Cheap and cheerful DIY Mods
Discussion
I've had the mx5 a while now and am struggling to suppress the modifying bug! So far all I have done is remove the cheap and nasty halfords stick on chrome trim that someone had kindly stuck all around the car! Eurgh
I'm on a tiny budget at the moment due to still being at uni so has anyone got any ideas of little mods I can do for cheap at the moment? I'd like to start looking at the engine tuning, I've heard of people making DIY gauges for AFM for some cars, is this something that anyone has tried on the 5? How complex is the stock ECU? Is it possible to access it via a computer with OBD or is it too old for that?
I'm on a tiny budget at the moment due to still being at uni so has anyone got any ideas of little mods I can do for cheap at the moment? I'd like to start looking at the engine tuning, I've heard of people making DIY gauges for AFM for some cars, is this something that anyone has tried on the 5? How complex is the stock ECU? Is it possible to access it via a computer with OBD or is it too old for that?
Mk1? Borrow or buy a timing gun, and set the timing to 14deg advance, and reset the baseline idle at the same time. Very worthwhile job, and one that I bet many of the older cars havent had adjusted/reset for years and years.
Shifter turret oil, nylon cup and shift boots is another one thats cheap and usually has instanlty noticeable benefits if its never been done before.
ETA I built a narrowband AFR display from a kit - you wouldn't use one for proper tuning but it is very interesting - it allows you to see how the car is working. When you start, you can see the car warming up and leaning out a little bit. You can see when the car goes between closed and open loop, and you can also see the acceleration enrichment kick in at certain loads as you squeeze the throttle. It also shows at what point the injectors kick in to 'anti-stall' on the rundown.
That, combined with a vacuum gauge is a really interesting way to monitor how your engiens running and also where the power and efficiency lies.
Its geek stuff, basically.
Also, again presuming early Mk1, your car is not OBD however you can build a DIY fault code reader which is worth doing too.
The best thing I ever bought though, was the Rod Grainger workshop manual. Available on Amazon usually, for not a lot.
Shifter turret oil, nylon cup and shift boots is another one thats cheap and usually has instanlty noticeable benefits if its never been done before.
ETA I built a narrowband AFR display from a kit - you wouldn't use one for proper tuning but it is very interesting - it allows you to see how the car is working. When you start, you can see the car warming up and leaning out a little bit. You can see when the car goes between closed and open loop, and you can also see the acceleration enrichment kick in at certain loads as you squeeze the throttle. It also shows at what point the injectors kick in to 'anti-stall' on the rundown.
That, combined with a vacuum gauge is a really interesting way to monitor how your engiens running and also where the power and efficiency lies.
Its geek stuff, basically.
Also, again presuming early Mk1, your car is not OBD however you can build a DIY fault code reader which is worth doing too.
The best thing I ever bought though, was the Rod Grainger workshop manual. Available on Amazon usually, for not a lot.
Edited by snotrag on Thursday 9th June 08:59
Go to autospeed.au (Or something like that, google Autospeed, australian website). Its a wonderful website.
They have a number of articles relating to interesting stuff like making AFR displays, interrupting sensor signals to fool the ECU, clocking AFM springs, all sorts. There is also a shop area where they sell the 'jaycar' (Another brill resource) electronics kits, all surface mount bits onto a PCB, spot of soldering and splice it into the loom.
You might be able to buy the Jaycar stuff elsewhere, but I ordered from their and it came from Aus in just a week or so and wasnt dear.
They have a number of articles relating to interesting stuff like making AFR displays, interrupting sensor signals to fool the ECU, clocking AFM springs, all sorts. There is also a shop area where they sell the 'jaycar' (Another brill resource) electronics kits, all surface mount bits onto a PCB, spot of soldering and splice it into the loom.
You might be able to buy the Jaycar stuff elsewhere, but I ordered from their and it came from Aus in just a week or so and wasnt dear.
Foamectomy is a worthwhile mod, especially the back part of the seat, nice and easy holds you in alot better as well. Base part takes a little longer but drops you down an inch or so.
Both of my recent cars have had slack throttle cables, worth checking out.
Clutch and brake bleed are worth doing.
Both of my recent cars have had slack throttle cables, worth checking out.
Clutch and brake bleed are worth doing.
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
If you want clear lenses on a budget
Mind you, I did mine and have now got some TSI's to fit anyway!
If you want clear lenses on a budget
Mind you, I did mine and have now got some TSI's to fit anyway!
GravelBen said:
Advance timing to 14° for starters. 
With this 14° timing business, is it a case of going to a garage and saying '14° timing please?' or is more involved?The reason i ask is i need a cambelt, waterpump, brakes and an MOT very soon and this could be done at the same time...
If you get the timing advanced, get the o-ring replaced at the same time otherwise it'll likely start dripping hot oil on the coolant hose below which will eventually let go in a very impressive cloud of steam.
