[dcoy]

Thanks

 

[Lostmanifesto]

Glad to hear the new job is going well. Having gone through it, I know it can be tough maintaining two households. You have to report back on the microbrew. :cheers: to a better 2011.
In other news, I have made some revisions/updates to the first post.

Edit: Not sure if you have seen this.

hey i took that photo

 

[TCao]

hey i took that photo

Great photos and article on DeMello Offroad in the Jan 2011 issue of Off-Road magazine. :bigthumb:

Speaking of DeMello, here's Jason working on my next mod.

 

[targa88]

Speaking of DeMello, here's Jason working on my next mod.

So you are going to keep us in suspense....

 

[TCao]

So you are going to keep us in suspense....

That's a definitely maybe! :jester:

I took a couple of photos of the Sparco seats installed in my FJC in the driveway but they're not "post-worthy" (and I don't want to get any grief from Jason for not knowing how to take good photos with a cool Canon L-series zoom lens ). In the mean time, here are a few of Jason and Jordan welding gussets onto my Sparco seat bases.

Here's a photo of the Driver's Side Sparco seat base with the gussets and the inner belt mounting tab removed. (before repaint).

Photos and lots of details on the installation to follow.

 

[FJ #8]

I cant wait to see the pics

 

[TCao]

Sparco R505 Seats Installation, Part I of III

It took what seems like an eternity (to me) to complete this modification because I wanted to keep all standard airbags functional. First, here are the photos of the seats installed in my FJC. The three-point safety harnesses are Schroth Rallye 3 ASM. The front factory seatbelts are also retained and functional. No more sinking feeling, no more slipping and sliding.

The best part is no SRS malfunction warning light.

I'll post up the installation details in following posts.

 

[TiFJ]

Looking forward to seeing how you solved the airbag issues, I often think about installing new seats but I struggle but don't want to mess with them.

 

[jeshua]

Love the seats T!

Where did you find those harness's that work with the stock system, more info on the belts for sure and maybe some pics.

 

[mtnkraut]

Come on, info on how you solved the airbag thing.....my light is bugging me.

 

[TCao]

Sparco R505 Seats Installation, Part II of III

As I've mentioned earlier, swapping the factory front seats for aftermarket ones affects the Supplemental Restraint System (SRS). Before I get to the how to fix the airbag light discussion, a short description of the FJC's SRS is necessary IMHO to put things in context.

For my Model Year (MY) 2007, the FJ comes standard with two front dual-stage airbags: one in the steering wheel and one on the dash in front of the front passenger seat. For MY 2007, Toyota also offered side airbags as an option; this option included curtain side airbags and front seat side airbags. The following illustration was taken from the Toyota Factory Service Manual (FSM) under the Body Electrical section.

The diagram below shows all the relevant SRS equipment on the FJC except for the two side curtain airbags.

Dual-stage airbags contain two ignitors (aka squibs) and two propellant charges. Depending on the severity of the impact and the position of the driver's seat, either one or both squibs will fire. The position of the driver's seat is determined by the seat position sensor which is located on the outboard slider rail of the driver's seat. For the FJ, the sensor detects that the seat is in the very forward (closer to the steering wheel) when the shielding plate is not in between the magnet and the Hall Effects Integrated Circuit (IC) (see illustration below).

The Occupation Classification (OC) ECU determines whether or not there is an occupant in the front passenger seat, based on the inputs from all four seat sensors. This information is reported from the OC ECU to SRS ECU so that this ECU can decide whether or not to deploy the passenger front airbag, side airbag, and side curtain airbag and actuate the passenger belt pretensioner. This decision is displayed on the Passenger Airbag ON/OFF display to the right of the stereo.

Looking forward to seeing how you solved the airbag issues, I often think about installing new seats but I struggle but don't want to mess with them.

Come on, info on how you solved the airbag thing.....my light is bugging me.

OK. On to the fixes. There are three things you'll need to do (two if you don't have seat side airbags).

