H6

[turbomacncheese]

Hi folks,

I'm looking for info on an H6 818 build. I have until January to make my parts list, then I have to start buying. Most of the threads I've found are old. If anyone is familiar with newer, more complete details, I'd love to get hold of them. Also, any info on performance with the NA 2.5 H4 would be handy. I'd really like to get back into the low 12s, and if I can do it without a turbo this time, so much the better for my wallet.

Thanks in advance.

[phil1734]

One post next time would be sufficient...

Much like most of the knowledge about the 818, you'll need to search through the build threads for any details. It has been done a few times.

As far as a 2.5NA, with the extra weight, complexity, and cooling issues of the turbo I couldn't be happier with mine. It's not going to be running 12's anytime soon, but this isn't a drag car. I have no problem lighting up the rear tires through second gear and it's much more driveable than a turbo car. Best of all it went from boxes to street legal in 3 months. Incredibly simple and straight forward.

To really get an idea of how much power you need find a car that performs like you want in a straight line and back track the power to weight ratio. You don't need 400whp like some on here seem to think. It's pointless to have that unless you're hot-lapping Circuit of the Americas everyday.

[turbomacncheese]

Thanks. I'm not used to people looking in more than one or two of their favorite subforums. I hope I didn't post twice in the same place, but it was late.

[DSR-3]

What info are you looking for?
I've been slowly working on my EZ30R project for 10 months. I have the engine in, plumbing done, and I'm about to start exhaust design/fab and wiring- both pretty big hits to the budget, so not sure which first. I designed and proto'd engine mount adapters you can see in other threads, but my source for the final parts is too busy to make them. I'm considering another approach. I don't have a build thread, and all pic's of my build/install up to July got nuked. I've not been documenting much since then.
There are a few others here building in EZ30R's and an EZ36, but I think Wayne's EZ30D is still the only one to run yet. Other than progress being made on builds, the "old threads" are still relevant. It's pretty straightforward, but you'll have to chose your direction on a few points.
As for building the engine and power- I haven't even thought about it. I'll get the stocker in there- then maybe.

[turbomacncheese]

Thanks, DSR. I think that's probably the info I need. I'm confident I could get it done, but I have to have a reasonable price/timeline to keep the missus happy... and I have to stick to it. Seems like I'll be better off NA 2.5, to keep this one affordable and short.

[DSR-3]

That's probably not a bad plan. The only thing I've seen that didn't look great was the NA exhaust routing- under the frame. Maybe worth budgeting for a custom design if that's an issue for you.

Thanks, DSR. I think that's probably the info I need. I'm confident I could get it done, but I have to have a reasonable price/timeline to keep the missus happy... and I have to stick to it. Seems like I'll be better off NA 2.5, to keep this one affordable and short.

[turbomacncheese]

I'll probably piece one together with a wirefeed welder to get it on the road and maybe have a better one built once it starts to rust.

[Sgt.Gator]

On the 2.5 H4 NA power, I've spent a lot of time talking to various builders and reading everything I can on NASIOC, LegacyGT, and RS25.
My goal was and still is to build an 818R with an NA engine with about 195RWHP/1950Lbs for NASA ST3/THill 25 racing.
RS25 is the most focused on the NA engine. They even have a sticky thread called "200 HP from a 2.5 n/a with just bolt ons??" http://www.rs25.com/forums/f5/2912-2...t-ons-102.html

The general consensus is it's very difficult to get to 200HP with an NA engine. Maybe 210 if you go full bore with 2.7 Stroker, high compression pistons, ported heads, headers, aftermarket ECU/tune. And that's a big MAYBE. A great deal of the problem is there is very little aftermarket support or R&D for a NA 2.5 since it's so much cheaper to use a turbo EJ255-257 and have more power.

As a result my focus is now on going lighter to get the 10lbs/Hp goal.

But I'll say again, Spec Miata racers have an absolute blast with 120Hp in a 2400LB car because it handles so well. So a 2.5NA 818R should be much faster than any Spec Miata and more fun!

[carrera1984]

I'll probably piece one together with a wirefeed welder to get it on the road and maybe have a better one built once it starts to rust.

You could always wrap the exhaust too if the welds don't look that great... keeps heat out too!

[Wayne Presley]

My H6 is in and runs well since 2013.

[flynntuna]

For those building an with a H6, what muffler are you planning on using? I've seen videos on YouTube of people using Borla,Magnaflow and Flowmaster on the Subaru H6. I'm leaning to the sound of the Magnaflow, it seems to have a more refined sound whereas the other two have a rasp to them. Any other candidates you'd recommend?

Here's a YouTube compilation ...https://youtu.be/Cwq-7UQHwj8

[DSR-3]

I'm going with dual Magnaflow- eventually... muffs2.jpg

[flynntuna]

That's what I had in mind. Have you gotten around to building your headers yet? The space in that area is tight.

[DSR-3]

Only at the mock-up stage. I decided to focus on other areas of the build until I can deal with the header fab. I have a box of parts though!
header-test1.jpg

[flynntuna]

Ok, now I remember you posting that picture before.