A new o-ring is only a quid, is easy to change, and it'll save you being stranded by the side of the road
A new o-ring is only a quid, is easy to change, and it'll save you being stranded by the side of the road
Burgmeister said:
With this 14° timing business, is it a case of going to a garage and saying '14° timing please?' or is more involved?
The reason i ask is i need a cambelt, waterpump, brakes and an MOT very soon and this could be done at the same time...
(Excuse anything patronising, thought this might be helpful to some!)The reason i ask is i need a cambelt, waterpump, brakes and an MOT very soon and this could be done at the same time...
Lots of cars wont have ever had this changed or set probably - I know some friends have bought cars that are way off. Its probably mentioned somewhere deep in the original service schedule to do it every bazillion miles or something but I'd guess most Mk1s havent been near a main dealer in years!
By correctly setting the timing, you can regain a bit of power and smoother running.
It generally increases the midrange a little bit - not a lot, but noticeable. Apparently greater effect on 1.6's but my 1.8 definitely responds well.
The Mazda ECU applies a preset timing advance curve throughout the rev range - as the engine revs higher and under harder load, the timing advances. Up to a point, more timing advance = more power (in basic terms). The ignition timing determines at what point in the stroke the engine fires the spark plugs, which in turn effects how the fuel burns and how much of that energy gets changed into forcing your piston back down again.
The advance curve has a 'base' level, which is set at idle. The curve might be something like, say - for every 1000rpm, advance 1 degree, for instance (I dont know what the ACTUAL figures are).
So if Base @ idle (1000rpm for arguments sake) = 10deg.
Then 3000 rpm = 10+2 = 12 degrees.
If you change the base level to say 14...
Then 3000 rpm = 14+2 = 16 degrees before top dead centre.
At standard, this base figure is usually set to 10 degrees. This is a very safe, or reserved figure, if you like - it accounts for you using really piss poor 89 ron petrol and such like.
In real life - its proven that you can safely run a much more advanced ignition timing. You can see how by advancing the base level, you advance the timing throughout the entire rev range, as the curve is fixed.
Its an electrical version of the way you can adjust the initial timing on a car with a distributor, by rotating it, and how that then might then have a fixed advance curve operated mechanically by vaccuum as the load on the engine changes.
Does that make sense!?
The adjustment is made by rotating the sensor on the back end of the exhaust camshaft (sticking out your cam cover next to your coilpack). Theres a long locking bolt tucked down the back that you loosen in order to twist the sensor, set, and tighten.
The timing is viewed using a timing strobe, the timing marks are on the main pulley, and the plastic cover at the front of the engine near your waterpump.
At the same time as doing the timing the idle should also be reset. This is done with the engine in diagnostic mode (Grnd and Ten jumped with a paperclip in the Diagnostics box near your airbox) so that the idle control valve is inoperational.
Its actually a juggling act - The timing needs setting at 850 rpm iirc. However if you advance it - the engine will speed up.
So you tweak the sensor, then tweak the idle screw, let it settle, measure again, tweak sensor again, tweak idle again, let it settle etc - until your getting a rock solid idle at the correct rpm with the correct timing.
This also means that your idle control valve is doing the minimum of work - and not having to open up or close up all the time to prevent stalling. If your car sometimes nearly dies, or stutters when you drop the clutch or come up to some lights for instance, then this can be a sign that the idle is not set correctly and the idle control valve is having to work too hard to maintain engine speed.
snotrag said:
Burgmeister said:
With this 14° timing business, is it a case of going to a garage and saying '14° timing please?' or is more involved?
The reason i ask is i need a cambelt, waterpump, brakes and an MOT very soon and this could be done at the same time...
Loads of very useful stuffThe reason i ask is i need a cambelt, waterpump, brakes and an MOT very soon and this could be done at the same time...
As for the cas o-ring, I changed that myself a few weeks ago after notice some minor drops of oil on the drive.
SimonV8ster said:
BBR.
Don't go messing with the ignition timing on a forced induction car unless you know what you're doing.Detonation = a bad thing.
I'm presuming you're using the BBR interceptor ECU and haven't swapped it out for an aftermarket ECU. if you have done the latter you adjust the timing via the ECU, not fudging the 'base' timing.
Richyvrlimited said:
SimonV8ster said:
BBR.
Don't go messing with the ignition timing on a forced induction car unless you know what you're doing.Detonation = a bad thing.
I'm presuming you're using the BBR interceptor ECU and haven't swapped it out for an aftermarket ECU. if you have done the latter you adjust the timing via the ECU, not fudging the 'base' timing.
Advancing the timing to 14 degrees is very worthwhile on a 1.6 - I adjusted mine a few months back and it makes the car much nicer to drive as the power is moved to the midrange, so it just feels more grunty and less out of puff when accelerating lower down the rev range.
I doubt it actually makes it any faster, but it is certainly more pleasant to drive.
I doubt it actually makes it any faster, but it is certainly more pleasant to drive.
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