orthojoe

Sorry it's taken so long for me to get this started. I have a lot going on this year, so time has been at a premium for me. That being said, I have some time today, so let's get it started.

Quick background on the car:

My local dealer/SA asked me if I would be interested in a GT4 back in May of 2014. I still hadn't taken delivery of the GT3 yet, but I said, sure. He made note of it and said that he would get me one. In March of 2015 the GT4 was official and I confirmed once again with my dealer that I wanted one. I was committed to the car, but that I also meant I would need to sell my boxster spyder to get one. I asked the dealer if I could sell my boxster spyder, and I was told, "yes, I will get you a GT4". I also clarified with the dealer that they would sell me the car at MSRP. I bought both a used boxster spyder and a new GT3 at MSRP already from this dealer. So I sold the boxster spyder a month later. Months roll by. Allocations come and go. Excuses are made as to why I don't have an allocation yet even though I was told I would get one back in 2014. May 2014. I learn through my various resources that an allocation at this dealership was sold to a customer at MSRP ahead of me. More excuses made. In September 2015 I walked into the dealership to speak to the sales manager to find out what the hell was going on. I was told that the market was hot for this car and they wanted market price for the car. I was offered allocations being purchased from other dealers for 25k over. I wanted one of the dealer's allocations at MSRP like they said they would give me in May of 2014. I was told that the general manager (who is, IMO, a greedy SOB that could give 2 sh*ts about customer loyalty) was not willing to let these GT4 allocations go at msrp. They wanted 'market price'. I walked away mad and frustrated. I trusted this dealership to follow their word, and I got screwed. I should never have trusted them, but they did well by me with the GT3. Because of this mistake, I lost out on other opportunities at other dealerships that I would have been able to enact on. At this point, it didn't look like a GT4 was going to happen because I called dealers across the country with no luck (september 2015). At this point, I decided to call in a favor, which involved getting the actual owner of the dealership involved. The owner made some phone calls, and I was told that I would be taken care of, the next allocation was mine at MSRP, and if any problems arose that I was to contact him directly. Shortly after, I got my allocation and I will admit that all my dealings with the dealer have been super smooth since then. This is not to say that the dealer has been well behaved, though. The same time I got my allocation, and friend of mine, who had a WRITTEN NOTE from the dealer saying that he would get a GT4 at MSRP was told that they could not honor the note anymore. Trust is a serious issue at this dealer. I have a new dealer now. One that has a great reputation, and doesn't gouge loyal customers.

Enough of the BS sob story. The car is here, I got what I wanted, let's get started with the real thread.

Posted in another thread, but this is the car:









I'm very happy with the build, and it came out as nicely as I hoped it would.

Now it came time to get the car ready for the track. What I purchased for the car:
1) Expel wrap of the entire front of the car
2) Tarett front tie rods (to allow sufficient negative camber)
3) Tarett front adjustable thrust arm bushings / caster pucks (to correct excess caster from running negative camber)
4) Tarett cup lower control arm monoball ends (the oem thrust arm bushings are rubber and once you convert to solid bushings, preload is transferred to the oem rubber lca ends). The cup monoballs include a thick shim and longer threaded rods in order to run lots of negative camber if you desire)
5) Tarett rear toe links (to allow sufficient toe/camber adjustability)
5) Tarret standard rear lower control arm monoball end (not pictured) The factory rear thrust arm bushing solid, as mentioned by BGB, so I followed suit with BGB's recommendation and went with a solid monoball rear LCA end. The cup monoball isn't needed since you won't run as much negative camber in the the rear.

I bought the parts for myself for valentines day...


Pictures of the parts installed:

Front tarett cup monoball with shims:



Front tarett thrust arm bushing (make sure they send you the spacers!)



Front tarett tie rod:



Rear OEM thrust arm bushing. You can see it is solid, and not rubber like the OEM front



Rear Tarett toe links:



Rear Tarett monoball LCA ends with shims



The setup?
Front:
-2.7 camber
1.5mm toe OUT (3mm total)
8.6 degrees caster
Sway bar middle

Rear:
-2.4 camber
3mm toe IN (6mm total)
sway bar middle

Next up, cage and harness. I decide to go with the Cantrell cage. I have a Cantrell cage in the GT3 and let me go on record saying that the install on the GT4 is MUCH MUCH easier than the GT3. It only took me 2 hours to do the install, and that was taking my time. Disclaimer, I did NOT reinstall the plastic trim and rear carpet that needs to be cut. I didn't have the time and felt bad cutting stuff right away. The car is a bit loud on the highway without the carpet, but it's not horrible. I'm not sure what I will do yet. Pics of the cage:



Next up is installing the harness. I wanted silver harnesses, and I ended up getting a pair of Schroth Profi-ii6 GT3 specific belts. They cost more, but you don't need to buy any adapters to attach the lap belts to the seat. I bought the cantrell anti-sub bars to mount the sub straps. Install here is a breeze as well. Remove the seats and the cantrell sub bars bolt on to the seat with 2 bolts.


bolt on the seat that is used to mount the cantrell sub bar



bar installed with belts installed



Final product




This is the OEM front spoiler that needs to be removed to increase rear wing downforce:



front spoiler removed



Now for the connection to the CAN line for my AiM Solo DL copy pasted from my original thread:

I took out my wire stripper, slit the insulation for the CAN lines and slided it over to access an opening of bare wire. I then tapped into the CAN lines through a direct wire connect and then covered the connection with electrical tape:




Then I used a fuse tap to grap switch power from an open slot in the fuse box:



Then I grounded to an stud/nut next to the fuse box:



Now I have a CAN harness that I can quick disconnect from my solo CAN line, which makes it easy to move from car to car:




15 minutes later I'm done:



I have brake switch AND brake pressure now (only through channel 4, the other 3 don't have anything):



Ok, I'm off to go see my kid at baseball practice. The fun stuff is to come tonight on my first track day in the car.

