cant decide which pistons to use
Turbo Mini Forums

I've finally settles on what to build for my new car, it was going to be a 1430 but i think i'm going to stick with a 1293 and a T2 after going out in keans at the weekend.

I'm going to pop up to simons on saturday to place the order for me new engine but i still can't decide what pistons to run, which ones would you guys recommend as this is only my 2nd turbo lump. me last one was running the AE21253's @ 15psi but only making 135 banana's but i want more this time round.

The basic outline of the lump will be the usual 1293cc, rev to 6.5k tops, i want to run up to 20psi on the track, but will just be 10 for daily driving.
My head is at 29cc already and i've got the box sorted aswell, it's juts the pistons i cant decide on.
Do i really need forged pistons as they're a lot of money, or would the cast mega pistons/omega's be ok? i only need around 11cc's in the piston to get down to my desired CR.

What would you guys recommend? i know its a bit of a vague question and down to personal preference a lot aswell but i was just after some advice really from people who've been there done that etc.

Cheers, Nick :)

I'd go for the minispares mega pistons and spend the money saved on a correctly matched T2* unit.

That route will (imho) make tons more power than a set of all-singing-all-dancing pretty pistons and a bog-standard Renault5GT turbocharger having it's neck wrung to flow more air than it sensibly can. If you size the turbo correctly, and use a wide-band the get your A/F ratio's spot on, and have it set up well - you won't need anything more than 16/17psi in the real world (again - only my opinion).

But perhaps you should take advice off your engine builder. He might suggest the exact opposite, and I'd hate to be giving out bum advice on a public forum...




*****TD edit*****
Please see this topic for up-to-date info on the suitability of the minispares 'mega' range of pistons for turbo use:

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=255230

Edited by turbodave16v on 17th Nov, 2008.

Cheers guys, thats pretty much the response i was hoping for to be honest.
Last time i spoke to simon he recommended the mega pistons, plus they come with 9.8cc's as std so they won't need much extra machining in them.
A wideband is definately on the cards after seeing how useful keans innovate one is in his dash.
It'll be running a stock R5 T2 for the time being but eventually when i've saved up some more then i'll be getting in touch with mirage to see about getting a proper one that suits my engine properly.
I think i'll see about getting my head worked a little more aswell as it's only really had the chambers opened up being a st2 one.

Cheers dudes :)