Stories from the world of RC car racing

First things first, results from tonights race at Hobbystation are posted in our results section.
The main interest for tonights racing (for me at least) was the continuation of the 4-cell modified experiment.

While Anthony had run 4 cells last time out at HS, tonight was my first experiment.
We pulled apart a couple of packs I’ve been using for a while (3800’s for the record) and made them into 3 * 4-cell packs (and when i say “we” I of course mean “Dad” did the work – thanks Heavy!) which I ran tonight in my usual Mi2-EC and running the Novak GTB/4.5 brushless system.
I ran a slightly higher gear ratio than I normally would at Hobbytation (9.5:1) and other than that made no changes to car or electrics. I didn’t run a receiver battery and had no problems with radio – even when the batteries “dumped” at the end of an 8-minute run. No run-time issues either!
Motor performance was suprisingly good – none of the brutal power of the 4.5, but still plenty coming out of the corners.  Darren Perry was running 6-cells with the GTB/4.5 system and whilst his car obviously had more power than mine, getting it to the ground was another story. Motor temp was fine. At one state we ran an 8-minute run and the motor was just barely lukewarm.
The car’s handling was also interesting.  I guess if you lop 120 grams off a car, it should be more agile and faster through the turns – and that’s the way it felt.
In terms of laptimes, I ended up running laps in the 10.2 to 10.5 bracket – about 0.2 off my best at Hobbystation.  For a 4-cell car I think that’s pretty good.  With a little work on maximising the performance of the car I would be quite confident of finding that time without too much major drama.
I’ll leave Anthony to share his thoughts – and his lap times.  Stand by to be amazed!
My initial conclusion would be that at a smallish track like Hobbystation, 4-cell is definitely a feasible option and probably an improvement.  Longer motor life, easier on car, tyres, motors etc. No significant loss in performance or driving enjoyment.  In fact the car was probably easier to handle on the tight confines of Hobbystation without the brutal power. It would definitely make modified more accessible to those moving up from Stock.  A big “tick” from me at this point.
Stage 2 will take place at Brendale Friday night with at least Anthony and Leonard (plus possibly Damien B) running 4-cell mod tourers.
Stage 3 will be Bayside this coming Sunday for probably Anthony and Adrian Beggs.
Feel free to join the guys and run 4-cell mod (or run 6-cell with them to give a comparison).
By this time next week we’ll have some information from 3 very different tracks about the impact on motors, cars, enjoyment, lap times etc.  Good stuff, keep reading!

14 responses to “Hobbystation Results & 4-Cell Modified”

  1. Jaybo Avatar
    Jaybo

    excellent news :~)
    i just toasted another speedy on the weekend so it’ll be another couple of weeks till i can give 4 cell a good testing down in melbourne 😦

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  2. Josh p Avatar
    Josh p

    good to see you guys looking to make racing better.
    i dont run mod but this makes me wanna oneday.
    let us know how ya go

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  3. anthony Avatar
    anthony

    first i should explain the equipment and the track conditions from last night.
    in the car i was running 4 cell intellect 3800 packs and a v2 7×1 18° timing geared 9.10 FDR.
    the grip at hobby station last night last night was the highest it has been for a club meet in some time. by no means as high as it was for the invitational (which is why the following results surprised me so much) but still quite good.
    my best run of the night was 31/5m5.75s 0m9.81s with my 2nd fastest run also a 31 lapper.
    which means that my fastest lap from last night was faster than my fastest lap at the hobbystation invitational and the overall run was also very close (cant remember exact race times from the event).
    the motor from last night had 10 runs on it. 6 of those in practice went for the duration of the pack (~8 – 10 minutes). the remaining 4 runs i did a few laps before and a few laps after each race (5 minutes).
    with all these runs on the arm it still looks much better than another armature i ran for 1 run with 6 cells (w/ low timing) at the interclub held at logan last weekend (which was strictly run for only the 5 minute race and then pulled in). it will only need one light pass on the lathe opposed to the arm run at logan which will need 2-3 pretty deep passes at a guess.
    the brushes from the motor used for 1 run at logan (the only run these brushes had) were burnt from end to end – had totally changed colour.
    while the brushes from the 4 cell motor used last night had only discoloured the leading 1/3rd of the brush.
    i know this is comparing motors from 2 tracks that are very different but even at hobby station with 6 cells brushed motors are burning up.
    again this week no reciever pack was used and again no problems with steering servo or the personal transponder missing laps.
    i ran the pack taped in the center 4 battery slots with a empty slot infront and behind the pack.
    i’m now happy to say that on a tight track 4 cell works and very keen to test with 4 cell mod at brendale friday night and hopefully wynnum on sunday.

