Fitting a turbo .........some do's and dont,s

First let me make clear what this is.

It is not a detailed account of how to fit a turbo to any particular car.

It is an attempt to explain that fitting a turbo to an NA engine isn’t simply a bolt on job

Hopefully it will explain what you need to know if you are thinking of doing this and how to choose the right turbo ( No any one wont do )

It isn’t meant for fully qualified mechanics or tuning gurus and has been kept pretty basic for that reason. If you are either of those this thread wont tell you anything .

I’m also not going to explain the ins and outs of how a turbo works because that isn’t the what the thread about.

OK so you have not been put off yet and are still determined to fit this turbo then read on………

Before a turbo is fitted it is essential to check that the engine is capable of running the extra power.

A lot are not without mods.

More power needs more fuel so the fuel system will almost certainly need to be uprated . Also the head has to be able to flow the extra gases or it will be mostly all be for nothing

Then the power gain and extra heat due to the higher boost level mean that some engine parts may not take the strain.

Rods , pistons and especially head gaskets are not always up to the job. The compression may also have to be lowered but again it depends on the motor and again this thread isn’t for any specific engine.

There are unfortunately no set rules because different engines can support different levels of power before needing work. A 1jz supra engine for example can double the stock bhp pretty safely while some will surrender after the smallest increase.

This info needs to be checked . I make no attempt to provide such a list because again this is a general thread. That doesn’t mean it isn’t important . IT IS VERY !

By very I mean that if the engine surrenders it could be a head gasket or holed piston or worse

But for now we will assume that the above has been sorted or is ok to start with.

Now you need choose a turbo.

They come in all sizes and you need one that will work with the engine not just one that is nice and shiny .

Turbos are driven by exhaust gases and produce little or no power until working at the right level

They spool up at different speeds - the larger the turbo the slower it spools because the vane being turned is larger so needs more air to do this

On the other side a bigger engine produces more exhaust gases that a smaller one so will spool up a given turbo quicker that a smaller engine at the same revs.

To make matters worse different turbos max out ( run out of steam) at different levels as well which may not suit your engine .

This information can be checked by looking at the turbos compressor map . These are easily found on the net .

They can be quite difficult to understand so the best bet is to see if your engine was ever turbo’d out the factory .If not look on the specialist forums for your car or cars with the same engine. If its possible someone will have already done it . The advantage of this is simple - you can get a list of the other parts that you need and know they will fit ( and work)

You also need to check the maximum boost level that the chosen turbo will safely run at.

Yes turbos can carry on producing more power up to their max out level but the vanes can break if the boost level is too high (for them ). They broken vanes will either go out the exhaust (if you are lucky) or go through the engine (if you are not ) with the latter you could easily destroy most of the engine.

A final mention on twin turbo set ups ………if you needed to read this post stay away from them

Most use a small turbo to start off and then a larger turbo that comes in later . They are notoriously difficult to match and often there is still some lag inbetween. So don’t even think about this unless the engine had this out the factory (eg some Subaru’s)

A few engine (some skylines for example ) run two turbos coming in together but it really isn’t worth looking at this set up unless the engine is at least 2.5 litres and then unless its been done before I would just fit a single turbo.

 

This is a good explanation of the differences between turbocharged engines and naturally aspirated ones. As described you cannot simply 'fit' a turbo.

 

It's a good write up. Some people seem to think adding a turbo is just like adding an air freshener.

 

It's a remote turbo

 

Assuming you have followed sleepers guidelines, you will need oil feed and return lines and depending on the turbo chosen, you will also need a water supply.

 

As claymore has quite rightly said there is still more to do .
Id forgotton the above and of course a new map is a must (plus a few other things Im sure)
The point is it really isnt a simple bolt on

 

ok after reading this post , i think i will just go with air filter, exhausted and chip....oh hi guys , new guy

 

OK, but what about superchargers. That's another story...

 

Absolutely which is why its a thread just about turbos

 

Sorry! I see that now. I miss-read. I'm new, not used to the interface yet.:embarrest:

 

Hi Sleeper, good article, now can u swing by diesel chat & give me a non expensive answer, pleeease...

 

happy to oblige...................

But unfortunately not the way you i expect you wanted - as the article says just because you want to do something doesnt mean it is possible or cost effective.

 

Hi Sleeper! I'm trying to finish a Vortech V1 S-trim gearcharger install in my 94 Mustang that someone else started. I've got most of the parts mounted and was wondering if you can give some advice on finishing. I've got plenty of pics if you need to see. I am a little overwhelmed...