1. Side Airbags Fix. AFAIK, there are no aftermarket seats with side airbags. Replacing the factory seats would mean fooling the SRS ECU to think that the side airbags are still there. From my research, nichrome squibs typically have a resistance of two ohms. Scanning other automotive forums, I've found that a resistor with a value between two to four ohms will work. Here's how I did mine. I used 2.2 ohms 2W flameproof resistors and soldered them to the side airbag harness. I double-checked before cutting these harnesses and there's sufficient slack so that they can be spliced back if I ever decide to go back to the factory front seats.

I also used heat-shrink tubing to protect the solder joints. Not shown in the photo below is an additional layer of heat-shrink tubing over the end of the harness and the complete pigtail harness is further protected inside some split loom.

2. OC ECU Sensors Fix. On the FJ, all four OC ECU sensors are an integral part of the passenger seat and cannot be removed and reinstalled on an aftermarket seat. Even if this modification is possible, the Zero Point calibration of all four sensors will need to be performed using a Toyota SST. This was by far the most complex technical hurdle to overcome. I literally spent months searching on the web to find this answer. One day, I got lucky. I stumbled upon the yarisworld.com website and found this thread. CTScott from this website did all the development work and came up with the OC Sensor Bypass Module for the Yaris. After carefully studying the Yaris' OC ECU and OC sensors, I felt pretty confident that this Bypass Module has a high probability of working for our FJs as well. I took a chance and ordered one from Scott. I was lucky. It WORKS. You can contact Scott at scott.mcclure at charter dot net (replace at with @ and dot with .) if you want to order a module.

As shown above, the Bypass Module comes with a 5-ft harness and a rocker switch to manually turn the passenger side airbag ON and OFF. This module replaces all four OC sensors and their harness. The fix is very simple. Unplug the gray connector on the factory harness and plugs in this module. Install the manual ON/OFF switch at a convenient location. Here's a photo of the OC ECU installed on the factory passenger seat.

Here's how I installed mine. I used zip ties to secure the OC ECU and Bypass Module to the Passenger Side (PS) Sparco seat base. The manual airbag ON/OFF switch is installed on the right side of the center console. To keep things tidy, I did separate the sensors harness from the OC ECU harness (the one with the black connector).

3. Seat Position Sensor Fix. The factory seat has the sensor mounted to the bottom seat cushion frame and the shielding plate is spot-welded to the bottom slider/seat frame. Prior to removing my factory driver's seat, I noted the position of the seat sensor. The shielding plate was between the magnet and the Hall Effect IC which detects changes in the magnetic flux density.

My quick and temporary fix is to use zip ties to clamp the sensor to the DS Sparco seat base (I used two pieces of neoprene foam to locate the sensor).

I'll be working on a permanent solution by making a shielding plate out of 1.5" x 1.5" x .063" CR1018 angle and attach to the Sparco seat base to duplicate the factory one. The sensor will be remounted to the Al alloy spacer and slide with the seat. If your driver's seat is much closer to the steering wheel and the shielding plate is not in between the magnet and Hall IC, then the seat sensor can be temporary secured anywhere convenient (no need to have a metal shield in between).

Edit 1: here's the permanent installation of the seat position sensor.

Edit 2: Adding description and photos on separating the PS seat harness for a cleaner installation.

Shown in the photo below is the complete PS seat wiring harness. From the left side, the yellow connector (unplugged) is for the seat side airbag, the gray connector (unplugged) ties the OC ECU to the SRS ECU in the dash, the OC ECU with the black connector on the left and gray connector on the right, and the gray connector on the right which ties the inner PS seat belt buckle to the OC ECU.

The PS seat wiring harness can be completely separated into two individual harnesses by removing the electrical tape bundling them. The harness on the left in the photo below is the seat sensors harness (no longer needed). Plugged into the OC ECU is the the inner seat belt harness.

Shown below is the OC ECU and PS inner seat belt harness.

WARNING. It's worth repeating the FSM warning here. When working on SRS, the negative cable needs to be disconnected and you should wait for at least 90 seconds before starting work (airbags do have a back-up power source). Also, do not use a Digital Volt meter (DVM) to probe around these circuits. The battery in the DVM can ignite and deploy an airbag.

