So, here I am with my performance high compression A15 naturally asspirated sedan and I am watching all these turbo A series making heaps more power and I am thinking hmmm how can I lower the C/R to make turbo power possible and make the most of MY headwork!.
I know your all thinking "isn't he selling his car???" yeah but it might not sell and I am hoping in the back of my mind I can keep it but just don't tell the missus
So as the title says, can I use some A14 rods to lower the C/R or would I need an A14 crankshaft to do the job, if so what would the C/R be after installing it, at the moment I have 11.0-1 in the A15

A14 and A15 use the same dimension rods....

difference is in the crank 5mm and gugeon pin position in the pistons.

Conceptually not a good idea either. the gap between the top rim of the piston and the head is set by your engine builder and is usually around 40 thou. increasing this gap *can* cause problems with detonation.This is part of the reason why most engine builders will advise against using a decompression shim. It seems to depend a lot on the engine though- plenty of people use decomp shims and have no problems.

I think pulsar ET pistons are the standard if you need to decomp an A15 for turbo..... hmmm search time.

Blofly, do keep us updated allright. Very much interested on the progress.

Yeah I guess your right, just thinking out loud, Besides my crazy cam would make the a turbo set up a nightmare to tune.
I think I will look around for a manual parts car and convert mine to a manual for a bit more poke and save the headaches of turbo tuning for another day
Cheers for the input it always helps to get oppinions of others, The car is pretty quick at the moment, quick enough to beat CIVICS and MAGNA'S what more could I ask from a 1.5L pushrod non crossflow 4 cylinder eh!

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You should be giving the V8 commodore boys a run for their money, I blew of a CV8R Monaro with my N/A A series.

yeah BUT.... I have an automatic slushbox

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well. whats stopping you?

manual 4spd 60series about 50bucks from the wreckers...

couple of days work (or less swapping everything over.)

maunal flywheel (i got a lightened 1 u sold me u can have)

clutch (110 from autopro)

tailshaft, i got one of them if u want, otherwise about 40 from wreckers

pedal/cable and other parts ive foregotten. $100

not so hard (or expensive) now is it....
considering my running total is up to about 8500-9000 and im not even on the road yet...

What I did, and yes I did learn the hard way, is to use Langley pistons, why because someone told me they are a drop-in replacement for the A15 pistons. so I believed this guy and went forth, only to discover that the piston would now stick out about 3 mm. in hind site, it would have worked like a charm, if it was an A14, So I'm not dissing this guy he probably did know, just that he did not realize mine being an A15, that it would mount to this much effort....

so I took 1.5mm off the top of the pistons, giving me a nice wide squish-band. Then chopped the rods 1.5mm. This to get me to what I can imagine to be a tad bit higher than Std CR. Now what... I went and got a Shim plate and sandwiched it between two gaskets, and Whua-laa.... been running at 1.2bar on 95/93 ever since....

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3Rotor you have me confused here. A14 is shorter stroke than A15 and Langley/pulsar E-15ET. I thought A15 and E15ET were the same bore & stroke??

so why was the deck height out- different gudgeon pin position and conrod length?

How did you shorten the rods!!!???? actually cut and shorten



cheers. I was looking into this for my next build.....