Nova - SPi With K&N

[vaughanmc]

Will a K&N from a carb engine Nova fit my 1.2 SPi?

If so, has anyone got one lying about..?

Cheers, Vaughan!

[BigStan]

Pointless

[Rich]

no.

Best thing to do if you want a k&n is to get hold of a corsa b 1.2spi inlet trunking. Think it should bolt on, and you can use a k&n cone filter.

[spunkymonkey]

You can get a Green Cotton filter to fit the 1.2 spi.
Pretty much the same thing as the K&N.

[Adam]

Dont bother with a green filter, there like ?80.
You can diy make an induction kit for less than ?20.

Like so:
http://img.photobucket.com/albums/v86/Nova-crew/Nova%20WIP%20pics/6.jpg (http://img.photobucket.com/albums/v86/Nova-crew/Nova%20WIP%20pics/6.jpg)
That was my old one, cost me a fiver to make.

[Jcb]

looks better than the "designer" ones too. any sort of guide you could give on how you made it? a parts list maybe? i want to do the same!

[craig green]

Expected power gain? 1/2 bhp

Irritating noise gain? 100%

Better off spending out on rust preventative measure IMO :thumb:

[Jack]

Isn't there some useful info still floating about that Kev (Aragorn) posted back in the day about putting together a makeshift induction "kit" for the 1.2i?

[Stuart]

yeah there is. I took the tech guides thread away as most links were dead but copied otu the bits of 1.2i tuning aragorn did.

they will return

[Adam]

1-Fit Corsa/Astra spi top box
2-Join two breather pipes together to make one long one, fit that to the box
3-Get a small piece of plastic drain pipe, fit that to the rubber boot that goes to the box
4-Fit a universal cone filter to the drain pipe.

Basically...

[Adam]

Aragorns guide is here, if admin want to put it up as a how-to:
Luckily i saved it,Lol. I did all of these mods to my own car too, and they worked well. So if you need any help, let me know :thumb:
The SPi engine IS a better engine than the 1.2carb, its just heavily restricted in standard form.

TUNING GUIDE
This guide is aimed at tuning the 1.2i engine as opposed to the 1.2 tuning guide posted by MC, although a lot of his stuff will apply he simply suggests changing to carbs for the 1.2i which isn't really and option for some people (k plate cars) and others may simply not want the hassle of carbs and prefer the reliability side of injected engines. I have performed all the mods in the first section myself and have had good gains from it (I'm awaiting RR readouts but have had an 18.8 sec 1/4 mile in my bros car with quite a high 60ft (2.9secs) his car has no rear seats and cobra Monaco's tho so some weight saving going on)

The 1.2i (C12NZ) makes 10HP less than a 1.2 carb as standard, however it makes identical torque due to the different design of cylinder head. The engine also has a number of factors which restrict it compared to the carbed engine (cam has lower lift and it has a restrictive cat fitted) and thats what were going to work on here mainly

Exhaust:
The first mod i would suggest is to fit a better exhaust system right from the manifold back, there are two approaches here depending on the age of your car and how much hassle you want come MOT time, if your car is a H or J plate then you don't need a cat at all, if its a K plate you will need a CAT for the MOT unless YOU can prove to the tester that the engine was built before august 92 (depends on the tester, only real date stamp on the engine is the cam).

If you don't need a cat (or don't mind refitting the complete original system come MOT time) then the first step is to find an SRi (or late 1993 GSi) exhaust manifold with lambda probe port - the engine needs this sensor to run properly so you need a hole on the manifold for it. Then you want either an SRi or GTE/GSi downpipe and a full system for a GTE (Ashley do a nice 2" system for ?130, or you can use a std system from scrappy)

If you do require a cat for mot then you can do it a different way, if you find a SRi in the scrappy and get entire exhaust from it, then get a decat pipe for the sri system and that way you can refit your cat for mot and put the decat on at other times. I personally would take the first approach and if your car needs a cat then modify the cat of the original 1.2i exhaust to fit the GTE system, that way you can fit the middle section of the 1.2i system for mot and return to the GTE/Aftermarket system afterwards. Or you can find a friendly MOT tester

Cam:
The standard cam on this engine is very restrictive, fitting a cam from a higher spec model will give great gains (I'd recommend getting one from an injection model(SRi, GTE, GSI) although an SR one would work too. If you want to fit it yourself the head needs to come off and the gasket and headbolts will need changed while your there

Air Filter:
The standard airbox looks s**t but does the job fine to a point, just remove the handle section off the front of it and throw it in the bin for extra noise - if you want an upgrade there are a few cheap ways of doing it...
You can use my guide to making a cheap induction kit here: http://www.novaload.net/forums/viewtopic.php?t=90933
Or you can get a 1.2i Corsa airbox and fit then then either shove a cone on the end or use an SRi airbox with performance element
don't bother wasting money on a green induction kit as its ?70 you can spend elsewhere - the Corsa top box shouldn't cost more than a 5er and neither should the sri airbox

