2018 STI RA Engine Block Teardown

[Scargod]

Originally Posted by lidrew

considering a build on my GR and deciding on using the RA block or IAG. I can save $3kish by going with the RA. Goal will be somewhere around 450 whp on flexfuel.

Anyone have any more experience with the RA block and how its holding up with high hp?

If you believe Mike Botti, I heard him say the RA's could do 500 all day long and 600+ for a while. Said that he had tuned cars for that. At 500 he said the engine was durable and went through a lot of hours being raced and was driven home...

I don't think 450 would be a big deal.

I think saying the stock rods can't take it is wrong. Perhaps not the best choice for 500 or a bit more but I have heard of people doing it. Look at "bragging rights".
If this is a street car I would do the RA SB. If you are going to be racing some and street mostly then I'd suggest buying the case, crank, bearings, rods of choice and Mahle pistons in 4032 aluminum alloy to allow for tighter cylinder to wall clearances and improved temperature stability.
I am building a DD engine this way and will make about 350. The thing is, it will be able to rev like crazy, safely. I will be cutting 30% (roughly) off the weight of the reciprocating parts.
It would be like an RA but with much lighter rods and pistons.

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[Homemade WRX]

Originally Posted by lidrew

considering a build on my GR and deciding on using the RA block or IAG. I can save $3kish by going with the RA. Goal will be somewhere around 450 whp on flexfuel.

Anyone have any more experience with the RA block and how its holding up with high hp?

I've always been a big proponent of DIY but if you don't feel up for working with your local machine shop to build an engine, there are numerous reputable builders that you can consult with.

Originally Posted by cboggess

I believe the rods have not changed. If I am correct in that regard then I would not run 450 on those rods. You're going to need something a bit beefier.

The rods (on page 1) do look a little different from the 08 but not notably.



OP:
1.) Guys have made big power on all years, and it's safe to say they're all time bombs.
2.) Then take into account "450 whp". Dyno's don't all read the same. For instance, we had a customer that was making 470 on a Dynopack and then made 360 whp on our Mustang. It was also notoriously a heart breaker with stock STi's making 205-210 whp.
3.) Is this a street car that might see 450 whp every once in a blue moon, or is this going to be raced? If raced, I would skip right to forged rods and pistons.

Just my $0.02.

[lidrew]

Does anyone know if 2019 STis with 2018 build dates will have the RA block too?
I’m looking at new 2020 or 2021 and some used 2020s and 2019s. Some of the 19s were built in 2018.

[lidrew]

Originally Posted by lidrew

Does anyone know if 2019 STis with 2018 build dates will have the RA block too?
I’m looking at new 2020 or 2021 and some used 2020s and 2019s. Some of the 19s were built in 2018.

Nobody knows if build date determines what cars get RA blocks? Is it all 2019s regardless of build date?