hi guys just want to know if its possible to fit a turbo to a standard engine if it is running at really low boost like 0.2bar boost. if this can be done how cud i lower the amount of boost that the turbo is producing

i have looked at getting the decompression plate but seems like a lot of work as it would change the distance between the block nd head dont really know how to over come that problem. if i did go down the decomp plate road would i need to do anything else.

whats the best turbo to use for a 1.2 8v cinp

cheers gregor

the best turbo for that application is (as far as i know) the garrett GT15.

When you say the decompression plate would change the distance between the block and the head, why is that a problem? it's what you want to do to reduce compression.

ye but will that not effect the timing belt and does it matter what gt15 as i have seen quite a few with different numbers after the 15 e.g. garrett gt1549....... ?

up to a point, you'll be able to get away without affecting the timing belt. similar things happen when you skim the head, just in the other direction, and if the change isn't big (and 0.2 bar of boost isn't big) you shouldn't have problems with the belt. As a matter of fact, i'm wondering if you'll need a decomp plate with that sort of boost, best wait for some of the more experienced posters to answer.

As far as the number after the GT15 is concerned, it represents the exducer diameter and is best explained on garrett's site, notably here:
http://www.turbobygarrett.com/turbobygarrett/tech_center/gt_basics.html

Also, you should take a look at their catalogue and see which turbo has the a/r ratio you need.

It's all in the FAQ, but, there are 3 ways of lowering compression and in order of expense they are:

machine the standard pistons
decompression plate
machine the combustion chamber to increase volume
forged low compression pistons

On a high boost engine, events have shown that machining the standard pistons probably isn't the safest way to go. Some people have used a decompression plate without a vernier pulley and got reasonable results, but ideally you need a vernier pulley as well -- it will put the timing out.

The easiest T15 to use is probably the one off the Astra 1.7 Deisel Turbo van, but others can -- and have -- been used.

You adjust the amount of boost by adjusting the wastegate actuator (the T15 has a built in wastegate).

There's no real point, I would have thought at running 0.2bar -- it would barely cover the parasitic losses (turbo power is not completely free). 0.4 is more like it. Up to that level you can probably get away without modifying piston or cylinder heads. There is a slightly thicker cylinder head gasket available.

All low boost turbos are doomed to become high boost turbos: people get used to the extra and want more.

Don't do it they are highly addictive and will empty your wallet faster than a WAG on speed

It's in the FAQ's but a low blow turbo 0.3-0.4bar should be OK a std compression ratio but remember you will still need to sort the fueling and fit a FCD

Anymore boost than that you will need to lower the CR a search will highlight the pros and cons of each method plus when you get there you start talking intercoolers, oil coolers, high flow fuel pumps etc too

Also don't forget if you haven't already you really should upgrade Brakes, Suspension and tyres

Yes, as Martin says elsewhere, these are crazy cars, they rob your wallet, drink your petrol and dash down the road intent on performing obscene sex acts on innocent BMWs.

We're still, I feel, searching for the definitive high boost turbo Cinq from the FIRE engines while FIAT have bought out a 180bhp SuperFIRE production version!

The cheap, easy and reliable way to go might be just to buy a salvage 1.4 Abarth SS engine and pop that in! (Probably someone in Poland doing just that at this very moment!)

so what does the vernier pullies attually do. are they smaller or ajustable or something and how do you test the amount of boost coming from the turbo as i dont want to have it set up on the car with the boost being high and blow my engine or something ?

The vernier adjusts the cam timing. For the boost you use a boost guage and, as boost rises with rpm, you can keep out of trouble (prior to adjusting it) by simply backing off the throttle.

If you're setting it up yourself, you need Megasquirt and MPI. Setting up an MF2 (the way most SPI turbos are controlled) is very strictly a rolling road job. Most of these engines die not because of excessive boost, but because the fuelling is wrong.

ok so right now i have a standerd 1242 could you run me through what needs to happen from here the easyest and cheepest way to turbo it

It's all in the FAQ, basically. What isn't there is non Cento specific and out there on the Net or in books. There is no cheap way to do it.

You will need:

Turbo
Adapted manifold or one off tubular manifold
Management/Fuelling System
Intercooler
Downpipe
Tubing and piping to fit it all together
Thermostatic oil filter take off, oil cooler, braided stainless oil hose
Uprated brakes, wheels, tyres, suspension

Optionally

Uprated fuel pump
Bigger bore exhaust system
Vernier cambelt pulley
Flowed head


The minimum you could expect to spend would be £2000 -- you could easily be looking at 4.

It's generally cheaper to buy a turbo car or -- they don't come up very often -- a crashed one or abandoned project.

If you want a fast car, get something else. You can buy fairly decent Imprezzas for that money,scruffy Evos and dog rough Integrales.

If you want a fast Cento, fine...............

It's all in the FAQ, basically. What isn't there is non Cento specific and out there on the Net or in books. There is no cheap way to do it.

You will need:

Turbo
Adapted manifold or one off tubular manifold
Management/Fuelling System
Intercooler
Downpipe
Tubing and piping to fit it all together
Thermostatic oil filter take off, oil cooler, braided stainless oil hose
Uprated brakes, wheels, tyres, suspension

Optionally

Uprated fuel pump
Bigger bore exhaust system
Vernier cambelt pulley
Flowed head


The minimum you could expect to spend would be £2000 -- you could easily be looking at 4.

It's generally cheaper to buy a turbo car or -- they don't come up very often -- a crashed one or abandoned project.

If you want a fast car, get something else. You can buy fairly decent Imprezzas for that money,scruffy Evos and dog rough Integrales.

If you want a fast Cento, fine...............

if i lowerd the boost to 0.4 could i just get away with a thinker head gaskit. i have an other cinq it still has the .1.1 8v in it would it be worth trying the whole low boost turbo on standard engine with that car as my plans are to take that engine out soon anyway as i want to fit a 1.4 16v to it

Yep, but you still need to do all the other non-optional stuff.

Yep, but you still need to do all the other non-optional stuff.

A 1.4 16v Cinq will eat a low boost turbo for dinner.

I give up with the double post stuff. It's happened about 8 times today and I'm peed off with deleting things.

It's driving me nuts, too! :bang:

ye a know a was thinking about making it a 1.4 16v turbo with the whole high boost deal but i dont hav the funds for it so im going to just put the 1.4 16v in it and then depending on how quick it is might think about a 1.4 16v low boost then after that who knows lol

its still going to cost you a fair bit to put the 1.4 16v in though if your not good at wiring tho tbh. have 5x low compression 1108 pistons if you change your mind about turboing it drop me a line!

Gaz

how much do u want for the pistons like its quite tempting to get them but to be honest i quite like the idea of the 1.4 16v but i do like the idea of a turbo

dont really have the foggyest what theyre worth tbh dude, theyll be on ebay soon anyway