XCELL

iTrader: (10)

For those of you attending the DHI cup what set-up have you come up with for 17.5? I am going to be practicing this weekend and start with Hara’s 17.5 from the IIC and tune from there.

Thanks,

Patrick

toptek

Yes they work verry good with the Tekin.

I tried the motor and it runs good and it is fast.
I used a lower Boost and a havier gearing.

Nilks

I am going to attend DHI Cup, and I have used the SP V3 17.5T through-out this winter-season.
My experience is that is can handle a lot of timing, but it also needs a lot of timing to go fast. I think Hara's setup will be good. My setup is a bit extreme, and keep an eye on the temps if using mine (my motor is only getting 57 deg celcius after 6 min, but I think that it can get hotter on the larger DHI Cup track).

My setup:
Boost: 50
Start: 5.000
End: 15.000
Turbo: 15
Delay: 0.25
Ramp: 3.0
FDR: 5.7
Motor-timing: 10

Hara's setup isn't as extreme, and is very smooth. So it should be a good starting point. I would recommend you to use 10 motor-timing - the SP V3 really comes to life when using 10 on the endbell.

XCELL

iTrader: (10)

Thanks for the information, been trying to gather as much set-up info possible. Looking forward to this race.

Patrick

twk-b

iTrader: (1)

Spent some time over the holidays and wrote a gearing app for Android... which I just finished adding to the Android Market.

The reason I am posting it here is because it comes with some features I have found handy since having my Tekin RS, along with being able to store your settings for it (so when someone asks you do not need to plug it in

I found often when changing up gearing, it messed up my RPM range that I had just perfected. By doing the math I found that if I calculated the speed based on RPM and FDR/Rollout and then reversing it with the new FDR/Rollout the boost seemed to work the same (and the motor temperatures too).

So this app shows the speed for your boost start and boost end (in km/h). After changing your Rollout/FDR you can adjust the RPM values to restore the speeds the boost affecting the car....

From my experience (carpet 80x36) the lower boost number is the apex speed on the slowest corner (and on our carpet track varies from about 12-20 km/h), and the max the speed at about 1/2 or 2/3 the straight (25 - 60km/h)

Big difference over gearing apps are:
* you to quickly skip throw spur/pinions using the volume buttons...
* you can calculate the pinion (using the set spur and tire diameter) from a given Rollout or FDR
* you can see the speed your boost start/end at before and after gearing changes which allowing you to correct the range (useful for Tekin RS and other boosted ESCs allowing RPM configuration)
* you can stop guessing which spur to switch to with the gear chart you can see which spur gives you the ratios with your pinions
* you can forget your settings because TwitchRC remembers them for you.

A future version will allow you to download setups to view/edit.

The homepage for TwitchRC is here:
http://bernie.dcbl.ca/wiki/wiki.php?...c&cscid=35&r=1

RC Tech thread for feedback and updates:
http://www.rctech.net/forum/electric...c-android.html

-b

toptek

Looks nice.
I have only 1 question. are the numbers behind the rpm's the speed in km/h? and are they right on the screenshot?
I made a topspeed calculater bassed on top rpm meassured with an rpm meter on the car.
As I fill in your info, than I get slower speeds.

StevenOlsen

tryed nilks sertup yesterday, and changed a bit
boost 50
start 2800
end 12000
turbo 15
delay 0,2
ramp 2
fdr 5,6 use as small spur as plausebul
motor timing 10
motor comes off around 70 degress celcius.

toptek

I tried today the AE BD speedo. It drives smooth but I can say that Tekin did a great job. It is not as smooth as the BD but the infield speed is the same and the straight speeds are faster.
I used the SP motor because the BD owner had that motor so we didn´t had to solder it to compare it with the Tekin.
To keep up with the Tekin, you must drive verry good in the infield els you loose to much and you can´t fight your way back.
The Tekin drives easier fast. With the BD I had to push each lap to stay ahead of the Tekins. I became second and that is the first time I lost a race in the last 3 years. It was just a trainings race but normally I´m always ad the nr1 spot.
I changed back to the Tekin to put some fast lap times. The one that won from me changed to the BD. He was impressed of the feeling but not the speed of the speedo.
He became 3th behind 2 Tekins.
Changed the motor back to my Tekin redline and improved my own track record with 0,1sec.

My setup with both motors was.
Boost 50
Turbo 15
Turbo delay 0,1 turbo ramp 2
Start rpm around the 6000
End rpm 12500
gearing with the SP 7.0FDR
with the Tekin 7,4FDR
Motor timing SP 10
Motor timing Tekin around the 8
The Tekin was smoother and it was fast.
The Tekin combo made the other cars look like silvercan drivers.
The Tekin motor drives like no other motor. best motor I have ever had.
I hope that the new motor drives like the redline.

The wider RPM range works good. Motor stays cooler and I could use more motor timing.

twk-b

iTrader: (1)

Thanks for taking a look.

The numbers should be right, I plunked them into my app and those are still the numbers it is still kicking out. I have not checked that 66mm is the right size for the Jaco Blue tires (i found that in a post on RC tech).

Does your math on the rollout match? I will double check the formula I am using for speed... can you give me the tire diameter/rollout/revs/speed you are using in your calculations?

Thanks again for the feedback.

-b

toptek

I use the same info that you use.
I get with the start rpm 12.86km/h
and with the end rpm 51.45km/h

tire diameter 66
fdr 6.96
start rpm 5000
end rpm 20000

It is possible that I make a misstake.
I used for calculating the tire 3.147*D

I have no Ipohne but I use excel on my laptop.
I make my own gear info sheets.

twk-b

iTrader: (1)

Good to hear others have discovered this little secret for getting the car dialed. No different then having to adjust ride height after adjusting shock positions.....

I was using 3.14159 but have changed it to 3.141592654 (avail in next version). I am guessing when that small difference is multiplied by 5000 or 20000 revolution it adds up to the difference?

-b

toptek

no I think it is in something els
But I think that there is a mistake in my formula.

I use this formula in excel

((rpm*60)/(FDR*FDR))*((3,14*D)/100000))=KM/H
I think that I make a mistake with the FDR. But I don't now for sure.

Dragula426

iTrader: (4)

Roll Out = PI x Tire Dia / Gear Ratio(including trans ratio)

Ave Per Lap = #minutes x 60sec / # of actual Laps

Ave RPM per lap = [(Size of track in ft) x (12 inches/ft) x (#Laps) / (#min)] / Rollout

Peak RPM = Ave RPM x 1.10 (or 10% beyond what you will use)

I use Peak RPM as my upper limit to start with so you usually hit the peak accel just before the turn. Seems to get me close, and then I tweek it from there. I keep track of all the lengths of the tracks I race at and all the settings i run. It helps me see where I want to be....

Now here is the interesting part, once you know a track to gear for it, you can reverse the formula a little when you see someone hit more laps than you ..... And you can gear for a targeted number of laps, but you need to be careful, because formulas and real world testing are two different games and you can toast a motor if your not close already.

You guys would freak if you took a look at my huge spread sheet I keep track of everything with.

All the cycles on my batteries on one tab, all the tracks, motors, rolllouts and gearing on another, and lastly a page for the car set-up from week to week, and I have 5 cars currently, so that's one for each car just about.

COLD AS ICE

iTrader: (19)

there would have to be a mistake in that somewhere, but i dont think its the fdr because if it wasnt fdr multiplied by fdr it would make your speeds come out lower, i used my peak rpm in the formula and it said i was only running a top speed of 24.2 KM/H then i converted that to MPH being the main measure of speed in my area, it came to 15.24, there is no way my car is that slow

toptek

I got it.

((rpm*60)/(FDR))*((3,14*D)/10000))/60=KM/H
this formula is right. now I get the same results.