MacGyver

iTrader: (17)

Hi guys. I've been driving a high compression (9.4:1) turbo around for nearly two years now with no problems, I'm looking to build a new high compression (9.7:1) engine for higher power output with a goal of 400HP on pump gas. This will be a daily driven engine, it may see an autocross one day but not often. There will be, of course, additional fuel upgrades and perhaps WI. The parts I need help with are

Apex Seals:
I've looked at 2 piece Mazda, Goopy and ALS. The Mazda have proven wear characteristics. The Goopy and ALS are regarded as great for high power applications and resistance to detonation events. Does anyone have any feedback on Goopy or ALS seal housing wear characteristics?

Stationary and Rotor bearings:
The engine I'm rebuilding has excellent condition stock bearings but I'm unsure how they will hold up in the long run at elevated power levels. Either way I will be using a Racing Beat high pressure regulator and machining an o-ring groove on the back of the oil pump body. I'll be keeping the stock ball and spring eshaft jet as well. Additionally I (need help with) was thinking RX-8 gears/bearings and Mazdatrix competition rotor bearings along with reaming the oil passages to 3/8". Plan is to keep the redline the same. Thoughts on whether is a worthwhile mod or waste of money?

Appreciate an feedback you guys can give.

j9fd3s

iTrader: (3)

if you're going to up the boost, you should either leave compression the same or go lower. i just posted my buddies dyno sheet, and he's been running pump gas and 8.5 rotors since 2008, power is in the 500hp range.

not that you'd need 8.5's to run 400hp, but just an example.

RotaryEvolution

iTrader: (30)

+1

higher compression will net the same power at slightly less boost and spool the turbo faster but at the cost of detonation buffer. more compression means you can run less boost safely so running even higher compression you may wind up killing the motor to find out the hard way the limitations of the engine.

if you want to go higher you will need to run octane enhancers, lots of water injection, E85 or race gas full time or lower your boost levels and live with what it makes.

as for oil mods, leave it alone. i see many shops pushing oil mods and in all the engines i have torn apart the most disastrous failures were on engines with oil mods, stock engines never had any issue pushing well over 500whp without even touching the oil system. the only times i have seen a stock oil system engine fail was when the engine was ran dry of oil, completely dry.

apex seals will not cure the detonation issue from the high compression engine, they may save it from a few runs but it will still inevitably fail if you push it too hard.

mono4lamar

iTrader: (32)

I can't necessarily agree with you on the oil mods unless they're done by someone who knows what they're doing. I'm the only one I know of that actually addresses the whole system and not just the "major flaws." Many people do mess things up by mindlessly reaming many oil galleys and calling it a day; There's much more work to be done but I won't reveal my R&D.

I will agree that there's nothing really wrong with the factory design as a whole but the way the front stationary bearing is fed oil. Other than that it's perfectly fine for the majority of the peanut gallery here.

I've finally finished our prototype oil pedestal that will fit all 13b engines and is a significant improvement over the factory unit. It ironically is shorter than the factory unit and uses a larger oil filter. Main intention was to design it to work for drag racers and down to Joe-blow with a simple single turbo. We were never satisfied with the $hitty sandwich plates many customers would bring us that leaked and made the oil filters simulate a sky scraper.

We'll ship a couple out to some of our trusted testers soon but we usually hit the nail on the head with these "simple" parts. Vendors sell products and lurkers develop solutions...

sharingan 19

iTrader: (16)

I'm running goopy seals in my S5 turbo engine w/ 9.4 cr. Its only got 18 miles on it, but I was very surprised by how well it performed after initial start up. With less than 15 minutes run time it was idling at 800 and puling 17" vac.

If I get a chance I'd like to do a compression test before I make this 300 mile trip, and another one once I arrive to see how compression builds. But so far I'm impressed.