|
|
#1
20-01-12, 08:56
|
||||
|
||||
|
Hewland FG question
I have a Hewland FG 400 gearbox.
It has been modified to a four speed by removing the first and reverse selector, hence the four gears in use are the ones which would have been 2nd, 3rd, 4th and 5th. The advantage is that first is no longer a fixed gear on the shaft, so the ratio can be altered. I am currently using normal size ratios throughout. I am concerned that with close to 500 bhp it is liable to shred first gear. What is the viewpoint on that happening ? There is a lot of talk of double width first gears. Are these generally a modification of the fixed first gear on the shaft, or are they a normal interchangeable ratio, but twice the width ? Any ideas who I should speak to about getting hold of one ? 
|
|
#2
20-01-12, 09:48
|
|||
|
|||
|
Hewland used to - and maybe still do - make special shafts that have what is effectively the second gear on a five speed box integral with the gear shaft. In other words its machined as part of the shaft. This is much stronger than the removeable second gear of the same ratio (ie that needed for starting) and is cerainly a much better prospect for 500bhp. They might seem expensive - but they're worth it. Breaking a second gear can lead to extensive damage of the gearbox - I know, its happened to me. With just over 300bhp through an FG400. Of course that's assuming you want to do the best 'first 64 ft' times you possibly can. The alternative is to pussy foot off the line to protect the transmission - which always seems to be defeating the object to me - but its a cheap solution!
Its possible someone on this forum might have some used " 4 speed firsts" that would be useful? I'd guess something that would give you about 70mph would be a reasonable starting point? But if not give Hewland a ring - and bite the bullet! It will be cheaper in the long run if you intend giving it plenty off the start!!!! W
|
|
#3
20-01-12, 10:05
|
||||
|
||||
|
At Doune in September I did exactly 2.00 secs for 64 ft, so chugging gently off the line is not my thing !
|
|
#4
20-01-12, 10:06
|
||||
|
||||
|
I would also suggest talking to Dave Whitehead, Ron Hand etc as I am pretty sure that they would know the pitfalls.
__________________
He was stopped stationary - James Hunt
|
|
#8
21-01-12, 11:29
|
||||
|
||||
|
Thank you everybody - I will contact a few of those mentioned and see what I can come up with.
|
 |
| Thread Tools | |
| Display Modes | |
|
|
Linear Mode
