Micra rally engine

C

chickenwaahoo

CG13 Rally Engine Mods.

We've been rallying our Micra for almost a year now with generally good results. When we built the car the plan was to run the standard engine for the first year; the car is fitted with a Harry Hockley 5 speed straight cut dog box and gripper LSD.

We have a spare cg13 engine, and plan to rebuild this. Our only limits are a 1400cc max engine size and the depths of our pockets!

What is the power limit of the MAF (including changing it for a 1.5/1.6 unit) and remapping the standard ecu?

Is the standard rev limit easy to overcome?

We would like 140bhp ish, can we get near to this with cams and headwork retaining the MAF or do we have to go to throttle bodies.

Any advice would be most welcome.
 
if you can get a new bottom cam, cons and heads then you can get the 1.4 to be a true 1.4 and not the 1.327 or what ever it is...

then cams, full exhaust, high flow throttle body like quad throttle bodies and a ram air induction kit plus a remap. should see you to 150bhp nicely.

the main points are the torc curve, you want it to be steep and hold the highest Bhp for as long as possible. bhp isn't everything and can be out by 10 bhp depending on where you go to get it mesured and the atmospheric conditions at the time...

if you are aloud to go forced then i'd recommend the mini coopers super charger too.

but if you want to do quick lap times then it might be more important to bring the centre of gravity down. dry sump the engine to bring it down as much as possible without putting the drive shafts out. also setup the camber right on the suspention and wide track the beast. and if you have really deep pockets then shorten the length of the micra, put the engine in the middle, convert to all wheel drive, have indipendent suspention at the back, coilovers and disks allround too. this will let you push the car further...

also if you start with a shell with out a sun roof then you have a slighly lighter car and never go for a five door!!!

have fun :D
 
chickenwaahoo said:
We've been rallying our Micra for almost a year now with generally good results. When we built the car the plan was to run the standard engine for the first year; the car is fitted with a Harry Hockley 5 speed straight cut dog box and gripper LSD.

We have a spare cg13 engine, and plan to rebuild this. Our only limits are a 1400cc max engine size and the depths of our pockets!

What is the power limit of the MAF (including changing it for a 1.5/1.6 unit) and remapping the standard ecu?

Is the standard rev limit easy to overcome?

We would like 140bhp ish, can we get near to this with cams and headwork retaining the MAF or do we have to go to throttle bodies.

Any advice would be most welcome.
Click to expand...



Hi, I have just got an ex NME micra works rally car in bits so I am building it up and I wanted to get some advice from you guys really. I did see this post but wanted to know if anyone can help? I want to run 8 injector I have a Pectal Ecu to run but I cant find an intlet manifold, any ideas?
Cheers
 
I would give Matthew Humphris a call, his number is further up the post. He had a Jenvey inlet manifold for throttlebodies left when I last looked, although this depends on what this particular car is running. I'm assuming that if you want to run 8 injectors on a Pectel it's a full out works spec ~150bhp kit car engine?
 
Pectel ECU

k6pfs said:
Hi, I have just got an ex NME micra works rally car in bits so I am building it up and I wanted to get some advice from yuo guys really. I did see this post but wanted to know if anyone can help? I want to run 8 injector I have a Pectal Ecu to run but I cant find an intlet manifold, any ideas?
Cheers
Click to expand...

Hi If you what some information on the Pectel ECU and running 8 injectors give me a ring either at work 01865 748000 just ask for Matthew or try the mobile 07778 838927
 
It gives the fuel and air more time to mix when running at high rpm. Generally i've only noted staged systems for people running into the 9000+ rpm territory but jenvey said that's what the kit cars ran back in the day. Must have helped but to what degree i can't say but in rallying where budgets aren't to critical every advantage counts.
 
Thats right, usually you would have 4 in an oem placement and another 4 injecting down the throat of the intake plenums. You get small gains in power at the top end, they are then set up for staged use in the ECU, I think there can in some cases be gains of about 5% from memory.
 