NephroC4S

Subscribed and looking forward to learning a lot! Thanks Joe!

RocketGuy3

Wow, to think I used to consider myself somewhat handy and knowledgeable about cars. The internet is a great place to pick up some humility.

24Chromium

You're such a romantic!

Shockwave

Subscribed!!

Loved your documentation and journal of the GT3. I also wait anxiously as you start posting your lap times at Laguna Seca. What is your solution for passing sound?

doborder

I will be an occasional contributor to the thread
I'm currently working on a write up for the 981 GT4 GPS PSE solution that I adapted from Mech33... Hold on as I'm still in testing phase!

Shockwave

I look forward to it since i plan on running Laguna Seca at some point next year.

Beantown Kman

YES!!! Orthojoe's GT4 track journal begins!!!!!!!! Subscribed!!

orthojoe

And a great place to learn. I learned a lot here from others as well!

LOL



Mech33 and doborder have been working on a solution. Apparently the wiring between the GT3 and GT4 to keep PSE closed is different.

Thanks, bud!

You convinced me! LOL

morefun

Sign me up! It's going to be hard to top your epic GT3 build thread!

jphughan

Looking forward to this! Quick question though: For rear camber/toe flexibility, you bought rear tie rods rather than the toe links everyone else has been buying; the ones Tarett designed for the GT4 are called rear toe control arms on their site. Why is that? Sorry if this is a newbie question; I'm trying to learn as much and as quickly as possible around here from the illuminati around here and share it with others as opportunities arise.

orthojoe

OK, let's move onto my first track day in the car.

Impressions:

1) Turn in on the car is very light/crisp and the car rotates much easier than the GT3 does.
2) The gearing and shifting points are the exact same as my old boxster spyder and the newer cayman GTS. No different. Yes, it's tall, but I find it funny that nobody every complained about how tall the gearing was in those cars as well.
3) Yes, the car could use more power or shorter gearing, but that doesn't stop it from being..
4) An absolute blast to drive on track. I find the car equally as fun as the GT3 on track even though it makes 90 less hp and costs 50% less.
5) That being said, the GT3 is the superior car. The engine is jut another league above the GT4 engine. No ifs, ands, or buts.
6) Understeer. Unless my setup is somehow unique and transformative, I don't understand all the hysteria about the understeer. Yes, it understeers, but only a touch and it's easily controlled with throttle. If you listen to Randy Pobst, he says the fastest setup for a car is a touch of understeer, which is exactly the way my GT3 and GT4 are currently dialed in. To recap my setup:

Front:
-2.7 camber
1.5mm toe OUT (3mm total)
8.6 degrees caster
Sway bar middle

Rear:
-2.4 camber
3mm toe IN (6mm total)
sway bar middle

If you enter a corner too hot, the car will oversteer. During corner exit, there is a touch of understeer, but this keeps the rear end planted and you can power down very early with this setup, and we all know the earlier you get on the power, the faster you will be. It's not a plowing understeer either, it's more like a 4 wheel slide as you power out. I'm going to go out on a limb and say that many of the people who complain that the car plows are running into that situation because they are adding or holding steering lock after the apex. If you are unwinding the wheel after the apex, the car will not plow. If it weren't for the fact that my right side tires from a CCW course are getting rollover and wear on the outer edge, I would leave my current setup alone and not change a thing. I am going to try full stiff on both from and rear bars to decrease rollover and hopefully not change the dynamics of the car.

7) As mentioned above, tire wear is an issue. I doesn't look like the front tires will last any longer than the GT3. I'm looking at 4 days at the most on these days, which is painful. I may have to look into running 19" wheels with RE-71Rs. This is my right front tire after one day. The outer edge is already touching bottom of the groove, and the next tread over is washed away on the outer 1/2.

After one day:


8) Stock brake pads and fluids worked just fine for me. A friend was get me a set of project mu club racer pads from Japan for me to try out. I love the Ferodo DS1.11, but this is a chance to try another pad which is priced even cheaper. I ran the pmu CR pads on my old BRZ and they were great pads. They were very similar to the raybestos ST43 pads I used to run on my EvoX. I will follow up once the pads are installed probably in May.

Video and Data from my first track day next.

orthojoe

That is a mistake and I have edited to correct. They are indeed rear toe links like everyone else is using. Thanks for pointing it out

jphughan

Cool! But judging by the picture in your original post, it looks like you got the ones with bump steer adjustment. Is that just because you wanted that capability?

jphughan

Ugh, just read your second long post about tire wear. That's not very encouraging at all considering I'm running a dual-purpose alignment with the front at -2.5 and 0 toe. I was hoping to get 6-7 track days out of a set of tires, especially with Macca's post somewhere suggesting that data from lots of GT3 owners around the world says they might be good for that many. If I can only get 4 I too will have to rethink my track tire setup, especially since I'll also be putting a fair amount of road miles on my car between track days.