[race_prep] Guernsey Hillclimb 205 Build

[Cameron 16]

£25 per kg saved.. can't argue with that! Especially on such an easy-to-install part.

[wardy18 33 1 Cars]

http://www.skyrichbattery.co.uk/

 

He will be able to do you a battery for around £150 mate. Li-ion, charged with standard alternator so plug-and-play. 220CCA, 4.5-35CA, 1kg, wont need extra boost or anything.

 

Would 220CCA be enough, the one i linked to above has 400CCA for the same weight and my current Varley Red Top 25 has 230CCA

 

Ill make some enquiries.....

[alexcrosse 124]

Does your varley rt start your car...?

[wardy18 33 1 Cars]

No but its pretty old and doesn't hold a charge well hence me now looking for a new battery, however they are not rated to start a 2.3ltr!!

[welshpug 1,661]

have a bigger poo

 

what was colin's car weight again? with 16v...

 

I think you need to look into whether all your "aero" actually does anything other than add weight tbh, given the speeds aren't particularly massive you surely begin to think if its really necessary?

 

it looks ace if you're trying to build a DTMalike though !

[wardy18 33 1 Cars]

Well you say about the aero, as it stands i currently run NO undertrays or diffusers, like you said looked great but just weighed too much, i am moving now towards carbon fibre, i am going to make 2 long sections of CF which will run from each sill to the side of the exhaust and from the back of the subframe right to the rear bumper just to smooth out the underside and have minimal weight, to be honest the car isnt low enough to appreciate a proper diffuser etc so the main aim is purely to smooth out the underside and reduce that 30% drag

 

i think colins was 690kg and looked like swiss cheese which unfortunately i cant do

Edited June 25, 2012 by wardy18

[alexcrosse 124]

what starter do you have?

[wardy18 33 1 Cars]

At the moment just a standard 205 one, i bought a 306 GTi6 Valeo Starter from Baz but its a bit hit and miss, had to buy new bushes and a carrier and the solenoid 13mm terminal wobbles around all over the place, need a new solenoid for it really!!

 

I dont want to continue running my 205 so need to repair the 306 starter asap, anyway got a new solenoid?

[wardy18 33 1 Cars]

WARNING -RANT

 

Why can't all companies that sell sh*t similar to other companies use the same comparisons so you can actually choose what is best suited to you for your money......

 

One company states CCA (Cold Cranking Amps) and not PCA (Pulse Cranking Amps) and vice versa and another can't be bothered to stated Ah (Amp Hours)

 

When spending that sort of money you have a right to be told every piece of information that they SHOULD know, it's like me selling my 205 for £20k buy with no justification as to why I should get that sort of money!!!

 

Wake up people and sell your sh*t properly and provide a proper service without making your customers guess!!!!

 

RANT OVER

 

(not pointed to anyone on the forum by the way)

[wardy18 33 1 Cars]

In your opinions what would you prefer:

 

200CCA (200 amps for 30 seconds)(don't know how many times though)

 

Or

 

400 PCA (400 amps for 10 seconds)(again don't know how many times)

[johnnyboy666 195 1 Cars]

how often do you need to crank it over for more than 10 seconds?

[stefan 4]

Just out of curiosity, did you work out how much weight you need to shave off for every second on a particular track, with your car and driving? What's your target time, or better said how much do you expect to get from your weight reduction?

[wardy18 33 1 Cars]

how often do you need to crank it over for more than 10 seconds?

 

Probably not often i would have to say

 

Just out of curiosity, did you work out how much weight you need to shave off for every second on a particular track, with your car and driving? What's your target time, or better said how much do you expect to get from your weight reduction?

 

Its purely a hillclimb car so the gains over a longer track would be different to that on a 35 second average squirt up a hill, the way i see it the less weight you have the less mass to drag up the hill!!

 

Aiming for a power to weight per tonne of 310bhp

[alexcrosse 124]

without research... id say 400PCA, if your engine doesnt start in 10 seconds you have an issue anyway. But I imagine that a battery would potentially have both 200CCA and 400PCA?

[wardy18 33 1 Cars]

So the shopping list is:

 

Racing Battery RBC400

Optimate Lithium Charger

Battery Volt Guage

 

- 6kg

 

Happy Days

[andy0075 9 1 Cars]

You can do this much cheaper if you go my route .

 

I use two 3S LIPO's, each with 8000mAh and 30C. I have connected them parallel -> 16Ah and 60C,

That means ~500A continuous current. When the Lipos are fully charged they have 12,5V.

