Technical Here Here! Turbo from a T Jet on a 1.2?? A little technical discussion to pass time:)

[MarkThompson4]

Yeah...I'm dreaming a little bit with the title of the thread but I just can't help but look and see what could be possible I've assumed for a while that the stud pattern on 16v cylinder heads for fiats were all the same, even without a definite answer, the performance manifold I fitted to my Stilo came from a 16v Punto 1.2 and that fitted no bother. But I was looking at the GP T Jet turbos earlier on and got thinking "I wonder if the exhaust manifolds on them have the same stud pattern as my car" lol so I looked up pictures of the manifold gaskets to have a look, and I found two good examples. And they seem to prove that they are the same

TJet:

http://www.protoxide.eu/en/manifold...ifold-gasket-fiat-t-jet-120-155hp-14-16v.html

1.2 Stilo:

http://www.ebay.co.uk/itm/EXHAUST-M...arts_Vehicles_CarParts_SM&hash=item35b7d514bd

The gaskets are a different shape but the actual stud hole pattern looks the same.

So my question, or rather - my ambition - is; if the TJet manifold gasket fits my cylinder head no bother then could I in theory just bolt on the manifold...and obviously - the turbo??

Now I know there's going to be a lot of pessamism about this and the "there's no point, waste of money" etc but I haven't even got my car running yet, and would make a nice wee technical discussion So if in theory the turbo can be bolted on then what other things need to be done to IN THEORY make this turbo conversion work?

Cheers guys

Mark

 

[Muppet1]

Think you might have to drop the er compression?? dont you on turbo engines??

Be an interesting project though if possible.

 

[MarkThompson4]

Yeah no doubt do that to stop a rod from flying through the block
Should probably look up what the compression ration is on the TJets, anyone know?

It would indeed, at least the turbo looks like it will bolt on with the manifold anyway :devil: Plus I've seen a ceramic manifold is available for the TJets, that would look immense also

I don't think plumbing in the intercooler is that difficult is it? I believe it goes Air filter>turbo>intercooler>intake manifold?

Oil send/return and vaccum hosing is where I'd be lost, and the boost actuator or whatever But atm my assumption is if the turbo fits then the majority of the piping can also be swapped over, or all of it with some slight modifications of course

 

[MarkThompson4]

Just found this doing a google images search:

http://www.italiaspeed.com/new_models/2007/fiat/bravo/104.html

Makes it a bit clearer as to how you go about fitting everything. I can see the oil breather which runs round the back of the engine cover to the intake side of the turbo, but what is the other blue channel showing just below the breather outlet at the throttle body?

Also the picture doesn't show where the hose for the actuator goes??

 

[MarkThompson4]

Stupid me...I've just noticed that's showing the path from the throttle body into the combustion chamber :bang:

I've been trying to find pictures of the TJet sump to see if they have oil lines in them for the turbo but I'm having no luck. Anyone know how oil is fed/sent back from the turbo on TJet engines?

 

[Shadeyman]

The 1.2 wouldn't produce enough exhaust gases to spool up a JTD turbo to a decent level unless you were running NOS.

And if you were running NOS and a turbo the 1.2 engine wouldn't last more than a few minutes without some serious modifications .. ..

 

[MarkThompson4]

Is the TJet turbo off of a JTD?

What if it was fitted with higher lift cams? Would that make much difference?

 

[Shadeyman]

Is the TJet turbo off of a JTD?

My bad, too many Guinness. Thought it said M-Jet.

T-Jet is a petrol engine ..

It might work, good luck ..

The most knowledgeable turbo guy I know on here is sussexa, mabe he can help ...

 

[MarkThompson4]

Lol no worries

Yes it is...

I may never do this, thought it would make a decent wee technical surprise discussion section thread, but as I said in the first post - the turbo will bolt straight on at least And I have so much room under the bonnet space is no issue.

Shadey, assuming turbos work in the same way whether it's on a petrol or diesel, do you know where the vacuum hose connects to for the turbo actuator? My first guess would be somewhere on the intake piping?

 

[Shadeyman]

It may be I'm accidentally correct.

After checking the ePER the Bravo M-Jet has 4 possible turbo part numbers.

55212914
55212915
55212916
55212917

All are also used on the JTD .. :shrug:

So I'm still not sure the 1.2 would produce enough exhaust gases to spool it up to an effective level.

Edit.
Please don't forget I've been drinking so could be completely wrong ...

 

[Muppet1]

Would it be a Vgt that you fit then. I'm guessing if a normal turbo was fitted at least you wouldn't need a vacuum feed or are all turbo's Vgt now.

Although im guessing it would have a lot of lag if it was just a straight turbo??

Just looked at Stu's post, I am surprized that the T-jet using the same turbo's as the Jtd's.

 

[MarkThompson4]

Found out the compression ratios for my Stilo and from a Bravo TJet (same thing as GP's though??). Compression ratios: Stilo 1.2: 10.6:1, Bravo TJet: 9.8:1

Is this a big difference? I'm not sure, also how do you go about reducing the comp ratio by that much?

 

[Shadeyman]

Just looked at Stu's post, I am surprized that the M-jet using the same turbo's as the Jtd's.

I guess its to save on costs but I have to agree, T-Jet and JTD's using the same turbo's ..

Someone please check and make sure as I'm a little drunk ..

 

[MarkThompson4]

Hmm that's odd, how could that turbo work for a 2L and a 1.4L?? If it is the same turbo then they must have different ecu maps or something? But if it works on 1368cc then 1242cc can't be a million miles away from it can it?

 

[Muppet1]

If I'm not mistaken, Don't they bowl out the top of the piston to reduce the compression??

 

[MarkThompson4]

Would that not be a bad thing on interference engines? Well I'd assume the valve recesses in the pistons would be removed if you bowled the piston crown. Dunno, at least if your timing's shagged you won't have to be replacing valves etc

 

[Shadeyman]

Hmm that's odd, how could that turbo work for a 2L and a 1.4L?? If it is the same turbo then they must have different ecu maps or something? But if it works on 1368cc then 1242cc can't be a million miles away from it can it?

I guess the VGT allows them to be used on different engines by closing the vanes for small engines creating extra boost and opening for larger engines so they create less boost. Maybe it could work if you can find a way to accurately control the VGT ..

 

[MarkThompson4]

So how is the VGT controled on the TJet/MJet? Would be easier to work if it wasn't electronicly controled I assume? Less electricals to work with in this the better And does VGT stand for variable geometry turbo?? :s

 

[Muppet1]

Yes you got the Vgt bit.

I too don't really know how these turbo's are controlled. Would be interesting to know how especially on the Jtd's. There has to be electronics controlling the Vgt through the use of the vacuum but how it all works is a mystery to me.

 

[MarkThompson4]

Coool

Perhaps I could get away with just having it vacuum controlled if set up correctly? Or maybe come the remapping stage something can be done such that the boost only comes in on low revs or something? I know on my car the peak power is at 5k rpm but I don't think that's desirable on a turbo setup?

I'm going to check what the ecu's are like on the TJets and see if they can at least cennect straight to my ecu connectors...