Hey i'm thinking of putting a turbo on my A15, nothing to fancy just something to give me about 5 lbs. of boost, but i need some help on the following:

1. Will a turbo cause damage to the engine seeing that its a 1.5?

2. Will the turbo make a difference in performance?

3. Will the turbo cause the engine to burn more gas?

4. What type of turbo will work on the A15 engine.

5. What modifications will I have to do on the engine to accomodate the turbo?

6. What other parts will I need to have the turbo functioning properly?

7. Will the diff and 4-speed gearbox be able to handle the additional pressure?

1. The size of the engine should not matter in relation to the damage a turbo may cause, any existing engine wear will be your issue.

2. Yes it will make a difference in performance. It is difficult to say how much, but it will.

3. If you increase the amount of air in the cylinders, you need more fuel to ensure that it doesn't run lean, so yeah it will go through more gas if you give it heaps, but otherwise it is generally quite effiicient.

4. A small turbo will work best. A small garrett gt25 or t25, something smaller even... have a search on the net.

5. A new exhasut manifold to accomodate the turbo, the piping for the intercooler, piping for the carby, maybe a new fuel pump. A bigger radiator may be needed if your current one is quite small.

6. An intercooler (small one) - not needed but will help performance.

7. The diff and gbox should handle a little extra power, but don't be surprised if they do die. Any amount of extra power may push or accentuate a problem that you can't feel or see at this point in time.

Someone on this site has recently done a twin turbo A15, do a search on the left and have a look.

RMS,
I strongly recommend that you read a few books like Corky Bell's "Maximum Boost: Designing, Testing, and Installing Turbocharger Systems". I found that this book greatly increased my understanding of why and how Turbochargers work.

corky bell's books are very informative but hardly relate to modern turbocharger technology.

get your information on how it all works from this book, but don't install one according to what you learn in this book. and certainly don't go installing a bloody holley after your nice ball-bearing turbo.

carbies and turbo's don't mix - and i stand by that. draw thru systems using SUs are the only exception to the rule, but they're far from perfect.

i'm helping my little bro make a suckthrough setup for his L20 bluebird, almost finished but have a few questions.

what sort of hose do you use for the oil feed to the turbo? is heater hose acceptable?

aslo we pulled the su apart and gave it a clean up but don't know wha sort of oil you are supposed to put back in it?

thanks in advance for whoever helps us out

Try using trannie fluid.
Saying that carbies and turbos don't mix may ne true but, a simple draw through on small boost will work fine, and be lots of fun for bugger all $$$$$! I have no time for knob jockeys who want to spend all their money on super clever Hi tech injection. If you are racing and are rich, then fine. But for a low buck street car,a cheap carbie set up has got to be the go! That's my beleif.

i used to use sewing maching oil, thats sposed to be the best for it

like i said, draw thru systems are the exception to the rule.

if you can size your turbo correctly to spool from 2000rpm then yes carbies are great. it leaves you with only 1200rpm (idle to 2000rpm) worth of poor tune - not exactly a problem when the power over 2000rpm makes the trade off negligible.

to some people though, this is unacceptable.

draw thru superchargers are fine as the airflow and fuel requirements are linear - similar to an NA engine - which is what carbies were designed for.

corky bell seems to favour blow thru systems and h-h-h-h-holleys (mop and bucket to aisle four please...).

and EFI isn't for rich pricks only. you can build a delco at home which has more mapping ability than a MoTeC for $300, and then have a tuner program it for you for around $500.

that's the cost of a new and jetted 45DCOE weber.

i recon turbos are the best power increase on a carby engine. and they work fine.

Quote:

your making an argument for turbo's in general not for or against CARBY turbos. turbos need to be correctly sized on any engine not just carby engines so lag is not the issue when deciding between EFI and carby fed turbos.

im not arguing against EFI, personally if i had the money is there and A-series is the way you want to go then injected would be much better. but i think the best power gain for your dollar is definatly to do a carby turbo set up and if you have all that extra money why not go a CA ...???

You can buy the correct dashpot oil from old school speed shops, and whats wrong with blow through systems? I have a blow through lpg system on my 120 and it works fine, there is also a couple of similar systems running 9's and 10's in X D,E,F falcons in melbourne without any problems AND they are 100% street legal. Also if you use heater hose as an oil feed, make sure you have a big fire extinguisher handy. Get a braided hose made from Pirtek, should have change from $80