Technical X1/9 turbo

Currently reading:
Technical X1/9 turbo


New member
Jan 4, 2006
I was wondering, has anybody turboed the 1300?
Also the guys who have turboed their x1/9's where do you put the intercooler and also what size intercooler did you use?

What size turbo would be best if you just want enought to kill a few 2L cars and maybe 3L?

What cr is good?

I have the F/I manifold from an uno turbo and a aftermarket FMS.
The simplest and easiest method of turboing the X1/9 is to fit the MkI Uno Turbo lump which just happens to be the same block (mounting point wise at least) as the 1500 engine used in the X1/9.

If you want to go giant killing I strongly recommend you do not bother trying to convert your 1300 engine. The thermal load is seriously big and without the little modifications in the turbo engine you will cook everything before you get past the 100bhp mark. The compression ratio you need will depend on what boost you want to run and what cam profile you use - anything more than an 8:1 ratio is going to be problematic.

The MkI UT engine will happily tune up to about 150bhp on stock components (including the diddy little IHI turbocharger). At 150bhp in an X1/9 with some suspension upgrades and a bit of a diet you should find that most of those 2l and 3l cars are no longer a problem - unless we are talking about riced up jap street racers.

If you want to take on the really big boys then you need to build a slightly more exotic engine (Punto GT block, MkI UT head, GT crank, pistons and rods, etc.). On a Garett T25 you should be able to reach 230bhp and with more mid-range torque than those FWD ricers can cope with. If you got the diet correct for your car that should be getting on for 300bhp/tonne in a beautifully balanced chassis. You'll need some reinforcement in places but nothing serious (a rollcage would be a good idea though).

For more than 230bhp you need to start looking at a T28 and this is where it all starts to go wrong - The T28 simply won't fit in the X1/9 engine bay. You would have to sacrifice some (or all) of your rear boot.

You're biggest problem is the water radiator (needs to be replaced with an aluminium double core), the oil cooler (use a Delta HF Turbo cooler) and the intercooler (again the Delta HF Turbo is your friend). Finding the items can be tricky but locating them in the engine bay is a nightmare. I've seen them shoehorned in but this is worse than useless as you need proper airflow through them and around the engine. You can open up the sidepods on the X1/9 to great effect and then you can put one of the additional coolers each side but you still need a cold air feed for the induction system.

If you fancy going a bit overboard there is always the option of using the rear deck from the Abarth Prototipo (look up Guy Moerenhout at and a snorkle to match. You could get just the snorkle by itself but it looks more than a bit lame fitted to the standard engine cover.

If you do choose to sacrifice the rear boot your options are much broader. Not only can you move the turbo clear of the engine, you can have some nice proper bananas on a short extractor manifold and you get the benefit of not superheating the engine bay.

Ultimately this is an engine swap and as with all engine swaps you need to be a little inventive. Just remember that you need a lot of air flow and you won't go too far wrong.
One last pearl of wisdom on the subject - just bolting a bigger, higher boost turbo onto the side of one of these engines is not going to do you any favours. The engine doesn't respond particularly well to the "bolt-on" upgrade philosophy. Get your engine spec right first time and stick with it.

If you want to see how it is done then email me direct and I can show you some examples.
I would get the internals sorted first. Make it stronger, get low compression pistons and so on.

The reason i ask about the 1300 is from the spec i have i believe that motor would be able to handle stress quite well.
If i have all the other things to turbo i cant really see the point going from 1300 to just another 1300.
I know what you are saying but I don't think you've fully understood why the 1300 UT engine is so much better. Primarily it is a cost saving exercise. To modify the 1300 NA engine is expensive by comparison with just swapping the block over. You have all of the oil feeds you need present for the turbo, the oil spray jets for the pistons. You have the right pistons and rods - you can get away with just changing the shells as a precaution and that is it as far as the block is concerned if you want to keep it really simple.

If you want to convert your 1300 block you need new pistons and new rods to start with. You need to find an oil supply to run the turbo, the oil spray jets are optional but personally I wouldn't try to build a turbo engine without them. You have to find the manifolds as well.

