450 Whp possible with 12.5:1 compression
 

I am putting together all the parts for my engine, but the piston decision is complicated, my goal is 400+whp, my turbo is an EFR6258 and the E85 option does not work for me. I don't have e85 nearby and I don't want to rely on e85. I just wanted to know if it's not crazy or which one do you recommend for this goal.

Maybe?
I've yet to see anyone actually try High Comp boost with those numbers.
Most are too afraid to try and find out, cause it it doesn't work it's wasted money or worse.

I'd say get a stroker kit to help.

to me that s not possible on 93oct and stock compression, even if you install a super huge turbo to keep charge temp down and it would anyway have an extreme lag

you'd want something like 10:1 with normal fuel to reach those hp, and a big turbo

Too much for pump gas imho, you'd need E85, C16, or meth injection to reduce knock.

EFR6258 is going to produce a ton of heat making 400+ whp

Get some meth

On a stock block or one of those HKS jobs?

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it is a stock block, I was thinking that maybe with an increase in displacement it could be possible

I could actually play it safe and go down to 10.5:1 but I really like the efficiency and the lag can't be giant

Now that I think about it, meth can be more easily adapted to what I'm looking for, I'll put it among the options, the problem is that with strong movements it may fail.

Has anyone achieved something similar?

Possible yes, longevity no.

Sounds like about 400hp is the most you want to do on a stock block. (If you want to drive it more than once or twice)

According to https://www.ft86club.com/forums/showthread.php?t=38494

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Possible? Yes.

How deep are your pockets?

You're gonna need race gas if you don't want to do e85.

if he doesn t want to rely to e85 that he could get on the street, it seems to me useless to propose racegas.. and with 93 oct those hp and stock compression are not possible

I see, it seems that the most reliable and least complicated thing will be to buy the CP 10.5:1 pistons and not complicate my life, thanks anyway, I know that many easily reach that goal with E85. and for the guys above it will not be a stock block the question is for me to decide which piston was more suitable for my goal, I already have a lot of accessories to help keep everything good, oil cooler, a configuration of oil cans that have lowered the pressure in the crankcase, oil deflectors, oil pickup, ect. The last thing I need is to build the engine.

You could get an IAG short block instead of building it. They also machine it to help the oiling issues.

I think the FA20F in the WRX is 10.6:1. People seem to be knock limited on the stock block sub 325whp with pump gas. I don't know if aftermarket rods and pistons can take a beating surviving 400whp with knock or worse. Direct injection helps, but lower compression ratio is a good idea. I don't know how much direct injection improves knock resistance. Older EVOs and STIs were maxing out pump gas around 400-425whp and that was with a 8-9:1 compression ratio.

Doesn’t seem like stock block lasts long over the 3-350whp range regardless of octane.

But is there even any documentation of anyone even hitting 400whp on pump regardless of built block or lower compression or not?

The other thread claimed 693hp was the record on the stock block (probably not pump gas though). I'm sure that isn't a daily driver, lol.

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Yeah not on pump gas. And making 693whp once on a dyno to never go over 10% throttle again and never actually use the power isn’t really the same thing.

300-320whp w/ sc or 330-350whp w/ turbo even on Ethanol seems the top end of reliable on stock block if you’re actually going to use the power.

But reliability aside, I don’t think I’ve seen anyone hit 400whp+ on pump gas regardless of compression.

I got it. Built Block. Head work. +1 Intake and Exhaust.
GTX2867R Gen 2. 18.5 Pounds. 420WHP On a Dynojet 93OCT.

Have a dyno? Build thread?

No build thread. But here it is.
Attachment 210102

Nice power.

What was the change from red to blue?

i haven t understood if that is with stock compression or lowered? i guess lowered?

2 different Maps.
Map 1, Red Line is gate pressure at 17 PSI. 380WHP I think somewhere around 320 TQ.

Blue is Map 2, 18.5PSI More timing. 420 WHP. 347 TQ.

Both gets on boost 3-3.5K. Lots of response, very linear power.

It’s my track car, so there was more power with more aggressive timing. But wanted to keep it more conservative.

Lowered compression. 10.5:1

My understanding is you start eating transmissions and axels at those levels. So you change one thing in a huge way, you need to reenforce everything else ancillary to it. I’m just puttering around at 252whp, but also research for the “one day” thoughts.

The gen 2 transmission is supposedly stronger, but I’m not sure if it is a direct bolt-up.

That’s awesome. Most power I’ve seen on pump gas.

What head work was done?
Larger valves?
Cams?
Port work?

It's a slightly uprated version of the same transmission. It will be a direct swap.

Larger valves both intake and exhaust. Very slight port work just to clean everything up leading up to the larger valves (Bowl blend, 5 angle valve work, etc). And of course springs and new retainers to able to support increased redline.

But 400 def possible on Pump. You just have to have the supporting mods.

4th gear has reliability issues on the current (1st gen) AZ6. I've personally seen it on friends cars who range from 400WHP-600WHP. They always seem to rip up 4th gear. But I got that all fixed up by the guys at Jacks Transmission.

=D:w00t:

How is the transmission holding up? There was a guy on Facebook who said the second day of regular driving transmission went out and just got jacks stuff. Was debating on getting jacks or saving up more for cd009

I am currently at 400whp on map3 but Ususlly in map 1 & 2 for track which is 306 and 360

2 years now with the built transmission with no issues. I personally didn't want to mess with cutting and welding brackets so I went with Jacks. WPC will cut down on stress risers on stock gears in addition on what Jack's does to the stocks transmission to make it a little bit more reliable. No problems so far.

wow, really? maybe a bad trans? but CD009 are known for their strength. its what 2jz peeps that make 1000 hp use for their builds.

I wanted the jacks stuff since easier to swap in. I have carbon synchros in mine and been okay. I only used the 400whp map twice since don’t need it and don’t want transmission to go right away. It hoping get a good deal
On either a jacks or cd009 mazworx conversion