Making a 1.2 16v faster

[M.C.]

This should be an interesting brain teaser.

Yesterday I stripped the intake system from the inner wing all the way to the inlet ports on the head. I did this for two reasons, one to see how it all works, and the other to see if there are any easy ways of getting more performance from this cracking little engine.
The intake system on the 1.2 is different from that of its bigger brothers. Theres no point me trying to describe it, youd have to see it first hand. What I want to know, is, is there another engine that uses the same throttle design, but with a larger diameter choke. This one is about 42mm, the housing is flat, and is made by Magnetti Marinelli. Does anyone have, or can get a part no? If the diameter could be increased, there will be some worthwhile gains in power as the rest of the system has very few restrictions.

I also put the car up on the ramps and checked out the exhaust (didnt realise some of it was stainless!) and manifold. These are so tight and restrictive its unbelieveable. What I want to know is, can the manifolds and systems interchange between different CC engines? I guess the easiest way to find out if the manifolds interchange is to see if the part numbers are the same for the exhaust gasket on each engine. Does anyone know if any of the slightly bigger engine, 1400 or 1600, have a better design? And finally at what cc does the block design change? Are the 1.2, 1.4 and 1.6 based on the same block like Vauxhalls?

Some of you might wonder why Im bothering to even think about this. Ive tuned many different engines to different extents, and Ive had the most satisfaction out of the smaller lumps prodominately 1400s. So its worth a try as this engine pushes out 75bhp as standard.

 

[Anders]

Find a big hill and a strong wind!! Even put a sail on the roof if it helps!!

Sorry couldnt resist it!

 

[M.C.]

Very good.

 

[BenR]

if you want to break 100bhp/ltr then everythingis goin to have to be cusom made and tested first. Just guesssing aint goin to be any good. I say put aside 3 grand.

 

[Adam Munn]

What you want MORE power???

Didnt you know your motor can beat an evo 6

 

[Ad]

Why all this sarcasm about 1.2 16v??? Ive read the thread and have the same opinion as you, that its complete bull s**t. Just because we have a 1.2 16v doesnt mean we cant modfiy it. I would have a 172etc. if it wasnt for the £3000 ins. Lets face it my clio set me back £9250 is group 3 and will cost me a grand to insure next year. I just think that we shouldnt get slated cause we drive a 1.2!!!!

 

[cDc]

dont forget the 50 mpg m8

 

[Goldy]

Have you noticed though people with 172 dont do them up coz they have paid nearly 3500 more for the car and the same for insurance...who cares how fast they go me clio will knock every single one of them just on pure looks alone!!!!! I drove the 1.2 16v car and i thought it had alot of grunt!

 

[Goldy]

Have you noticed though people with 172 dont do them up coz they have paid nearly 3500 more for the car and the same for insurance...who cares how fast they go me clio will knock every single one of them just on pure looks alone!!!!! I drove the 1.2 16v car and i thought it had alot of grunt!

 

[Griff]

LOL My insurance is £800 which I consider to be quite good. I would consider modifying the looks but I grew out of max muppet type magazines years ago..

 

[Goldy]

If you are not a muppet max power hero then what you doing on here...surely all you want to do is put other clios down because you have a 172..thats not right...this site is for everyone and not just 172 muppet heads...i had a saxo vtr and vts owners did exactly the same thing!!!!!!Why bother turning on your computer!!!

 

[Ad]

Agreed. I see what you are saying about modifying and I am not denying that if my insurance was £800 on a 172 I would have one. However, its not and bein a 20 year old, I dont think I have done bad to get myself a new(at the time)car. Its just sometimes I come on this forum and feel second rate cause I have a 1.2 16v. Lets face it, I could have afforded a valver, but i wanted a new car.

 

[Griff]

"surely all you want to do is put other clios down because you have a 172..thats not right"

Goldy find 1 single post where i have put other clio owners down. If you can then fair enough.

As i havent seen your name on here before I will assume you are fairly new and are obviously testing the water as it were. Just dont be a prick next time!

 

[BenR]

if your gonna mod the 1.2 your gonna have to design and make allyou own bespoke stuff. Aswell as porting the head you should do this if you want pure power and an engine that revs to 10,000rpm.