The point is that Fiat have already done all of the work for you - all you need to do is bolt it into place. I can certainly see the argument for building the engine yourself but without the time and budget it is a seriously hard task to pull off!
I have all the manifolds, everything, just need a motor to bolt it on to. Pistons are quite easy to get. I will drop the cr to the same as the std UT...ot even lower if i want to boost more.

What i am worrying is if the say everything in both 1300 block where exactly the same9 as in strenght and so on) and only the bore and stroke is different, what motor would be best to turbo?
The important differences on the UT engine are high pressure oil feed on side of block to feed the turbo, all head studs replaced with bolts (very important as the bolts cannot be reused and there are 14 bolts not 10) and eight oil sprayers tapped into the crank journals (two per bore) aimed at the back of the pistons. Stroke and bore are identical.

The block itself is the 1500 version not the 1300 version so there are slight differences (not least of all is overall height). Overall strength is very similar.

Something else that springs to mind - are you aware that the 1500FI head uses different head bolts/studs than the earlier 1500 and 1300?
Last edited:
That makes alot of sense.
2 things bother me though...
Here the guys with the uno turbo's actually convert to studs and get rid of the bolts....
and My question again...which one would be better to turbo, if you had 2 identical motors, and just the bore and stroke was different, but the same cc? In my opinion shorter stroke would be better, because you would be able to rev higher and use the turbo better.
The bore and stroke of the 1300UT and your 1300 are pretty much identical (I think the UT has 0.1mm less stroke) so there really is nothing to choose there. If you are talking hypothetical then it really is a matter of taste, both solutions are equally viable - it all depends on what turbo you decide to use.

In most cars the turbo is running out of puff at the top end, increasing the rev capability just makes it worse - the turbo starts to over-rev as well. If you go to the Garrett website ( and have a read through their turbo-tech section it explains all the ins and outs of how turbos work but the last part (tech103) introduces and explains compressor maps. Once you can see how the engine interacts with the turbo through such a map you can see why a stock turbo is not so good at top end. You could of course select a different turbo (or turbine/compressor combo) and move the efficiency band to the top end of your rev range and then you could indeed make the most of those extra revs.

The reason for using the studs is because the bolts don't work very well when re-used. This is 100% Fiat's fault - all of their documentation says they are reusable when in reality they are stretch bolts and should be thrown away after each use. The tell-tale sign is that the torque settings listed give the last two stages as angular movement instead of torque.

If you use the bolts correctly then you have no trouble. The other reason is, of course, that the old SOHC head is a nightmare to bolt down if you have the cam carrier fitted. You need a crowsfoot spanner for the back. Using bolts makes it even harder.
I was just interested in knowing.
We dont have 1300 turbos in SA, so i have no idea what there specs are.
If i use and uno trubo engine it would have to be 1400, and then i could just aswell go for a 1600 turbo.

I want to do my homework first before i start spending money on something useless. Sorry if i upset you or anything with my questions, but i'd rather be safe than sorry.
If you have any mechanical experience, I did two Fiat X1/9 with engine swap. Keep in mind turbo charging with uno or modify turbo kit will only gain you so much on the 1300. I put 2.2 Mopar Turbo engines in my x1/9's and the performance was a huge improvement. I was able to race and beat 95 and older corvettes in a drag race. the 2.2 litre engine is prefect engine swap candidate because the exhaust and intake manifold are on the same side as the fiat x19. Email me at [email protected] if you want picture of my cars swaps.
I turboed my bone stock 1.5 x19. 1/2 a barr of boost. been running it this way for more then a year now without a single issue. No internal engine mods, an msd boost timing master, and megasquirt fuel injection with a gm 300tbi., turbo is a garrett gt1544. Ive never had any detonation..

