"Maxi Micra" project....by EBBdude.

[EBBdude]

@alexzaki
There will be magic moments in any engine regarding AFR.
some engine react different then others of where the best afr throughout the entire rpm range is to be found.

Micras will perform all day long in the 15:1 range in everyday driving and on power demand situations.
They will not produce peak power at this range , rather at 12,4-12,8 :1 , as a normally aspirated angine , depending on where you are about in choice of ignition profile , camshaft set up , compression ratio etc.

When you fiddle around with camshaft timing and ignition timing you will discover many different combinations of them and afr used giving multiple differences in power curves.
That is why i use the DYNAPACK as this gives me incredible repetabillity and accuracy in minute details to sort all these changes out in best possible and compromiseable way.

You could basically say that for economy go higher number and for power slightly lower.
14,7 :1 is only a teoretical number , not a untouchable bastion in realtime.

 

[alexzaki]

Thanks for explaining (Y)

Im wondering....whats the consequence of running avg. AFR 16 on long term? Will it melt pistons?

Using the modified manifold and modified TB you gained 9.8bhp with avg. AFR 16. Then you lowered the AFR and obtained even some more bhp. My friend explained this to me like that....Oh, he even got a few bhp, interesting. That only means that he was loosing power while running avg. AFR 16 although he gained 9.8bhp. Is that the right explanation? In other words, you optimized the AFR which helped you gain some more power.

Just out of curiosity, whats the stock fuel pressure for the CG13DE? And what pressure were you running when you obtained even little more power and lower avg. AFR? I guess you had to increase the pressure to drop down the AFR. Whats that doing to the original injectors?

Thanks for replying,

See ya,
Alex

 

[EBBdude]

If the vehicle is not loaded to hard and have problems like wrongly set ignition , faulty spark plugs etc then a avg of 16:1 afr can be ran in almost any vehicle.

Yes , you could say that in your second question that i was "loosing " power while i was gaining power. That is because the increased amount of air and profile of the aerodynamics gave a increase as a modification , while loosing at the same time by acheiving not so ideal afr as a result of it.

Stock fuel pressure of a 1,3 cg13de is listed as 2,5 bar vacum regulated and 3.0 unregulated.
Vacum regulated = means that the pressure is at idle , low load , high vacum situations is lower then running low vacum , open throttle asf.

The different power levels and afr at any given time will ultimately be a mix of combination that you will have to " look for while aiming for your wanted end result.
If you want to get lower afr reading you increase pressure and vice versa.

The Nissan`s stock fuel managment system is capable of almost anything we enthusiast throw at it but sometimes it just wont do the stuff we want it to do. Then you find alternate way of doing things.

The original injectors will play along this path but of course there will be limitations both ways in terms of how the end result will be.
example ; to high pressure could make idle and low rpm running difficult and to low pressure could give you a realy tame beast at higher rpm when fuel is neede the most.

Basically it is all details you have to sort out as you go along and play around with your car

 

[EBBdude]

Before i do anything more to the engine of the Maxi Micra i want to source out some details .

Any engines performance characteristics can be altered via changing the timing of the camshafts set in perspective of their position in relations to the crankshafts position at all times.

Move , on a 16 v engine with 2 camshafts , either one of the camshafts or both for that sake to a retarded or advanced point in relative to its std factory set position and you will alter the way the engine produces its power & Nm at any given rpm.

Nissan Micras came from factory with fixed position that the In & Ex camshafts starts doing their work from in terms of timing relative to the crankshaft.

Here you can see the camshafts in the head and you see the pin and the slot that decides where the camshaft is positioned relative to the crankshaft at any given rpm:

Looking at it with the camshaft on the workbench it can easily be seen here :

With the pin locking the camshafts position you cannot alter the camshaft timing in any way.
I want to get the timing adjustable to move the produced Hp / Nm graphs curves around a bit.

First I will grind the front and back of the 2 cam-gears with very coarse grit grinding paper :

Just slap a piece of paper onto a flat surface and grind away.
Hm,,,,what is the purpose of that then you might think,,,,,,tell you later.

Looks like that when its done :

Next i`ll do is to strap it down on my mill machine like this :

Find my center indicator and find the center of the gear:

Enter a circle frame program to make a elongated slot so that my camgear now can be adjustable :

Voila , I now have adjustability in both my camshafts :

I did show you some grinding of the camgears and here is what that was about :
Don’t want to make a complicated solution of calculated positions to drill series of holes to have just a few positions to set the camshafts to , so I want it all in a twist and that’s exactly what I now have but I need to make sure that the camgears don’t move around as after they have been torqued down in their position by the large bolt and washer in front of the cams.

