KevinS

Actually I think the "705 lola bumper" is the one for the impact, with a different label. I had to cut at least 10mm from each end for it to fit under de 200mm GTP body.
It was getting too dark for pics w/o body, so I'll post some in the 705 thread tomorrow. We're talking about the wrong car in this thread anyway.

rwisejr

That 300M looks sweet Kevin .Good luck with the ride.

JABRONI

Great Article Glenn, Thx for the info, I will try some things soon!!

Sow&Steady

That is a really nice looking Porche! How do you like the performance of this body?

Sow&Steady

My friend, even worse ... I just checked the forecast here and it looks like you'll be rained out for the rest of the weekend too!

rwisejr

Great Glenn Thanks!!! Keep em coming I love all of your articles they are very helpful.

InitialD

Woow ! You cut the center aluminum bar out?

InitialD

Very nice body Kevin. I might want to copy that colour scheme !

Hey, is that the RDLogic pipe? Why are you using such a long fuel tubing? Not enough cc in the tank? Still with original rear shock tower?

InitialD

Let it rain man... Let it rain... (j/k)

InitialD

Yes, I thought of making it strictly to a GTP / Lola machine too. I think Schrijver99 made his also to a GTP / Lola machine.

InitialD

ROTF

That's a good one.

InitialD

Final Drive Ratio (FDR) = (Spur / Pinion) x Internal Drive Ratio

Internal Drive Ratio is not the same as FDR.

For the 710, the Internal Drive Ratio is 1.875 (Rear Diff Pulley / Brake Pulley = 45/24).

Why is Internal Drive Ratio important? It is part of the FDR equation which determines how fast the car can go and how well the car can accelerate given the available spurs and pinions...

Just a small note. A bigger Internal Drive Ratio usually gives a car better acceleration with a little sacrifice in the top speed. This means that the internal parts and pulleys rotate more times = more rotational mass. A smaller Internal Drive Ratio usually means the car has better top speed with a little sacrifice in the acceleration department. As internal parts and pulleys rotate less, less rotational mass and inertia. Changing speeds (acceleration and deceleration) becomes better because of the lower inertia and braking becomes better too. Less wear on the pulley and belts too because of the less rotation.

So the gear ratio (Spur / Pinion) is very important too to compliment high and low Internal Drive Ratio. The most ideal is of course a high gear ratio (Spur / Pinion) in conjunction with a low Internal Drive Ratio.

Pyramid

Great Article!!! as alway. Please give me more info on the following,

When adjusting the preload on the clutch spring, start with a preload setting of 0.5mm between the end of the flywheel nut and the top of the tension collar. I strongly recommend using the 1462 Centax Nut Tool to adjust the spring tension.

In case yellow brass conus and exactly 0.5mm shims are not available at that moment, how to know the preload measurement? Can you tell me the measurement of the end of centax clutch-nut (6582) to the end of crankshaft? Can I use this as the starting point or it does not matter at all?

Some other questions.. I notice later production of the first pinion gears, after installed, the bearing could not go through (it is ok before installed onto housing. If I installed the bearing first inside the housing, then onto the housing, the whole housing with its pinions are wobling which will stripped the spur anytime. As of now, I lathe a little the inner diameter on the whole assy (pinions installed in housing) and it gives me near perfect turnings, but that would be a little hard to do for others. Any other easier way to do it?

Profoxcg

iTrader: (2)

Thanks for the response,

so i can make my car accel faster by reducing my spur gear correct?

what about the front pulley and the two sides ones? do they have any say in the equation?

does serpent make different size pulleys for us to play with?

InitialD

Usually, the preload measurement depends from engine to engine. Different tuning requires different measurement. Driving style and preferance also determines this preload.

So what I do is to start it tight (maybe up to 1 mm) and then loosen it step by step (quarter of a turn at a time) to find the best clutch engagement from standstill and out of the corners without the clutch slipping.

The method of measuring from the end of centax clutch-nut (6582) to the end of crankshaft as mentioned in the 705 manual will yield different results for different engines. It depends on hte shim behind the brass collet used and also the length of the crankshaft.

So a better method of measurement is between the end of the flywheel nut and the top of the tension collar. That way, the measurement stays relatively the same from engine to engine.

A larger measurement (tighter pre-tension setting) yields a harder clutch engagement. Engine may rev a little more for the clutch to engage. Most of the time, this setting goes hand in hand with the clutch gap spacing. The rule of thumb I use is smaller clutch gap, harder pre-tension nut setting. Larger clutch gap spacing, looser pre-tension nut setting.

That said, I actually like my current setup which is 0.7 mm clutch gap, 1.1 mm between the end of the flywheel nut and the top of the tension collar with the stock soft Centax spring with the 3 flyweights mounted in between the flywheel pivot post.

I did find that the 5x10x4 bearing that goes into the 1st gear pinion to be a little tight. Before I screw the 1st pinion onto the 2nd pinion, I mount the bearing first. Then I screw the whole 1st and 2nd gear pinion onto the clutch bell. I did not find the pinions wobbling problem.