Shameless questions that don't need a whole thread

4A-GE · Post by **4A-GE** » Fri May 30, 2014 9:28 am

I'll start.

Where are safe jacking points front and back on an NA?
At the mo I'm jacking up a side, sticking a stand underneath it, and repeating on the other side. Light shed on a front jack point would be great. I'm assuming it's safe to jack up the rear at the diff?

Also, when I'm not on the gas but I'm say, rolling down a hill in gear, is fuel still going into the motor?

That one's always puzzled me.

Angreal · Post by **Angreal** » Fri May 30, 2014 10:31 am

Yep fuel is going into the engine when you're going downhill. Try turn the key off next time and give it a go (I'm going to guess it's probably not a good idea? does the oil pump still do it's thing with the engine shut off?) The amount is negligible though as there is minimal load on the engine.

CordedBowl · Post by **CordedBowl** » Fri May 30, 2014 11:03 am

We jack up the racecar from the rear sills on each side, when you jack it up high enough you can fit a stand under the front sill and we put a stand under the rear A arm joint so it's solid, requires jacking it up twice to get stands under all four corners.

We've jacked it up by the diff a few times but jacking from the front and rear center becomes difficult on a lowered car (with our front bumper especially) and we generally find it easy to just jack up the rear sills.

Good idea for a thread, considering the thread title about 'shameless questions', always jack from the sill where the two notches are front and rear, even 30mm away from those notches can cause the sill to fold on itself

.

marcellarius · Post by **marcellarius** » Fri May 30, 2014 11:47 am

4A-GE wrote:Also, when I'm not on the gas but I'm say, rolling down a hill in gear, is fuel still going into the motor? That one's always puzzled me.

It's going to depend on the car. Many will do a fuel cut on overrun because it improves economy. This could be conclusively tested on the MX5 by back-probing the fuel injector control wire and watching the pulse width on an oscilloscope.

Coasting with the clutch in however will require fuel to keep the engine turning over.

Angreal wrote:does the oil pump still do it's thing with the engine shut off?

Yes. It's a mechanical gerotor pump driven directly off the crank. Your gauge will drop to zero when you switch the ignition off but you'll still have oil flow.

SkilletKid · Post by **SkilletKid** » Fri May 30, 2014 6:09 pm

On jacking:
At home where I don't have much room either side of my car, I jack from the front subframe (near the sump) and the diff. With jack stands in between the rain notches. (my jack is gigantic so I need to drive up on planks of wood to get it under - despite my stock ride height x[ )

When I went to the Ardmore Autocross and changed wheels/tyres there I made a little block to cradle the pinch weld/sill out of some plywood. Jacked one side from the center - change wheels - drop car - repeat for other side. Didn't bend the sill.

Same method can be used for putting the car on stands (placing the stands between the notches as my first method).

flyforfun · Post by **flyforfun** » Tue Jun 03, 2014 7:56 am

Have a question for you all, need some help with our 2000 MX5. The central locking is not working on the passenger door.
Can anyone please offer some advice on what is wrong or how to fix this. Is this a common problem?

Regards

Barry

On Friday, 30 May 2014 9:28 AM, 4A-GE <mx5talk@mx5forum.co.nz> wrote:

I'll start.

Where are safe jacking points front and back on an NA?
At the mo I'm jacking up a side, sticking a stand underneath it, and repeating on the other side. Light shed on a front jack point would be great. I'm assuming it's safe to jack up the rear at the diff?

Also, when I'm not on the gas but I'm say, rolling down a hill in gear, is fuel still going into the motor?

That one's always puzzled me.

------------------------
The P in MX5 stands for Practical.

[Posted via external email]

4A-GE · Post by **4A-GE** » Tue Jun 03, 2014 2:41 pm

Common indeed. I would go switch or relay and work backwards from there.

Timmo · Post by **Timmo** » Fri Jun 06, 2014 10:42 am

What causes springs to droop/uneven ride height?

I have mazda speed springs on Bilstein shocks. At the back, the ride height is uneven - I can fit about three fingers between the top of the tyre and the guard on the left side, whereas I can fit two fingers on the right side (when I'm not in the car obviously)- I've also just failed my warrant on ride height.

warrior · Post by **warrior** » Fri Jun 06, 2014 10:57 am

Mine was the same with brand new springs......

marcellarius · Post by **marcellarius** » Fri Jun 06, 2014 11:35 am

Timmo wrote:What causes springs to droop/uneven ride height?

I have mazda speed springs on Bilstein shocks. At the back, the ride height is uneven - I can fit about three fingers between the top of the tyre and the guard on the left side, whereas I can fit two fingers on the right side (when I'm not in the car obviously)- I've also just failed my warrant on ride height.

A difference in corner weight is the most obvious explanation. The front-right is the heaviest corner. My car has a similar ride height difference with left and right struts set up identically.

If you have adjustable spring perches, the preload may be set incorrectly?

Old springs will tend to sag a bit, rubber bushings can deflect too -- all of the bottom bushings in my OE struts were noticeably off-centre.

SkilletKid · Post by **SkilletKid** » Fri Jun 06, 2014 6:44 pm

Not all springs are created equal. So a mix of corner weights and different spring stiffness at each corner can lead to the difference in ride height.