(Since the pin is only there to position the gears form factory the pins will no longer hold the camshafts to a locked position after the modification)

Using a old trick that I have done to multiple cheap-ass setups earlier and go for this method :

Top secret diamond-powder in water based solution spread on the sides of the camgears and the rough surface of the gears and the diamond powder locks the gears seated so hard that they wont move before you want them to do so.

Have done this for many years on many cheap diy projects without ANY camshafts / gears EVER coming loose or changing position.

In fact it locks so good that I have to realy work to make them loose enough when a adjust the cams on the Maxi Micra.

Then I need some sort of quick reference to adjust the cams against and I have chosen this simple method :

A angle-ruler ( 1,5 Pounds ) , a magnetic welding-helper ( 4,5 pounds ) and a piece of welding rod as a marker.

The magnetic-helper thingy just snaps down onto each cams flat surface shown in red circles here :

Closer look of the set up with the welding rod pointer onto the angle-ruler :

So I just loosen the bolts in the front , adjust where I want it and tighten the front bolts again and snap you can play some more around for even more fun.

Some results of the fiddling of camgears position comes soon….

 

[Scott]

How come the CG's and the GA's have two chains?

 

[EBBdude]

sjacksin
i guess that Nissan just designed it that way
It seems to work though....

 

[Scott]

Hmm, i just cant see why though?

The SR's and QG's only have one chain and they are all roughly the same time period of production. hmm

 

[EBBdude]

Sjackson :
Sometimes i wonder also why the car producers do as they do.
There are horrible examples from any manufacturer og odd and strange ways of doing things but as i said there must be a good reason for it or maybe they just had a bad day and thought " lets make something silly today guys and go home early "

 

[MrMigs08]

How come the CG's and the GA's have two chains?

Thats like asking, how come micras last 17 years xD,

Its hard to say really, but i'd think twos better then one anyway lol.

 

[Scott]

Thats like asking, how come micras last 17 years xD,

Its hard to say really, but i'd think twos better then one anyway lol.

I suppose lol

 

[EBBdude]

Now after lots of playing around with the adjustable camgears i have got a bit smarter
( depends on how you look at it )

There is a sea of combinations turning up at this game and its all about personal preferences in the end of which “ profile “ you want to have in all this variations of cam positions.

Here you can se an example of what happens , in a certain stage of tuning level , when you move the timing of the camshafts around a bit.

The not so bright RED graph is the starting point before i adjusted the camshafts for more bottom end torque in the lower part of the rpm area and the more brighter RED graph is the result.
We can see that there is not to much to separate them in Hp under 4000 rpm but there are in sense of torque. Its all a matter of give & take a bit.

Here i have turned the cams for more power in the top end department of the rpm range and almost otuch 69 Hp in the process but looses a bit Nm under 4000 rpm but even then gain more Nm higher up.

Here , from 4800 rpms i realy get a kick load of more power , about 13 Hp more on top rpm that if very well felt when driving.
Note how the YELLOW graph shows how Nm still pulls stronger from 5000 rpm and higher.

This can go on endlessly and there are so many combinations turnig up that you could use for your preference.
As a rough guideline i could get about 6-8 Hp more og 5-8 Nm depending on the used combination of the camshafts positions.

I have done multiple changes and adjustments :

And I have now found the combination that I am pleased with .

Here is the result I have chosen to use at this stage of tuning and at the same time you can see what the level was when I started the Maxi Micra project.

I did manage to pass over 73 Hp in one combination andmore then 107 Nm in another but they will not come along at the same time….
This is all about give and take as i said.

Let us have a look of what i now got from the MAxi Micra project then :
Result so far :
68,7 HP @ 6400 rpm @ hubs
99,6 Nm@ 3465 rpm @flywheel

At the start of the project:
51, 1 HP v / 5370 rpm @ hubs
79,4 Nm v / 2850 rpm @ flywheel

Result =

+17,6 HP@ hubs
+20,2 Nm @ flywheel

Feel free to calculate the percentage increase(Y)

All this without changing one single component OR buying ANY new high performance parts…..
But there will be more to come,,,,,,lots more !

What do you think so far guys ?

 

[frank]

you,re the man EBB did you retard then both ?

 

[Eliot]

Bring on the nitrous!

 

[Seb_]

Wow big gain !

 

[euro_micra]

Very nice EBBdude, I'm impressed you managed to get those gains just by altering the timing on stock cams(Y)

One question though, what position did you set each cam at eventually for that last graph?

