inspired by a recent threat here about lightning gears and there benefits ,i decided to give it a shoot and wire edm 1st and 2nd gear .the weight difference form stock to modified is
3rd gear .3764kg ( the lightest gear to slow down for shifting)
2nd gear was .5078kg is now .4398kg
1st gear was .6754kg is now .5468kg
gears have bin cryo treated after the machining
for testing the transmission will be mated to a 200hp /4 engine
i let everybody know if the gears survive and if it makes a difference in shifting

I hope it works well. I am really interested in how the light weight gears perform as well.

I got the impression that the main advantage was better synchronization. Any other benefits?

Cool!

BTW you sound normal when you type.

Wouldn't the holes / shapes promote a little more cooling ??

Jaxdream

thanks ferg
better cooling,i don't think so,holes will be covered by the dogteeth

Naaah. He STILL sounds German.

You guys quit picking on Thomas about his "Moder"....... HI T.

And you wish you had his "Moder" ...
Andy

less mass to accelerate and less torque needed to change its state. I think its the sickest of the sick! I would be willing to gamble that it's worth several tenths off the clock...and since it is also less mass to decelerate, I speculate it to wear less on teh synhcros. EDM is great for that.. nice radiuses

Well looks to me like a fools paridise.You have just increased the number of places for stress cracks, (and failure) to occur by a zillion fold. You did mention cyro treating the gears, but what about , actually rehardning the gears, as they surely lost their surface hardness from EDM cutting.,and with all those holes, keeping the gears from distorting(even a little)..is going to be impossable...Need to have a gear run in machine like the factory does, to get the proper mesh for that SET of gears....This is why Gears are made in SETS, and numbered,.thats why mixing gears ,with the same ratio, is not a good Idea...and generally results in noise from that gearset..(for a while, if not forever)..OK you have a race car.You won't hear the noise., but you have a handgrenade waiting to go off., in my opinion.

You seem very skeptical... It appears that the original hardening was only effected at the actual cut points, cryo treating the entire gear provides similar hardening characteristics and seems overkill, these gears aren't going to be behind a 400 hp V8. I hardly think that these gears distort during usage, the centrifugal forces are null and any power torque forces are released as the gear spins. I think it's a cool idea, let's see what happens once it get's reinstalled in the the same car it came out of, a good control for comparison.

I'm interested to see how this works out and if there are noticeable differences in how the car drives and shifts. I don't currently have any use for this type of modification, but it sure is interesting none the less.

Having spent 2 decades as an NDT for military aircraft, I've seen my fair share of cracked parts and the modifications needed to stop them. I can surely appreciate the concerns brought up by ME733 as to the addition of lots of stress risers. It looks as though the ID of the cuts were well radiused to the eye but is doesn't appear as though the top and bottom where the cuts transition to the face of the gear have any radius; it looks like a bit of a knife edge transition. Having a radius on all transitions will help it be less crack-prone during use. Also shot peening prior to final heat treating (or cryo in this instance) will relieve stresses that EDMing and other machining induce into the gears.

A a rule, cracks almost always originate in a corner or on a knife edge be it in the shape of the part or from a stray machining mark

Hard to tell in the original photo, but brightening it up and zooming in, looks to me like everything has a radius.

The proof will be in the pudding. I'm glad to see this is being tested in the real world. In time we won't have to speculate.

Thomas,

Do you plan to run it for a few events and then pull it apart to see how it worked out, or are you planning (like me) to run it till it breaks, then figure it out.

Rich

we will run it till it breaks or needs new syncros,wire edm is done under water so there is no head buildup,cryo treating strengthened the gear by 50-60%,
i talked to one of our customers ,a gear maker (action gear in costa mesa)and he sad, no problem with 200hp,well, will see

You have data to prove that?

The fella that talked of radii & shot peening has made the most sense to me.....
Of course I'm another aircraft guy.

well jake raby uses it for years and so do a lot of other engine builders,http://www.nitrofreeze.com/cryogenic_treatment.html?gclid=CMmY1ZORrpwCFRxNagodJj2Sjw

Basically it is my understanding that NASA first noticed that when bringing stuff back from space the composition of the metal had changed.

