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[El Tel]

Hi Team,

This is a hypothetical question, I want to know what can be done to get the best out of a stock ForFour 1.1 70kW engine, or any naturally aspirated forfour, for that matter.

I understand that in some cases it will probably be cheaper to buy a bigger forfour, but I'm curious.

So far, I've thought of:

• Foam (v paper) air filter
• 98RON all day long
• ECU remap
• lighter flywheel (the 1.1 loves to rev)

The 70kW 1.1 engine has a fairly high compression ratio of 10.5 (thanks, workshop manual), and I live at sea level, so I started to use 98RON anyway. as Mr Singh says, the engine seems to have more 'pep', and I reckon it's worth a few quid extra given what I've learned so far.

I'll also be sticking in one of Evilution's pipercross air filters on my next service...

So, what do you think? is there any cost/benefit ratio advice, other ideas, or is it just plain nuts to put a lightened flywheel on a 1.1? (of course it is )

A remap would squeeze an extra few horses out and remove the RPM limiter. - worth it?

Discuss.

[mr singh]

just rag the nuts off it!

honestly my mate thought my 1.1 was a 1.6 the way i drove it.
remap is a little pointless on a N/A engine as the gains out weigh the costs, you'll possible make 10 BHP with a remap but will cost £££, and when you say remove the limiter, i assume you mean the top speed limiter, if that is the case then i believe you would be better off altering the gear ratios for a higher top speed. if your on about the rev limiter then prepare to dig DEEP for your engine 'blue printing'. that involves stripping the engine and machining the internals closer to manufactures specifications and lightening certain components.

a lightened fly wheel will help it rev faster but may not make any more power.

have the valve clearances checked and adjusted, throw in not 1 bottle but several bottles of good fuel treatment. i used fortron petrol fuel treatment BUT that isnt available to the general public to my knowledge.

[Alex]

Theoretically, anything is possible. Practically, the gains may not be worth it, especially if staying normally aspirated as the power will come on at the top end and not at engine speeds you typically drive at.

You can port the head in the hopes of improving airflow into the engine. And remap it to advance timing and take advantage of the higher octane fuel you're using.

A lighter flywheel negatively affects idle and setting off. Airfilters elements have little impact in airflow and power, you can verify this by removing your airfilter completely (leave the box empty and try it on a clean road). When they advertise X filter made 5 more horesepower, that's on massive engine with lots of HP so the increase percentage wise is negligible.

Similar effect to lighter flywheel can be had with lighter wheels and tires, with the added bonus that breaking effort is also reduced.

You can also try subtracting weight, the backseat and spare wheel are easy enough to remove but this has it's own drawbacks too...the car gets louder and not as safe in a rear collision.

As they are, smart engines are pretty good, so just keeping yours maintained will ensure reliable fun for the foreseeable future. (thin synthetic oil, make sure valve clearances are correct, cat and exhaust are in good condition)

If i had the skills i would buy a 4a92 (1.6) and use it to stroke my 1.3 (i don't dare hope it would fit in as the engine mounts are molded into the block and the ASX/Lancer have pretty different engine bays). For a 1.1 it wouldn't be worth it as you'd just end up with a 1.2 and a quarter 4a92 left over.

[Problemchild]

Sell and buy a Brabus

JJ

[Sparky777]

Make the wife walk. Easier than taking the back seat out.

[cecil]

Interesting how changing cat and exhaust for one from a bigger model has not been mentioned.
There is also a performance gain from removing all clutter. It makes less noise than removing wife!

[Ocracoke]

I can't recall if yours has alloys or steels but in the name or losing weight, steels are much lighter than the alloys. I wouldn't bother with head porting, I asked that once and the reply here was that it would affect the VVT aspect of the engine (if yours has it that is...).

If you are serious though, go and find a rolling road and know what your starting point is before doing anything else. You may find that your "75bhp" car is actually making a bit more to begin with (as I found out with mine).

[CrazyG]

What's not been mentioned in respect of reducing any weight from the
flywheel is that the 'pulling power' will decrease as there is less inertial
rotating mass and therefore less torque, so although the engine may well
rev qucker, it won't have the same pulling power !
The affect is more pronounced the heavier the car is.
In other words, a light car (on the lines of a Caterham 7) will be fine with
a high powered motor bike engine fitted and used on a race track, but
for road use with all the usual stop start related driving, plus 2 people in it
and oft times a rack with luggage on it, it'll be a lot worse than it was when
it had a 'normal' car engine fitted to it.

So, as has been said, keep it well maintained, carry as little 'excess'
weight around in it as possible, use 0-40 oil + top line fuel and it'll be fine.
Splashing out loads of cash on anything other than that, with the veilled
hope of shaving possibly one measly second on the 0-60mph time
would be money better spent on 'trading up' to a 1.3/1.5
So start saving your pennies.

Finally.....for anyone considering removing the back seat of their 454...
I have no rear seat in my Brab as my daughter needed one with ISOfix
to enable the fitting of my grandson's Recaro kiddy seat.  Anyway, when
I next to took it for an MoT I was told that I had to remove the rear seat
belts as they would fail it otherwise ! Apparently it is a requirement that
if there are seat belts, then there should be a seat. Further checking at
another MoT garage confirmed the initial advice given by the first garage.
Also...one MUST advise your insurers, as it is then deemed as being
'modified', or changed from original. What you gain in performance
is lost in the payout for the occasional pleasure of it.

[mr singh]

i would highly recommend against using 0w40 oil in our engines as its likely to burn oil. its ok to use if its low mileage but the likely hood of finding a forfour with sub 40,000 miles is getting slim. most forfours out there will be heading close to 100k if not higher.

id use 5w40.

its pointless fitting a 1.3 exhaust as will be the same as the 1.1, as im sure you need a centre section in order to fit a brabus rear silencer to the 1.1 and 1.3, but its a direct fit to the 1.5.

[brulaw]

i would highly recommend against using 0w40 oil in our engines as its likely to burn oil. its ok to use if its low mileage but the likely hood of finding a forfour with sub 40,000 miles is getting slim. most forfours out there will be heading close to 100k if not higher.

How about 34,470 ....... ( one owner , full history  )   

[Problemchild]

I’m way way off 100k miles

JJ

[Coverman]

the first figure in the oil description is the cold temperature viscosity; it is the second one that refers to the normal temperature running viscosity and thus is the one that is to be thickened to compensate for wear. However a worn engine might also appreciate a slightly thicker oil when cold 

[mr singh]

How about 34,470 ....... ( one owner , full history  )   

I’m way way off 100k miles

JJ

while i appreciate that there will be some out there with low miles but look on autotrader and tell me how many you find with mileage less than 40,000 miles

iv just had a look and found 22 forfours for sale on auto trader and only 1 with less than 40,000 miles, 4 with mileage from 45-60k, and 17 with more than 60k

https://www.autotrader.co.uk/car-search?sort=sponsored&radius=1500&postcode=ls141ja&onesearchad=Used&onesearchad=Nearly%20New&onesearchad=New&make=SMART&model=FORFOUR&year-to=2008

[CrazyG]

Much though I am sure everyone appreciates all the comments etc
we are detracting from the initial reason for this thread.....so......
I think it fairly safe to say that having it properly serviced, with
the proper oils and decent petrol, plus tyres at the correct pressure,
then you'll be getting the best out of the 1.1....and as mr.singh
and Brabs would tell you, don't be afraid to 'give a bit of stick'.

Dismiss any thoughts or idea's of remapping etc, and instead save
your pennies for a 1.3 or 1.5 if you want more 'go'.
(That's assuming the idea of a Brabus is out of the question)