New set has arrived! Front shaft uppgrade *Finland-Fix*

[nando]

that is my car, on H&R sports with hoosier slicks. Yeah, I dunno - I'm pretty certain the car handled better/got faster after I upgraded the suspension from that point.

I did have a couple oversteer incidents in that time, but mainly during transitions like slalom sections the car rolled so much it just wasn't as responsive.

here's a couple months later with much stiffer suspension. this was 2 or 3 suspension changes ago, but the main difference from what I have now is ride quality and suspension travel:


the car did get faster and I won my class that year. I added an accelerometer to my Megasquirt at some point and I can sustain 1g+ on R-DOTs no problem.

Man, I miss those 14" wheels. They were so frickn' light and the tires were like gumballs. I like the 15" I have now but I could pretty much one hand those things when switching tires. I pulled a stock 16" wheel off my wife's E91 the other day, good god that thing was heavy. the 14" wheels were only around 20lbs a corner including the tires!

[mw044]

I have now spring rate something like 60kg at the front and 110kg at the rear.
Rear is pretty soft and I like it. Rear tyres rub right at the end of inbound.

I've got 95kg/180kg.

How I'x should be cornering

I have to disagree with this. This exact picture was used in some other thread/forum about ix cornering. If my car would lift inside front wheel when cornering (exiting corner) it would lead to a massive uncontrollable oversteer, because no LSD in front diff - front power would "escape" from lifted tire and car would basicly behave like RWD (with too much torque applied). When trying to counter steer, car would shoot towards the outer corner when front tires get grip again.

This is the way 4wd should look like when cornering:


Well actually that's quite extreme example (especially for ix's rear biased 4wd), but hopefully you see the point.

[jute91]

I have now spring rate something like 60kg at the front and 110kg at the rear.
Rear is pretty soft and I like it. Rear tyres rub right at the end of inbound.





How I'x should be cornering


If you Matti ever think about joining facebook, there is always room in my ix group. reached 200 members long time ago. If you would like to craft something you would sell ;)

[TehRaydarlover]

Along with that and few minor tweaks to front diff - I hope that front diff breaking is a thing in the past.

What was your final solution to the front diff?

[mw044]

Haha great to hear from you, any new videos?

No new videos. After dyno I took the engine apart for checking and few mods. More to come next summer. :D

Needs more weight transmitting to rear tyres

https://www.youtube.com/watch?v=Cm4swT9WSCg

make the rear suspension softer. it might give you more traction to rear.
that's how they make it at rallycross series.

Naaa.. car is a street car driven on dragraces, not a drag car driven on street. :D I had softer suspension earlier and yes, there sure was weight transfer... It was pretty undriveable @ WOT. A lot easier to drive with stiff suspension.

[jute91]

Street tires can't do more than ~1,1g

Jute: Only one transmission broken so far (3rd gear). The one in that video above.

By the way - I'm now using your driveshaft upgrade, great product. I was going to use two guibos, but there's no room for second one unless you modify the bodywork. I'm now using organic clutch. Along with that and few minor tweaks to front diff - I hope that front diff breaking is a thing in the past. At least at this power level (~800hp).

Too bad the engine seems to produce a lot more. :D

Needs more weight transmitting to rear tyres

https://www.youtube.com/watch?v=Cm4swT9WSCg

make the rear suspension softer. it might give you more traction to rear.
that's how they make it at rallycross series.

GTR makes pretty good time using torque pretty well. and slicks. and sequential gearbox :D

https://www.youtube.com/watch?v=U1jRXiQTzAA

305hp is enough for 11's though https://www.youtube.com/watch?v=GcejMk3n1F4

[Nisse Järnet]

Haha great to hear from you, any new videos?

[mw044]

https://www.youtube.com/watch?v=IZA50jk7t4g

and here we go again.. matti has huge problems with the traction tho..

https://www.youtube.com/watch?v=Cd7eLII-6x8

10.7s 1/4mile. hear the slipping at first gear

Street tires can't do more than ~1,1g

Jute: Only one transmission broken so far (3rd gear). The one in that video above.

By the way - I'm now using your driveshaft upgrade, great product. I was going to use two guibos, but there's no room for second one unless you modify the bodywork. I'm now using organic clutch. Along with that and few minor tweaks to front diff - I hope that front diff breaking is a thing in the past. At least at this power level (~800hp).

Too bad the engine seems to produce a lot more. :D

[jute91]

https://www.youtube.com/watch?v=IZA50jk7t4g

and here we go again.. matti has huge problems with the traction tho..

https://www.youtube.com/watch?v=Cd7eLII-6x8

10.7s 1/4mile. hear the slipping at first gear

[Nisse Järnet]

It's like the ZF 320, always 3rd gear :P Reduce boost a little on 3rd and you're good :)

[jute91]

Matti with his +800hp ix is going for two flex discs at the front driveshaft.

By that it smoothens the torque peaks to front diff making it last longer.

the G260 has been on hard too. 3 gearboxes exploded at 3rd gear. I guess aluminum cover and so narrow axles cant handle that much torque.

[LJ851]

Would you use a guibo?
I don't know of an application in which BMW used a shaft with a flex disk at either end. That would be a little sketchy to me.

My '68 1600 has a driveshaft with 3 flex disks and no u joints from the factory.

[AndrewBird]

Would you use a guibo?
I don't know of an application in which BMW used a shaft with a flex disk at either end. That would be a little sketchy to me.

Also, all guibos are larger than the 4 bolt diff flange. There may or may not be clearance between the 4 bolt diff flange and the floor pan. Going to a flange larger than the 4 bolt would certainly require "work" on the floor pan and maybe cutting and welding.

You don't need a guibo.

All you would need is two rings (1/8" thick maybe?) with an ID the same as the OD of the shaft and an OD just big enough to fit a 3-4 bolt pattern around it. You wouldn't even need to shorten the shaft, just cut it. Maybe even use this technique to make sure everything is aligned straight:

https://www.youtube.com/watch?v=r0wMIF6EPfY&feature=youtu.be&t=10m23s

[DRTSRFR]

One end of the coupler would be welded to the Jute's fitting, the other to the cut down driveshaft. Installation order would be: Jute's fitting in the T-case, then the rest of the driveshaft, engaging the coupler, then the guibo at the diff. As long as the guibo is thicker than the depth of the coupler, spline engagement won't be any less than what it would be with a fully welded shaft.

Got it. I do see how that could work.:)

[The Dark Side of Will]

Why not to just add another flange like that connects front diff and front drive shaft?

Would you use a guibo?
I don't know of an application in which BMW used a shaft with a flex disk at either end. That would be a little sketchy to me.

Also, all guibos are larger than the 4 bolt diff flange. There may or may not be clearance between the 4 bolt diff flange and the floor pan. Going to a flange larger than the 4 bolt would certainly require "work" on the floor pan and maybe cutting and welding.