Timmo · Post by **Timmo** » Thu Jun 19, 2014 3:38 pm

Another question- I've just bought a replacement set of headers, this time they are Chinese stainless steel ones....on which the distance between the studs that connect the header to the midpipe are of different spacing (i.e. the new parts won't fit)- On the new parts they are between 85-90mm (slotted holes), on the existing parts they are 100mm (mid pipe I think is aftermarket)

Can anyone tell me what the 'standard' distance between these studs should be before I go back to the supplier and say 'they don't fit, gimme my money back'

2low2c · Post by **2low2c** » Thu Jun 19, 2014 4:18 pm

timmo na is 95 nb is 110 so i would guess you have na headers not nb

Timmo · Post by **Timmo** » Thu Jun 19, 2014 4:43 pm

OK cheers for the fast reply- I'll get in touch with them. Another question, since my existing headers are leaking at a crack between the flange and the pipe weld at the number 3 cylinder, will continuing to drive cause damage (apart from sounding a bit crap?)

I really want to come for the winter windeez meet haha!

warrior · Post by **warrior** » Thu Jun 19, 2014 5:17 pm

No you wont damage anything, except you hearing.

Jesse Pinkman · Post by **Jesse Pinkman** » Sun Jul 13, 2014 12:25 pm

Hi all i need help finding a suitable roll bar for my NA8C, i really like the look of the Automotive Plus rollbar, the one for $785, but they quoted me almost 500 to get it shipped over here, i sent mainfright in aussie an email to ask how much it would cost to put it in a container and have it sent that way. Has anybody had something large sent from overseas really cheap and how did you do it? Are there any rollbars that can be sourced in NZ that are as good as the Automotive Plus ones? I kinda want one that is hardtop/softtop friwndly, doesnt block the rearview vision too much and is easy enough to install.

Any help would be greatly appreciated, I thought I did aee another car on here with the rollbar i want but i can't remember where.

Thanks heaps

siren676 · Post by **siren676** » Sun Jul 13, 2014 12:51 pm

Depends whether you are after weld in or bolt in, you could easily get a custom made one in NZ for under $700

SLYDIT · Post by **SLYDIT** » Sun Jul 13, 2014 5:00 pm

Roll bars are a tricky thing.
it is very difficult to get one just right for the following reasons...
1) if you are tall, a floor mounted bar restricts seat travel and interferes with the seatbelts.
2) ones that are mounted just infront of the seatbelt mechs up on the shelf, give you seat travel, but still interfere with the belts..
3) ones that give you seat travel and dont interfere with the belts (like the brown davis ones) would not get MSNZ cert but would be fine for clubsport and playdays/trackdays.
4) if you have a hardtop the bar has to be slightly lower than a softtop bar.

theres a lot of bars ive seen that "technically" dont actually meet MSNZ specs and yet they have a MSNZ sticker on them...go figure.

Jesse Pinkman · Post by **Jesse Pinkman** » Sun Jul 13, 2014 5:35 pm

Ok cool, yeah i am tall, (6 foot 4inches) and need one which doesn't interfere with the seats at all and can fit under a hardtop, also I would rather it be bolt in so I can take it out if I need to, (http:// store. automotiveplus. com. au/p/8507485/mx-5-na-nb-roll-bar---single-hoop-torque-box.html) this is the one I want to get but shipping it to New Zealand is the only problem I have , does anyone know how to get something like this shipped over here cheaply?

Thanks guys for the help

SLYDIT · Post by **SLYDIT** » Sun Jul 13, 2014 5:45 pm

do a search for "brown davis" roll bars from australia...its gonna be the best design for a road registered car that has a hard top...your gonna have to get a decent seat too to get you low enough also. getting one fabbed in NZ is your best bet as shipping is a killer.

i'm in the process of making a brown davis copy bar for track days etc

Angreal · Post by **Angreal** » Sun Jul 13, 2014 5:53 pm

I just don't like the rear of that bar. I prefer where the harddog bar mounts at the rear. I guess I'll have to have something fabricated with how I like

SLYDIT · Post by **SLYDIT** » Sun Jul 13, 2014 6:03 pm

yup i agree. mine has the brown davis front mounting with a "normal" hard dog etc rear stay mounts down just infront of the strutt tops

Jesse Pinkman · Post by **Jesse Pinkman** » Wed Jul 16, 2014 8:58 am

Alright thanks for the help guys it looks like I'll just have to copy one cause I cant afford the shipping

SLYDIT · Post by **SLYDIT** » Wed Jul 16, 2014 6:09 pm

when i can actually get my car into my workshop i'll finish mine and post pics... its got a bloody Series 5 RX7 in the way now.... think i'll have to do a midnight run so i can call dibs on the free space.

Jesse Pinkman · Post by **Jesse Pinkman** » Fri Aug 08, 2014 6:28 pm

Hi all is it true that NB hubs will fit on an NA and are the NB hubs wider than the NA ones?, so if I wanted to fill the guards without getting new wheels or spacers could I get NB hubs? Cheers

Shameless questions that don't need a whole thread

Shameless questions that don't need a whole thread

Re: "Shameless questions that don't need a whole thread

"Shameless questions that don't need a whole thread&quo

NB hubs

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