NOTE. This is presented as a purely technical discussion. There are legal ramifications with modifying OEM automotive safety features. I've done my research and fully accept the risks of modifying the SRS on my FJ.
__________
Reference:

 

[spincycle]

This is awesome. Well done.

 

[FJ #8]

I dont knowwhat u do for a living,but you do the cleanest install of anyone on this forum. everything alwayslooks factory or better!

 

[TCao]

Love the seats T!

Where did you find those harness's that work with the stock system, more info on the belts for sure and maybe some pics.

Thanks Josh. I'm working on Part III of the seat installation and will cover the Schroth harness installation details. Forgot to ask you about Iceland. How was it?

This is awesome. Well done.

Thanks Chris.

I dont know what u do for a living,but you do the cleanest install of anyone on this forum. everything always looks factory or better!

Thanks! I'm a Mechanical Engineer by training but have worked for many years in the aviation electronics industry.

 

[TCao]

Sparco R505 Seats Installation, Part III of III

I've ordered one Sparco R505 seat and the DS seat base and one set of Sparco slider to work out the installation steps prior to ordering the PS seat, base, and slider. Taking measurements of the factory seat lead me to believe that I will need to use spacers to raise the Sparco seats. I decided to use 2"-high spacers for both seats so that the seat belt mounting will be similar (mirror image). Browsing through the Industrial Metal Supply store in San Diego, I found some 2" x 3" x .125" 6063-T52 extruded aluminum tubing which can be made into seat spacers. I would prefer using 6061-T6 alloy (slighter higher strength) but this rectangular tubing only comes in 6063 alloy. The 3" width allows me to place the seat belt anchors at the same width as the seat and also room to tighten the nuts and bolts.

I drilled clearance holes for M8 bolts to match the tapped holes in the seats. There is also a 7/16" hole on the side of each of the spacers for mounting the lap belt anchors.

Here are the parts needed to mount each Sparco seat. Notice that the seat base is still stock, without the added gussets and the inner belt buckle mounting tab is still on. it's difficult to see in the photos but the aluminum seat spacers are Alodine treated (chromate conversion coating using Henkel Alodine 1201) for some corrosion protection.

As mentioned in an earlier post, I asked Jason DeMello to add gussets to further stiffen the Sparco seat bases (PN 400SB069L and 400SB069R). Here's a photo of the DS base prior to repaint.

I haven't had rear seats in my FJ for almost four years now and have remove all the rear seat belts. I also had plan to mount off-road safety harnesses with these seats and have known about Schroth for a long time (my BMW and Porsche days). The Schroth harnesses are the only one I know with the patented Anti Sub Marining (ASM) technology. The energy converter is an extra fold of shoulder belt material sewn on the inboard side to allow the upper torso to pivot slightly in a frontal crash, preventing the body from sliding (submarining) under the lap belt. I chose the Rallye 3 ASM model as it has a single tail strap which can be mounted on the C pillar using the rear seat belt upper outboard mount. This is the only hardware on the FJ I've found that's not metric. All seat belt anchor bolts have 7/16-20 threads (the inertial reel mounting hardware is metric). I disassembled the rear upper outer belt anchor as I wanted to reuse the shoulder bolt and spacer (the spacer is 25mm long).

Below is a photo of the Schroth tail strap anchor (a B23B) with the correct sleeve and a Grade 8 7/16-20 x 1.75 bolt. the sleeve (also made by Schroth) allows the anchor to pivot and align the tail strap to the load being applied.

The Schroth tail strap is shown installed on the PS side C pillar. Torque for this bolt is 31 ft-lbs per the Toyota FSM.

Same installation on the DS C pillar.

Another reason to use 2" x 3" rectangular tubing is shown in the photo below of the outboard lap belt anchor. You'd need room to use a wrench on the nut to retain this anchor. The bolt used here is a Shroth 7/16-20 x 38mm with a low hex head and the round spacer under the sleeve is also a Schroth part that came with the Rallye 3 ASM harness (about 12 mm long).