1st: is it a very underswaure motor? what the stroke and bore?
2nd: is it a steel flywheel and rods?
3rd: there is no vvt right?
4th:whats the max flow raet of teh standard injetors.

from this you should eb ablt to decide on what the limitations of the engie are ruoghly gonna be.

if money is no object then get everything balnced and shot peened/tuftrided or nitraded.

of not, get arrows to make steel H section copies of your rods.

use stronger arp end bolts.
port your head and check flow rates along the way. get a company to make a 4-2-1 exhaust manifold with the longest primary pipes you can find, min of 32" (roughly). A bore of no more than 2" maybe even .75 if you dont reach high rpms for gas flow.

larger valves, cut the valve spring pockets deeper so you can get longer spring sofr higher lift. get stonger valve springs, 3 and seat jobbie of 30-45-70 deg bottom to top cuts.

get newman cams to grind up a cam for you (you will need to figuer outthe profile), but if you require a lot of lift on overlap (high rpm power), then an CLA of 108 deg is more than enough!!!

Then the injection system will be come the limiting factor. Try maing someof your own TBs out of old carbs, or cut a car board cutout of the inlet manifolds face (where it joins the head) then get this cut out of alloy, and tig weld an old similar dcoe carb manifold from any similar pattern and tidy it up with a die grinder.
attatch yuo TBs to this ( no larger than a 40mm body) if you use carbs then twin 40is are probaably the best, but at 10Krpm 45s with the smallest venturi could be better... youll need to test.

its gonna take alot of development to make this engine scream. I suggest you study a few rebuld and theory books before you start work if you feel your not competant.

 

[M.C.]

PHEW! Tanks Ben R for taking this seriously, I thought it was gonna be like your average Nova forum then!

I currently drive two cars. One although road legal, is only really suitable for the track, a 550kg 1.4 16v Nova thats running 185bhp @ the fly. So you can see why I dont feel the need to have another fast car. The Clio was bought as a sensible day to day car when I got married. Unfortuanately I find it impossible to leave cars alone, and Im intrigued to see if I can do any simple mods to gain extra horses. Im not gonna go balls out and fit TBs, raise the comp, balance etc coz the Wife would string me up.

These few things Im looking at are the sort of cost effective mods that as soon as one 1.2 owner has done them, others will be able to use that knowledge. In the world of Novas, a 1.2 owner knows that the full manifold and exhaust sytem and camshaft fits from a 1.6GTE and the inlet manifold and twin choke carb of the 1.3 SR bolts straight on. These are very good mods that release real power for the price of parts down the scrappy. If the Clio world wants to take off like the Novas did in the late 90s then this is the sort of knowledge that needs to be developed. How many 1.2 owners do you think are out there that have only changed their filter and back box because they think there is nothing else they can do without spending big money?

I was really just hoping that parts would be interchangeable from model to model. I have the facilities to make a manifold, and have done for the Nova, but once Ive had the flange lazer cut and spent my vauable time on it, it isnt that cheap. I always try to examine every possibility first.

The ports look like they can be taken out quite alot, but as the standard inlet doesnt taper down into them, it would restrict too much for the head work to benefit. The major restriction is the throttle, being only 42mm.

Ill see how it goes. Ill probably do more and more gradually in my secret workshop sessions without the wife knowing!

Do any of you guys work at Renault, and have access to this information?

Cheers.

 

[BenR]

taper down into the ports? why would you want them to do this?
and 42 mm aint too bad, the s1600s rum 220bhp with a 60mm restrictor.

not sure about parts compatablity and cant check it here as we only sell the 1.4 16V and 172.

why dont you pop down your local and compare in the workshop.

185@flywheel and 550kg!!!!!!
sound f***in mad if not impossible.

FULL spec please!!!!
you gotta be running some crazy rpm to process enough air!!!

i know the old 1.3 supersports reved to 10,000rpm and made 130 odd bhp.
so yours has gotta be something spesh.

whats the 16V motor out of.

If you get some work done to the valve throat this usually liberates the cheapes and bet increase in BHP....
especially the valve angles, change the bottom cut to 70 deg and a 35 deg cut on the top of the valve.

otherwise, your just gonna have to compare manifolds yourself......sorry mate.

for this sort of trouble, buy a 1.4

and with 185bhp on the noVAN im surprised it aint ripped its fron sub assembly off yet, they tend to crack at the struts (as you probably know) around the 150-160 mark.

or have you got 10kg (not by the sounds of it) of steel holding the front on the back!!! ahaha

 

[M.C.]

Ill try to give you the best spec I can, as I havent built most of it. After building my own Nova and using it on track I was lucky enough to find a sponsor/builder who is also a very good friend.

Yep, the chassis has been seriously modded with seem welding and strategic strengthening. From the front cross member through to the rear trailing arm, all weak spots have been identified and elliminated.