 

[alexzaki]

Project going pretty well so far (Y) Guess we are all waiting for NOS grr

 

[baguete]

How many degrees (negative or positive) on each cam?

Did you saw my PM?

 

[EBBdude]

Thanks guys for comments

The thing about adjustable camshafts is to be able to fine tune , at any level ,the last details of how you want the charateristics of your power curve to be.

For me it is a neccessity when i want to have the car running at the street and next day maybee powering away on a track or Autoslaom.

If the cours at the autoslalom event is wery short and with short distance between cones etc then i can adjust for maximum low end torque and if it is a sleeker course i can get the last drop of power and rpm out of it.

You could say that it would be Dr Jekyl a& Mr hyde at the same time:laugh:

The last chosen set up i did i think was with the In camshaft about 4-5 dgr Ret and the Ex camshaft 3,5-4 dgr Ret.

But be aware of using just dgr as method. I use dgr as quick reference and mm lift at changeover tdc as final control.

Wear on chains , sprockets , height of cylinderhead etc etc will all give individual variations to take into considerations.

The N20 is coming along but there will be more of other stuff before that.

Baguete ; have you sent a new one lately , if so i havent got it....

 

[baguete]

I thought that you didnt saw the PM because you didnt replyed... :wasntme:

My next step is to mess with the cams timings (but im using 260º/10mm lift cams, same as frank's cams).

Keep the good work mate... (Y)

 

[EBBdude]

thaks for " thanks " guys

Baguete :
Just start of easy with the timing changes and in small steps. Keep track of what you are doing so that it wont get confusing when you are at it. snapshots with a digicam is great to log some work with regaring positions.
If you start of with just changine the inlet and then just the exhaust and to the end both you will learn even more as you play with it

 

[baguete]

thaks for " thanks " guys

Baguete :
Just start of easy with the timing changes and in small steps. Keep track of what you are doing so that it wont get confusing when you are at it. snapshots with a digicam is great to log some work with regaring positions.
If you start of with just changine the inlet and then just the exhaust and to the end both you will learn even more as you play with it

The problem is that i dont have a Dyno, have to do it other way, maybe using Franks method... :grinning:

 

[frank]

The problem is that i dont have a Dyno, have to do it other way, maybe using Franks method... :grinning:

all 4 valves open 1mm @ tdc seems to suit a daily driver with those cams baguete :grinning:
and the stock 1.3 timing is 42/0/0/42 so they have a negative overlap when you take into account the running clearance (in reference to EBB,s quote of "I use dgr as quick reference and mm lift at changeover tdc as final control")

 

[COZ!!!!]

another great way of getting cheap power. Can this be used on a DOHC 16V engine?

 

[Scott]

another great way of getting cheap power. Can this be used on a DOHC 16V engine?

That engine is a DOHC 16 valve buddy....

 

[mckenziecz]

another great way of getting cheap power. Can this be used on a DOHC 16V engine?

k11 micra is DOHC 16V engine :grinning:

EDIT: Sjackson beat me to it

 

[EBBdude]

Frank:
Have you done away with the shims in your buckets yet or are they being spit out at high rpm by the regrind profile you use ? it was something near 10 mm lift and,,,280 " was it ?
At what overlap position does these cams you use give most upper rpm power ?

Baguete ;
You dont need a dyno. All you need is a dedicated road surface ( preferably flat and safe one ) , run a fixed rpm step in a fixed gear and run the NT " speed trial " as reference to time used each time.
Floor the pedal from chosen rpm to end rpm and read the times as you do the timing changes.

Ex ; run 3rd gear from lets say 3000-6000 in "time mode" at the same stretch of road every time and you will work out what works which way etc.
You could also run the same test in 2000-4000 rpm and measure time at same stretch.
Use the exact same stretch of road strip as reference doing the tests otherwise no good.

You probably get the idea...like a road dyno

 

[frank]

Frank:
Have you done away with the shims in your buckets yet or are they being spit out at high rpm by the regrind profile you use ? it was something near 10 mm lift and,,,280 " was it ?
At what overlap position does these cams you use give most upper rpm power ?

it only spat the 1 shim EBB (and 260deg/10mm), and i,m tying out the top shims with a radius around the top edge at the mo (definately quieter at idle now, will see how they fair over time) i may also grind the lower shims into a square to reduce the weight :grinning:
and i think plenty of retard helps the top-end (especially the inlet) but i,ve only relied on the highly inaccurate "bum dyno" tbh :wasntme:

 

[COZ!!!!]

ment to say on ANY DOHC 16V.

