gearbox troubles

[bcl]

Actually mine started to go after quite a few dyno runs, when power was around 320rwks, before the next tune that took power up to 341rwkw.

So, this is now the 4th case I've heard of .... a trend is starting to emerge.

I know it's a small sample, but based on this information I'd say that if you go over 310rwkw then you should budget for manual gearbox upgrades or modifications.

Is there anyone running a manual T5 with over 300rwkw that has had no problems (apart from APS who report no problems).

I’m not trying to be alarmist here, just realistic, as people should be aware that there are potential problems, as I pointed out 4 months ago. There’s no benefit to anyone pretending that no problem exists.

Brian

[cdm]

I will see how much replacement parts are today but I race a ea salooncar which I have a pfitzner gears made for it and may go do the same road.dont realy need to speng 8gs at the moment

Could you please explain a little more about these 'pfitzner gears'? From what I understand they are a straight cut gearset yet I'm not entirely sure I understand this concept. Can anyone provide a reasonably detailed description of this in Laymans terms and also how they affect the driveability of the car/smoothness of the gearbox? A quick search on google revealed they can be purchased for $6500 for the T5.

Cheers,

Chris

[sharkey]

Reflecting my technical ignorance about gearboxes, but I thought torque was more the issue than the rwkW? Yes/No?

Any layperson explanation would be much appreciated.

Safe and happy driving...Dr Z.

OK, I am a layperson giving an explanation.

Torque is more important to gearboxes than power, but the two are related.

Going back to basic physics Power = Work / Time.

The Torque is the work component. Work = Force x Distance (ie Nm).

Therefore the power output is dependant on the torque being produced and the RPMs (the time part of the power equation).

Torque is more important to gearboxes because it is the 'instantaneous' component of power. It is how much force is being applied, regardless of how fast the engine is turning.

If you know how much torque is being made you can calculate the power being produced with the following equation.

Power (kW) = (Torque (Nm) x rpm x 0.105 ) / 1000

So with a standard XR6 T making 450Nm from 2000 rpm to 4500 rpm you get perfectly linear power (in theory).

450 x 2000 x 0.105 / 1000 = 94.5kW at 2000rpm

450 x 3000 x 0.105 / 1000 = 141.75kW at 3000rpm

450 x 4000 x 0.105 / 1000 = 189kW at 4000rpm

And with peak power of 240kW at 5250 rpm there must be 435 Nm being produced at that point

435 x 5250 x 0.105 / 1000 = 239.8kW

This is my understanding of the relationship between Torque and Power. I am sure there are more technical explanations but I know you like to see numbers and formulas Dr Z.

[badxr6]

I will see how much replacement parts are today but I race a ea salooncar which I have a pfitzner gears made for it and may go do the same road.dont realy need to speng 8gs at the moment

Could you please explain a little more about these 'pfitzner gears'? From what I understand they are a straight cut gearset yet I'm not entirely sure I understand this concept. Can anyone provide a reasonably detailed description of this in Laymans terms and also how they affect the driveability of the car/smoothness of the gearbox? A quick search on google revealed they can be purchased for $6500 for the T5.

Cheers,

Chris

hi cdm the pfitzner gear wont be straight cut but not the same as standard I am going through the program with him now as I help him with the devolment of the salooncar ones which by the way are not a lot different. I will keep people posted the box will be around $4000.00-$5000

[Dr Z]

Very impressive sharkey!

Sharkey, I am keeping a copy of your post in my personal archives for future reference, and naturally, will fully credit and reference you as the original contributor.

Safe and happy driving...Dr Z.

[cdm]

I will see how much replacement parts are today but I race a ea salooncar which I have a pfitzner gears made for it and may go do the same road.dont realy need to speng 8gs at the moment

Could you please explain a little more about these 'pfitzner gears'? From what I understand they are a straight cut gearset yet I'm not entirely sure I understand this concept. Can anyone provide a reasonably detailed description of this in Laymans terms and also how they affect the driveability of the car/smoothness of the gearbox? A quick search on google revealed they can be purchased for $6500 for the T5.

Cheers,

Chris

hi cdm the pfitzner gear wont be straight cut but not the same as standard I am going through the program with him now as I help him with the devolment of the salooncar ones which by the way are not a lot different. I will keep people posted the box will be around $4000.00-$5000

Thanks badxr6... This may well be the cheaper alternative people (such as myself) are looking for. I would certainly think that the weekness of the gearbox is what stops a lot of people looking for the BIG power figures ie 300rwk+.

Can you provide any more technical details on this? Does it alter the driveability of the car at all etc etc? Thanks.

Chris.

[Ford_Power]

I am curious... I like the idea... but even if you have a gearbox with pfitzner gears, will the input shaft etc be bigger? or can it be part of the kit? I ask as we have all seen as per Brian's photos that his input shaft was actually twisted and buckled due to the sheer torque.

Merely upgrading the gear set will not help this problem?

[Turbo6man]

Reflecting my technical ignorance about gearboxes, but I thought torque was more the issue than the rwkW? Yes/No?

Any layperson explanation would be much appreciated.

Safe and happy driving...Dr Z.

Your Q has already been answered to a degree but to be even more specific to your direct Q:-

Each is as important to the rating of the gearbox - torque because this is the force which applies twisting force to the shafts, the contact force between the meshing gears, side loads on the shaft bearings, and the end loading on the thrust bearings. But also the rotation speed of the gearbox components is important and we all know torque by speed is power (very simplified). So you will see gearbox manufacturers quoting torque ratings AND rpm ratings for their products. So they are in fact stating a power rating, just in an indirect way. They will also quote max weight ratings for the vehicle in which the gearbox is to be used. Hope this helps you a little further in your understanding

[badxr6]

hi ford_power yes the input shaft will be replaced as well as all the gears in the gear box here is a sample of the race box gears

[badxr6]

sorry guys having trouble with pic if you like I can email