I use my TT02 for bashing too. As I have the tamiya aluminum motor mount, my lowest FDR is 5.74 so I think 4.1 should be just right.
For the springs I prefer orange (medium) springs at the front and red (soft) springs at the rear. But it also depends where you bash. If the surface is flat with few small bumps and holes, you can use harder springs, otherwise with softer springs the car is more stable and easier to drive

What spur gear are you guys using to get to 4.1 FDR?

I noticed that with the Kimbrough 66 paired with a 35T pinion gives me 4.9 FDR, and the pinion is rubbing on the gear cover.

You have to cut a small hole in the gear cover. You can find what to do here: http://www.thercracer.com/2014/08/tamiya-tt02-guide-mods-tuning-and-tips.html?m=0

Reading the guide I though you only had to "make room" for a 50T and larger 64P gears though I could be wrong. I went with 64P gears and 74T on the spur and 44T on the pinion which I believe gets me to 4.37:1 FDR.....Sorry I had 4.1:1 on the brain for some reason when I originally posted.

So...I am old but in my younger days I must have done 15-20 bodies and always cut them out using scissors which was always really tedious, this was before the internet was really a thing. Last night I decided to check YouTube to see if they had any videos on cutting out bodies and of course they did. I used the scoring method and within 15 minutes I had a pretty decent body and them another 15 minutes with a drum sander on the Dremel and some hand sanding I had a very well cut out body......I no longer loath cutting out bodies .

Another funny story. Last night I am talking with our 9 year old son who has helped me a bit putting the TT02 together. Two years ago I resurrected my original gold pan RC10 from 30 years ago, I put a BL motor in it and spruced it up a bit and gave it to him for Christmas and it now gets run fairly often and he really enjoys it so he is looking forward to running the TT02. Anyhow we are in my office and I was asking him about how we should paint the body. I showed him Haywood's RSR and he looks at it and then points to a print on the wall of Hurley's 1990 911GTLM (still numbered 59) and asks if that is the car.....I did not put the two together but good eye little man, just off a few years.

Cheers,
Jim

Thanks for the link. I'll be looking for my Dremel tool after I get home from work today.

What pitch gears are you running?

Curious.

Cheers,
Jim

48P

If I did my math correctly that would be like a 47 tooth 64P pinion.

Am I the only one who read the article as meaning that you have to make clearance for 50T 64P and larger gears?

I will be curious how much you have to remove out of the cover to make room.

Cheers,
Jim

Anybody have any luck with installing a 55T 48P spur?

So I have had quite a bit of track time with this diff conversion and I opened it up to see the results. No Leaking at the out drives as a result of the installed orings

The diff internals were holding up well nicely. I did have some build up of diff fluid in the gear box, due to the lack of gasket, but it definitely has helped in reducing the diff action, over antiwear grease

At the suggestion of a top driver, I have coated the diff case with AE black grease (supposed to do a better job than green slime) to stop the leaking.

As for the drive, I was posting some impressive lap times running 21.5 / USGT tyres.

Raman,
Good to know the mod works. With that said what are you running for diff grease? This is my first foray into playing with diffs on RC cars and it intrigues me. When I built my TT02 I used a bit of 500K fluid in the front which added a bit of resistance compared to the rear, open, diff but is still pretty "open". To be perfectly honest I am not sure home much resistance I am looking for and I guess once I get the car running I can play around to see how different amounts of "lock" affect the handling.

Cheers,
Jim

I heard back from Callie Graphics who I have used to do some custom graphics on a couple scale planes I have built, BTW, in my experience she does great work. I have given her the go ahead to make a set of graphics so that I can do a tribute to Hurley Haywood's RSR car, the white with red/blue stripes and not the original yellow car.

So much for a budget built but looking forward to seeing the end result.

Cheers,
Jim

Jim,

I'm running 2.5 million in the front which makes it close to locked. In the rear, since I am on high traction carpet, I run 10k in the back.

How much does she charge for printing? Can she print white on clear vinyl?

For the stripes down the side and over the hood and trunk was $25 shipped. She uses colored vinyl and then layers it if the coloring is a it more complicated . when I get home tonight I will take a couple pictures of one of the planes she did, it looks pretty darn good.

Cheers,
Jim