Iv been day dreaming as usual and in need of some advice and feedback

Now firstly fuel system

Standard 20vt injectors are rated at 330cc/min
16vt injector are rated at 384cc/min,

So the 16vt injectors are a decent upgrade is that right?

I assume these flow figures are on a 3 bar FPR. But what pump voltage?standard feed I assume. Which is what?

Has anyone tested how much more these injectors flow with a 3.8 FPR and the fuel pump wiring mod individually and collectively.

I'm well aware that the pump would flow a lot more stable and higher volumes of fuel at a higher voltage up to a certain mark where the pump fails.


Next thing is exhausts,

2.75in system is good for a 2 litre turbo'd engine producing 120-150hp per litre.so 300HP tops and becoming restrictive.

What is the best pipe and results had off an engine developing 320HP-360HP? First hand experience

Dump valves,

has anyone ever relocated one and positioned it between the turbo and intercooler, in essence this would save a small amount of heat soak happening in the intercooler as the wasted/dumped air isn't being cooled thus letting the intercooler work less, or to a more efficient cause shall I say.


And a recirculating DV would probably have more effect as its not dumping any air that the charger has laboured into the intake system but rather returning it back into the systemm.

Would the recirc pipe back onto the induction piping have to be welded on at a taper to promote smoother integration or air, can you see much difference with pipe join angles

Throttle bodies,

The 20vt TB is very sufficient, probably never going to be a restriction in fact until you have spent 5k on the engine , but a quick browse pulled me into the coolant bypass modification on here. Has this had any outcomes? Everything there makes sense to make that little extra Horsepower.


Downpipes.

From what I know 20vt uses a 2 inch V that bends onto downpipe which inturn is a 2.5? Are these sizes correct.

What power are you looking at gaining from using a 3inch down pipe? Is it worth the cost?

And then onto manifolds,

I have seen a lot straight 6 engines using the split pulse turbine and divided exhaust manifold to prevent exhaust gas back flow blowing back into other cylinders upsetting combustion etc etc.

Now more on the divided manifold,( a splitter in the turbo flange sort of) this would make sense as the 5 pot is as much a straight 6 as it is a 4. (Yes I know its a 5) lol


Has this ever been trialled on the coupe?

Next is the harmonic balancer or (the rubber band in the main crank pulley)

I see there are aftermarket solid alloy billet ones availible, with a hefty weight saving ability,have these been run and proven ok to use, without the balancer incorporated.

And has anyone ever had a standard harmonic balancer slip position due to wear etc? Or fail completely.

Turbos

Why oh why did fiat fit such a small turbo on the coupe. All the nissans have plent of room to add bolt ons and increase boost still way withing the efficiency map.

Oil and lubrication

I have caught on from this forum that mobil 15w50 is the stuff to use in coupes. Not only is this great news but I couldn't agree more as its great stuff and recommended for most highly stressed competition engine,(of which the coupe fits highly stressed)

Now one thing that baffles me is with oil tech being so good these days, the ideal operating temperature is 95-110 degrees c.

Oil breakdown and etc will occur if temps exceed 130 degrees for anything more than very short periods of time,
And if temps often exceed 120 deg c, then bearings and oil life will suffer.

So what temp does the coupe normally run at, and what temp does it rise to when pushed hard.

So here is the question,

Does the coupe really need the cooler, with the small diametre pipes and torturous bends my opinion is its more of a restriction than it is an aid for the oil and engine.
As far as I know it is not fitted with a thermostat so it is cooling cold oil on start up thus keeping the oil colder for longer.

And finally. Mapping

What map resolution does flea etc use when mapping the 20vts.


questions,opinions arguments and answers are very welcome.
At best Group5lancia/barbs/barnacle will have a field day on this topic.

Hopefully we can get some excitement going here.

Not that I have the resources to do any of this as the 2 kids are raping me financially. The wife is raping me mentally and the dog is raping me physically.( Biting I mean) my hands. When I play with him, (oh never mind) pspl

Some of your questions can't be answered fully without knowing your power ambitions - e.g. it's difficult to answer the fuel pressure/injector questions withouth knowing your goal. The highest number mentioned above is 360BHP - is that your target?

