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Discussion Starter #1
Hi,
I have a 2000cc Nord engine of about 160 hp and wonder how much hp can withstand the standard gearbox to Alfa? This is a 1972 model Junior (bertone cup).
They seem solid built gearboxes for these engines, but they have to limit them as well as everything else.

In the longer term I want to increase power up to 180hp, but now that I take the gearbox first I need to know if the standard gearbox can withstand power increase?

Anyone with answers, advice? Are there any vital parts that need to be replaced with stronger version? Anyone can give me a link, tips?
Appreciate all input, please.

Regards
Arne
 

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There are guys racing with stock gear boxes and 200+ HP. The key is to shift smoothly. I have seen one with a hole in the casing when it was driven by a former stock car racer.
 

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I would think torque kills gearboxes more than hp. My turbo spider was probably pushing around 180ft lbs of torque (nothing but wheelspin if I floored it in 2nd above about 3,500rpm) before I took everything apart for version 2.0. No gearbox issues yet other than a crunchy second gear synchro when cold- mine was bog standard. Version 2.0 with the built motor should make enough torque to eventually break the gearbox on a high boost map, but fortunately gearboxes are relatively cheap and plentiful if I discover the limits the hard way. Our cars are fairly light, and the gears were overbuilt for their task.

Bottom line, I doubt anything you can do with a naturally aspirated Nord will by itself break a gearbox. Of course, abuse can break a gearbox at stock power levels. I'd also point out that tires/suspension can also make a difference. Your box might be fine on relatively stock tires, but not stand up with the same amount of power on slicks because tire adhesion limits how much stress is cborne by the drivetrain. .

There are also two relatively common transmission swap options if you find the Alfa gearbox is not up to the task. Many people have swapped T5 Transmissions, which can be done without cutting if you combine a Mustang GT box with a Chevy S10 tailhousing (good for around 300hp in a Mustang, which is 1,000lbs heavier). There are adapter plate plans on the BB. If you want to spend $$$ (and also get something pretty amazing), Alfaholics sells a Quaife sequential kit.
 

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Discussion Starter #4
Thanks for the information. The same impression as you write I feel the same that the gearboxes withstand the power increases from the North engines. I was not sure and did not find any information about this and had to come in here to get the facet. By inserting the trimmed engine and slick tires you have a completely different torque and grip that can be tough on the gearbox, but with my 160HP it should withstand well. This will also affect the rear axle with diff as well. I'm not going to make too much of this, but that the gearbox can withstand the impact increase I've made. When you increase the effect on the motor, one has an easy to forget drive line. Thanks for the good answer and appreciate your knowledge. Was educational for me. Thanks
 

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There are quite a few people with the Alfa V-6's bolted up to the Spider gearbox. So thats anywhere from 150 to 200 for the 12 valves. I know there are a couple of the 24 valve V-6's in some 105 series. Which are around 220 or so.
 
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