hi guys,

finally bit the bullet and bought my second bec which is a mk indy 2005 with a 2007 busa engine. It has been recently rebuilt to a very good standard i must say. I literally only got hold of it last night but have came across a couple of issues immediately and need some help. Firstly i have a wandering issue, the car has a tiny steering wheel (max 10" and i was seriously struggling to keep it in a straight line at general motorway speeds. Bear in mind i havent driven one for a few years but my last car (an mk indy r1) was a dream to drive at all speeds.
Ive managed to check the tracking this morning with just general super tracking gauges and set both front and rear to toe in very slightly as suggested through this forum (it was all over the place). Ive also dropped the tyre pressures to 20 rear and 18 front and yet although it feels slightly better its still a bit lively. Ive sinced ordered a larger 12" steering wheel as i just dont like the small one on the car but have no idea if this actually has any affect on the way the car drives in general. There is also a fraction of play in the wheel which appears to be coming from where the wheel attaches to the column (i assume the boss?) this also provides extra annoyance and possibly assists straight line difficulty. The car has fully rose jointed suspension but has only been set up by original owner. I dont really wanna spend out extra dough on a full suspension setup and wondered if there was someone local in the kent area that could help me out with this issue as i believe it to be setup based????

Also the car has a digidash which in my opinion has only been setup for mph purposes. I believe its reading the right speeds but is useless on gear selection and other alarm purposes. The thing is i dont actually know certain things about the busa engine ie. oil pressure limits? oil temps etc. Has anyone dealt with digidash and busa's and can help with the setup. i know i can connect it to a laptop but without the correct info i thought it was pointless.

Any help is much appreciated.

Thanks

Not going to comment on the "wandering" it needs a geo set up, there I just did comment.

The digi dash, you can download full setup instructions from etb's website, don't panic about the oil pressure at idle, the busa is notoriously low particularly when hot, the digi dash can work around this as you can set a rpm below which it won't alarm to avoid the warning constantly coming on at idle, I set mine to warn at 25psi but only if the engine is above 3k revs, make any sense?

Eta, there is also a calculator on there to get the right settings for gear indicator, the gear ratios you can get from a Haynes manual, I have one if you don't have access to one.


[Edited on 19/7/14 by Jon Ison]

quote:

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Originally posted by Jon Ison
Not going to comment on the "wandering" it needs a geo set up, there I just did comment.

The digi dash, you can download full setup instructions from etb's website, don't panic about the oil pressure at idle, the busa is notoriously low particularly when hot, the digi dash can work around this as you can set a rpm below which it won't alarm to avoid the warning constantly coming on at idle, I set mine to warn at 25psi but only if the engine is above 3k revs, make any sense?

Eta, there is also a calculator on there to get the right settings for gear indicator, the gear ratios you can get from a Haynes manual, I have one if you don't have access to one.


[Edited on 19/7/14 by Jon Ison]

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Another possibility is bump steer.

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Originally posted by Ivan
Another possibility is bump steer.

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Have a search on here regarding bump steer, plenty of info to keep you reading most of the day!

Steering rack height/length of rack extensions seems to be a main point on seven type cars.
looking from the front do your track rods run out to the hubs at the same level as your wishbones?
I've just had to cut off the rack mounts on my Mac1 chassis and lower them as the rack was too high, so when the chassis goes down, suspension up,due to the track rods being on a downwards angle to the hub the hubs are pushed outwards into 'toe out'.
I could see it happening on mine just by pushing the chassis down.

quote:

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Originally posted by CosKev3
Have a search on here regarding bump steer, plenty of info to keep you reading most of the day!

Steering rack height/length of rack extensions seems to be a main point on seven type cars.
looking from the front do your track rods run out to the hubs at the same level as your wishbones?
I've just had to cut off the rack mounts on my Mac1 chassis and lower them as the rack was too high, so when the chassis goes down, suspension up,due to the track rods being on a downwards angle to the hub the hubs are pushed outwards into 'toe out'.
I could see it happening on mine just by pushing the chassis down.

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quote:

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Originally posted by kentmagpie


when I checked yesterday on the manual edit mode the gear ratios had already been imputed but I don't think the gear calibration had been setup. when I bought the car the guy kept banging on about connecting it to a laptop to set it up all properly. (

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Before lowering;



After lowering rack circa 25mm;

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Originally posted by CosKev3
Before lowering;



After lowering rack circa 25mm;

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The easiest way to check for bump steer is remove the front shocks and jack the front of the car up and down, excessive bump steer will be easy to detect by the eye.

Nothing as come adrift at the rear ? A pickup bracket for instance broken on one weld and flapping about whilst still fixed to the chassis will allow the car to wander, I have had this on a irs 7 ?

quote:

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Originally posted by Jon Ison
The easiest way to check for bump steer is remove the front shocks and jack the front of the car up and down, excessive bump steer will be easy to detect by the eye.

Nothing as come adrift at the rear ? A pickup bracket for instance broken on one weld and flapping about whilst still fixed to the chassis will allow the car to wander, I have had this on a irs 7 ?

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quote:

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Originally posted by kentmagpie

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Cheers for uploading the pics, i understand the format more now. As the chassis drops and the suspension raises it pushes out the track rods forcing excessive toe out. that correct??? so by lowering the rack and shortening the track rods ur correcting the issue. I assume it would wander on uneven or bad surfaces and on a complete flat surface it shouldn't.

When i get to work tomoz ill get a shot of the front suspension and upload to see what u think.

thanks for your help

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That's it yeah, was visible easily on mine when pushing the chassis down.

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zx12r dug - 20/7/14 at 09:15 PM

Hi brent you mentioned that the wheel has play in it .I would start with getting that secure you'd be surprised how much that bit of play could effect the wondering. Good that you have got another bec.

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kentmagpie - 21/7/14 at 08:29 AM

quote:

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Originally posted by zx12r dug
Hi brent you mentioned that the wheel has play in it .I would start with getting that secure you'd be surprised how much that bit of play could effect the wondering. Good that you have got another bec.

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hi mate, how u doing???? hows ur build going????? if I remember right ur building a zx12 indy aren't u???

Ive got to work this morning and we're all discussing the steering wheel security, its on a quick release boss and there just appears to be play between the boss and the column. Im not that fussed about the quick release and my mate has just suggested drilling a hole through it, tapping it and either get a grub screw down there or just an ordinary bolt to tighten it up. Ive just ordered a new 12" steering wheel as I don't like the other one at all

How do u post pics???? ive got a pic of the front suspension I wanna share to get ur thoughts of bump steer. if anything the rack sits slightly low but I need to post it first

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kentmagpie - 21/7/14 at 09:34 AM

]http://locostbuilders.co.uk/upload/IMG_5627.JPG[/img]

not sure if its worked but I should be posting a pic of my front suspesnion

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kentmagpie - 21/7/14 at 09:40 AM

[/img]

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kentmagpie - 21/7/14 at 09:41 AM

sorry for size but u get the jist

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kentmagpie - 22/7/14 at 09:42 AM

just an update,

had a new boss and steering wheel fitted this morning, also had 4 wheel alignment done again yesterday and the car feels a lot better. had the confidence to actually really boot it this morning and find out how quick this car really is

Still wanders but its much more controllable now and not so violent. Just need a proper good suspension setup, anyone know of any good places within or near the kent area?????

thanks

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