markp27

Now I've driven the solid front diff for a bit, I can see what the advantages/disadvantages are: loads of breaking!!!! bit of loss in turn in steering and must be careful with power coming out of the corner.

Certainly difficult to say if it is quicker on a lap - I'll persist with it for a while until I get completely used to it and then try the one way again.

Cheers, Mark.

InitialD

My venerable Impulse PRO with Wolfpack upper deck and chassis.

Well, although this is a 705 thread, my Impulse PRO has gone through many changes and most 705 parts in it. The rear ball diff, the rear sway bar, pulleys on grub screw mounted aluminum pulley adapters, FC steering blocks. The Centax and the 2 speed gearbox is still the old one. I also modified the front upper arms of the Impulse PRO too.

InitialD

As mentioned earlier, I have used the FPS rear diff's 47T pulley on the ball diff. You need to use the balls from the 15 x 28 x 9 thrust bearing that is used in the original FPS.

The result is the belt will not slip off due to the wider FPS diff pulley, no side play like can be found on the stock ball diff, bigger balls would give better reliability (in my opinion) and most importantly the 47T diff pulley seals the internals from dust better. The only downside with this assembly is that it's slightly heavier.

InitialD

Well, this is what happens if I use the 8 mm aluminum hex wheel adapters. I used them in order to get a rear trackwidth of 198 mm. This is on the Impulse PRO. On the 705 with the same rear camber and rear toe in setting, I manage to get 199 mm with the stock 11 mm aluminum hex wheel adapters. Yes, I had to mod the rear upper arms using the adjustable ones from the 950.

The results from this is excellent. Rear traction is still excellent because the tire contact patch still remains the same but steering is increased !

InitialD

Yeah. Try softer front tires, less caster (more clips to the rear of the upper front arm) and you may want to soften the front shocks (more horizontal mounting, more piston holes, thinner shock oil). You could try more rear droop too (i.e. +7 to +5).

Hey, I almost forgot... I think you can send the parcel to me.

ksrcracing

Anyone runs Impulse Pro with 705 conversion kit? Worth? The conv. kit costs around $140......
Any 13 or 14 tooth pinions for centax clutch?

Schrijver99

Work in progress!

My Stratus 2.1 Spiderman

Arun

No 13s or 14s, unfortunately.

To achieve an equivalent, you can do the pulley conversion here:
http://www.mytsn.com/publ/publ.asp?pid=7186

Or, I have seen someone at my local track using a 14t NEO pinion gear on their Impact, which has the same clutch.

InitialD

Yeah I thought I posted that Serpent USA is having some kind of sale. Note that the conversion kit will not have the Centax II and the new LC lightened 2 speed gearbox. I don't think you'll even get the rear ball diff. In any case, the reduced price is a good price.

If you're living in Europe, you can get the 14T Centax pinion from Serpent Austria (www.serpent.at) that will screw on to the existing clutchbell. Else, you can order from RCCarinternational the older fixed pinion clutchbell from the Serpent Excel car. They come in the following combination and part numbers;

6592 CENTAX CLUTCH CASING 12-16T
6593 CENTAX CLUTCH CASING 13-16T
6594 CENTAX CLUTCH CASING 13-17T
6595 CENTAX CLUTCH CASING 14-16T

The last I enquired with them is that they only have 6592 and 6595 left and Serpent does not produce them anymore.

You can fit these Excel clutchbells onto the existing Centax II or the older Centax. For guys who have Centax II, you need 2 of the 5 x 8 x 2.5 flanged bearing (1312). You also need the 4 x 9 x 4 thrust bearing (1372) and the Centax thrust bearing spacer (6589). Centax II has 5 x 10 x 4 thrust bearing.

If you have the Centax I, then you only need to get the extra 5 x 8 x 2.5 flanged bearing as the Centax I already has one inside it.

To mesh the pinions and spurs properly with the Excel pinions, you need to use the 50T from the Impulse (801420). With this, you need to use the 8 mm one way drive flange from the Impulse (9633) to mount the 50T and the counter clockwise M19 nut (9634) to lock the spur onto the one way drive flange. The 6628 cap too if you want to protect the one way bearing from dust.

InitialD

Here is a closer look at the Excel fixed Centax clutchbells.

When used with the low ratio internal pulleys (47T/22T/17T), you'll get the following ratios;

13T/16T Clutchbell

50T/46T - 8.22/6.14
50T/45T - 8.22/6.01
50T/44T - 8.22/5.88

14T/16T Clutchbell

50T/46T - 7.63/6.14
50T/45T - 7.63/6.01
50T/44T - 7.63/5.88

When used with the stock internal pulleys (46T/23T/18T), you'll get the following ratios;

13T/16T Clutchbell

50T/46T - 7.69/5.75
50T/45T - 7.69/5.63
50T/44T - 7.69/5.50

14T/16T Clutchbell

50T/46T - 7.14/5.75
50T/45T - 7.14/5.63
50T/44T - 7.14/5.50

RoyU

iTrader: (2)

Where are you getting the 705 conversion kit for $140?

Pyramid

Hi, I'm just about to do the front mod. Please clarify the followings;

Whe you said 3mm inwards, is it 3mm in between the outer hole (3mm starting from outside diameter)? Meaning drilling new holes inward at 6mm in between its center

2mm upwards, same method of measuring like above? Your pics doesn't look that way, I think they are 2mm between center diameter upwards, isn't it?

Last but not least, you need to do it front-front and front-rear at the same measurement?

Thanks

InitialD

No need to complicate yourself. The measurements given are from the current center hole position to the new center hole position.

You only need to do the front (left and right). Good luck !

markp27

Thanks for the info Mr D!

Do you mean the one-way parcel?

Just got a couple of Protoform Stratus 2.1 bodyshells - be painting them up in the next couple of weeks. They look good!!

Cheers, Mark.

paulfitipauldi

Hi,, Initial D,,

Just one little question, but first of all,, Thanks for all the reports from your latest R/D department, they are very helpfull around here!! , and congratulation in your last flawless run with your 705 , is good to hear some good news in here, besides the other part of the world ,,

Well my little question is ,, when you refer in your report to the stratus 2.1 shell that performs great, did you do the 5th post mod, ?? or without it??,,

Ciao!!