 

This thead is specifically a general one about the reasons why fitting a turbo isnt as easy as it may seem.

But I am always happy to help if i can.

But american cars are not my thing at all and consequently I know virtually nothing about them . Same with a supercharger which are a comletely different thing to a turbo.
Your supercharged low revving v8 is about as far away as you can get from a twin turbo high revving RB26 engine

No advice is way better than bad advice and Im afraid thats all I can offer.

 

hi there sleeper, really good post on the turbo. Im lost when it comes to this sort of thing so i need all the right advice i can get. please give me an outline of what i'd need to do to turbo my 4.1XF falcon, Im not looking for huge boost, im sure i'd be happy with 5-7psi, any ideas?

 

Hi Aaron May I suggest you log on to a local Aussie forum as I am sure that it has all been done and the bugs sorted out by now.
FWIW turbo boost can be very addictive and you will want to wind up the boost when you get used to the power that your 5-7 psi delivers and seems to be slow. I started with 120 hp at the wheels and now have 350 at 18psi and am having it remapped/tuned for 20 lbs and looking for app 400 ATW

 

happy to read this thread, yeah some people think install turbo is very easy n direct boost up their hp...but its complicated n need serious think of the purpose (track, daily use, drag, etc etc)...not only internal engine (piston, con-rod, valve, stud, etc) or add on turbo support (injector, surge tank, oil catch, manifold header, etc) but the body and undercarriage (the axle, reinforced chassis, bars, etc) also need to be modified due to new power....thanks to sleeper to start this thread so people will have clear description about adding turbos, big power comes with big responsibility

 

One important thing I forgot to mention is a brake upgrade as you will need them if you use the new performance a turbo gives as you will be braking from a higher speed due to much improved acceleration between corners because IMHO no one fits a turbo to drive slower.

 

Awesome write up. Cheers

 

Depends on the engine, fuel system upgrades will be needed and oil lines for the turbo and an exhaust manifolds or 2 of them depending on the application,
as for head flow most NA engine will be up to the job at flowing way more than the original intended engine output with the introduction of some kind of forced induction, turbos and superchargers lend themselves well to a head design that doesn't flow well since the extra is being forced into the cylinders, obviously it isn't as cut and dry as that... but I'll give you an example
Peugeot 306 GTI6 (yes I know another Peugeot but I have chosen this example since its something I actually know something about)
Standard power for these is 167 bhp and they tend to make around that power in the real world
a company called Lynx engineering offers a supercharger kit they offer 3 stages 250hp 400hp and 500hp
they all use the standard head (no machine work at all) cams and exhaust manifold, they use a different inlet in order to create space for the supercharger as the gti6 inlet is rather large. The point being is that this is an NA engine and the standard head is still fine for 500hp with forced induction, granted its a supercharger and not a turbo but the same rules apply

as long as the rotating assembly can take the increasing in power and the fuel system is able to deliver the correct amount of fuel, the rest is easy really....

 

Where to start.....................................

The title of the thread is fitting a turbo to a petrol na engine,

it isnt about supercharging a 306 which just isnt relevant at all to turbos . (sorry)

Harsh ? let me explain.........

First the same rules do not apply - Superchargers and turbos are chalk and cheese.

superchargers give extra horsepower acoss most of the rev range and the power is linear. (best word I can think of ) Turbos are not like this at all.

A turbo does not give linear power . Usually you get a much more noticeable power surge that comes in suddenly at a specific rpm with nothing before that . Turbos also have a maximum power output and unlike superchargers stop being efficient outside their limit .

This means that a turbo changes the power band acompletely so a cam change can make a huge difference.

And isnt the motor coping with the extra power it is the motor coping with the extra heat and the extra power . The heat bit is critical as turbos produce it in spades, And that is what a lot of NA motors cant cope with

Boost means heat and more boost means lots more heat so intake tempretures are critical so intercoolers are important which is a whole thread in itself

And because again the power band has changed big time you need a completely new map and often this means a new ECU

Hardly easy (really)

 

I was talking from a flow prospective fella, I am well aware of the difference between a supercharger and a turbo, I was merely giving an example that is relevant to this discussion,

and in the grand scheme of things, fitting a turbo to an NA engine IS easy to make power, build an NA engine to make power is way hard to do

 

Buying a car with the engine you want is easier still