IM NOT THAT DUMB HHAHA

 

[pollyp]

The problem is that i dont have a Dyno, have to do it other way, maybe using Franks method... :grinning:

hey didn't you have nistune? you could use the speed trial timer on nistune or nissan datascan to time 1000-7000rpm on an isolated road for each mod?

 

[baguete]

Yes, i have, maybe i can give it a try... (Y)

But atm the car is stopped, the engine is still bubbling, i will get another engine so i can mess up with it... :laugh:

 

[EBBdude]

Now it is about time to start with the Maxi Micra`s next step on the ladder of evolution.

Some abolutes will eventually sneek into the project when the engine is going to meet his creator in heaven.

I have seen a lot of talk about exhaust systems on Micras at Nissan ” hang-around spots ” and the influence of better and other than OEM systems.

There is of course a lot of things to buy to the car but for me that is boring and not the same challenge.

So I want to build a cheap , easy and functional system and that’s what I will do now.

The OEM exhaust system in a 1,3 Micra look , from underneath , like this :

On ex-manifold with a separate housing for a cat , a downpipe into another cat , a “ mystic “ exspander tube ( hollow ) into a hoop over the rear axle into a rear silencer.

It starts off with a rather sad small ex-manifold and a front cat as here :

The front cat is quite often tragic in its condition and it is not uncommon that It looks like this inside after some many thousand driven k`s :

The inner web will more than likely look like this :

Easy to understand why it can create havoc and problems for both performance and iex AFR values etc. That is actually wh you can find so many different AFR values out of the exhaust even though they are in principal identical cars….

Have a look into one of them that has run about 100 000 km and you will see this :

This will limit the performance level of any car.

Exhaust manifold itself is not exactly “ high-perf “ type from Nissan :

The botthleneck downwards to the cat tube and the 2 outer runners are bringing its performance attitude down to poor level.

I have done something about this earlier in the Maxi project by modifying it to this :

A quick fix like this is worth a rough 6 Hp at the hubs , done right , and it is fully operative with 02-censor and all bolt onto the stock ex-system afterwards.

Oki , to have some fun on tracks etc with the car i want to build a system that are going to run without the cats and have a large rinner dia and a couple of mufflers.

You could by such a system but i dont think that is half the fun then building one myself.

So , here we go :

First ill do is to rip out the rest of the cat-material in the front cat. Just give it a few blows with a mallet and normally the stuff just falls out by itself.

Looks like this afterwards:

( have already done this to the Maxi Micra )

After that i just bolt up the cat-tube onto the ex-manifold.

These are the parts that i will build the complete system from
2 “ parts of tube straights , bends and mufflers. That I will build in such a way that I can take it off in a snap and no time.

Nothing fancy & dancy , just easily available parts from the shelf of car parts shops.

Exhaust build to be continued soon…..

 

[MrMigs08]

so should i expect my cat to look like a bin full of rubbish after my cars been driven 11 years flat and now has 110k miles on it?

Thats quite scary to see that build up, although that silly mani is tiny (nissan you foools ) xD

 

[r-reg-sr]

so should i expect my cat to look like a bin full of rubbish after my cars been driven 11 years flat and now has 110k miles on it?

Thats quite scary to see that build up, although that silly mani is tiny (nissan you foools ) xD

thats what is being shown,i am in the same boat
ebbdude fling us all the spare platinum:laugh:

 

[EBBdude]

The Platinum is probably on its way to China as recycled metal

I have looked into at least 5 other front cats that all looked like that inside.
On had just a enormous hole burnt right through it so maybe that could be classified as a performance parts----ha-hagrr

 

[baguete]

Have a look into one of them that has run about 100 000 km and you will see this :

My 1.0 has done almost 200.000km with the same CAT and doesnt have any of that (still clean)... :laugh:

 

[EBBdude]

yes Baguete , i have seen cats from cars having passed 220 000 km and still having a perfect front cat.

There will normally be or have been some issues with those that has rotten cats.

 

[MrMigs08]

We'll i wont attempt to take my cat off, until maybe i have money for some expensive tools haha, my mani looks like its corroded to the engine like crazy rofl, and i still have a sludge problem to deal with, curse you cg10de abuser !!

