Registered User Join Date: May 2003 Location: Nashville, TN Posts: 118 iTrader: (0)	disappearing hitch also I just finished an install by my wleder on a disappearing 350Z hitch that does not depend on the rear bumper frame due to others experience with a weak bumper frame connection that weakens over time. My design was like others who used the open space offered by the Injen Straight Tip exhaust to avoid using the bumber frame bar. The hitch frame is a square tube/bar welded from exhaust hanger to exhaust hanger, with a T brace going back to the cross frame member in front of the differential. That gives ita good triangle of support with a verticale reciever and a 90 eegree hitch ball unit. Just a little over $100. My ZToo track trailier is in the paint and fabrication shop (my basement) and the test run with full tool load and track wheels/tires will be next. My welder did a wonderful job on the wheel tire rack that solved all of my 350Z track wheel/tire design criteria. He will be offering this track tire rack to fit on the Harbor 4x4 trailer we all use. He will ship it too you ready to go on the trailer. I will post pics in a week when the paint is dry. It will be sold at $200 plus shipping from KY by DW Welding with order and mailing on his web page.

01-23-2005, 07:18 AM	#6
Skrill Registered User Join Date: Jun 2004 Location: Nashville, TN Posts: 455 iTrader: (0)	Please keep us informed on these items. I would love to have a track trailer for my Z. __________________ SE-R Cup Racer and proud Ultra Yellow Z owner

01-22-2005, 04:19 PM	#4
EnthuZ Banned Join Date: May 2002 Location: Chicago Burbs Posts: 1,955 iTrader: (2)	I like! Someone else mentioned that the aluminum bumper mounts weren't strong enough for towing loads mounting like this.......don't mean to put this great design down.......I really like that it can be removed from site when not needed.

01-23-2005, 01:16 PM	#7
roark Registered User Join Date: Nov 2002 Location: Va Beach Posts: 622 iTrader: (2)	Last night I completed the wiring. It was very simple, especially since the tail lamp harnesses have service loops you can tap into without butchering the harness. Today, Dispite the cold (low 20's with wind chill down into single digits) I hitched up the track trailer fully loaded (4 tires, toolbox including air tank and jack, approx. 650 lbs total) and took it for a test run. I toured bumpy, winding back roads, surface roadways and interstates for several hours. I'm very satisfied how the hitch performed. I'm going to keep the trailer on during the week, and have my aluminum expert examine the extruded aluminum bumper on Thursday. I don't see that this amount of load will weaken the aluminum bumper, even over time. EnthuZ, I agree that this design is not sat as a class 2 hitch (3500lbs gross/300lbs tongue) but as a class 1 design it is a good compromise of towing capacity and weight (receiver assy. weighs under 20 lbs.) I could make a class 2 hitch, which would bolt directly to the bumper mounts on the frame, but it will weigh nearly 60 lbs. if designed properly. Tomzz, for a tire rack, I simply used the 3/4"x3 1/2" siderail slots (conveniently the nominal size of 1"x4" lumber) in the frame. I mounted some 1"x4" 6" long pieces to the ends of some 4"x4" posts, dropped them in and bolted them to the existing frame holes. Tires sit between the 4x4s. This was very inexpensive, wood won't hurt the tires, and they can be easily removed if I want to use the trailer to haul something else. I would like to see your tire rack design as well. I can't wait to see the pics. Last edited by roark; 01-23-2005 at 01:22 PM.

01-23-2005, 03:07 PM	#8
roark Registered User Join Date: Nov 2002 Location: Va Beach Posts: 622 iTrader: (2)	I finished getting the bumper cover installed. here are some pics of the final product.

01-23-2005, 05:43 PM	#9
EnthuZ Banned Join Date: May 2002 Location: Chicago Burbs Posts: 1,955 iTrader: (2)	Cool! Thanks for the pix! Looks like you have one of those cool Nismo mufflers. Me too! I gotta find some time to look further into this...... Please elaborate on the wiring......I nearly melted my Lotus switching from a generator to an alternator.