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  4. anthony Avatar
    anthony

    forgot to mention that my car had the weights in my car that i needed to add to my car to bring it to legal weight when running 6 cells at the interclub last weekend.
    the only weight reduction done came with only running 4 cell packs.

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  5. anthony Avatar
    anthony

    sometimes i like to proof read with my eyes closed… my car!

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  6. Leonard Avatar
    Leonard

    Hi Flea,
    I too am itching (just like a true flea!!!) to test out 4 cell mod at Brendale, but I might wait till next Sunday and do it against the 6 cell mod guys. (to get a decent comparsion). I might be convinced to make a trip to Bayside if I know that there will be others who are willing to run 4 cell with me. It would be good to see what differences there are on larger tracks.
    As most know, I had 2 brand new motors self destruct at the interclub on the weekend. (one had only done 3 laps in total and self destructed) It was rather amazing and frustrating at the same time. having 2 brand new motors throw winds (and get this, they weren’t even geared that hard or timed up….go figure???)
    Looking forward to some 4 cell testing very soon. (hopefully sooner than later)

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  7. Heavy Avatar

    For me at least part of the interest tonight was in having Adrian drive the Academy. I am usually too busy running the race meet and chating to people to make any changes to the car but Adrian had some time and the interest to make some changes. He reported that the car was very responsive to every change made and his lap times improved through out the night. Another step in proving to me that the STR4 Pro11 is another worthy touring car and one worth looking at especially if your budget is a bit tight.

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  8. anthony Avatar
    anthony

