couldnt find another thread with an answer,
does the t jet come from factory with some sort of boost cut, say you upgraded the turbo actuator or used a stiffer spring, or installed an electronic boost controller or manual bleed valve, does the punto have an ignition cut to prevent over boosting and killing the engine
cheers

The t-jet already has electronic boost control.
I think it uses boost-by-gear ( max torques is limited in the lower gears to protect clutch and gearbox).

I'm not 100% but:
Boost can be controlled in 2 ways: it first tries to control it with the wastegate.. if that fails it will then open the recirculating valve and maybe throw an error ->car in limp mode ( turbo will still be spinning but it will not make boost).


If you put on a bigger turbo that will flow more CFM at the same boost pressure, then your car will be running lean.

Hi there,

sorry to correct you Aurick, but more CFM - in the same engine - will result in more boost pressure ! It also means more sucked air, the ECU will detect that thru MAF and MAP sensors and adapt the AFR up to a certain limit to respect the stochïometric ratio. After a preset threshold it will go in limp mode with a turbo boost pressure error on the OBD...
Agree ?

Regards, Bernie

t-jet only has a MAP... there's no MAF.

You are probably right ... so more CFM with same restrictions(the engine itself) as before.... yes... that would mean more boost.
As long as the N75 valve is still adjusting boost... it should keep the boost constant only resulting in a turbo that works less.


Thank you for correcting me !

Cu Plecere !

No Mass Air Flow on petrol car: absolutely true, shame on me, the air quantity is computed via temp/pressure sensor in the manifold (MAP) + atmospheric pressure sensor on the 1.4 8v only.
Anyway upgrading to a bigger turbo, changing this or that doesn't make sense if the ECU is not remapped accordingly, it's just playing the wizzard...

Thank you as well for correction, regards, Bernie

So a bleed valve to restrict the waste gate from opening as much/ as early wouldn't work on the tjet, with vl36 turbo?
Can only be controlled by ecu or remap?
Also anyone had any experience with the bluespark boxes, looking at getting one for now.
Cheers fellas

Hi Alex,

haven't said it won't work, actually it will but only up to the preset limit, then will go in limp mode to avoid engine destruction...
No feedback about the bluesparks, but I'd like to get some too ;-)


Regards, Bernie

Ok, I'll get one and up the boost until a safe level is found.
I'm going to order a blue spark on Friday, probably be here next week and then on a dyno. I'll let you know how it goes

Ok so the bluespark arrived, I installed the one with the map for the abarth, seeing as I have the abarth turbo and intercooler etc, and wow what a difference these things make. Especially as I picked the box up for only £50.
Was sceptical because of the easy install but it's gone from 0.7 bar to 1.3 peak holding steady at 1 bar of boost, so really improved.
Haven't tried the other eco, or torque settings, but It's due on the dyno so I'll be sure to see what it makes[emoji4]

Hi Alex, seems very promising ! What sensors is this bluespark interfereing with ? Did you bought that one on the bay ?? £50 is quite cheap I mean...

Regards, Bernie

If the Abarth sensor is 3 bar, that's why you have more boost (because the ECU still thinks i's run-ing at a lower boost pressure)
(whenever you put a bigger MAP you should also modify the maps in the ECU so it can tell what voltage equals what pressure)

Be careful, as i don't see anything to add extra fuel.
To be safe get it on a dyno where they also have a wideband and see what the readings are.

yeh found it on gumtree, its due to go on a rolling road soon, it plugs into the map sensor and boost pressure sensor.

at least get a 4 bar pressure regulator to bring the fuel up a little bit.

would you have a link to one? when i can afford this will be going to a td04L and vxr injectors:yum:

bosch part code:
0280160575

search e-bay or any parts store.

cheers for that bud! how will this help me though
also do you know of anywhere that does univeral 4 bar regulators for the t jet? that ones a little pricey for me, cheers :slayer:

that one is a little expensive, would a universal 4bar one suffice? also is it worth installing a pressure gauge to keep an eye on things, cheers:slayer:

~30 euro? that is expensive? How much is a engine these days?
I would say bosch, or other known good quality part. This is not the part to cheap out on.

You do understand you are likely runing the engine lean at the moment.
Even with the small increase of fuel the extra 0.5 bar brings.. the engine will still likely run lean.

A bit of theory (again;-) ?

a PETROL engine does need the mixture it gets in to be at a certain air-fuel ratio (AFR) so it can start burning when the spark ignites it. This is called the stochïometric ratio and is about 14,7 gr of air for 1 gr of petrol. This ratio can vary a little bit from this ideal value, more air: lean mixture, less air: rich mixture.
One might thing "cool, let's run lean and save money..." True in a certain way, less fuel (more air) give less power because less energy is available from a smaller fuel quantity ! Obviously that's not what we're looking for here... AND a lean mixture burns at higher temperature and also the vaporization of less petrol reduces the heat quantity absorbed by evaporation -> engine parts (usually valves) might get hotter than what they can support and get dammaged. Not what we like neither... Not mentionning that the catalytic converter needs more petrol to reach its functionnal temperature !

"So let's put more fuel in there !" enthusiasts would say... Yes, it is possible, the ECU calculate the time the injectors are open (sequencially) according to (but not only to) the calculated air volume, and accelerator pedal position. The longer the time the larger the fuel quantity... As the (bigger) turbo forces more air in the engine, the manifold pressure increases so the ECU calculates a larger air volume and adapt the fuel quantity accordingly following its internal tables up to a certain pressure amount, then will switch to limp mode; P 0234 turbo boost condition...
You can fool the ECU so it "sees" less boost pressure and calculate the air volume to be less than it actually is, resulting in a lean mixture so one wouldn't feel much difference here. Since the opening time is computed by the ECU, how do we increase the fuel quantity without modifying the tables ? Increase the fuel pressure, or upgrade to higher flow injectors (vrx ??) !

Conclusion: modern engines CAN output more power than they do in most cars, but hey, they'll need some modifications to achieve this. Remaping is one of them, bigger turbo is another, bluespark or alike is another as well but each has pros and cons and mainly depend of one's wallet opening resistance.
Some will open it large, others may buy sticky bonnet air-intake, fake disk brakes, and carbon-look fuel trap ;-)

Regards, Bernie

thanks bernie, very much appreciated!
i think ill go for the 4.0bar pressure regulator over the vxr injectors, as injectors would require a custom remap, and as you rightly guessed ones wallet opening resistance is strong.
ill get on with finding a 4.0bar and get back to you.
-appart from the obvious with fueling, so far so good on the bluespark, very pleased.
will be plugging in diagnostics to check fuel pressures, faults etc very soon:slayer: