how much boost have you guys run on c20let pistons in your zetec turbos? (without pistons being skimmed)

 

as much as the mapper can map in with out det. i pritty sure its all down to intercooler size fuel grade ect ect

 

as much as the mapper can map in with out det its all down also to fuel grade charge temps ect ect

 

im trying to work out weather i should have a fraction off my pistons or if they can reach good boost levels no prob, thinking of it as the pistons are coming out to change the rods anyway

 

Strength wise you will have no problems.

You need to work out your CR though. get some measurements!

 

not too sure how tbh, was thinking of taking into burtons to work out a nice compression to run biggish boost, what compression ratio do you think id want for say 25psi? through a boost controller obviously lol

 

I wouldn't machine anything off those pistons if your going to push the power but definately check the c/r as I'm sure they come out at something very high when using them on a zetec

 

fiestaturbo.com says it gives a 7.4:1 compression ratio, if this is checked and correct should i have any problems with biggish boost?

 

If it was a LET I wouldn't be worried at all, can't comment on the Zetec but thats surely classed as safe

 

il get all the compression checked over when its apart to be sure

 

As above, how much boost you can run isn't just about compression ratio. Fuel, cams, spark angle etc. - all of these factors affect it.

However, 20 psi on a T34 will typically net you around 300bhp with these pistons - so unless you're planning to get a pukka head done, you won't be running 25 psi anyway. You should figure out what power you want, rather than what boost you want and then design the engine around that.

 

280-300bhp is the kindo of power im looking for, well i gues il just work out the compression ratio then the rest is down to davw walker

 

You have to MEASURE it, not calculate it

 

I disagree!

Chamber volumes for most common heads are known and if you know how much has been skimmed off, if any, you can calculate your CR quite easily to the nearest tenth of a point. All you need is some reasonably acurate dimensions of your components.

 

That's fine, but I prefer to KNOW the facts.

 

I was told comp ratio is much nearer to 8.4:1 when building my old one.

As stated have to measure really.

 

i have seen some 1.6 civic turbo's running the 10:8:1 compression ratio with no probs at all. Im sure it can be done with a zetec

 

what boost and turbo though, running 7psi in a smalle turbo aint the same as running 25psi in a T34

in fact is TOTALLY different

 

but to be fair when we took your head off evon you looked confused when compairing my c20let pistons to your "c2let piston" lol

 

I'm afraid i disagree, i've measured 2 standard 2.0 zetec heads and found them to be 4cc apart, which makes quite a difference in a zetec. Measuring everything properly is the only way to know.

 

if you only want want 280bhp i would go well into the 9-s on your t34.

 

thats probally because his were different to yours and both my sets lol

 

Still made the power

And I was just stating the comp ratio of C20LET pistons, NOT what mine was

 

well ive read a few time its 7.4:1 but will get mine checked if anyone knows where to get it done?