Printable Version of Topic

Posted by: buck toenges Oct 18 2004, 10:42 AM

I am going to redo my stock 901 tranny to get the most out of my 3.2. Right now I use 2nd,3rd, and 5th gear. I use 2nd as my first gear and it is o.k. I got enough torque to make it work but it ain't perfect. In 5th gear I am running 70mph at 3100 rpm. I would like it to be lower for better fuel economy. That all said I use my car for nice trips but I would like to try some ax. I know I could go with a 915 box or 930 box but I sort of want to stick with the 901. You guys have any thoughts on what gears to go with and or try and talk me out of the 901 box? One thing about using the 901 box is that if I go with another box I'll have to switch out fly wheel and clutch.

Posted by: Martin Baker Oct 18 2004, 10:49 AM

I know a guy here in Sac that has the perfect gearbox for you, $800.00 with a limited slip, fresh ready to go. I would buy it, but its set up as a four speed, not 5. This guy knows transmissions. He is going to build mine. Mike at Auto Werke, 916-488-4283, it was for his car, but he decided to go 915. It is based on a 911 case, so it can use push or pull type clutch. Worth your while to make the call. I did not want it because it really lowers your rpm in 5th gear. I will time trial my car eventually, and want a more sport type box.

Posted by: skline Oct 18 2004, 10:54 AM

Wow, if he is not interested in it, I sure am. I have not even driven mine yet but I know mine will be the same. Let me know. I cant afford a 930 box or I would in a heart beat.

Posted by: Martin Baker Oct 18 2004, 10:56 AM

He said this was built for V8 conversion...It looked F'in sweet on the stand, he had it at the swap in Sac. I wanted to buy it just for the limited slip.

Posted by: skline Oct 18 2004, 11:01 AM

Is that the guy who put it up on Ebay about 3 or 4 months ago? I remember one from that area. It never made the reserve. I think I had bid like 1200 on it and was the high bidder.

Posted by: bondo Oct 18 2004, 11:07 AM

I had thought the 901 from the 911 couldn't have the pinion reversed. I had also heard that the case was weaker. If it's a 915 with a reversed ring and pinion and highway ratios then that is a VERY good price.

Shameless plug: I have an H gear for sale in the classifieds that will give a great highway cruising 5th. I have many other gears too, and pretty much any trans part you can think of, big or small.

Posted by: skline Oct 18 2004, 11:11 AM

I saw your ad for the H gear, not trying to be an ass or anything, I thought $500. 00 for it was a bit high. There is a place in LA that sells them for $300.00 new. I just didnt want to say anything at that point.

Posted by: bondo Oct 18 2004, 11:15 AM

Dang. When I was needing one, the new price was $650, and the going good used price was around $500. Who sells the new ones so cheap? Looks like I need to lower my price. Thanks for the info, and you're not an ass

Posted by: James Adams Oct 18 2004, 11:56 AM

You are probably thinking of the aluminum cased 901 from '68 and older 911s. The '69 901 trans from the 911 has the same case as the 914. '70 and '71 911 trans is nearly the same as 914, but it has the different throwout arm pivot.

Posted by: bondo Oct 18 2004, 12:16 PM

Yup, that's what I was thinking of. Didn't know the 911s went to magnesium 901s before going to 915s. Learn something new every day!

Posted by: TimT Oct 18 2004, 12:30 PM

I have a 3.2 in my 914 and use short gears (A GA M S X) which isnt what your looking for...

But if you want to lower he cruising RPM in fifth you need a taller gear like a Z,ZA, or ZD. Alot of the 911s came stock with a Z fifth, do you know which gearset is in the box?

Posted by: Martin Baker Oct 18 2004, 05:38 PM

The guy who built it knows, call him for details, he added some 915 parts to the 901, pinned some other stuff. Guy just really knows these gearboxes.

Posted by: Red-Beard Oct 18 2004, 08:20 PM

http://members.rennlist.com/chuxter/901&915ratios.htm

Posted by: Red-Beard Oct 18 2004, 08:21 PM

The 915 is taller because of the ring and pinion on the 1975 and later. The 1974 used the same ratio.

Posted by: Martin Baker Oct 18 2004, 09:23 PM

He also talked about some of the parts from the sport-o-matic being stronger, and sport-o-matic ring and pinion ratios. This guy, I am telling you knows PORSCHE gearboxes...