Anyone know these two 108mm applications?
Both (on the right) are 108mm course-spline flanges. But as the pic below shows, the center flange has the same dimensions as the 914 flange (left) on all turned surfaces.
The 108 flange on the right is the same dimensions (on turned surfaces) as the 100mm SC flanges I use with 944 cv's on my 914.
I can just barely make out what I think may be the part number on the rightmost flange.
915.332.209/01 but this may be incorrect. It's not very distinct.
Anyone run into both at some point? My guess is that the flange on the right is from the SC era and the center one is an earlier turbo, but I'm basing that on the SC dimension match, not from actual fact.
Ideas?
They did away with coarse splined flanges after 76 I believe so, the first year Turbo would have been the last. No SC's had them that I am aware of.
Check Sporto vs, Standard...
I'll look into that. I didn't think of the sporto because all of it's parts were so small compared to the 901/914 transaxle equivalents, that it was hard to imagine a 108mm cv with one. I'll report back if none of us knows the skinny up front. I've never even seen a 915 based sporto but I may have to cruise through the PET to find the answer.
I have a friend's 914 race box in for a seal installation and his 108's are the same as the pic on the right.
I'm still running the 914 trans and a GT LSD/100mm 944 cv's and a 3.6L engine. The turbo flanges won't be used until a big horsepower conversion is on the table. I'd rather put the money into driving experience, safety and suspension upgrades, and get more horsepower (for now) by lightening the car.
The turbo (axle) gear is so much heavier than the 944/911 gear that it didn't seem to make sense to convert to it yet.
I've always understood the 930 cv's to be 108's and you're right about the 110mm measurement on the flanges. But both of these flanges are identical in that respect.
The difference in the two flange pairs makes for about 1/4 in in total length, which will potentially make a difference in the axle length if I specify a custom axle.
I hear you about the 930. I don't have one sitting around but have a Quaffe diff ready to put into either a 915 (which I do have) or a 930. What I don't have are fine-splined 930 flanges. But that's another story.
I still want to find out what application the longer flange is for. Perhaps it's an aftermarket flange for off road. A man's gotta know what he's working with!
Question answered by GT's Matt Monson. The longer ones are for the factory ZF LSD's and the shorter ones are for the open diff's. In a post on another board he stated the following on a different but related topic...
_________________________________________________________
The mag case 911 gearboxes (which includes the 1969 type 901s) use the same differential as the 914. The very early 915 gearboxes also use that same differential.
If one were to acquire a factory ZF LSD for the 911/914 be sure to get the proper LSD stub axles flanges to go with it. The length is greater and the open diff flanges will be too short.
... The length to the step on a standard open diff flange is 56mm. The length to the step on the LSD version is 61mm...
Our (GT) LSD or TBD does not require LSD flanges. You can use the stock open differential flanges with our units.
Kind Regards,
Matt Monson
Guard Transmission LLC
__________________________________________________________
It seems ultimately a wash in strength overall, but the 915 R&P is certainly better, even in the 7:31 version simply because it's bigger... more meat, and first gear isn't cantilevered so you can explode from a start with more confidence. Especially the AX crowd. I also think a late side-cover is required in any case magnesium or not.
And I don't have a problem with the mag-case 915 differential housing since it's bearing race bosses are steel like in our 914 transaxles.
So, if the material cost of replacing more 914 boxes over time is the same as higher cost 915 boxes but fewer overhauls, I'd choose the latter to avoid down-time if the gear ratios are to my liking. My ultimate take is this. If I didn't have a few at the house I wouldn't do it.
But since I do, The 915 build/install will be a really fun project so why not? But I won't use 108 CV's until my torque/hp demands it. And you're right.
Smooth shifting saves these boxes... both of them. To the G-50. Yummy
That's a really nice machine and I love the thought of a six-speed short bell housing G-50. But like the 108's the darned thing is so heavy I'd have to run a lot more torque/horsepower to justify the hit to the power-to-weight ratio.
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)