Similarly, for the inboard anchor mount, I used the shoulder bolt from the rear seat belt assembly to hold the factory inner seat belt buckle and the Schroth lap belt anchor. All lap belt anchor points have large (Grade 8 equivalent) 7/16 USS washers under the 7/16-20 Grade 8 nuts. Torque is 31 ft-lbs and Loctite 242 is also used. The DS inner belt buckle has two sensors to detect whether the DS seat belt is fastened: one contact and one noncontact (Hall effect). The contact switch is for the seat belt chime reminder; the noncontact switch provides status to the SRS ECU. On the PS belt buckle, there is only one noncontact switch.

Here's a photo of the DS outboard anchor with the seat installed.

Oh yeah, almost forgot. I found some polyethylene caps to close off the seat spacers on McMaster-Carr website.

Another view of the PS outboard lap belt anchor.

So, why did I go through all the trouble to make these spacers and mount the lap belt anchors the way i did? One, the anchors move with the seat, maintaining the relative position of the anchors with seat back. Two, the anchors are loaded in tension (in the direction of the load applied on the lap belt). Three, the lap belts are as short as possible (the belt will stretch in an accident). Four, the lap belts can pivot and lay flat on the iliac crests. BTW, I did measure the front headroom. From the bottom seat cushion to the headliner is 38.5".

A close up view of the ASM feature and the tail strap quick-release buckle which allows the harness to be quickly disconnected and reconnected to access the rear cargo area.

List of hardware used to mount one seat

A. Holding seat spacer to seat:
4X M8-1.25 x 30mm Grade 10.9 bolts
4X M8 lock washers
4X M8 flat washers
Torque: 18 ft-lbs

B. Holding seat spacer to top of slider:
4X 5/16-18 x 3/4" Grade 8 socket head cap screws
4X 5/16-18 Grade 8 nylok nuts
4X 5/16 SAE flat washer (equivalent to Grade 8)
Torque: 24 ft-lbs

C. Holding bottom of slider to seat base:
4X 5/16-18 x 3/4" Grade 8 socket head cap screws
4X 5/16-18 Grade 8 nylok nuts
4X 5/16 USS flat washers (equivalent to Grade 8)
Torque: 24 ft-lbs

Weight per Sparco seat, including slider, base, spacer, hardware and Schroth harness: 52 lbs
Weight per factory seat, including slider: ~50 lbs

When I did the permanent chime disable, my ulterior motive was to be able to wear 4-point harness when off roading without being distracted by any flashing lights or beeping noises. :rocker:

I officially have no factory seats in my FJ now.
__________
References:

1. Off-Road Tech Article: Better Ways to Build Safer Trucks Buggy

2. Schroth Installation Instruction for Rallye 3 and 4

3. Schroth Hardware Guide

4. PCA Tech Tactics

5. Sparco Flat Seat Base Installation

 

[mtnkraut]

Nice. I did not put risers on my seat but I think I need to. I anchored the lap belt to the seat frame so i can get my final snug up by pulling the seat forward.

 

[fjessence]

amazing work on the seat sensor delete and sliders!!

 

[DominicG]

Awesome T!


Seats have been at the top of my list for years.. but always seem to get put aside buy something i don't need. :lol:

 

[FJ #8]

great install and writeup!

 

[TCao]

Nice. I did not put risers on my seat but I think I need to. I anchored the lap belt to the seat frame so i can get my final snug up by pulling the seat forward.

Danke!

amazing work on the seat sensor delete and sliders!!

Thank you Sang.

Awesome T!


Seats have been at the top of my list for years.. but always seem to get put aside buy something i don't need. :lol:

Grazie mille, amico! I'll help you with the install when you're ready to swap the seats. In the meantime, Godspeed young man for soon you'll be at the tip of the spear in A-stan.

great install and writeup!

Thanks again.

I'll post up update of the seat position sensor once it's done. Need to get some 16 gauge steel sheet to make a new shielding plate for the Sparco seat base.