These are the main cheap mods for this engine before you start hitting big money, and the majority of it is cheap stuff (air filter shouldn't cost more than ?30 if you follow my guide, cam is probably about ?30 then another ?30 for the bits to fit it (unless you pay a garage), exhaust is a bit more but the advantage is that its usable on a larger engine you may fit in the future

Weight:
If you want to go fast your main enemy in a small engined car is weight, lots you can do in a nova to lose it but it reduces flexibility, removing the rear seats and rear belts will save you about 20-30kgs and the car can still look cool, if you want slag then you can remove all the door panels, fit Plexiglas windows and ditch the dash board, you could probably shave off 70kgs in total if you did all that and thats gonna be similar to the difference of driving alone and driving with a passenger which will be very noticeable in a 1.2i nova :p

Suspension and Brakes:
Acceleration is one thing but if you car handles better and stops faster you can drive faster as you wont lose as much speed through corners and can leave braking later, a good quality matched spring and shock kit is what you need - springs alone wont help handling much (they will help but just not very much) and some Astra GTE16v (or Cav 2.0) 256x24mm disks and callipers will help stopping power greatly Do not underestimate tyres either, s**t tires will make a huge difference to the cars performace and handling and stopping characteristics, best for the nova would be some 6x15" wheels with ET49 offset and 195/45R15 tires, Uniroyal Rainsports and Goodyear EagleF1's are good grippy tires and are decent in the wet too. Don't go sticking ET38 or 7" wide alloys on and expect the car to handle well, it wont.

Service:
I'd recommend giving the engine a good service while your here, new rotor arm and dizzy cap, new plugs and leads (don't buy performance crap, just standard NGK plugs and normal Bosch or whatever leads, also do an oilchange with a new filter and replace the thermostat if your taking the head off to fit the cam

Gearbox:
A point often overlooked in tuning smaller engines - the standard 5 speed 1.2 boxes are very wide ratio, you ain't got a lot of power so theres no point having gearing that can manage 150mph when the car will only do 105 an F10CR box from an SR or F13CR box from a GTE would be a good choice and fitting a 418final drive to either of those boxes would give an excellent gearing for acceleration

Taking it further:
At this point your not gonna get any major power hikes without spending lots of money - its arguable wether its worth it at this point but as long as you only buy stuff thats transplantable onto a new engine you should be alright in terms of wasted investments.
The head is very restrictive so fitting either a 1.2 carb head or a 1.4SRi head(skimmed to sort compression) would be the next step
You could then either fit the complete 1.4SRi injection system (arguably a waste of money) or fit some twin 40's (these can be fitted to a larger engine in the future if required)
if you used the 1.4sri system you might need a remap but it does have a lambda so it might work out whats happening by itself
fast road and rally cams are available with varying attributes - a 285 cam should be alright in the std engine and you should be able to push to a 295 if you fit the SRi stuff or twin40's

fully modified with worked sri head, 40's 295 cam full exhaust etc you could see the friendly side of 100HP

So there we are - hopefully that will answer most of your questions and provide a solid base to work on

Aragorn

INDUCTION KIT GUIDE

What u need:

Corsa/Cav SPi top box (u can see it in the picture below) - ?5 (scrappy)
Universal cone filter - ?25 (halfords)
125 degree 68mm rain gutter bend - ?2.50 (homebase)
length of 68mm rain gutter - ?5 (homebase)
piece of rubber hose about 66-68mm ID - ?1 (scrappy off an escort 1.6 efi)

ok i started by purchasing the 125 degree bend and i hunted down a piece of hose from the scrappy that would fit that and the spi top box - i finally found a bit from an escort 1.6 efi that fitted with a bit of percerverance
i then returned to homebase and got the length of gutter (might wanna take somthing with u to cut it as they wont cut it instore and it wont fit inside a nova and I ended up smashing hell outta the middle of it with my wheel spider to break it into 2 halfs)
the spi box has a silly valve contraption on the back - remove this by breaking off the metal clip and removing the valve from inside - the 2 holes will need filled now (i glued some drawing pins over the holes from the outside to seal it)
i then cut a length about 12" long out of the guttering and got the correct adaptor ring from the universal filter kit (70mm one) - i had to use some tape to pack up the 2mm difference as the jubliee clip didnt like clamping down the slack
attached the gutter to the filter and then fitted the filter to the 125degree bend
you will also need to extend your breather hose to fit on the outlet on the airbox

fitted the whole lot to the car and bingo

a nice induction kit for a whole ?38.50

[Stuart]

cool, handy to have a few copies.

[Jcb]

very good guide. i'll get a copy too :D

[novaboy.p.]

hello mate i have got a induction kit like in the the pic also cost me like a 10r i got a air box of an spi astra a air pipe from a renault trafic and a k and n from the scrappy duno wht off and a collant pipe from a ford siera for the oil breather :) cost abou ?25 with the k and n :)