 

http://www.hobbyking.com/hobbyking/store/__16225__ZIPPY_Flightmax_8000mAh_3S1P_30C_.html

 

I have meassured the following currents with an clamp meter :

 

When my engine is running (EFI+ignition+fuel pump on ) : 8,5A -> with my 16AH batterie it will run 2 hours.

When the starter turn the engine to start it -> 480A ( The 2 Lipos are able to supply 80C burst -> 640A )

So no problem for the Lipos. The engine starts much better with these Lipo's compared to my old lead battery.

For a test, I started the engine 20 times in a row and the Lipos still had 11,4 V !!!

 

When the fan is running add ~8A (but the fan is not running very long if you drive :-)

When the whiper is running add ~17A

 

For the i really get in batterietrouble ( no problems till now ) i have another set of 2 Lipo's :-)

 

The two Lipos have a weight of 1,2kg -> -11,5 compared to my old lead battery

I have no alternator in my car -> -5,5 kg

I have no crankshaftpullye for the alternator -> -1,4kg

 

Andy

[johnnyboy666 195 1 Cars]

interesting stuff! could they be run with an alternator attached? just wondering if this setup could be adapted for a road car

[andy0075 9 1 Cars]

interesting stuff! could they be run with an alternator attached? just wondering if this setup could be adapted for a road car

 

No, that's not possible. You have to charge the Lipo's with a special charger.

[wardy18 33 1 Cars]

Hmm now that does seem interesting, rather more out of the comfort zone than even the L-Ion were with not running an alternator but then like you have done having 2 spare sounds like a good back up plan

 

Would i still be able to plug in Jump packs into the system to boost the voltage upon start up with normal lead batteries?

 

Do they have a minimum voltage like l-ion batteries do at which point they begin to get damaged if used below?

 

Thanks for bringin this option to the table

[alexcrosse 124]

I've got alot of experience with Li-Po's... One advantage of Li-Ion batteries is they are very stable and safe if the casing is broken, Li-Po's are prown to splitting / exploding / setting on fire when they reach the end of their life, or are stretched past their environmental or technical limits.

 

LiPos also require alot of looking after, not just normal charging you need to have a cycler which discharges and charges the battery to its full level. And yes if you drop them beyond 'x' (cant remember) voltage it will damage the cells.

 

I should get my Li-ion in the post later on, which I decided was a good idea after seeing comparing to a mates nova who is running a very high compression 1800 in a 'road legal' spec, and goes to the nurburgring regularly. He has a lead acid varley in with the same CA & CCA. And for £135 posted and 1.1kg... why not!

[wardy18 33 1 Cars]

To me the L-Ion route does sound safer just for the fact that running the alternator always guarantees you will have enough charge!!

 

Yeh it would be lovely to not run an alternator but ive been there before and almost 2 hillclimbs because of not enough charge an that was on carbs let alone TB's

 

Its a difficult decision i must say

 

Even if i was to buy 6x Li-Po and have 2 pairs for back up that would get me through a day and by the looks of the price $44 each still be cheaper than the L-ion route however thats not taking into account a proper charger for the Li-Po.

 

To be honest there's not enough info kickin around about the Li-Po to be confident on that route.....

[welshpug 1,661]

You should see what happens when a Lithium battery goes pop...

 

Sealed lead acid for me tbh, go on a diet, its cheaper and you're taking weight from the right place n the car !

[stef205 92 1 Cars]

i use lipo batteies in my rc racing, big step up, no drop off in power they cant drop below a certain voltage or there scrap. I also have to balance each cell when charging or as said bang!

[andy0075 9 1 Cars]

You can buy a charger for the Lipos for about 20 Euros!

 

I have a PVC batterie Box installed in my car and the Lipo's are inside the box. In the case

they pop - nothing / nobody will be damaged / hurt. But the Lipo's never got warm till now.

I have a Voltmeter in the car and when the voltage dropps under 11V i change them.

I think everything is safe enough.

 

A raceday i my case consist out of about 15 times starting the car and about 10min driving around.

The Lipos start at 12,5V and drop to 11,5-11,6V. So they are still half loaded!

And i wrote it before, i even have another set of Lipos to change if it would be really necessary.

 

Andy

[Cameron 16]

Seems like a total ballache to me!

 

Especially when you can get a much more stable and reliable Li-ion battery weighing only 1.1kg! I can see the attraction of Li-po for RC cars or electric vehicles; but for just starting / running a car, why bother with all the hassle?