Hayabusa SV

[timbo]

 

thinking of next 7 project. Am no stranger to the hayabusa. lots of questions folks.

 

Has anyone built a SV hayabusa? If I was factory ordering a chassis what you request the factory make additions to on the chassis if at all possible.

 

What is the highest ratio BMW diff?

 

Am trying to avoid a proposhaft reverse transfer box as they are generally sho"te. Reverse alternatives?

 

As anyone used the TRT cush drive adapter on the output flange. My last had the 2 piece centre flange Bailey Morris resilient tube. Any advantage?

 

Gear change set up - still like the idea of a lever system. Anyone other applications?

 

 

[paul jacobs]

Caterham Cars in Canada make a production Hyabusa SV, have a look at their website for some answers. They may be prepared to sell you some of their bits and pieces, but then again, may not as it could contravene their agreement with CC UK.

 

Sounds like an interesting project, do keep us informed with your progress.

 

Paul

[timbo]

Thanks Paul,

 

Yeh have looked at there site and pics in detail. Very little application for eng mounts, chassis detail due to LHD. Their PS footwell is a shortened cockpit version due to the complex reverse engineering unit affixed to the hayabusa gear casing/output flange.

 

Making engine mounts is not a huge problem for me but rather limiting the chassis welding.

 

The induction tract modification is a neat solution to retaining the induction inside the bonnet lines.

[paul jacobs]

Yes, I should have guessed you'd know all about the Canadian one.

 

With regard to the reverse gear problem, I've always wondered whether the reverse gears could be adapted from a quad bike, or one of those little off road pickups, that use a motorcycle type engine. There should be quite a few around these days.

[Violet Elizabeth]

Quoting timbo: 

The induction tract modification is a neat solution to retaining the induction inside the bonnet lines.

 

Not without its problems however.

 

I run the same configuration, turning the TBs through an angle so they fit under the bonnet but with less of an angle so I can run the induction feed from a duct on the nose, although I use silicone hose rather than those rather lovely shiny inlets ☹️

 

Absolute bugger to tune at low throttle openings and revs, as the injectors (and I assume the GSXR1000 ones are much the same as the the 1300) are angled so that the fuel is splattering off the top of the inlet rather than going straight into the cylinder. We ended up having to overfuel at this point in the map, once the revs get up the the airflow is enough to carry the fuel along.

 

Others have found that fuel can get trapped in the inlets, and cause hesitation when coming off the throttle and then back on, in a corner for example.

 

Must say that I haven't noticed this problem, nor is there any issue with revving, throttle response is instant

[timbo]

 

Thanks ... that did cross my mind. With SV I have a bit more room to play with. Am not averse to opening a small bonnet hole for the induction if necessary. Though again has IVA noise implications doing so :-(. With the IVA noise regulations I may need to do some work on a temporary induction and temporary bonnet.

 

 

[bluenose]

I think Jason Fletcher has built one.

 

Nick

[Ian Mackenzie]

Hi there

 

A lot of kits are now using a small gear on the nose of the diff and a starter motor for reverse. may still be tight for space on a Caterham.....

 

Here is a pic: http://www.locostbuilders.co.uk/photos.php?action=showphoto&photo=DSCI0714%20[640x480].JPG

 

Cheers

 

Ian

[timbo]

 

Mackie... had a smilar setup many years ago on a Stuart Taylor track car. May use this setup but would prefer a constant mesh between the flange gear and pinion gear on the starter. The particular picture will have problems meshing unless the flange gear teeth are correctly aligned with the pinion gear.

[Myles]

The late Lawrence Hoy's Hoyabusa had the starter-motor reverse arrangement and this wa fitted to a standard S3 chassis...

[Violet Elizabeth]

Simplify and add lightness.

 

If you have to go backwards just get out and push 😬

[timbo]

Currently have that method,.. Infact I have an even better solution...LSD

[timbo]

 

Can anyone confirm the current metric chassis diffs are from which model year BMW 118.

 

Are there any significant mods - such as output flange?

 

I will need a sub 3.20 differential.

 

Did BMW produce any with standard LSD?

[aerobod - near CYYC]

Quoting timbo: 

Can anyone confirm the current metric chassis diffs are from which model year BMW 118.

 

Are there any significant mods - such as output flange?

 

I will need a sub 3.20 differential.

 

Did BMW produce any with standard LSD?

This should be the standard BMW diff that Caterham use. It is the same on a wide range of BMW models, it has a 3.64:1 ratio: BMW diff link

 

The output flanges are removed by levering on each side until they pop out (they are held in place with spring clips), the Caterham drive shafts then directly insert into the internal splines of the output.

 

There aren't any non-///M BMWs that have had LSDs for at least 15 years or so.

 

Edited by - Aerobod on 8 Jan 2014 06:11:30

[timbo]

Thanks.

 

It appears the side flanges are machined off and mounting holes for the forward support cage tapped and threaded. Also various other small machining points. The rear casing looks to be a bespoke caterham unit again with mounting points for the cage.

 

I am looking for a ratio around 3.07 to 3.2 to better match the gearbox output drive.

