Technical Karolis Punto 75 Turbo project

[Karolis]

CaliforniaCento uses a K04 and don't seems with big spool problems.

A K03 is in full boost at 1800 rpm on a 1.8T if the declared numbers are correct, so on Fire should be around 2800-3200 rpm, exactly like wojs rhb4... But obviuosly this is my immagination, maybe in reality the situation is different.

 

[fingers99]

Dunno. I think in Garret. Ideally you're looking for something that doesn't spool up ridiculously quickly -- no boost/torque spike -- and is big enough to not need 1bar of boost.

Once I speculated that a GT25R would be pretty much ideal on a 1.4 (I think) but everyone laughed.......

 

[Karolis]

Try and see

I think it's really too big, very late spool on a little engine. Don't know exactly how it goes on Punto Gt but if I remember well, it spools very late (4000 or more?).

Personally I decided to give a try with 1.8 T k03, because it's possible to find it used at decent prices

 

[fingers99]

The idea was based on the RR map of a Mk1 MR2 (1600) which had been turbocharged. Flattest torque curve you ever did see, and well over 230bhp using sane boost levels. Remember that the R is a ball bearing turbo and spools up much quicker than a journal one. (Although the MR2 in question used a journal bearing one). I'll try and scan the map.

Doubt I'll ever do it --my next turbo Cento projects are putting an MR2 turbo engine in the back of a Cinq (what, 250bhp out of the crate, 650 if I need to show off) and a T Jet transplant (most cost effective way of turboing a Cinq).

 

[fingers99]

Here you go:



Even at 600dpi the scan required that I highlight the curves in colour!

Specs:

Based on JDM Supercharged 1.6 litre 4AGZE engine
Mitsubishe Eclipse T25 turbo running at 15 psi
Ported wastegate
550cc/min injectors
1:1 fuel pressure regulator
Megasquirt EFI
MegaJolt Lite Jr ignition system (Edis based) -- in those days, EFI was seperate from ignition and this car was a development vehicle for MegaJolt
Stock cams, pistons, rods, 1mm oversized valves
ARP fastners
Mild porting, balanced and blueprinted.

Car is featured in Mark Warner, Street Turbocharging, HP Books, ISBN 1-55788-488-9 from which the scan of the dyno chart was taken.

Car competed in Street Mod 2 Class in SCCA Solo 2 Autocross (somewhere between longer autotests and sprints over here, I think).

 

[J.R Racing]

You need something like a GT2554R on a 1.4.

Decent spool up and capable of 230bhp ATW with proper setup and decent mapping.

 

[Karolis]

It's time for some update.

Got the manifold welded. I'm very happy and continued to thinking how to plan next moves. Microsquirt is coming, so that's good too. Will put it inside before going for turbo.

A lot of pieces are still missing, also I realized that I'll need a km of IC hoses, couplers, reducers, elbows etc etc etc... And it makes me feel sick when I saw the prices, but there's no escape

Pictures:









Il pezzettino più stronzo di tutti:












The missing list is loooong...

Now the next step will be turbo feed line, little oil filter, making nice the manifold (needs some cure after welding) and will fire up without connecting the turbo to the engine, just to see it spin... :yum:

 

[fingers99]

On

Boia! The 7th one down.


take a die grinder (carbide burr) and cut the rib thingy in the middle right back -- they've been known to snap off destroying everything in their path!

It's much easier if you use the forum's picture hosting -- saves the links going dead after a few years, too!

 

[Karolis]

You mean that flux separator? It can snap off? O_O damn, it's inside welded all long the way... Pieces of it snaps out?

 

[fingers99]

This bit. Don't worry, with one of these and one of these you can get to it easily and zap it out in a minute or so. Handy -- if not everyday -- tools to have.

Any decent engineering shop in Emilia Romagna will have at least two waiting for something to do.

 

[Karolis]

You say that I must remove it at all or only "the beginning"? Deep digging if want to remove it all... Job that should be done before welding. But are you sure that it wants to crack and go down? Seems very strong piece by simple look...

 

[blu73]

it is normal to remove it - my manifold has that been removed on my turbo sei.

Its gets hot.... Really really hot compared to when its bolted to an NA engine. You only need the tiniest bit to crack off and you can say bye bye to the turbo - it will be totally destroyed by a small piece of metal flying through it.

 

[fingers99]

You'd be surprised how deep a die grinder (OK, a long nose die grinder) will go -- after all, a common use is in porting cylinder heads. In extremis, you can get 3mm shank burrs to fit Dremel and similar tools (I prefer the mains voltage ones), or "pencil" air driven ones. But the big 500 watt ones make very light work of it. (I recently had to chop a completely buggered wheel nut and stud out to remove a wheel, and believe me, Toyota wheel studs are tough, tough, high tensile steel, not soft cast iron.)

Get as much as you can out -- the less unsupported iron there is, the less chance of a crack and carnage.

 

[Karolis]

Thanks for the advice and tips. Very useful. I didn't thinked that it is so dangerous. Heard (read) something abouth thin wall cracking but when I saw that it's not thin, I thinked that everything is allright... You saved a little turbo :yum: With my intentions and test rides the carnage will happen for sure

 

[blu73]

hard to say from them pictures but i am thinking the mani looks too long and like you are gonna end up with issues with the oil return to sump from the turbo backing up. Looks like the oil pipe would have to be horizontal and it needs to be pointing down all the way to the sump. It perhaps is just the angle but worth a look before you get exhaust downpipe etc made up.

 

[Karolis]

Yes the turbo is low, the return pipe will be made a little bit different, and it will be a little bit diagonal, not totally horizontal.

Some cars by the way has it horizontal, so I think it should not make big problems.

Seems horror, but if it works... Mine will be better anyway, just need to discover the exact the oil level in the sump for mounting the return hole low as possible.

 

[blu73]

totally random, they don't look like they would work at all, they even have a slight u-bend at the bottom. I never been happy with mine but not had problems and it looks better than that so perhaps you will be ok :shrug:

 

[Karolis]

I hope so, if not, will cut and weld again

And now, the most important moment from my mechanical life, my first thing that I never had opportunity to touch, modify tweak etc... Now it's done! I have it!

The most expensive "go fast" part that I've ever bought, and it's also more expensive than the car if looking to value listings



It's the opening of a new, never seen, totally uknown world for me :slayer:

A big step in my personal mechanical evolution.

 

[fingers99]

Microsquirt? (Just a guess.............)

 

[Karolis]

Oh yes, it is.

Choosed a Microsquirt instead of Megasquirt2, because it's similar (for me no real advantage with the additional MS2 options), and it was more simple to get.

My first programmable ecu :slayer: