14.2 second 1/3 mile? (oval)

[glassdoctor]

I was thinking of short runs on the oval...

I really think 8000mah will work very well in the car... and I don't think you will like the brick the car will be going any bigger.

What is the final drive ratio of this car?

Originally Posted by glassdoctor

I was thinking of short runs on the oval...

I really think 8000mah will work very well in the car... and I don't think you will like the brick the car will be going any bigger.

What is the final drive ratio of this car?

Originally Posted by A4DTM

fdr is around 6:1.

.....

[glassdoctor]

I was wondering about target speeds for this... fdr and the tire diameter to get estimated speeds for your setup. I don't know what the tire dia is though.


But knowing that the nitros can hit 70mph... and guessing that the nitros likely max out around 40k rpm?? Just duplicate whatever rpms they are pulling and you will get the same top end... or beat them by a little bit. ;)

[jhautz]

Originally Posted by glassdoctor

I was wondering about target speeds for this... fdr and the tire diameter to get estimated speeds for your setup. I don't know what the tire dia is though.


But knowing that the nitros can hit 70mph... and guessing that the nitros likely max out around 40k rpm?? Just duplicate whatever rpms they are pulling and you will get the same top end... or beat them by a little bit. ;)

Nitros are 2 speed trannys. This is a single speed. Are you just running using 2nd gear only like an emaxx? Or are you using a diferent gear ratio?

glass, the tire dia is 3".

j, I'm using the stock "2nd gear" spur, which is a 45t. I'm not sure what the recomended clutch gear would be for nitro.. I didn't get a manual w/ the car.

also, I got the stuff I ordered today.
the lipo's didn't have deans plugs on them.. which I swear I added, and if I didn't, the email I had send before I made the order said female deans =\
so I need to order some deans plugs now.. also, I plugged the packs into the 505's.. one of the packs blinked a few red leds, then went to solid green. the other pack blinked cell 3 for about 2 minutes, then went to green, but only for a few seconds, then went back to blinking on cell 3. then green again, and ect.. continued this for about 5 minutes, and unplugged it, because it won't stay solid green. only momentarily? i'm not sure if that means the err/check LED is blinking? or if it's going solid, and then deciding cell 3 is still out of balance?
and I forgot, but ordered a lipo sack today while at work.

[MetalMan]

Seems like cell 3 is out of balance if it keeps flashing the red. It's a small imbalance, though, suggested by the fact that every so often it thinks the pack is balanced.

ok, I just wanted to make sure it wasn't "blinking" the err/check led.

[glassdoctor]

I'm not sure where you are on this car... I what motor/batt/gearing you are going to run. Maybe I need to go back and read the thread for a refresher. :)

You said once that you had a 1512 2.5d in the car but then mention a 9L...

I crunched basic #'s on the 1512 and 5s lipo geared 6:1 and 3" tires.... note that this is just "back of the napkin" math and it's just meant to be a basis to go off of.

I think you can break 60mph depending on how stong the lipos are.

Not accounting for some losses (efficiency etc) the numbers say 61mph with the battery holding at 3.2V per cell. I think this is about right because I'm guessing the volts will actually be a little better than that, which may offset the "real world" losses. On paper, in theory,..... doesn't always translate to real world results.

At the very least I think this setup would do mid 50's (that's assuming 3.2v per cell and 10% loss from the "paper 3"#)

Paper #'s:
3.5v = 67mph
3.2v= 61mph
3.0v= 57mph

1512/2.5d / 5s2p 8000mah lipo / 20/45 for gearing.

I've been using http://www.scriptasylum.com/rc_speed.html quite a bit, because i've seen alot of people post that it's been very accurate for them..

I also put in the figures for Nic Case's cars. his 160mph setup was calculated at 158, and the 130mph setup calculated at 135mph. good enough for me :)

i'm pretty sure I need to get a new pinion made up, and possibly try a higher kv motor.

I've got a 540c-9l that I've never used, and has been sitting on my desk for 6 months lol. I just got 3 female bullet plugs for it, so I'll be able to try it out in the car.

[Serum]

Don't you think the 2P setup weights too much? I am working on a serpent as we speak, i like it's light weight, but the 5S2P maxamps packs i have got are too heavy for it IMO..

[squeeforever]

Serum, he was originally gonna run 2 of those 5S2P packs in parallel for 5S4P 16,000mah....Now I think he is gonna run 2 of the 5S1P packs in parallel. Not sure though...

yeah, what squee said.
the two 5s1p packs feel lighter than the 16subc's. (i don't have a scale to weigh), and the car was very easy to drive and very quick off the line w/ the weight of 16 subcs, so the lipo's shouldn't be a problem.

[Serum]

Yeah, i know what they weight, but still.. A 5S2P pack of the maxxamps 4000 cells is relative heavy.

bump lol.

i have to keep this short, but an update.
first, my quark quit making the programming tones.. but the three startup tones are still there.. kinda makes programming a hassle.. anyways..

oh and the front belt on the car is cut down the middle around about a 3rd of the belt... but it survived a short test run, and looks like it won't cause any problems

before, with the nicd's, i had all power related settings turned up, and did 48mph. w/ the lipo, i had everything turned down, as well as throttle epa 25%. in a walmart parkinglot, i hit 55.1mph. i also hit a snow bank, and a pack popped out.. no damage at all, which surprized me.. it looked worse on video lol. i'll try and up that tommorow. here's some pics.

charging setup


pack that fell out of the car



front belt cut?






wiring headaches

[MetalMan]

Damn... 55.1mph at 25% throttle... Can't wait to hear about this thing breaking the sound barrier :).