JimmyMac

iTrader: (2)

That's like a 6.8 ratio. I tried that with a 104 spur and 33 or 34 pinion and it was a dog. Now I'm using a 112 spur as well. I think the spur just hangs out the bottom.. if that. Might even be level with the chassis. I'll probably switch off to a 110 spur though when I can get a new one. Anyways, the magic number here for me is 7.1 final. 104 with a 32 pinion. I like using 6.9 final with a Monster stock tuned with rpm instead of torque. However I ran a Fuk/Mako Monster Stock this past weekend with a final of 6.3.... I won. So who knows, each motor has it's own personality I guess.

TJ

So thats what you did Rod I'll have to remember that next year if I go back.

JRRobiso

Ran the car with a spool & center one-way drivetrain setup two fridays ago at my LHS asphalt track and it handled preety good despite having a center one-way pulley. Track layout was a technical type of layout with medium bite/traction. Ran the car the 1st time w/orig drivetrain setup and car carried to much speed when entering the turns (can't use brakes w/that setup). Switched the front w/the spool I got from SpeedTech, change to softer springs in the back and the car was stable but still missing something in terms of traction.

Will try next to switch sway bars to soft (red) F/R, blue/yellow springs. Guys at my track normally don't run swaybars on their cars & if some do, it's only up front. Gearing on my car for a monster stock was 102/37 (motor was too hot after a run) then switched to 102/34 (didn't have a 35 pinion gear).

Going back the the spool/center one-way setup drivetrain, the result was better compared to the front one-way. Didn't use my brakes the whole run. Car didn't carry too much speed when entering the turns & was like a rocket upon exit. I think I might just stick with that drivetrain setup and see if it will also work with 19 spec motor.

NealP

Hi everyone...must say a great 415 forum going on here!!

I was wondering if anyone can give me a few tips to dial out corner entry understeer and improve initial steering response/turn in. I'm running on tarmac but its quite tight and not a huge amount of grip. Currently running -
Springs - Blue F 45w ,Yell rear 35w
No spacer under front or rear axle bars
Shock pos 1 Front pos 4 rear
2.5 toe in rear and 0.5 toe out front
One way front diff
C1 hub on left C2 on right
Std 4deg castor
CS22 tyres.

Any help would be appreciated and sorry if the information above is a bit vague.
Cheers,
Neal.

Martin Crisp

Hi Neal,

You might want to try...
* changing the ackerman - if you connect the steering tie rod to the hole closest to the front of the chassis, this will provide more steering response
* Shortening the Wheelbase
* going to a blue spring in the rear and standing up the front and rear springs. I don't know which position is 1 or 4 so I am not sure where you are running the shocks.
* If you increase the rear droop this will give you a quicker turn in response when off power.

Hope this helps.

Martin Crisp

Scotty Ernst

Hi Martin, See ya Thursday at the Reedy Race, have a safe trip. CYA,Scotty

Martin Crisp

Hey Scotty

I am sooo looking forward to this race.....cya there.

NealP

Hi Martin,
thanks for the info much appeciated...
I'm running the shocks at present fully inboard at the front and on the outer most hole at the rear.
Cheers,
Neal.

Martin Crisp

Hey,

For those of you running a spool with the 415, are you getting a lot of front wheel chatter when you turn the wheels like KilRuf refers to earlier in this thread.

Has anyone figured out how to get rid of this. I spent the better part of a day yesterday to get rid of this and was not successful. Like KilRuf, I noticed that moving the front arms back and going with toed out hinge pins helped the inside wheel because the universal did not have as much of an angle to deal with. But you need to balance that out with the outside wheel, as this setup will add more angle to the outside wheel depending on how much ackermanyou are running.

I worked on the universals themselves to make sure they had a smooth action when the wheels are turned. I noticed that with the wheels off the car everthing is very smooth, but when you add the rotating weight of the wheels this enhances the vibration and causes the chatter.

I notice that with a one-way there is zero chatter and with a normal diff there is only a hint of it at the extremes. I am not really sure why this happens mainly with the spool. I even disconnected the universal from the outdrive on one side so that only one of the front wheels/universals was connected to the drivetrain. I did this to see if it was somehow the "locked" aspect of the spool that caused the problem.

I am stumped with this one...anyone else have any ideas?

Martin Crisp

Hey Neal,

Thanks. With the shocks layed down the front end feels lazy and less responsive. Layed down shocks have a softer and more progressive effective spring rate. Thus the initial turn in will feel lazy. However this layed down shock will give you more steering through the rest of the corner then a stood up shock tower.

rtypec

iTrader: (2)

Hey Martin, wait until you hear it on the track...is that a body rubbing? When I first installed my spool with new universals, the chatter was very noticeable and I could not find a way to get rid of it. However after a couple of weeks, it went away because the axles were getting worn in from the pins. I just installed new universals for this weekend's race and I'm looking forward to going "crrr-tha-tha-tha" around corners I know it's not good but I've gotten used to muting that sound out of my head.

To all of those travelling here, please have a safe trip and we'll see you in a couple of days.

jeffreylin

Hi Martin, I wonder if you have your wheel shaft shimmed? I had the same problem when I changed the front geometry to the inboard toe out. Since that effectively made your front end narrower, the shims I originally had in between the wheel axle and the steering block was binding and eventually destroyed the bearing inside the steering and stripped the inside of the block. Once I took the shims out (and replaced the broken parts) everything was smooth again.

Martin Crisp

Rod,
Glad to know I am not the only one with this issue. The thing that worries me is the drain on the battery. The amp draw spikes way up when we have this extra drag. I know what you mean about already broken in universals. When I build a new univeral I always use the old pin as it has already been broken in. A completely new universal just does not work.

My flight leaves early on tuesday. I hope to arrive in la la land mid afternoon your time. I think some folks were talkn' about going go-karting on wed night.

jeffreylin

I do shim my universals betwen the wheel adapter and the bearing. I thought this might have been binding things up, so I removed the shims, but had the same result. The only thing I have not replaced is the bearings in the steering kunckle. I was planning on trying that tonight.

cya

Iniral

Martin,
The reason your wheels chatter is due to the universal shafts. Even though manufacturers claim that they are CVD (Constant Velocity Drives) there not. So when you steer, the wheel axle must accelerate and decelerate four times for every one rotation of the axle in order to equal the rotation of the out-drive and dog bone. The spool obviously does not absorb this effect and the weight of the wheel and tire acts like a flywheel which significantly magnifies this in the form of the chatter you refer to. This is also why you don’t notice it when you remove the wheels and tires. When using a diff or one-way, these units absorb the chatter, hiding the problem.

The best thing to do is to make sure your spool has no wear grooves, and that the dog bone and universals are well lubed. Also, try to adjust the suspension arms so that the drive-shafts are as straight as possible or even swept back slightly. This will reduce the angle of the universal at full lock at the inside wheel. The inside wheel is almost always carrying the greatest angle due to Ackerman. Doing this will compromise your set-up as it effects weight distribution and wheelbase.

Good Luck!

FUK_WRX

iTrader: (1)

Can someone kindly post a picture of the spool, im curious how it looks like.

Thanks,

Luie