Sunday, September 17, 2006

Transmission Calculator - Z Design Studio

Transmission Calculator! Yeah, this is a very good tool. I used this online calculator to check out what is the maximum speed at certain rpm this car (or any other car can go). It is very simple. Key in the gear ratios, and rear differential ration. Key in also your tyre size and the desired rpm. A graph will be plotted. From this graph, one can obtained how mph the car could get in corresponding rpm. Log in to this site --> http://www.geocities.com/z_design_studio/transmission.html

From http://new.volvocars.com/ownersdocs/1989/1989_240/89240_04.htm#pg99, I obtained full specifications for this 1989 240. The gearbox used for this model is the M47 II (manual transmission) with following gear ratios;

1st gear 4.03:1
2nd gear 2.16:1
3rd gear 1.37:1
4th gear 1.00:1
5th gear 0.82:1
Reverse 3.68:1
Rear axle reduction ratio: 3.31:1

I just put up all the above values, plus the tyre size of 185/70/14, and;
rpm of 4000 rpm, the max speed calculated at 5th gear is 106mph or 170.6kmh,
rpm of 4500 rpm, the max speed calculated at 5th gear is 119mph or 191.5kmh.

The question is how accurate this calculation will be? Yeah, I am pretty sure this car is able to reach that given that at 3500 to about 3800rpm, it can reach up to 150 to 160 kmh. There are so many lagging factor which contribute to some reduction from those calculated values. It may include the wind drag, engine wear and tear, tyres condition, suspension system and so on so forth. But its good to know that 240 can run that speed :)

Monday, September 04, 2006

BATTERY TERMINALS !!

Hi guys! Its sad to tell that my hard disk crashed, all VOLVO related pictures, videos, even some pdf documents gone, just like that. OK, for this post, I am going to enlighten on battery terminal placement issue. Tribute goes to Mr Mark for enlightening me on this.

VOLVO 240 originally comes with DIN type of battery. This type of battery basically have lower height of terminals, therefore the chances of getting them short is very low. For this matter also, please take note that the terminal allocation for DIN battery is that, the negative terminal will be beside the fender wall while the positive terminal be beside the air filter box. The main reason between this is that to ensure that if accident occurs, and the fender wall dented into the engine compartment, and hit the battery, they do not shorted because of common ground points between the firewall itself and the negative terminal of the battery. (NOTE:Car body act as ground).

However, the popular NS battery (I have been using now) have reverse polarity allocation of the terminals. This is dangerous as if accident occurs, the fender might get in contact with the positive terminals and they will get SHORTED! This will then produce sparks and some sort of fire likely will occur. Again this is VERY DANGEROUS! Yeah, I am warning myself and you all. As the battery was new, very new, I am planning to cover the terminals and hope for the best. So guys, give extra attention when you change your next battery. GOOD DAY :)