The suspension has been altered too with coil-overs, lowered front tie bars, strengthened control arms, and its all rose jointed for full adjustment of camber, caster, toe etc.

The brakes are willwood 4 pots, and cav discs and calipers at the back.

The fuel tank is a one off using a Nissan Sunny GTi pump and swirl pot. The lines have been re routed through the car.

The engine is a 1.4 8v block modded to fit the corsa 16v head. we kept the Nova block as some comps require original engines be used. The block has lightened , de-seemed shot peened rods, and the crank has had the same treatment. The block is skimmed down and the pistons re-shaped and pocketed to protrude into the head (also skimmed)to increase compression. The head has been ported and the valves and seats re-shaped like you said to three different angles. The stems were left alone as we dont want them snapping at high revs. I believe they are also sodium filled, but not sure. Oh and increasing these valves on the 16v head isnt worth it as they are pretty much the optimum size. The cam duration, lift and overlap is unknown to us as the engineers didnt let on what they had done. Then its on to the 40mmTBs and DTA management. The zorst as I mentioned b4 is home grown using an existing 4-2-1 with primary pipes around 30ish inches and short secondaries. The flange was lazer cut and the pipes reshaped from round to oval to fit. (we have a friend who is an ex MOD welder). The box is SCCR quaife with a longish FD of 4.18 (working on that, it aint close enough). Quaife ATB diff, quickshift and a combination of grp N and A clutch parts.

Weight wize, weve tried to shed as much as possible using FG where possible and using acrylic windows. Obviously no interior!

There are so many little things that I cant possibly do it justice. Its all finished of in the works BTTC livery too.

Driveability is a pain in the arse. I do drive it on the roads when we test new things, but for a day to day, no chance. Its very peaky with little or no low down torque. It revs to 9k with power still climbing at the limiter (we cant afford to risk going any higher on our budget). The useable power band is 6-9k and pull away is a nightmare, to not bog down, but once you get on song, its one hell of an adrenaline rush.

This engine has been built in collaboration with Velos motorsport, and they offer it as a package. A guy called Lawrence Bond races with one in sprints and HCs and has been timed at 0-60 in 4.5 seconds in competition. We are a long way off that, but thats our goal.

I wish it was actually mine, but I do get to drive it as Im far quicker on track than my sponsor.

One last thing. Having suspension like that sounds great, but what a learning curve. We still havent got it perfect. Hopefully well start doing some sprints next year.

 

[BenR]

tell me about power bands!!!!!

the karts i raced we hellish.

the 100s were probably the most torquey, with drive from about 4000rpm till 13,000.
the 125 water cooled, 6 speed, all round discs, no body work (allowed on the same tracks as the 100s) was about the worse as we got about 60bhp out of 125ccs!!!!!!!
power band was between 12,000 and 14,000rpm!!!! below that, fuel just fell out he cylinder into the exhaust and you would stall ( no joke, 10,000 rpm and teh engine would splutter and die, then you had to change plugs (often carried plugs and a wrench in my race suit so i could hop out and change them if i span, why waste a race....others could spin off infront of you again).
the best kart was the 250cc formula E karts which made about 105-120 depending on the circu we would change motors....the 105 made lots more torque fro about 8500rpm till 13,000rpm.
the 120 was really bad and didnt come on song till 11,000 and send your balls up your spine!! (you were in a lying down position). The boxes were so closely geared that you could got through the box in about 11-12 secs....and reach top speed after that....which theoretically we could gear for 180MPH!!!!!!!!!!!!!! but there was never enough space....the fastes i have reached was a recorded 163mph with a max rev recorder.



But 0-100mph in 5.5 sec

 

[Simon]

Ive been driving around in a a 1.2 for the last week. They are bloody nippy for a 1.2 !! I thought it was 1.4 until I looked under the bonnet. Have driven the 1.2 Corsa before and this has got more go than that. Not sure what mods. are available for the 1.2 but at a guess you could go for a more efficient manifold, straight through exhaust. Port the head, change cams. Improve the inlet system such as cold air feed. Dont know what that would give you or how much that would cost though.

 

[M.C.]

I suppose thats another thing. If the 1400s and 1600s are the same block, there is a fair chance that the cams are interchangeable too. If so is there a difference in lift and duration? There must be someone on the inside that can find this stuff out.

If I do start playing with it, the head look very staright forward compared to others that I have ported like Vauxhall 8vs.

 

[BenR]

working at renault as i do, its very difficult to get real tech info.
we cant get cam specs and anythign deailed on the newer cars. Renault for some reason dont want people to know. Im having a b*****d of a time trying to get a workshop manual!