Also, a lot of questions are answered in 'The Knowledge' so have a read there, though I am happy to give my input once I know your BHP target.

with regards to exhausts and the manifold, I would leave the manifold alone unless you have deep pockets and it perfectly capable of handling big power, 400bhp without any issues, if you are going to do anything have Barbz port it slightly

you mention a 2.75inch exhaust, the blueflame which is a 2.75inch exhaust i would suggest is capable of over 400bhp, it certainly won't be a restriction at 300bhp, a well designed 2.5inch exhaust will handle 300bhp without being restrictive

I would suggest that the reason that fiat chose the turbo which is on the car is that it provides goods low to mid range response at the expense of top end pull, the car is more of a gt than an out and out sports car like some nissans or subarus, and i would imagine it was invisaged that most people would prefer low to mid range grunt rather than having to rev it hard to extract the performance

360 Horsepower.

403.2cc/min per cylinder required,(no margine)

I would prefer to have 500cc/min for margin but will have to see what you guys know about pushing standard injectors.

Standard internals ?

Does it matter?? Hyperthetically yes and no, injectors don't care what bottom end you have last time I checked.

440cc injectors at 3 bar FP or 384cc 3.8 bar FP will be more than sufficient for 360BHp, even rated at 80% duty cycle. The fuel pump wiring mod will be required - this is just to ensure you get full battery/alternator voltage at the pump without any losses.

As mentioned above for manifold and downpipe, just get the standard manifold matched to the head/flowed and save a shed load of money. A 2.75" downpipe is good enough for 400BHP. I would say a 2.5" is good enough for 360BHP - but others will argue! As an aside, note also that a split-entry turbo only works with an even number of cylinders - 4, 6, 8 with 2, 3 or 4 cylinders respectively feeding each half of the turbine. With 5 cylinders there is no obvious answer as to which half of the turbine should see the fifth cylinder and none of the gains that can be had by separating intefering cylinders.

Turbo will need to be a GT28RS (GT2860RS) or a T3 hybrid, such as the TB0385 modified by Turbo Technics S112 or S114. These are modified Integrale Evo 1 type, which are good for about 320BHP standard or 380BHP modified. There are other turbo options.

I would suggest the best intercooler you can find - the cooler the charge temperature the better the power.

When the dump valve is open, the turbo is not compressing the air so there is no temperature rise. For that reason I can see no advantage in mounting it in front of the intercooler - in fact there may be some disadvantage. As the dump valve is open only when you are not trying to make power, a mod to smooth the flow back into the turbo inlet would be a waste of time.

Coolant bypass mod on the throttle body would not be detected on a dyno - so forget that too.

Ask Flea direct about the mapping resolution - but of course you will need a remap after upgrading the turbo and fuel injectors.

Group5 thanks, I will comment in more depth in a minute, I know the turbo isn't compressing off boost, what I was getting at is the heat transfer in the intercooler, the air is getting flowed, and then further up dumped, waste? Brb

And the GT series 28rs is what size compressor?

No - because the air that will be flowing will be quite cool - about ambient temp. So it may in fact help COOLthe intercooler.

I agree. slightly higher than ambient temps would be a cooling effect to the cooler, So off boost the compressor flows slightly above ambient air charge, even though the turbo is redders. Hmm

In that case the coolant bypass is a drop in the ocean,

Advice on exhausts taken, sounds pretty ok, anyone have proven results with different dia pipes,

What are we talking in terms of downpipes then. Standard or jump to 3inch.

Any thoughts on the harmonic balancer and the oil cooler points raised?

Well yes possibly. The HP you are after is on the threshold of having to go forged. But i expect you know that allready.

Thanks and yes that is known,

However we are talking HP and not torques and the rising rate of it all,

In my experience you can push tuning pretty far on standard bottom ends if done wisely and the car is run properly and strictly as to how the tuner depicts it should be.

(Disclaimer) don't do what I just said, stick with +50% HP rise or there abouts and all will be fine to punish it,

Your oil cooler points are pointless, what you see as restriction are far better than having oil massively over temperature. You need a oil cooler on this engine period. I do belive there is an oil stat in the housing.

Balancer does a job, I would change if you really wanted to or were aiming for huge rpm, which I doubt so not worth worrying about.

So there is a stat in the housing? Any more info on it?

Oil cooler needed on this engine) ok that's an answer, what temps does this engine run its oil up to?