01-23-2005, 06:03 PM	#10
PDX_Racer Registered User 2005 Nissan 350Z Join Date: Dec 2003 Location: Maple Valley, WA Posts: 1,779 iTrader: (0)	Looks great, although I would be concerned about the load on the bumper. However, I also have the tendancy to overengineer stuff. Keep us informed about availability and price! __________________ 2005 350Z Track Model - RevUp engine (no oil problems), 6MT (original trans.), 245/275 tires on stock Track wheels (285/30 for Solo)

01-27-2005, 07:54 PM	#13
roark Registered User Join Date: Nov 2002 Location: Va Beach Posts: 622 iTrader: (2)	Ready for a group buy? OK, I've got some interesting news. First, I talked to my aluminum structures expert, and he is confident that the hitch as designed, will tow up to a 1000 lb. load without weakening the bumper, even over time. Excellent. Second, I talked with my fabricator about limited run manufacturing. We discussed reducing costs, increasing quality and lead times. Some of the custom welds would be replaced with press brakes (bends). The plates would be stamped instead of cut and drilled. The draw bar would be a solid piece, double bent, instead of lots of welds. The dimensions would stay exactly the same, as well as the function. Powercoating (base coat and clearcoat) would stay the same. They would look VERY nice. The kit would include the same two custom pieces, nuts and bolts, hitch pin & wiring kit. Hitch ball not included, so you can match the size with your trailer, and save the cost of shipping this heavy component. So, with all that said, here's my proposal for a group buy. Minimum participation of 5 units would put the price at $379.00 each kit, plus shipping. If I get a list of at least 6 (never get full participation) I'll collect payments via PayPal, and have the fabricator start. It will take two weeks max. to get the fab, welding, and powdercoating done. This is not what I do for a living, and I'm not making any money at this price. I'm just trying to support the community.

01-28-2005, 12:12 AM	#14
PDX_Racer Registered User 2005 Nissan 350Z Join Date: Dec 2003 Location: Maple Valley, WA Posts: 1,779 iTrader: (0)	PM'ed __________________ 2005 350Z Track Model - RevUp engine (no oil problems), 6MT (original trans.), 245/275 tires on stock Track wheels (285/30 for Solo)

01-28-2005, 12:27 PM	#15
roark Registered User Join Date: Nov 2002 Location: Va Beach Posts: 622 iTrader: (2)	The list so far... John PDX_Racer Four more under 'very interested' but I haven't heard a GO yet...

01-28-2005, 01:34 PM	#16
daveh Registered User Join Date: Jan 2004 Location: CA Posts: 1,253 iTrader: (9)	That looks nice. Can you describe the installation procedure in a little more detail. This looks like it's a standard bolt on. Do you have to drill through the aluminum beam or does it use existing holes. Also how difficult is it to remove the rear bumper. I've never had to remove it myself. Will you include some installation instructions with the finished product? __________________ NASA TTC 350Z - Team Z Car Garage : NASA TTB champion 2006; TTC 2nd place 2007; 2007 Instructor of the year.

01-28-2005, 05:31 PM	#18
roark Registered User Join Date: Nov 2002 Location: Va Beach Posts: 622 iTrader: (2)	The list so far... John PDX_Racer luttmeister Three more under 'very interested' but I haven't heard a GO yet...

01-29-2005, 07:46 AM	#19
roark Registered User Join Date: Nov 2002 Location: Va Beach Posts: 622 iTrader: (2)	New List.... John PDX_Racer luttmeister jbenedict

01-30-2005, 08:56 AM	#20
roark Registered User Join Date: Nov 2002 Location: Va Beach Posts: 622 iTrader: (2)	Da List.... John PDX_Racer luttmeister jbenedict tomzzy One more to go... Looks like this is going to happen soon. Guys, please PM me with your mailing addresses so I can start calculating shipping charges... Last edited by roark; 01-30-2005 at 09:04 AM.

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