[elie boone]

Mercedes have a 3.07 rear diff that might fit in the chassis from the first look. otherwise source a Sierra diff 3.14

[rj]

Quoting elie boone: 

otherwise source a Sierra diff 3.14

 

 

Quite rare, aren't they?

 

 

[timbo]

 

Spoke to me ole mate Phil at R&R - have decided to go Ford and not BMW

[timbo]

 

Is the same differential Caterham use but in the ratio I require

 

3.07 118 diff

[The Pikey]

Quoting timbo: 

thinking of next 7 project. Am no stranger to the hayabusa. lots of questions folks.

 

Has anyone built a SV hayabusa? If I was factory ordering a chassis what you request the factory make additions to on the chassis if at all possible.

 

What is the highest ratio BMW diff?

 

Am trying to avoid a proposhaft reverse transfer box as they are generally sho"te. Reverse alternatives?

 

As anyone used the TRT cush drive adapter on the output flange. My last had the 2 piece centre flange Bailey Morris resilient tube. Any advantage?

 

Gear change set up - still like the idea of a lever system. Anyone other applications?

 

 

Mine was a S3 but I guess the changes will be the same.

 

Short passenger footwell

uprated diff supports

Removable diagonals in engine bay (don't forget these otherwise the engine won't go in)

Bonnet without louvers to allow to be cut out for filter

 

 

 

I used a quaife reverse box, it was crap. I have seen the MNR version and it certainly looks the nuts with no backlash at all.

 

If you use a TRT rear prop shaft then you have to spread the chassis apart by the diff. Sounds drastic but a neat job can be done with a scissor jack.

 

Be careful of the angle of the engine. I used Force racing engine mounts and these put the engine at a to big angle to the cush drive disintegrated on long runs because of heat build up over the period. Previous to me, their mounts had only been used on sprint cars where they worked fine. The second owner fitted a UJ in place of the cush and said it was fine. You have the extra width with your SV so this should help anyway.

 

I like the gear lever that Arch do, like all their stuff it's very well designed. I did spend a fortune on proshift paddles and a Flatshifter but on the road it was crap.

 

Check Ebay for the 3.12. There is a guy on Eastern Europe selling them a a decent price and seems the get good feedback.

 

Jason

 

 

 

 

[The Pikey]

oh and specify no exhaust cutout either and make sure the washer bottle mount is not fitted.

 

 

[timbo]

Hi Jason,

 

Thanks for the post. Order with factory confirmed.

 

In regard to the chassis mods I had already requested the diagonals removed, additional mounting plates for oil cooler etc Caterham can accomodate all these but and its a big but... Delivery time would be 6 months rather than 6 weeks plus as chassis would be via Arch and not metric. Oh an the princely sum of an additional 1k. I'll do all this myself. Can agree no exhaust hole cut.

 

Caterham guages supplier have agreed of return of rev counter for modification to 0-12000 rom. I would like to keep the dash Caterham original rather than slapping the busa clocks in.

 

I have a GEN 11 2013 engine with 600 miles. USA model so no sais immobilser. Engine mounts I will fabricate. The only issue will be getting the gearbox output flange exactly perpendicular to the diff flange face, though with a slight offset to let the UJ flanges work efficiently. I will get 2 bonnets... One butchered for IVA to suit std induction for noise lessening and emissions control.

 

Thanks.. May hae a look at the MNR reverse system... But my history with any of these is less than romantic lol.

 

The Bailey Morris prop should not require any chassis bending. The OD of the rear resilient tube is no greater than the OD of the diff flange if I recall on the megabusa. Hmmm

 

Have you a picture or link to the ARCH gear lever set up... As I too much prefer the gear lever control. I was planning to obtain the westfield kit and modify to suit.

 

 

 

 

[Violet Elizabeth]

Agreed. My BM TRT fits a standard S3 chassis with no mods other than for the centre UJ in the tunnel. Tight, but just about fits.

[The Pikey]

Quoting timbo: 

Hi Jason,

 

 

The Bailey Morris prop should not require any chassis bending. The OD of the rear resilient tube is no greater than the OD of the diff flange if I recall on the megabusa. Hmmm

 

Have you a picture or link to the ARCH gear lever set up... As I too much prefer the gear lever control. I was planning to obtain the westfield kit and modify to suit.

 

 

 

 

yes the diff flange is way bigger than the TRT outer tube but the flange won't go thorough the chassis either which is why it needs fitting before the diff. My chassis certainly needed tweaking to get it in. Maybe they do different sizes?

 

Sorry no pics of the gear lever but it very nice.

 

I've had three new chassis's from Arch. Two came via CC and every time CC tried to make have a metric version. It's never a 6 month month wait. I bet if you spoke to Bruce he would say 4-5 weeks tops. You can then get the removable diagonals and use the left mounting points for the engine mounts and the right one goes back in after the engine is fitted.

 

J

[charlie_pank]

I can't remember having any issue with the diff flange on the Bailley Morris TRT. I'm pretty sure it went in after the diff. I certainly didn't have to bend the chassis to make it fit.

 

I've made do without reverse so far, I still don't feel the need for it.

 

IIRC the Hyabusa and all the gubbins is nearly as heavy as a K-series and only 180hp... more torque than other BECs though.