Synhro helical pfitner gearbox
Thread Starter
Joined: Apr 2002
Posts: 4,857
Likes: 0
From: Gold Coast
Synhro helical pfitner gearbox
The owner of Pfitner racing gearbox just gave me a call and said one of you guys from sydney just sent him a box to build one and whether I want to get one while he's at it 
I have 24 hours to think about it 
So which one of us order this
Elauq was it you? or was it u AusS2000? Is this your secret project AusS2000?
I will drop down to Pfitner and see what's the helical box for the S2000 is like tthis afternoon (as I did not have time to talk to my friend earlier).
Does anyone know what are the benefit of this one?
How is it different from a dogbox?
Is it very noisy compare to the OEM?
The owner at Pfitzner said he will custom make all the gear ratios. What is the best gear ratio combination for occasional track with a 4.44 rear diff ratio?
I have 24 hours to think about it So which one of us order this
Elauq was it you? or was it u AusS2000? Is this your secret project AusS2000?
I will drop down to Pfitner and see what's the helical box for the S2000 is like tthis afternoon (as I did not have time to talk to my friend earlier).
Does anyone know what are the benefit of this one?
How is it different from a dogbox?
Is it very noisy compare to the OEM?
The owner at Pfitzner said he will custom make all the gear ratios. What is the best gear ratio combination for occasional track with a 4.44 rear diff ratio?
Joined: Sep 2002
Posts: 1,938
Likes: 4
From: Sydney
Not me (yet).
The standard box uses helical cut gears with syncros so it sounds like a simple ratio change. The gears are ground off the shafts and new gears laser welded in their place.
Race boxes normally use straight cut gears and dog engagement. In simple terms a dog box uses very simple dovetail shaped teeth to engage gears like a motorbike or older truck. A dog box can be a real pain in the ass on the street, but on the track you can change gear as quick as you can move your hand without worrying about shredding syncro rings.
Straight cut gears are noise, helical mostly quiet, and semi helical reasonably quiet.
Advantages of a close ratio set are that you drop far less rpm between gears, you will tend to have a ratio to suit most corners and because there is less rpm drop between gears the syncros dont work as hard and last a lot longer. One downside is your first gear can get a bit tall. One solution is to use a relatively low first gear ratio, with second to sixth the close ratio set.
Ratio wise, there is one thing to consider with the S2k gearbox. It uses a output pair of gears in the back of the gearbox. Changing this back gear is the same as changing the diff ratio. You could get the equivalent of a 4.44 diff ratio, and close ratios by only touching the gearbox.
Ratio wise, have a look at the Quaife web site. Their 6 speed ratios are pretty well thought out. Decide what top speed you want and work backwards from there.
Speedracer.
The standard box uses helical cut gears with syncros so it sounds like a simple ratio change. The gears are ground off the shafts and new gears laser welded in their place.
Race boxes normally use straight cut gears and dog engagement. In simple terms a dog box uses very simple dovetail shaped teeth to engage gears like a motorbike or older truck. A dog box can be a real pain in the ass on the street, but on the track you can change gear as quick as you can move your hand without worrying about shredding syncro rings.
Straight cut gears are noise, helical mostly quiet, and semi helical reasonably quiet.
Advantages of a close ratio set are that you drop far less rpm between gears, you will tend to have a ratio to suit most corners and because there is less rpm drop between gears the syncros dont work as hard and last a lot longer. One downside is your first gear can get a bit tall. One solution is to use a relatively low first gear ratio, with second to sixth the close ratio set.
Ratio wise, there is one thing to consider with the S2k gearbox. It uses a output pair of gears in the back of the gearbox. Changing this back gear is the same as changing the diff ratio. You could get the equivalent of a 4.44 diff ratio, and close ratios by only touching the gearbox.
Ratio wise, have a look at the Quaife web site. Their 6 speed ratios are pretty well thought out. Decide what top speed you want and work backwards from there.
Speedracer.
Registered User
Joined: May 2001
Posts: 211
Likes: 0
From: Sydney
Hey Guys, thats my box, since I broke my second gearbox, I needed to strengthen it, I have broken second gear 2 twice.
Gearbox should be a lot stronger, and it should be ready at the end of the month, I am planing on boosting my car to over 20psi, so I need a stronger box. I will also be replacing the diff at the same time,
I will keep you guys posted if your interested to see how strong it really is, I will take it to the track when it is ready
Regards
Gearbox should be a lot stronger, and it should be ready at the end of the month, I am planing on boosting my car to over 20psi, so I need a stronger box. I will also be replacing the diff at the same time,
I will keep you guys posted if your interested to see how strong it really is, I will take it to the track when it is ready
Regards