JAG Racing

I found it interesting that my R40 with all stock pulleys does not have "front over-drive". In other words, the front tires do not rotate at the same rate or higher than the rear. I assumed that most 4WD cars would benefit from a "slight" over-drive on the front tires. Thanks for the explanation.

InitialD

Yes. Stock pulleys (36T/18T and 23T/19T for the front and 19T/46T for the rear) would give you the same front and rear drive pulley ratio (2.421) which gives you same rate of rotation front and rear.

NP. To take an example, the 710 is slightly overdriven in the front i.e. 1.875 rear pulley drive ratio and 1.842 for the front. What we normally do is to true the front tires 1 mm smaller than the rear to get 1:1 overdrive ratio and along the way, you will find the front and rear tires are about equal diameter and hence you get slightly overdriven front.

CHUCKMANDO

iTrader: (4)

Not too many r40s at Floyd, but I do get there with my ntc3. Unless you get there early, you will have to deal with the 1/8 guys too. If you have questions let me know.

HarKonnenD

iTrader: (23)

If there are any, that will be fine. I got the R40 since the LHS was out of the NTC3's and out of the box I did find the HPI to handle better. Are there any scheduled races going on, or just horsin around? You mean they have mostly 8th scale drivers there now instead of nitro sedan? After a while I'll be going 8th onroad as well, so it's good to have both.

JAG Racing

InitialD - Good information - Thanks.

CHUCKMANDO

iTrader: (4)

Hoses are set up on a 1/8 scale size track. ON Sundays, sometimes road rails are set up. There is no organized racing there anymore. If you get there around 9-10 esp on a Sat, there is hardly ever any 1/8 racers there. Unsually around noon, they start to show. I give even some of the better 1/8 guys hell in the infield, but the straight is just too much for us 1/10s. There are a few r40s, but not many. I did drive my friends and if felt good. If I want to lot race with just 1/10s, I stay in Staten island. We use the road rails on Sundays mornings.

HarKonnenD

iTrader: (23)

Cool. What engines are the nitro sedan guys running? Any NS12s, or Rody tuned Rbs?

CHUCKMANDO

iTrader: (4)

Many different engines since so many go there. but mostly ns12s, mugen x12s couple of jps. One guy had a Maxy mod. rbs too. My main engine is the ps12. Only one on the block to have one.

HarKonnenD

iTrader: (23)

PS12? What's that? I'm thinking of some lightweight upgrades an an NS12. How good are those Sirio EVo2 in your opinion? I hear they aren't worth it that much.

fastrcracer

Where can you get the one piece engine mounts like the guys were running at the nationals this past year ?

AMGRacer

I got mine from RCChamp who is an advertiser on this forum. It is an Atsushi Hara product.

Speedbug

Hi Guys, i am running the R40 pretty much standard as per the manual and I am going through a set of rear tires in 4X 4 min races. Is there something i can change in the set up to try to save the rears a bit, the car is handling great and the fronts are still like new.
I have locked up the front diff with modelling clay and the results were great on our tight track, have to buy the solid axel now.
I was thinking of upgrading from an OS.12TR(P)T to something with a bit more sting, maybe a SirioEvo2. Any other suggestions?

Rapid Roy

I'm assuming that you are running foam tires. You can try harder tires in the rear and go with a softer rear spring.

What shore tires are you using now?

Speedbug

The tires were the original ones that came with the kit, I have just bought some 40 and 45 shore rears and will give them a go.
I have also taken some toe in out of the rear to run 2mm instead of 3mm. Sacraficed some rear grip but it does seem to make a small difference to the tyres and the handling is still good.
Any thoughts on engine upgrade?

CHUCKMANDO

iTrader: (4)

PS12 is topgun777's engine. Check palmaris engine thread It is totaly different. Sirio's from what I see is hit or miss. Never owned one myself, but on staten island, they are the most used at our lot. ON the most part, tuning is pretty easy from what I hear.