New Build for WTAC

[NitroDann]

Basically quite a lot of people believe that the strength different between 5 and 6 speed comes down to case stiffness. With the same sized gears made of the same material similar bearing size and no additional supports on the shafts the only real significant advantage that the 6 speed has in terms of strength is the case itself is stiffer.

By having the engine and gearbox reasonably solidly mounted using a gearbox crossmember and race car style engine mounts we are eliminating the torsional force that comes from the engine and diff rotating in opposite directions under acceleration and the nose of the diff lifting under acceleration which also flexes the gear box case via the power plant frame.

And it's lighter.

Apart from lots of clever people thinking this and basic observations of both 5 and 6 speed, a good example is Ron and Keith's NA8 sports sedan, 380rwhp and slicks with multiple records held and no worries so far on a stock used 6 speed gearbox, with a solidly mounted drivetrain.

Dann

[plohl]

So, with big power, they find the PPF isn't stiff enough, the flex causes the gearbox case to warp and a gearbox dies. So adding dedicated mounts (and removing the PPF to do so) reduces flex and the box lives a relatively stress free life?

right, that's interesting.

[NitroDann]

Yeah thats (hopefully) right. It's well documented they last longer with solid engine mounts and enough evidence that solidly mounting the gearbox helps in addition to solid engine mounts helps more.

Dann

[NitroDann]

Some paint.



Dann

[SKYHI]

Keen to hear how testing goes.

[Swile]

Thats tough! Looking forward to seeing it in person if i make it to WTAC this year

[Tim_cyc03]

What are the dimensions on your front duct?

I have a radialised (spelling?) intake shroud sitting on my scrap table.

As per picture.

22861845_1555528684526254_8397493330951627655_o.jpg

[chrons_rotary]

What are the dimensions on your front duct?

I have a radialised (spelling?) intake shroud sitting on my scrap table.

As per picture.

It is currently 130mmx450mm.
I do have 2 spare sheets if I need to replace the dam.

[chrons_rotary]

Some pics from AUS Time Attack 2018 @ Wakefield.

[lightyear]

17's look big on an NA.

[chrons_rotary]

17's look big on an NA.

They are way over sized, but it's what we need to run to get the tyre width for WTAC.
I would be running 15s otherwise.

[mr bender]

do you run spacers on the wheels?

[chrons_rotary]

do you run spacers on the wheels?

Yep, but may need bigger spacers as they are a high offset wheel.

[lightyear]

We should partition to get them to make some 15" tyres in a mans size. 17's or even 18's is the only way to go for WTAC.

[The American]

Very interested to hear how your 6 speed lasts with the new mounting arrangement!