And yes the balancer does a job, do you know what job it does

The comment from magooagain was related to the power level you are targetting not the injectors. Typically the torque rating that the bottom end can "safely" run is around 300lb/ft. Much above that and you should consider forged internals. From memory the rods bend or the piston rings give up.

I've been running the tb coolant bypass for a long time and through winter with no problems. I'm also in the every little helps camp.

Magooagain comment was taken well,

The every little helps club is a good place to be,
So good to meet you.

If your getting say 2-3% HP increase from smaller mods, then these start adding up, and makes the car feel more wholesome in my opinion, like its not just a turbo bolted onto a 5 pot being ragged stupid.

Just 1 point on the balancer sedi. 6k plus is where the balancer starts worrying,

So I see flea etc is raising rpm limiters to 7k plus. There might be another small reason or knock on that belts are being bitten and big ends are being battered, although I'm not hiding the fact that more power equals reduced engine life if not done right

Just to add incase no one has found these . Forged rods, H beam - 4340. tested at 600HP, no other figures provided iirc,

£370

JW-racing.de

They also sell shells etc for the 20vt

They will be crap chinese copys. Avoid.

I'm half chinese but I won't go on about racism,

True a lot of stuff is not up to the task, but there are a lot of people running cheap chinese knock off turbos with no problems, and yes there are a few that have problems.

I have seen problems with all turbo manufacturers, where do we meet on the , good/bad parts

So I see flea etc is raising rpm limiters to 7k plus. There might be another small reason or knock on that belts are being bitten and big ends are being battered, although I'm not hiding the fact that more power equals reduced engine life if not done right [/quote]

Yes thats the million dollar question.
I dont have anywhere near enough knowledge to build my track car,so rely on input and advice from others. All of it is well meaning but some is just not right and can be an expensive trial and error.
I like this thread with all you're questions. Keep going.

Thank you (smiley)

quick one on the turbo ..its cheaper to run a stage 3 hybrid (again barbz can supply) than a gt series and you wont need to sort a 5 stud downpipe.. they see 350 with correct supporting mods and are a quick spooler if thats something you want..with a mildly worked manifold(again barbz) and a blueflame no reason you wouldn't see 360(though its pushing it)especially with good headwork(barbz again)...i made 358bhp 316lbsft with a similar set up but used a 28r with rs comp wheel and no headwork..i believe barbz has a new turbo set up he is trying out that may suit what you are trying to achieve he is definately worth a call

Ktm is the turbine on the 28R the same size as the 28rs,

And is that a worked inlet or exhaust manifold, what prices do you guys look at for mildly worked manifolds?

358HP I assume this is on an evo intercooler? Did u use silicone pipes, with the shortest route underneath to the turbo?

and was 358 made on the standard downpipe? (Oh I see) u used a GT series, same diametre 5 stud DP still or did u just use a Vband 5 stud adaptor?

And a point I think a few are missing from earlier today is, ok the standard manifold is ok up to 400Horsepower, fine,

but with working the manifold you increase HP,(maybe and depending on what you do)

I'm not thinking of it as a restriction, rather a tool to extract more Power,

You wont need to worry about the balancer at the RPMs you are running. If the rubber looks perished by all means get a new OE one. The harmonic balancer is a mass damper dampening out vibrations of the crank, standard on production units.

According to the Garrett site, both run the same turbine wheel and housing.

there is a "cheaper" way of sorting out the internals & that is to simply have the crank / conrod assembly balanced.

The FIAT tolerances are something crazy like +/- 5grammes per rod !

can't remember now, but that alone will allow you to rev the engine higher ( if that's your aim ) but also give you a more stable base to work from.

It would also be a good opportunity to check the bores, rehone & fit new rings.

All depends how much work you want...

To be honest for 360hp, you can get away with a decent exhaust, turbo / intercooler & a good fleamap & some DECENT fluids.

oh, DO the brakes FIRST !

Correct, just bringing up the balancer to show the general public there are other things that can play there part in engine wear, ok so I won't worry about it, it looks pretty good nick, when it brakes and throws the engine shall I come running to you lol joke)

I personally would get it checked out, condition etc, and put a substancial mark across the 2metal parts and the rubber band of the balancer so you can tell immediately if has started failing, oh and this means that you have to inspect it regularly too. And this is what I have done,

Thanks for the GT series reference,