Alfa Mito 1.4 multiair 532hp & 61 kg - most powerful MULTIAIR engine
( RECORD updated ! )
After some years of inactivity on hunting the absolute limit of this engine ,
some challenges and unanswered questions occurred. So here we are again…
Several theories have been written about multiair’s reliability and Marelli’s ecu fuel management…
But these subjects will be analysed on future posts..
for now let’s see how MTD broke the limits again using 3 bar of boost pressure with oem Magnetti Marelli ecu .
We choose to measure on Dynojet because it’s considered the most accepted and reliable from competition community.
Let’s talk about numbers…
First things first, let’s see what happened on dyno .
Car was measured in 5th gear , as with 4th gear it was constantly spinning and there was not the ability
to use the stabilisation bar due to Mito’s front section configuration. You can see photo below ( 5th gear measurement ) .
According to dyno’s most experienced operator, this will occur to a 10-15whp loss due to increased parasitic
losses ( pull ended on 300km/h! )
( Al agrees also , as it gives 2-5 % increases losses )
As for the Dynojet losses , according to a research from several owners and tuners who have tried to compare
results with crank converting dynos , losses vary from 12% to 14% for FWD , depending on how restrict the
other dyno is. Let’s see what this means….
The equation for drivetrain loss :
Bhp = whp / ( 1 - %losses )
In order to have a clear , realistic and fair estimate of engine’s power we will calculate the minimum
and maximum possible power …
1. Minimum. 12% + 2% loss from 5th gear
14% loss. Crank power = 532 hp
2. Maximum.14% +5% loss from 5th gear
19% loss . Crank power = 565 hp
So the vehicle shout NOT be LESS than 532hp and also should NOT be MORE than 565hp.
So it would be fair to use the average value of the min and max calculation, which is 548 BHP ,
but we will just keep the minimum 532 BHP , so no one complains.
Torque will vary from 61kg crank to 64 kg crank , average value 62.5kg crank torque .
It’s much more than net values…..
Besides numbers , the power / torque curve is outstanding for 1368cc engine .
Let’s see what it delivers :
4500rpm -> 180whp ( ~ 210 hp )
5000rpm -> 320whp ( ~ 370 hp )
5500rpm -> 400whp ( ~ 460 hp )
6000rpm -> 430whp ( ~ 500 hp )
6800rpm -> 457whp ( ~ 530 hp )
OVER 430whp (500 hp) 6000-7900
rpm!!!!
Below you can find also an Al recreation of crank power / torque Vs rpm graph based on the whp Dynojet graph .
We are possibly speaking for the best power curve ever produced by 1400cc engine in general .
Just for reference 1.4 Tjet engine needs 8000-9000rpm to produce this power band , something which is
catastrophic for long life operation. We have also never seen these numbers on a Dynojet .
Only some “in house” dynos .
What is happening with Marelli… ?
We used oem Magnetti Marelli 8gmf ecu.
Many words have been spoken. Perhaps we will make some analytic posts in the future ,
about Marelli’s abilities & bugs as well .
For now , 3 bar of boost without knocking and perfect operation.
Boost : 3 bar peak / 2.85 @ limiter
Fuel : 100 Ron + meth
AFR & timing values , not announced .
Is this calibration close to explosion ?
Not at all…. engine worked perfectly healthy without knock or EGTs…
We think we could bring it close to 500whp on this setup, but we wanted to analyse some data on road conditions firstly.
Specs ?
Borg Warner Efr turbo
Custom TS (twin scroll) manifold & setup
Custom camshaft to match TS specs
Billet aluminium intake manifold
Fully forged engine
Fully tuned head
Stage5 tune
Disclaimer
This project is totally about engine development for the present . Objective purpose is to
discover the ultimate limit of 1.4 multiar engine . Once this goal is achieved, a whole new transmission &
chassis development will start in order for the vehicle to able to use and take advantage of this power
in road and real acceleration terms . Finding traction is a problem of next step,
so until then stop asking about draggy times .