The theory that the fiat 128 engine does not respond well to boost is a MYTH.:eek:
It responds very well to boost.(y)

I placed my intercooler in the engine compartment in front of the drivers side vent.
I wouldn't make too many assumptions on that - the federal spec engines run a lower compression than the euro-spec engines, the result is that your 1500 is almost pre-built for slapping a turbo on while the euro-spec engines can only manage a tiny level of boost before things go south unless some precautions are made.

On the flipside the 1300 head breathes remarkably well for an 8v sohc engine and a little bit of boost goes a long way as a result. The 1500 doesn't breathe that much better (less in proportion to the swept capacity) but still enough that the turbo doesn't have to strain to provide the low levels of boost you are talking about.

With the fed spec engine the only internal mod I would want to see for reliability is some better pistons with a taller landing and slightly lower compression. With this you could easily aim for 2/3 bar boost - maybe even 3/4 bar - without any risk to the engine just so long as you can provide the necessary fuelling.
hello meneer if you want to see how much modifiying goes into an engine swap come past me i have fitted a 1600 palio motor to my x with turbo running a ut gearbox(the weakest link)my motor cost me about R60 000 to build thats fancy pistons rods etc etc
If the compression is higher you run less boost
less timing and still make more power than I'm making. It's just a different formula.
I thought this thread was dead and buried...

There are ways to do both (high compression and high boost) but you need some trick mapping to make it work.

Audi have a boost control valve that supplements the waste gate and dump valve to deliberately waste excess boost but under computer control instead of mechanical control. On a stock 180/225 turbo motor these are limited to 1 bar boost but a competition version is available that allows a boost map up to 2 bar.

So far so good but if you just slap a big turbo on to a regular turbo motor you get lots of lag due to the low static compression ratio. So you up the compression ratio back towards that of an NA motor, with the control valve and a big turbo and all of a sudden you have a rather nice combination. At low revs where the head breathes well you have low boost and little lag, at higher revs where the gas flow on the head starts to restrict things the boost can be allowed to rise, the big turbo is spinning nicely and any excess that would pop the head is still being wasted through the valve.

You still wouldn't want to built a turbo motor with 11:1 compression (or higher) but a sluggish 7:1 is no longer needed - 9:1 or even 10:1 is feasible. You just need suitable engine management that can control the boost on a supplementary map. Your standard engine management is based around two maps, one for ignition, one for fuelling - each mapped against load and revs. On top of this you normally have a closed circuit lambda map and a water temperature map that modify the main two maps to cope with generating a smooth, clean idle and a warm-up map to get you going on a cold day. Some management systems can't go beyond this while others can include an extra map (for the turbo and some even explicitly state this), some even come with switchable maps so you can have a comfort (emissions test safe) and sport (who cares about emissions) mode.

Ironically the critical bit in all of this is how well the head can flow. If it can't flow well then you're going to need lots of boost all of the time which just generates lots of waste heat and doesn't give you much power gain. On the other hand if the head flows well then you hardly need the turbo and you can get away without all the fancy trickery and run lower boost from a smaller turbo to achieve the same.

Of course if you can spend the money, get the head flowed *and* go for the trick setup and you'll have a monster. My race motor dynoed at 350bhp at its regular 1.4bar (from a 1300cc uno turbo base) and could run 450bhp (2bar) for short periods. The rev limit was about 12000rpm but did most of its work between 2500 and 8000rpm. Such a motor (if you can find the right people) will set you back about £40k these days (or more). You can buy a factory 300bhp rally spec equivalent (superfire) for a lot less - still not cheap of course.
This thread will never die!

Mapping fuel is not tricky. You start rich and slowly lean it towarjmld a safe target.

If you go with programmable ignition, you need a timing table and that would be very difficult to build without a dyno. I did so on my 1969 spider. It took over a year to get right. I used a msd boost timing master in the x19 set to pull 1 degree per psi of boost.

If you understand what can go wrong and how to avoid it there is not an engine you can't add boost too. My x19 has over 100k miles on the engine, I did an oil change and turbocharged it.

Believe me when I say if it were a high compression. Engine I would be running less boost and making much more power, and I wouldn't even hesitate.