5e forge build

[bigash86]

Hi guys am starting my 5e forge build but before I order parts I wanted to know other then size what do bigger pistons give you in size I have seen you can get pistons in 74 74.5 and 75mm is it the bigger the pistons the better low end power and torque? Also what are the considerations for the larger piston sizes?

[AdamB]

I wouldn't run the stock 74mm piston because this doesn't allow much material to be removed from the cylinder during honing and won't give a good tight seal. 75mm pistons I personally wouldn't opt to run because if anything happens the the cylinder you can re-bore.

A larger piston increases the compression ratio and increases the engine capacity slightly, meaning slightly more torque and better spool up of a larger turbo because engine capacity has increased, but it won't be anything noticeable so don't get too hung up on it.

[bigash86]

Cheers mate 74.5mm it is then

[AdamB]

99% of people am sure would use a 74.5mm piston because it gives room for error if anything ever happens, more so to a fairly rare 5E engine. It's only those that are really looking for that extra spool up of a large turbo that would opt for a 75mm piston.

[bigash86]

Am looking to run a td04 maybe one of the new hybrid ones that ricky has I want about 280bhp at wheels with the spool of a ct9 or ad close to it as I can get which I rekon everyone tries to do lol

[turboloon]

i'm making 275bhp on a forged 1.3...

[AdamB]

The td04 on a 5e will spool similar to a ct9 mate, but it will run out of efficiency quicker.