Temperature in space is approximately 2.725 Kelvin. That’s almost -270 degrees Celsius, or -455 Fahrenheit


From the internet.

http://www.finishing.com/340/78.shtml

Good job THOMAS. It's great to see someone trying something new.

I don't think THOMAS' car will spend much time in outer space.

Thomas,

If you would like some more data, PM me and I will put you in touch with Insco gears, they make the baker six speed gearbox, as well as many industrial gears....some are three feet in diameter.

They have all the tools, laser, underwater cutting etc etc.

I am sure they will know the affects of what you did on gears....just in case you need another datapoint.

Good luck and please remember to post what happened...

Rich

Thank god for people who ignore the naysayers.

lol no. I was explaining where the idea for cryogenically treating metal came from.

Yo T H O M A S,

I have a BUNCH of stock gear sets if you are interested. PM me if you want them

I thinks its very cool... no pun intended. I can't see EDM causing enough heat to re-aneal the gear teeth. EDM is done under oil/or coolant. Should only get hot right next to the cut only. My only concern would be overheating the gear oil. I think the extra holes will cause some major increases in foaming. Too much oil on gear stacks and bearings causes a lot more friction and heat.

If'n you need a test pilot I promise to run the piss out of it.

2316 in a dedicated race car. and it's running somewhere all the time.

the foaming might be a problem ,one side of the holes is covered by the dog teeth and the other side is close to the intermittent plate, will see ,the first gear set is going in a daily driver with a big /4

Let me ask this.

Why?

Just curious.
Is there a significant weight savings?
Will the motor spin up faster?

Any basis, or is this a fun test?

Rich

less mass is always better, less rotating mass is always better, it's taking a pound off, but it's gonna matter somewhere.

Oh, also re: naysayers, I can't count the number of times I've had people tell me I can't do things that I was already running on for 6 months.

Yeah no one has really gone into this but I think it's more about a longevity thing. Heavier gears cause the syncros to wear faster. Also can make it so you can shift the transmission quicker.

Of course I don't know shit and shit and this is what I imagine it would do.

Dismissing someone as a "nay sayer" precludes the possibility that * they know something you don't*.

That said, this project is worthwhile, IMO.

The object of any such undertaking should be to do everything possible to ensure that the modification survives the test period. The suggestion was made to use sound engineering principles that strengthen the existing materials. This was dismissed by at least one person that doesn't recognize sharp edges even when he blows up the pics. It's obvious that some here have little/no real world experience in actually building things for a living. A fella that has 20ish years of experience of NDT in the aircraft industry *knows something you don't*.

I have been working on my own weight reduction in the same area. It is only worthwhile in the narrow area of autocross. The first section of testing is about over....is the basic precept worthwhile......It seems to be. The next section is the actual weight reduction. This would have gained about 300 times the rotating weight loss over what has been described here. That may be worth a tenth or 2.
The bits needed are on the shelf.....but I'm selling the car. The next owner can deal with it.

longevity of the gear components (syncro,dogteeth and slider)is what i am looking for,90% of all the transmissions i am rebuilding need new components on 1st and 2nd,if you want faster shifting you have to go with a dog box( straight cut gears)

Why would constantly meshed straight cut gears shift faster??

no side load and no clutch for up shifting or down shifting

asd

I like this type of grass-roots experimenting and testing; it's what makes the hobby fun and ever changing.

Those straight cut gears must make for a loud tranny. Of course for a race car, who cares, right??

"every gram must be accelerated, braked and cornered"

The straight cut gear teeth have nothing to do with the faster shifting. It is the lack of synchros and big locking blocks instead of dog teeth that make the shifting faster. Since this type of gear engagement is only practical for racing they also use the straight cut teeth. The straight cut teeth are noisy but there is less friction loss than with the angle cut teeth.

Jim

There are many things that go into a fine shifting trans. The 901 presents several challenges and there are many ways to attack this. I wish you luck.
Mine shifts finer than frog hair under trying circumstances. There are only one up & one down in this vid...("many ways to attack").

http://www.youtube.com/watch?v=7_nANXY8KBs...player_embedded