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#1
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Turbo options?
There's a few of you Turbo boys on here, and I had a question for those of you who have gone to the dark side.
What turbo did you choose, and how does it spool? Has anyone been daring enough to attempt a twin turbo setup? Not necessarily for lotsa power, but rather for seamless spool and power delivery. I was wondering how the EG33 would handle spinning two GT2876's. Max boost would only be around 7psi. How much boost are you guys running on otherwise stock motors? How much power are you making? I have no intention of turbocharging a stock internal'd motor, but I'm debating compression ratio, and which direction to go. From what I recall, the stock CR is something like 10:1 or so, and it requires premium fuel. I am considering a turbo or a supercharged setup, where low-end torque is of the utmost importance, second only to perfect reliability. What do you guys think? |
#2
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A twin turbo settup has never been successfully done in an SVX, to the best of my knowledge. It's been tried on EG33 engines in other applications, but I haven't heard of one that works. TomsSVX has probably gone the furthest in trying a twin turbo system for an SVX. *Searches for thread*
http://www.subaru-svx.net/forum/.... The single turbo guys are Phast SVX and cdigerlando. They can probably answer your turbo questions better than most. Of course, several members are running the ECUTune Stage III supercharger as well. From what I've read, if you want low end torque that's the way to go. The blower makes boost from idle, so you've always got power.
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Chris 92 Ebony Mica LS-L "A Rolling Restoration": 223,250 KM - Sleeping 2007 STi 6MT, Stance GR+ coilovers, PWR Rad, JDM hood badge, svxfiles 6000K HIDs, JDM Clear Corners, $15/15 min mod, $20/20 min mod, Energy Swaybar Bushings, Hella Supertones horns, Gold STi BBS rims, Group A lightweight crank pulley, A/C system removed, Custom header-back exhaust, Hybrid carbon/metal rear sway bar, restored headlights with CCFL halos 2008 Subaru Legacy Spec B - Diamond Grey Metallic - Sold 2020 Ram 1500 Longhorn - Red Pearl |
#3
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As far as boost pressures go, My Stage III has been running at 9lbs with no major issues for about a year now. TomsSVX was running around 12lbs and his ring lands gave out. The only issue we're having with our setups is the breathing of the engine. The heads and cams cant scavange enough of the gasses out at higher RPMs. Our dyno graphs are a down hill slope. You can check my locker if you want to look at the dyno plots.
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#4
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Really? So a set of forged pistons and rods and I'll have a bullet proof bottom end for my application.
I'm not TOO concerned with top end power. Low end torque is more important. The only caveat, I do not want to intercool the setup if possible. At the MOST, I want to do no more than an air-water intercooler. That's a part of the twin-turbo idea. Get two turbos pumping half as hard, and I can drop intake temps. The SC idea is a good one, but until the kit is available with parts only, it's not an option. I must be OBD2 emissions compliant. I was planning on replacing the cams with something designed for forced-induction at some point down the line. If I could get the SC kit with just the intake manifold, the pulleys, and such, that'd be great. I would want to use the Whipple 2.3 blower though, not the Lysholm 1600AX. I'd be happy with 300whp/300lb-ft. Ideally, I'd like to see around 450/450, but I don't think that'd jive with the daily-driver aspect. If I could make 300lb-ft from 3,000 RPM to 5,500 RPM, I'd be very happy. What's the factory rev-limit on these engines? 6500 like most other Subaru's? |
#5
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There are buys right now for the valvetrain and cams. Pistons and rods were just ordered though. You can try LAN and see if you can still get them. Yes 6500 is the rpm limit
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Former: 1994 Barcelona Red(x2), 1995 Brilliant Red, 1992 Liquid Silver, 1992 Ebony(x2), 1992 Pearl White (x2) Current: 2017 Ford Raptor 2017 Kawasaki KLR 1995 Guards Red Carrera 1995 Spec-ish Miata - track car 1957 CJ-5 |
#6
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we are only seeing tops of 250 whp right now so reaching 300 is gonna be a tough task
Tom |
#7
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Quote:
I sure hope the new cams aren't shooting for more scavenging. Since that is what we don't want to go on with forced incuction... we need less overlap (hence less scavenging). I hope to see these new cams and exhaust clear up the power restrictions. I would imagine 9 psi would generate around 300 whp and 12 psi making well over that, like you said, Tom. I've actually been wondering if anyone has engine analyzer pro to test out new ideas. I just started using it for my thermodynamics class and wow does it do a good job of estimating. It usually overshoots power predictions by about 5% but it provides a great idea of what actually works and what problems you could run into with the changes made (like valve to piston clearances and detonation problems). I'd like to put the EG33 into the program but there is a lot of info I'd need.
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-Aaron SVX: '92 Dark Teal 101k '97 Legacy GT Wagon: dead '99 Civic Si: daily driver... stolen and stripped with all my tools! '92 Yamaha FZR 600: garage 2011 Jetta: Daily disappointment |
#8
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Quote:
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~Phil Teal 1992 Subaru SVX Turbo - Sold in May 2011 to peace-frog. |
#9
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Theory works for basic and simple modifications, but changing cam profiles, pistons/rods, compression ratios, etc. to take advantage of forced induction while getting the best result (efficiency) for the work/money you're putting in... some good software sure does help. That would be why most serious engine builders use these programs. Could make the difference between 300 and 350 ponies for the same amount of money spent.
Have you driven your SVX lately? I'd love to see you make 600 hp... even if you're not looking to.
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-Aaron SVX: '92 Dark Teal 101k '97 Legacy GT Wagon: dead '99 Civic Si: daily driver... stolen and stripped with all my tools! '92 Yamaha FZR 600: garage 2011 Jetta: Daily disappointment |
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