I suppose that outboards might widen the powerband a bit at the top end - I just didn't really see how much difference it could really make at such a small power output when compared to other race crswith outboards - e.g. Sierra RS500
Craig
 
I'd prefer to look at is as bhp/litre rather than just high bhp figures.

I'm sticking with 4 injectors on my setup but they will be mounted directly after the butterflies and around 1/2 way up the inlet runners, 2/3 if considered from the back of the valve, so should give a good balance of tractability, response and overall power output.

5% is a worth while gain if power and torque are the ultimate goal, that's enough difference to make a race winning engine anyway.
 
True, although Micra vs RS is 115 to 250, although I digress, sounds like you're mounting your injectors in the same place that mine will be - I don't doubt that they didn't do it for a good reason, just in my mind I can't see that it would make a great difference - how high did the kit cars ver to?
Craig
 
if i remember rightly about 13,000rpm....
almost motorbike teratory.

allthough i have seen a CGA engine on throttle bodies at over 14krpm
 
I've always wanted to go watch a rally, I've seen live truck racing before (wup de do), what sort of websites would I have to visit to see rallys with Micra's in? (NOT WRC)
 
13000? Who told you that? Lol! The kit cars only ever ran standard rods and I severely doubt they would sustain 13000rpm. 155bhp@7950rpm is more realistic give or take for dynos.

Matt, any chance of some realistic figures so we keep factual? :)
 
pjg1979 said:
I've always wanted to go watch a rally, I've seen live truck racing before (wup de do), what sort of websites would I have to visit to see rallys with Micra's in? (NOT WRC)
Click to expand...

I have been to the Grizedale stages rally - just two weeks ago and (low & behold) there was a slver Micra..........Brilliant to see it racing around the forest!
 
I now have photos, but cant seem to upload them, do I have to be a member to post photos?
k6pfs


The car is being built at the minute and will have a Peter Vaughan engine, cams, dogbox, LSD and hopefully will be rallying it in June.
k6pfs
 
NeX said:
if you are aloud to go forced then i'd recommend the mini coopers super charger too.
Click to expand...

Forced induction is a big no on rally cars. The MSA (governing body) don't like it (the regulation is H265 in the Blue Book). Also you can't fit an engine 50% bigger than original without dispensation. So difficult to put a 2 litre in either :laugh:

There are a couple of forums dedicated to rallying and there are regional association websites. They all tend to have calendars of events. But wether you will see a Micra all depends. But having found a rally you fancy there may well be a websiite with an entry list available nearer the date. But make sure spectators are allowed. Quite a few ralies take place on MOD property and some of them like Caerwent and Brawdy (both in Wales) don't allow spectators. Epynt on the other hand does in restricted areas.

Now I am going to go and cry 'cos I can't afford those the bits to make mine go faster & santa didn't bring me the C/R box
 
k6pfs said:
I know have photos, but cant seem to upload them, do I have to be a member to post photos?
k6pfs


The car is being built at the minute and will have a Peter Vaughan engine, cams, dogbox, LSD and hopefully will be rallying it in June.
k6pfs
Click to expand...


woh! thats bare shell
 
Has anyone tried using a Nissan Cube engine? As the Cube exhaust manifold is slightly less restrictive than the Micra one. Also the inlet cam is different too, and the C/R is 10-1 not 9-1.
Has this been tried anyone?
 
i have a garage down the road from me has roughly about 25 cubes in stock as they import them, I can ask if they can get a damaged car sent over cheap and then try it with that?
 
It is only the X-Alpha CGa that has the 10:1 comp. ratio as far as I can tell, the inlet cam and manifold have been tried and tested and give respectable gains.
Also the ECU will be written to run on 100 RON fuel, but I don't think that will help you any.
Craig
 
k6pfs said:
i have a garage down the road from me has roughly about 25 cubes in stock as they import them, I can ask if they can get a damaged car sent over cheap and then try it with that?
Click to expand...

I just wondered if you ever got hold of a Cube exhaust manifold? and if you tried it on your car?

Thanks
 

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