Help me design a proper TA-02SW chassis (no mods needed to fit porsche body)

[smirk-racing 177]

Hi TA-02SW fans. I've gotten in touch with a very skilled designer who is willing to make a proper chassis kit for the TA-02SW (one with a 230mm wheelbase, and with adapters for the body mounts so the body mounting holes can stay in the original location).

I am aware of the chassis made by maxspeede and discussed here and in other threads (maxspeede by the way seems to be on a semi-permanent vacation - I've been trying to buy a chassis from him for months to no avail):

Is there anything special that the designer should consider other than removing about 27mm of length (which sounds like a lot when you think about it, but I think that's correct) from the middle part of the chassis? Basically, the area that holds the servo will get a lot smaller.

I'll take some pics of my TA-02SW along with some measurements so the designer can get this just perfect with minimal errors, but I'd very much appreciate help from you all (who are experts with the chassis).

One question that has arisen is location of the steering posts. I can't really see anything special (or problematic) in that area but someone mentioned on a YT video once.

 

Thanks! I hope to nail down a basic design in the next few days and then see about getting a prototype.

[Superluminal 3408]

I thought the reduction was 6mm overall length on the chassis plates- the rest of the shortened wheelbase is achieved by the reversed TA01 type rear arms used on the standard TA02SW kits - not sure about where the 27mm is from unless you are using the standard rear arms for the regular TA02?

Ive got the Maxspeed ones on my 934 build and didnt have to do anything different with the body posts. The only modification I made was making a new 6mm shorter proper shaft by using a piece of brass tube and soldering in the spade ends cut off of the regular prop shaft (can also be done by cutting a deeper groove into the drive cups as an alternative)

[TurboRSR 219]

As @Superluminal writes you only have to reduce the length of the plates by 6mm. 

[smirk-racing 177]

27 minutes ago, Superluminal said:

I thought the reduction was 6mm overall length on the chassis plates- the rest of the shortened wheelbase is achieved by the reversed TA01 type rear arms used on the standard TA02SW kits - not sure about where the 27mm is from unless you are using the standard rear arms for the regular TA02?

Ive got the Maxspeed ones on my 934 build and didnt have to do anything different with the body posts. The only modification I made was making a new 6mm shorter proper shaft by using a piece of brass tube and soldering in the spade ends cut off of the regular prop shaft (can also be done by cutting a deeper groove into the drive cups as an alternative)

@Superluminal Thanks! You called it correctly - I was imagining using standard TA02 arms. I am trying to see if we can design the "optimal" TA-02SW chassis. My understanding is that the current TA-02SW starts out with a standard chassis (260mm wheelbase) and gets down to 236mm by using reversed TA01 arms. However, this creates two issues: 1) the dogbones are at an angle and 2) the suspension links need shims (since they're starting out at the gearbox, but need to meet with hub carriers that are swept inwards for the shorter wheelbase). In my build, the 2nd issue in particular creates a lot of slop.

Would the chassis perform better it if really were shortened about 27mm, so that you could use straight TA02 arms, and resolve the issues noted above? I'm not entirely sure, but I'd certainly love your feedback on it.

@TurboRSR Thanks for your comment - also keen to hear your thoughts.

 

Basically, if you could have anything you wanted in terms of the chassis length, what would you want? What would create the best-performing TA-02SW (given that these are not modern race chassis, so we're not pretending they're anything but charming classic vehicles)?

[sosidge 514]

https://tamiyablog.com/2006/10/110-rc-30th-anniversary-porsche-934/

[smirk-racing 177]

1 hour ago, sosidge said:

https://tamiyablog.com/2006/10/110-rc-30th-anniversary-porsche-934/

@sosidge awesome link thank you!!!

Ok, so for what it’s worth, when Tamiya when absolutely wild and made a true 230mm wheelbase Porsche in race-edition spec, they made all the arms, links, and driveshafts straight:

https://www.tamiyausa.com/shop/110-4wd-belt-drive-road-ta/rc-porsche-turbo-rsr-type-934/

(zoom in on the pics)

Again, not sure this matters a lot, particularly for casual street driving, but if we might have an opportunity to get any chassis we want, it is useful to have this reference point. 
 

 

[KILLorBE 23]

Everything matters, but it really depends what your goal is, best performance or something more realistic (Rear engine, RWD)?
Are you thinking about designing other parts as well, or just modify the upper and lower deck and possibly use readily available parts from just about any car?

Keep in mind that prototypes can get stupid expensive real quick, not to mention having small quantities made, or large quantities and ending up with lots of unsold chassis'/parts...

[Honza 463]

17 hours ago, smirk-racing said:

Would the chassis perform better it if really were shortened about 27mm, so that you could use straight TA02 arms, and resolve the issues noted above? I'm not entirely sure, but I'd certainly love your feedback on it.

TA02 arms are not straight either - they are extended to the back.

https://www.tamiyaclub.com/showroom_model.asp?cid=48983&id=2193

I personally don't like angled driveshafts, since they generate lot of anti/pro squat.

I think that closest to the ideal is TA02T, which uses reversed TA01 arms (orientation used in the SW is actually right for TA01 arms - they were used to shorten DF01 wheelbase) - you'll gain a few extra millimeters on chassis compared to TA02 arms.