Pukekohe

RMS · Post by **RMS** » Sun Oct 23, 2011 9:11 am

It was cool to see so many MX5's at the track this Saturday.

I uploaded a couple of onboard videos to youtube if anyone's interested.

http://www.youtube.com/watch?v=YvUSb_aFDBY

http://www.youtube.com/watch?v=x-Xfj3M1vz0

WideOpenThrottle · Post by **WideOpenThrottle** » Sun Oct 23, 2011 11:27 am

Great video's shame about my car-had to limp home on what feels like two or three cylinders...my air/fuel meter is all over the place with irrelevant readings,my boost gauge goes too high & i've got rough idle although the motorway home wasn't too bad luckily at 100k-did run it a bit hot on the standard radiator so out it goes along with what else is broken...probably should start with a compression test and see where i end up.My first two or three sessions went well but shame i couldn't break the 200k barrier only got to about 195k so maybe next time

RMS · Post by **RMS** » Sun Oct 23, 2011 1:39 pm

That's a shame. I'm sorry I didn't introduce myself but i was the guy with the orange shirt checking out your car.

Re the radiator, I'm running one of the trademe ones which I picked up when the seller had them at $199, so far so good, it's definitely better than the stock one and it's got a large IC right in front of it with a lot of bent fins.

The engine usually sits around 85-90C, at the track my logs show a peak of 110C full load, it drops about 10-15C on gear shifts when I'm off the throttle.

WideOpenThrottle · Post by **WideOpenThrottle** » Sun Oct 23, 2011 3:00 pm

So far i have found one totally burnt,one nearly all burnt with no crush washer,one partially burnt and one ok spark plug!-two of them covered in oil...........tried another set but symptoms so far unchanged.

The primary coils are reading 1.0 & 1.8 ohm which is slightly high than the recommended reading so does anyone know if thats way too high from the correct tolerance of approx 0.7 to o.9 ohms?
Plug lead resistance measures ok!

Was i under the car at the time as i cant recall the orange shirt sorry!

m4vr1k · Post by **m4vr1k** » Mon Oct 24, 2011 4:00 pm

Well, I had a blast. Couldnt quite get down to 1.20, but best time was 1.21.5, so I am very pleased about that.

RMS · Post by **RMS** » Mon Oct 24, 2011 10:34 pm

I measured the primary coil resistance when I added the turbo to my MX5 and they're way out of spec; both ~1.7ohms.

It hasn't stopped the car from running 12psi but I did notice that the since I upgraded my injectors it's been running a bit richer (~10.5 AFR compared to 11.5 full load) and this was causing it to misfire.

WideOpenThrottle · Post by **WideOpenThrottle** » Tue Oct 25, 2011 8:17 am

Cheers RMS-at this stage then i wont worry about my coil readings then.

I have checked the AFM,injectors,fuel,ingnition & all seem ok so as soon as i can get the extension for the compression test to confirm what i think is now stuffed valves &/or pistons from pre-ignition.I had set my timing to around 0 degrees so i need to find out why things are burning up!

RMS · Post by **RMS** » Tue Oct 25, 2011 9:39 am

what plugs do you have in there?

which wideband do you have? and when you say the readings are all over the place, is that all the time or just when you're in boost?

Do you have larger injectors? I'm not familiar with the voodoo box but am I right in thinking that it does nothing when not in boost? Does it retard ignition as well as add more fuel?

WideOpenThrottle · Post by **WideOpenThrottle** » Tue Oct 25, 2011 10:30 am

Plugs were Autolite 3924 which came from the 323 turbo motor so from memory they should be ok!.....the wide band 02 is a Flyin Miata one i got at the same time as the AEM guage & Voodoo Box. The readings are erratic even at idle without boost.....i have standard injectors and i think you are right that the Voodoo Box does not retard & only adds more fuel.....i must admit it was a bit of a pain to tune so in the end i left it at there recommended settings.
The Voodoo Box has installation/tuning info at FM - search Voodoo Box-click on it and highlighted in blue is the word 'here'which brings it up.

Maybe i should take it to a Dyno shop next time!!!

sprsta · Post by **sprsta** » Tue Oct 25, 2011 1:44 pm

how much boost are you running?
if you are using the standard injectors over about 7ish psi you will more than likely be maxing them out
i know my 390cc's are at their limit at 10psi with my low flowing t25
you may like to consider a bipes setup for your ignition
http://www.miata.net/products/perform/bipes.html
or move to a full stand alone ecu

WideOpenThrottle · Post by **WideOpenThrottle** » Tue Oct 25, 2011 4:42 pm

Hi sprsta-boost max 8-10psi. ... the bipes i suppose is an option but until i win lotto i need to make my current Voodoo Box work properly

.
So my plan is better spark plugs, bigger radiator,bigger injectors [bigger intercooler perhaps]? & see if a tuner is able to set up the Voodoo box.Hopefully by then my inheritance from lotto will materialise so i can get a link

he-he!

Donovan · Post by **Donovan** » Thu Oct 27, 2011 8:38 am

Who was the track day run thru, was it just an open day at Puke, or organised via a car club?

WideOpenThrottle · Post by **WideOpenThrottle** » Thu Oct 27, 2011 10:29 am

Keith Jones from this forum let my mate who is an MX5 club member know that is was on.
All i knew was that you turned up,paid the $90.00, signed your life away,put on a helmet & then put your foot down until something broke!

Keith Jones · Post by **Keith Jones** » Thu Oct 27, 2011 7:52 pm

Hi Donovan
It was just a normal public test day at Puke.
I suggested the date as, not being the day before a race meeting, it was likely to have been quieter.

WideOpenThrottle · Post by **WideOpenThrottle** » Sat Oct 29, 2011 12:29 pm

Its got no compression on 3rd & 4th cylinders & no change with a drop of oil in them so at this stage its vavles or head or gasket or all three.Compression in 1 & 2 is 215psi which is above factory minimum....so unless i have holes in the top of the pistons then its only a head job for now!

Pukekohe

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