Advice for a guy that hasn't raced cars for a long time.

[Alfonzo]

Chef, these new fangled Lipo's are a whole big improvement over the old Nicad / Nimh business. Brushless motors are awesome too. Way less maintenance, way more power. In fact far more than the average driver can tame fully. Hence the bizarre situation where people are now bolting bits of brass and lead into the cars to calm them down!

[The Chef]

Orion or reedy looking favorite then?

[The Chef]

Originally Posted by Alfonzo

Chef, these new fangled Lipo's are a whole big improvement over the old Nicad / Nimh business. Brushless motors are awesome too. Way less maintenance, way more power. In fact far more than the average driver can tame fully. Hence the bizarre situation where people are now bolting bits of brass and lead into the cars to calm them down!

You serious? OMG! How do the brush less motors work, I mean I understand how they work but in the day I would carry singles twins triples and quads. How doe they work now? Less torque more top end and vice versa? Or do you guys just have one motor? what are the "winds"? 13T = what? just as an example.

[Alfonzo]

Forget yer singles etc.

There's still tunability in the motors by playing around with the different rotors if you must, but it's nothing like the old brushed days. There's so much power available due to the motors being more efficient (no brush friction!) and the Lipo cells can supply enormous current (much lower internal resistance). So the speed limit is the chassis nowadays. Do not use the hottest motor combination you can find in the shop, you just won't benefit. I'm speaking as an average club racer, any of you Jedi drivers feel free to step in if you see it different.

Brushless & Lipo has made it all much nicer to live with. No cycling of cells, no dumping, no brushes, not so fussy on gear ratios, etc.

There are a few golden rules for Lipo though, make sure you get up to speed on this front.

[The Chef]

Originally Posted by Alfonzo

Forget yer singles etc.

There's still tunability in the motors by playing around with the different rotors if you must, but it's nothing like the old brushed days. There's so much power available due to the motors being more efficient (no brush friction!) and the Lipo cells can supply enormous current (much lower internal resistance). So the speed limit is the chassis nowadays. Do not use the hottest motor combination you can find in the shop, you just won't benefit. I'm speaking as an average club racer, any of you Jedi drivers feel free to step in if you see it different.

Brushless & Lipo has made it all much nicer to live with. No cycling of cells, no dumping, no brushes, not so fussy on gear ratios, etc.

A massive help thanks you

[/QUOTE]There are a few golden rules for Lipo though, make sure you get up to speed on this front.[/QUOTE]

Do tell? And what are the charge bags all about? do the blow up often?

[Alfonzo]

No worries Chef. I haven't raced for 12 months or so, things might have changed somewhat so let someone else on this forum give you the very latest chat. The principle of Brushless is very different to the old motors though, so there's some new lingo to pick up. Lipo's mustn't ever by fully dumped, it destroys them. They must be charged with a Lipo specific charger, else you risk serious fire.

I should point out that you could still be totally competitive (at club level) with a decent old school brushed setup, because as I said there's really more power than the chassis' can take, but mostly because it's all in the thumbs.

[The Chef]

I think my thumbs are green at the mo

[The Chef]

Originally Posted by Alfonzo

No worries Chef. I haven't raced for 12 months or so, things might have changed somewhat so let someone else on this forum give you the very latest chat. The principle of Brushless is very different to the old motors though, so there's some new lingo to pick up. Lipo's mustn't ever by fully dumped, it destroys them. They must be charged with a Lipo specific charger, else you risk serious fire.

I should point out that you could still be totally competitive (at club level) with a decent old school brushed setup, because as I said there's really more power than the chassis' can take, but mostly because it's all in the thumbs.

I think my Bosscat has had it's day and If it hasn't I damm sure that the Nicads have. time for new???

[Alfonzo]

The Bosscat transmission wouldn't be too happy with a hot brushless setup, but otherwise you could happily race it at club level.

[The Chef]

I did love the bosscat. But If I'm honest I'd really like to build a new car.

What are the transmissions made from these days? Is it still nylon gears of something a little stronger?

[DCM]

LiPo - ALWAYS charge on a LiPo charger set at the correct charge rate and Cell number (2S) and if possible, balance charge.

ALWAYS set your esc's voltage cutoff to match the cells, some will say 2S, some will be 3.0c per cell, or 3.1, 3.2.

As long as you follow those guidelines, you should have no problems.

Any swelling of a cell (you will see it straight away), then the cell is toast.

Good LiPo's are far more robust than NiMH's.

Brushless, 6.5 is more than enough for most peoples needs!

[mark christopher]

Unless your club specifies brca lipos then you can get good hard case ones that are a match for those on the list. The most important is a good brand charger. The cheaper ones use cheaper components and Lipo failure is mainly down to overchargeing.

