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Discussion Starter #1
How much power will a ZF gearbox from a Alfa Sei handle? i am building a 24v suprcharged 164 engine and have acquired a Sei ZF gearbox to be able to have the gb up front. expected horsepower will be in the 350 bh range with plenty of torque...:)

I have also a long ratio getrag gb ready to use but i really would like to use the dogleg ZF...

Anyone know what kind of clutch plate will fit the Sei mainshaft? the guy at the partsstore told me the Sei item is no longer available... :(
 

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Richard Jemison
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Sei Trans capacity

You will be at the limit for the box driving it normally. If you will measure the input shaft outside Diameter, number of splines, and pilot shaft OD, it should not be difficult. Do you have the flywheel & PP.. (101/105/115 use a 1 inch 10 spline, The 116 type uses 7/8 inch 19 spline. If it is not those it wiull most likely be BMW/Mercedes type).
I can build any size any spline size or spline inc. non Alfa. See my web site.
 

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Accodingto Dawie de Villiers, the Alfa sei should have no problem handling that HP, but if you're going to that trouble you would be better lookinbg at a latee ZF normal 'h' pattern or the later 6 sp BM m3 type box. I am assuming that you are installing the Alfa sie diff as this is the weak point in the drivetrain, the standard crown wheel and pinion may not be able to handle the torque, it depends how you drive it!
 

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Discussion Starter #5
I actually have two diffs from a Sei, a 2.0 version and an auto version (short and long gearing) , which i plan on using. I just bought two of these gearboxes for 300 Euros total... They are the easiest to fit the alfa v6, they bolt right on. I really like the dogleg pattern and the only other gearbox that uses that is a Getrag which is a very rare and expensive gearbox... If dawie reckons it should hold up i'll probably try it. i have two so i can kill one...
 

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ZF / Getrag gearbox

Just curious as to what car you'll be putting the motor/gearbox combination on. While the ZF is your preferred gearbox, the Getrag may have other advantages (depending on which one you have), like a smaller physical size, gear placement within the cabin, different ratio's, etc.

As others have said, the ZF should have no problems handling the power/torque, it's just how it may fit that you may need to do some research. It may be that a particular ZF gearbox will bolt up to the Alfa V6, but another ZF variant may have the selector set in a better location, so you may need to swap & play for the best solution.

Dino
 

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Discussion Starter #7
The engine and gearbox are going into a Giulietta 116.

The tunnel will have to be modified no matter which of the two gearboxes i use. the getrag is the one from the bmw 535 e28, it's not very different in size compared to the ZF.

The ZF bolts right up to the engine. The getrag will need an adapterplate or custom bellhousing. That is the only extra modification i would need to make. All of the other fabrication work is the same for both boxes; custom mount, custom propshaft, enlarging tunnel...

I'm still trying to decide which one to use...
 

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Richard Jemison
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116 Gearbox for 400 HP

Richard, Can you make a 116 gearbox that can handle 400+ horsepower?
Probably, as long as the driveshaft has 2 Guibos minimum and a
lighter rear flywheel & clutch. It would have to start with the large bearing case.
The triple 5.5 clutch in the RjR project is rated at 600+ lb ft torque.
I would not want to use welded on gears for this application however. Different ratios are available & some listed in my website.
How are you getting the HP?
Sold my Nissan SPO car as a roller & kept the new 550 HP dry sump SBC motor, and have been "considering" fitting it into the RjR chassis :eek:& that will certainly test the transaxle. But I have two finished 3.0 liter Alfa 12V motors built & finished for it.
What to do???:rolleyes:
Rj
 

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Discussion Starter #9
I think you need straight cut gears for 400 bhp in a 116 gearbox. or else it will push open the gearboxhousing... and if these horses are forcefed horses it is most likely that the axle will snap behind the pinionwheel.

Alfa did build gearboxes that could handle 400 bhp, check 75 IMSA 1.8 Tb!

One guy in holland uses a ferrari gearbox, i think from a 550 maranello, wasn't cheap either...
 

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ZF and Getrag gearboxes

While the ZF should handle the power and torque, and is a direct bolt up to the Alfa engine, the disadvantages are its weight (there were even instances in other cars where block failures were attributed to the ZF), and the shift quality (the box was used in some light commercial vehicles, so this should give you an indication of its strength).

You can read more at the following site: http://www.westnet.com/~mfrank/FiveSpeeds.html

In fact, my brother did some research on the ZF transmission, and found that in some of the light commercial applications, the gear selector was positioned further forward towards the bellhousing, so if you do decide to use the ZF, this may help locate things in the cabin.

Have a look at the following site (Transmissions section) regarding the different types of Getrag boxes available – you may be able to locate your ‘box in the list, and if so:
• see what model BMW it was fitted to (if the engine has similar power / torque to yours, then it’s looking good)
• check gearing, etc for your car (will help in determining what diff gears)
• determine what modifications you may want to do

http://www.metricmechanic.com/catalog/catalog.php

For my brother’s project, http://www.alfabb.com/bb/forums/showthread.php?t=38223 he’s decided that if the synchros or longetivity of the Alfa 105 series gearbox is compromised due to the V6’s torque, he’ll source a Getrag 265 as it has a removable bell housing and improved synchros. With the Getrag that you have, just make sure that it isn’t the smaller Getrag 260 unit, as this would be too weak for your project (Getrag’s suggested torque application was 300Nm). However, they fit the Getrag 265’s behind V12 Jag XJS’s, so I would assume that it would do for your application.

If you're still after a source for Alfa Sei parts, feel free to PM me.

And if you do happen to find any good Getrag 265’s in Europe (commonly used in several BMW’s and Volvos), please drop me a line as he may be interested if the price / model year is right……..
 
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