[SlotCar]

I think these are for the 400. Per GRP website the GT (and 430) stock sizes are:

Front: 19x8.5" Offset +55 Recommend tire size: 245/35r19
Rear: 20x10.5" Offset +60 Recommend tire size: 295/30r20
5X114.3 Lug Spacing, 68.1mm Hub Bore

GRP admitted that this info has two typos - OEM stock for GT should be Front 19x8 and rear offset 69. They actually have it correct on another page. The OP has it right.

 

[SlotCar]

Dang I almost ordered wheels with the spec I posted! Thanks for the correction...

Glad you caught it. What are you getting?

I just ordered wheels with the OEM rear spec but with 19x8.5 ET50 fronts. Should have them in six weeks, so fingers crossed.

 

[SlotCar]

There's a company called Laforge Industries in Singapore that makes custom forged wheels for a pretty good price. I chose a Vossen design split 5 spoke. I wanted it to match the stock GT size because I like the stock fitment. Should take 8 weeks shipping.

Question: Is the bore size 68.1 front and back. I found two sources that contradict each other. GRP says 68.1mm F/R and the other (a post I saw on here) says

• Front 69.06 mm
• Rear 68.06 mm

What bore size did you go with?

They are the same, 68.06. That’s what I went with.

I think the 69.06 comes from a typo in some versions of the service notes. To my knowledge, the rotating parts of the hub are actually the same (A132D0021F)

Just checked out LaForge…they have some sweet wheels! Didn’t know about them ;

 

[SlotCar]

Which ones did you pick? What did they cost?

 

[SlotCar]

Nice! Classic and cool…Already ordered?

I worked with John from BSPK; we took his Teresa and modified it…they will have brushed dark gunmetal faces with brushed natural aluminum rims and center caps.

I was a PITA on details, but John was pretty patient and very collaborative. I like that his designs don’t overdo lightness - his/my priority is strength. He does the design and analysis work himself, and is happy to discuss the details.

I’d suggest hitting him up if you hadn’t already spent the $. But yours are pretty hot…😜

 

[SlotCar]

I did order them but have to change the spec so I emailed them the new specs. I am going to go wtih:

Front: 19H2x8.0J ET55
Rear: 20H2x10.5J ET69
Hub Bore 68.1mm (give that little 0.4mm tolerance 😂)
I'll have them do the bolt holes too with a 60 degree taper.


Your wheels look Nice! How much did those run you?

Looks good, but I’d take out the 26mm part, not that I think they will care. A lot of folks are using 31mm thread-length bolts now. But it shouldn’t impact the design of the wheel hub.

Mine wound up being $2600 shipped, but 8 weeks to delivery.

 

[SlotCar]

Nice. Can't wait to see them!

I ordered some custom 2 piece forged wheels for my GT and they're likely coming from the same Singapore factory. I went with 19x8.5 45et and 20x10 et57. Will report back when they arrive!

What did you get?

 

[SlotCar]

View attachment 1384510




Tad lighter with a slightly more aggressive offset while still working with my 295s. We'll see how things fit once they arrive.🤞

Awesome super-cuteness!! Def a perfect fit for the car’s personality. Will get you all kinds of attention from the younger crowd. So jealous

One consideration is sidewall profile - it’s why putting a wider tire on the same size rim doesn’t always improve handling. There are a fair number of tests that show handling improvements for narrower tires that are better matched to the rim width. A 245 tire will almost always perform better on an 8.5 inch wide rim, than it would on an 8 inch. YMMV

 

[SlotCar]

Rolling my own . Using Alligator Sens.it RS+ I programmed using their ATV-41 programming tool. Alligator is the OEM for GTs, and they have been super helpful in making sure everything works.

If anyone needs a set, let me know.

 

[SlotCar]

You know I'm in! Did they program ok on the test bench? Still waiting to install on wheels right?

Programmed and verified. An S1 set should be going in next week to complete the verification. S2’s work fine, no concern there.

 

[SlotCar]

So off the shelf S2 TPMS sensors from Gator work out the box?

Alligator Sens.it RS+ work for S2 but only after being correctly programmed. Just have to make sure the programming tool has been updated in 2024 or later. Some tools don’t differentiate between before and after 2016, and some have an older program load. I suspect that’s why folks have had problems.

 

[SlotCar]

Mine finally showed up…

Wheels are still not done... The wheel designer contacted me and after running the wheels through FEA (Finite Element Analysis) over 30 times (!) there were some issues with potential stress damage on the spokes under heavy shifts in force (like track use but daily use would've been fine) so they have to redesign them and strengthen those areas. The high offsets and requirements for caliper clearance made the design slightly compromised. I'm glad they are doing all this to ensure the wheels hold up to any stress I can put them through (though I'm not really a track guy per se).

Really impressed with their diligence. And for the price, I wouldn't have expected all this attention. So big props to LaForge Industries!

While it’s good they’re doing this, it makes me wonder about their design and manufacturing capabilities. They should be telling u what is causing the issue and asking u which facet of the design they can alter to make it work.

You might want to ask them what design/safety margin they are after - eg 1.8, 2.0x, a multiplier for the load rating or other reqs from JWL, VIA or SAE J2530. Curious which tests are the wheels failing: radial, cornering, impact, torsion, etc?

Hoping it all works in the end

ps: mine just showed up-pics to follow shortly

 

[SlotCar]

They did. They sent me pics of the areas and the issues they found in the analysis. Beyond my intelligence for sure 😂 but they were pretty communicative about it.

Cool! Would love to see those…