[RogerM]

Firstly welcome back to the sport ... a hell of a lot has changed, I've been racing since the mid 80s and more has changed in the last 3 years or so than the previous 23!
I think LiPo's have been covered well, all I will add is that it's not worth getting hung up about having huge C rating cells as there is no "standard" I can find to determine it.
It is absolutely the case that you can get cells with the same capacity (say 4600mAh) and different C ratings (say 30C and 40C) from different manufactures which will perform the opposite way to expected.
The theory is that the C rating is absolute max discharge loading the cells can give (so 4600*30C = 138000mA or 138A if you prefer).
Other things influence this, not least the load across the cells whilst the test is happening.
So if your comparing two different Orion cells then the C rating is likely to be meaningful, if it's an Orion and an LRP it might not be quite so clear cut.
The biggest single thing with the LiPo cells is the power delivery is brutal and consistent, no drop off as the load increases or the charge depletes.
Brushless motors, they WILL take some getting used to. Basically as a rule of thumb (definitely not and equivelence factor though) you would use an 8.5 in place of about a 14/15, 7.5 in place of a 12/13, 6.5 in palce of an 11 and a 5.5 in place of a 10 turn brushed. As I say not exact but a go approximation.
The other thing to remember with brushless, and something I only really got to grips with at the back end of last season, is that the old rules of "mild" & "wild" motors no longer apply. In the old days if the car was a bit of handful with an 11t in you might change to a 13t to calm it down.
With brushless I have found (thanks to Matt Dodd's advice) that actually now you go the other way! Let me try to explain, the high wind motors (say 8.5) may rev less and give less power in terms of W but the way they do it is with brutal torque where as a lower wind (say 5.5) will rev more, and have more watts but it will have less low rev torque.
The gearing range is quite wide on brushless motors compared to brushed so you can match speeds via that route and have the bottom end characteristics from the low rev torque of each motor.
For example I have a 5.5 in both my 2wd and 4wd cars and a 6.5 on it's way for tracks that need a little more immediate grunt (say an awkward gap jump following a slow corner or similar) and I used to run circa 12x2 in 4wd and 13x3 in 2wd.
The other thing with brushless is the ESC is far more important than it was in terms of smoothness as now it is the ESC which controls the ramp rate of the motors not the abilities of the motor itself.
The smoothest ESCs I have found are the HobbyWing (rebadged as Speed Passion and a couple of other brands too but at much more money than buying a HobbyWing branded one) and the Tekin. Whilst I like the Tekin (it's tiny) I can't get over the fact it's twice the price ... 2 for 1 can't be overlooked IMHO!
Tuning brushless with rotors has been mentioned. I'm no expert, but the theory is more air gap (smaller OD on rotor) is more revs, less torque, less efficiency; opposite is being true ... this mainly applies to the mid and top end range though when the motor is already spinning. Larger ID on the magnet giving less low end and vice versa. As I say, no expert.
Chargers have been covered, basically anything branded from a UK model shop is likely to be fine ... buyer beware if you insist on buying outside the UK.
As has already been said the days of aluminium and titanium screw kits, the thinest carbon parts and drilling holes in stuff has passed. Whilst the minimum weight limtis are still the same the cars are running fatter, 2wd cars typically coming in around the 1650-1700g mark (1474g limit). Have a look at the Rudebits website to see the typical ballast we carry around.
I have just been working with a guy who is coming back to racing after 15 years away and he was blown away with the punch of the current power plants (and most racers say my car feels soft as I've tuned the agression out) but also how strong and reliable the cars have become. In case your interested in what he has chosen to use it is HobbyWing ESCs and Kyosho cars, will be going to Orion power very soon.

I think the thing you will find the most suprising is that with all the other advances we are still running the same tires as we were in 90s!!!!
I hope that has been of some use (by the way ... what are you running in the front of the Mk2, 20vt?)

[The Chef]

That is a huge help thank you.

I'll re read that in a mo and try to digest it better.

The MK2 is My Jetta running a 1.8 8v Callaway turbo and NOS

It was the cover car on December issue of PVW.

Thank you again.

[RogerM]

Cool, just putting together a turbo'd ABF 16V to go in my Mk2 Scirocco track car

[The Chef]

Nice, very nice. What year Rocco is it? I'm selling the MK2 as we are currently building me a MK1 Jetta TFSI on a 3076 turbo and 4WD

[RogerM]

That sounds awesome .. TFSI lump is a bugger to work with unless you have the whole loom and ALL ecu's so I'm told, be great to hear from somebody actually doing it rather than the forum warriors!!

The 'rocco is on a J plate, one of the last of the injected cars. Totally solid but scruffy, that will be sorted before it heads back out again.
300BHP is easy enough from turbo'd ABF lumps, my calcs suggest about 350bhp from the combination of parts I have.

Anyway, we seem to be driving this thread off topic .... naughty naughty

[The Chef]

We already have one Fully functional in a mk2 golf the whole lot working with some electric magic the mk2 golf clocks work and every thing pushing around 365 BHP.

And were looking for around 450-500 out of the jetta.