Monti

iTrader: (44)

I've been running this FFG mod now for two races in Florida and have won both of them. As for bulk heads I've just raised the the rear 1mm and kept the front the same. This weekend I will try my same car in Jackson, NJ to see if it works as well there.

Monti

WesRaven

Are you running toe in or out up front on this setup? I'm assuming out... but I tend to be wrong when I assume things...

Going to try this setup out at my local asphalt track this weekend, should be interesting. How did the initial turn-in feel?

To anyone running this mod; What is the theory behind why this helps? I can speculate, but would rather hear it from people that actually know.

geeunit1014

iTrader: (14)

Toe out always in the front for me. For me, turn in is awesome. I just think where i want the car and it was there. If you think its too much, you can add more front damping, or maybe take away some of the toe out.

2 things going on with the ffg. One is, you are not transfering the twist front the front gearbox to the rear of the car anymore. The 2nd is, i found the flex on the car to be different. Instead of the rear being super stiff and the front kind of flexing around that, the flex is more even front to rear. The car is certainly more planted like this.


Also adding to what FJ said, I found the ffg to have a little less travel l/r than before, but as long as it still moves free it works properly. It will take some playing with the set screws clamping it to the am49s to get it right

WesRaven

Thanks again Mike, the setup sounds perfect; I love lots of turn-in and a super responsive car.

The explanation makes a lot of sense; I have also noticed how stiff the back tends to be so I adjust my rear AM50 back .2-.4 mm (I usually don't run with a top deck). Looking forward to playing with this mod once I get another AM49-3.

edit: Just realized I don't have any AT21S, just the standard AT21. How essential are these to this setup?

geeunit1014

iTrader: (14)

There is definitely more steering with the at21s's. Maybe if you have low grip and need stability the higher roll cneter would be ok but my car was much better with the extra steering

WesRaven

Ok thanks, I'll try to get my hands on some AT21S before the weekend.

So after shimming my bulkheads up (what a pain to get those shims in there without falling out during assembly) and doing some reading on roll center I'm curious about something: What is the difference between raising the whole bulkhead up vs simply raising the inner upper links?

geeunit1014

iTrader: (14)

The Idea for shimming the bulkheads up is to adjust the diff heights. When I initially did this, I changed the shimming on the upper links to keep them the same.

erchn

iTrader: (7)

Pro-tip: get some of this tape apply a small piece where the shim goes and cut open the hole. Stick the shim on, enjoy simple mounting onto the chassis.

It doesn't take much. I usually put on the bulkhead (read: bottom) so it's hard to see and easy to trim, when compared to putting on the chassis itself.

WesRaven

Interesting, it never occurred to me that the diff height would impact the handling. Thanks for the info.

Thank you sooo much for this, I figured there was a better way. I was considering putting some grease or something on the threads to hold the shims in place, but this is a much better idea

bkspeedo

iTrader: (5)

Moving the diff's up surprised me as well. But I'll tell you now it works great for asphalt racing. I tried it on carpet and was not so happy. Seems to stick the car in the carpet not letting it rotate well. Was over a tenth off pace on average.

Raising the diff changes the dog bone angle which changes on power starting. Its called the Jacking Effect in car lingo.

Team_Krusty

iTrader: (3)

Quick question regarding the cutting of the ffg rod. I understand it's to try find the right flex characteristics but I also note in the pic that this mod was on the a car fitted with the alloy chassis. Wouldn't swapping over to the evo2 carbon chassis provide additional flex options rather than cutting parts? I've always wanted to try the alloy chassis but here in Australia our outdoor tracks are low grip and unpreped so the carbon chassis has always been suggested. Its obviously working for you.... I'm just thinking out loud

Are any of you doing this mod and running the carbon chassis?

Simon

Monti

iTrader: (44)

If you look at my pic I posted its on a race berry v2 chassis. The aluminum chassis is softer than the carbon chassis.

Monti

tbamsey

iTrader: (1)

A700-UB1 does do the whole car or one section ( front or back) does this make a difference in freeing up the drive train more

hanulec

iTrader: (28)

Whole car
I never ran ub1 myself. Make sure to check your bearings and replace any bent drive shafts....

WesRaven

UB1 comes with enough bearings and pins for all 4 dog bones. I don't think I noticed an immense difference in how smoothly the drive train ran (its already so incredibly smooth) I mainly run UB1 to avoid any extra wear and slop from the bushings, and in 17.5 blinky I'll take any less resistance I can possibly get.

I don't think I would recommend these for running mod though; the only time I have ever broken one was while running boosted 13.5, and I doubt you need the resistance reduction with that much horsepower.

edit: The best thing I've done to reduce rolling resistance (aside from checking every bearing before race day) is lubing the front and rear beveled diff gears with a dry bicycle chain lube like this. Makes it butter smooth, and reduces the "angry woodchipper" sound the car likes to make on the track (at least compared to the belt cars).