    with brendale having been rained off friday night the only 4 cell mod testing i got to do this weekend was at wynnum.
    for those of you that are unfamiliar with the track, wynnum is quite large (the front straight is long and the back even longer) and has a bumpy medium grip concrete surface. the left hand side of the track has 3 tight sweeping corners and the right hand side has a series of hairpins. all in all demands alot from both the car and the motor alike.
    in 19t & modified 4 wheel breaking is the hot ticket with breaks being used at the end of both front and back straights, while in stock one-ways seem to be the preference.
    motor wise i usually run an 8×2 here. the reason for this is that due to the bumps a single can suffer a bit from over revving. the work load for the motor is very high with heavy breaking used twice a lap at the end of long straights. on the back straight most people’s motors are hitting their absolute maximum rpm’s due to the tendency to under gear because of the tight sections on the track and shorter front straight.
    my aim for the day was to learn as much as i could about gearing & timing with 4 cells on a longer track. so i made a point of not changing the setup nor the tyres all day.
    i started the day with an untimed practice run to try and sus things out a little before racing started. i again was using 3800’s and a 5mm 7×1, 18° timing, geared at 29/104 (7.84) which to be honest was a bit of a guess based on what i have learnt so far running 4 cell at hobby station.
    after a few laps it felt like it was a little under geared so i pulled in, geared up a tooth to 30/104 (7.58) and went back out for a few more laps before the track was closed.
    again the seccond half of that practice run felt just slightly undergeared so for the first round i geared up another tooth to 31/104 (7.34).
    against the other cars my 4 cell car did seem to feel a bit better in the corners. also felt alot more ‘in check’ when applying the power out of the series of tight hair pins but could still be spun out if you were careless with your throttle finger.
    obviously if 4 cells was going to lose out to 6 the place where that was going to happen would be the straights. against the fastest cars out there i did lose a few car lengths to them on the longer back straight – the difference on the shorter front stright was harder to pick. interestingly it couldn’t be said that i had the slowest car on the back straight amongst the field of 8 cars, there were a couple of 6 cell cars that mine was about indentical in speed to.
    on a green track i did 17L 5m 3.84s with a best lap of 17.28.
    for the seccond run i again geared up another tooth to 32/104 (7.11).
    the gearing felt pretty good but seemed like any bigger pinion would be too much.
    with the track now feeling much more like its usual self i turned 18L 5m13.35s with a best lap of 16.87. which i was very happy with as i reached 2 milestones i had hoped, but not expected to acheive – an 18 lap run and a 16.xx lap.
    for the third run i decided to try something a little different with the motor – turning the timing up to 24° and dropping the gearing back to 30/104 (7.58).
    this felt slightly better for the first 4 minutes of the race but did drop off over the last minute of the race. after putting the pack from this race it was clear why – there wasn’t much juice left!
    infact over all 3 runs so far there wasn’t much more than 30 secconds of run time left after the races due to the sheer ineffieincy of a 7 turn at high timing.
    this further makes me question the viability of ultra low winds and/or ultra high timing that some people are saying that 4 cell will require.
    i decided to clean the motor up after its practice run + 3 rounds of qualifying to see how it was coping. it looked quite good – it had a redish tint to it from the heat and had slight arching (probably from the round where i ran 24° timing) but only took 2 very light passes on the lathe to have it looking like new (was taking very fine cuts so as to know exactly how deeply scored it was). the brushes changed colour towards the tip but didn’t look to bad at all.
    for the final i set the motor back up at what i felt the best gearing and timing combo so far today – 31/104 (7.34) and 18°. my aim was to do my best possible run and see how far up the all time fastest runs list i could make it with 4 cells.
    18L 5m 5.81s with a best lap of 16.82.
    this time placed me inside the top 10 drivers best runs at wynnum (6th i think) and would have qualified me in the middle of the 2004 qld titles modified a final.
    this is only ~5 secconds of my fastest ever runs at the track (lots of 18l 5m 0’s) which i was especially impressed with because many people will say that wynum doesnt have the same level of grip that it used to (would’ve been pretty happy with this time if it had been done with 6 cells).
    now that the motor had just one 5 minute run on it i was able to pull it out and compare it against the armature that i had run at the interclub held at logan 2 weeks ago as both tracks have long straights and multiple heavy breaking zones per lap.
    the arm from the logan interclub was run on 6 cells at 6° timing (also a 7×1). this motor is very discoloured from the heat but the worst is the size and depth of where the arching bas burnt the comm. almost half of each comm segment burnt. the whole of both brushes had totally changed colour.
    the arm used at wynnum on 4 cells at 18° timing has a slight reddish tint to it and almost litterally no burning from arching! the brushes have the slightest colouration towards the leading tip.
    after this day i am happy to add medium-long tracks of medium or less grip to my list of tracks that i vouch for 4 cell on.

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  9. Leonard Avatar
    Leonard

    Nice work Flea. I will soon be out there testing right alongside you. Bring it on at Brendale on Friday night!!!

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  10. anthony Avatar
    anthony

    i should add again no receiver pack used and again no problems with personal transponder or steering servo.

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  11. anthony Avatar
    anthony

    it’ll be good to have some company 😀

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  12. Jaybo Avatar
    Jaybo

    very interesting indeed :~)
    cant wait for wednesday night now 😀

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  13. scott Avatar

    I have to say when I saw the results I thought “Anthony must have run 6-cell in the final”. That race pace is far better than I would have imagined. To be only 5 secs off the 6 cell winning pace from the Bayside cup earlier in the year – and again without spending time re-tuning suspension or re-thinking tyres. Wow, that’s impressive. If memory serves me correctly the 19T winning pace at that same race meeting was about 18:5.09 or so? So the race time is probably about mid-way between open mod and 19T on a reasonably sized track.
    All good info. I like it.

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  14. AJR_WA Avatar
    AJR_WA

    I know this is a long time after the fact… but I am wondering what the lower voltage did to servo speed/response?
    After a bit of time away from racing I am slowly getting back into the swing (was hoping to get to the QLD titles this year but thing are against me)… and I think doing something like 4 cell mod for a while might be a fun way of getting back up to full pace… to get the chops back so to speak

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