Keep going with the awesome work EBB, i show alot of my friends this thread (even they dont own micra) and they all enjoy reading up on EBB Freshness!!! (And they complain that there forum sucks in comparison haha.) (106 owners mainly lol)

 

[EBBdude]

@mr migs08

Thank you for kind words

It is actually fun to see how many people who reads threads like this.
The " Micro MIcra " thread cought over 120 000 click on the three forums that it was presented during some few months.
who says little granny cars cant be interesting ?

ps ; the mani comes normally off quite easy. Just use a lot of penetrating oil on nuts and let soak for a few hours. If not use a gas torch to quick heat the nuts heads and they will loosen easy.

 

[alexzaki]

Nice, love to see the new exhaust system packed up and running on the dyno (Y)

BTW, 2" or 50mm is the outer diameter or inner diameter?

 

[EBBdude]

@alexzaki

Will show what the results are afterwards yes

I belive the system is 2" outside diameter,,,will check that.

 

[1275]

Is that Jetex stuff? http://www.jetex.co.uk/website/custom_parts.php?mat=Aluminised+or+mild&dia=2.0+inch

 

[alexzaki]

Ok (Y)
BTW, sent you PM

 

[EBBdude]

@1275
i am not sure what name it is on the tubes that i have used.
Looks very much like the one you linked to.

@alexz
Have replied to your pm

 

[EBBdude]

Here is the continue of the exhaust system making :

I want to make the system as easy as possible som i first make use of a 45 dgr. Tube ( 2” ) and take a look at how that will fit as a part of the new downpipe I am going to build.

Wow , it fits very well , almost to good to be true and just a small chop with the angle grinder gets the right angle at the top joint towards the old cat thingy. ( get back to that )

Add a straight piece of tube to see how it matches further back and towards my 45 dgr pipe end.

Not to bad at all I would say and I just have to mount the dampener onto my downpipe and almost half the system is then finishied in a blast…

Then i detach the OEM front downpipe and remove its heat shield :

You see , I want this little piece of flange here that I just chop of with a hack-saw :

In that way I get a excellent way of attaching my new system to the old ex-manifold.

The little chopped of flange fits perfect to this piece here:

My first new 45 dgr pipe will now be adjusted for optimal fit onto my chopped flange and the new bigger dia of the tube.

I don’t want the chopped flange to be a restrictor in the line here so I find my die-grinder and a rotary file and open it up

Gring and adjust

Then i weld the flange and the pipe together :

And i have my new downpipe.
Easy peasy !

Now for the rest of the exhaust system further back:

First tube is just a slip fit into the first silencer that replaces the second OEM cat.

This silencer I hang up in the removed cats OEM hanger locations using some old leftover Nissan cylinderhead bolts and welding them on the pipe:

Building further back with some more tubing and a couple of 90 dgr pieces.

Making it as simple and functional as possible is my goal and I want to be able to snap it off in a hurry to change between street & track system.

Here the rear silencer is on its right chosen position with it driveshaft loop piece fitting perfectly straight out from the shop:

Chopping the OEM hangers off with a grinder and just weld them onto the silencer and hang it up in position.

Did anyone say recirculation ?

Rear silencer spot on from behind peeping out :

Here you can see the simple layout of the new system from underneath :

This goes intp the trash and a new OEM system will be used on a daily driven basis :

The total cost of the parts were about 65 pounds and if you work and don’t hang around taking pictures you will spend a couple of hours making it a complete high performance system.

So then , all that is left now is to run this new superduper High performance system in the car and multiple runs in the DYNAPACK unit for some results.

Is that a east way of doing a new system or what guys ?

So then , for todays quiz :

WHAT WILL THE OVERALL RESULT BE NOW THEN GUYS ?

 

[mintyfresh]

Looking good! Is it just the photo or is the tubing before the back box really close to the panhardrod? How does it sound, any different? Wish I could weld!

 

[1275]

The exhaust bits worked out quite well

When you're next hooked up to the dyno can I ask you to do a couple tests please

One with and without the airbox feed on. and another with and without the throttle body mesh fitted.

Thanks, great thread, keep up the good work

 

[alexzaki]

Looking great as ever, cant wait for the dyno run grr(Y)

 

[superls]

good work witht he exhaust, a couple of places look a little close tho, i hate a banging exhaust

The exhaust bits worked out quite well

When you're next hooked up to the dyno can I ask you to do a couple tests please

One with and without the airbox feed on. and another with and without the throttle body mesh fitted.

Thanks, great thread, keep up the good work

check his 1 liter blog im sure he did the tests you need.

 

[MrMigs08]

70-72Hp in results, maybe alittle torque gain (Y).

Just my guess

 

[r-reg-sr]

good show!
them dam tig welders are amazing-the way the seam looks like art work