You won't be able to use 83mm pistons unless you have a perfect block to build into. Any used block will need a slight overbore to correct for wear, and that puts you to 83.5mm in most cases. Few, if any, manufacturers will offer an off-the-shelf forged piston in stock bore size.

If you keep asking the same basic question over again and keep not liking the answer, asking it a few more times will certainly change the answer. That's usually how it works.

BP engines are more detonation prone than some other engines. Compression ratio is one of the biggest factors in whether or not you can run more timing or more boost in our engines. Every point of static compression ratio will hurt your ability to make Power.

Your block will need to be removed from the car for the rod installation and you will have to have the Pistons pressed onto the rods. Your cylinder bores will need to be honed at a minimum to accept different piston rings and have them seat properly. The difference between honing and boring and honing is probably $20 a hole.

I assume from your repeated questioning that you never read any turbocharged engine theory so I will pass on some information to you because I'm feeling benevolent. Power is created by the pounds of air you are able to put into the cylinder to combust. Generally speaking, more are means more power. We are detonation limited by the type of fuel we use. We cannot add as much air to a high-compression motor as we can a low compression motor and still avoid detonation.

You keep asking about compression ratio making a difference in the drivability of the car. I can tell you from years of dynomanometer software modeling that on a 7.6 l V8 the difference between 8.5:1 and 9.5:1 is 12ft lbs at PEAK torque. Divide that 12 down by roughly 4 times for the smaller engine and you get about 3ft lbs. at PEAK torque. That's the equivalent force of one 12 week old kitten being placed on a 12in long wrench. So each one full point of compression ratio drop is about one kitten power loss. the good news is you get to add much more air without detonating. You will make dozens more kitten power in return.


TL;DR: Putting higher than ideal compression ratio brittle stock Pistons up against a fast spooling Borg Warner on pump gas with your limited knowledge and apparent lack of appropriate funds sounds like a fantastic idea. You should totally do that. But I prefer to add kittens instead.

Technically speaking, a BP is over 1.8L anyways. So... nothing of value is lost.

Many people on here done what you wish.
Some even set up shop doing it for other people.
Some were absolutely mental enough to build these monsters 10+ years and berate them on track with 400+whp and solve basically all the issues any person is likely to have.
One of those nutcases is Savington.

If you have a question and he answers it.
It will be quicker and cheaper for you to just take his advice.

Increasing displacement (by only that) shouldn't affect anything insurance wise and the added volume will mean more combustion volume meaning any decrease in CR already has a helping hand.
In all seriousness a change that minor you'd be hard pushed to measure accurately and it will mean your motor won't die. Those are both good things.

Show me one other EFR TWIN SCROLL build on here

At your intended power level, the twin-scroll setup would be a detriment for several reasons, including reliability and response.

are you getting the efr turbo kit from trackspeed?

What manifold are you planning on mounting the EFR too? Stock MSM?

He says he's getting an Artech manifold

Consider a cast manifold instead. Artech makes nice stuff, but no tubular manifold will be as reliable as our 347SS investment cast manifold.

So you are getting the turbo manifold, downpipe and 3" exhaust from artech?

Did you talk to Abe at Artech? i've heard he is kinda retired and no longer does turbo setups. so make sure you talk to him.
If that doesnt work out, i recommend you get the trackspeed EFR kit, its excellent quality, and then have a local exhaust place just fab up a 3" exhaust for you.

You have quite an extensive list of parts. gonna be one hell of a build. make a build thread about it and post lots of pictures.