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What's Your Boost Setup & Curve
What’s your forced induction set up, boost curve and how do you like it. Mine is 3.0 liter w/ twin K24 18G turbos. Comp. Ratio 8.9:1 RPM/BOOST/ : 3K/1.6, 4K/3.5,5K/9.3,6K/15.1,6.6K/19.2. This set up works for me because I think it’s easier on everything and fast 60-130 which is my driving style. Maybe a shot of NOS later for down low.
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1980 911 SC Euro 3.0 Twin Turbo, 466whp |
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Brando
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swap out those turbos.
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Turbo powa! 1977 911s. it's cool |
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Well taken! Any suggestions?
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1980 911 SC Euro 3.0 Twin Turbo, 466whp |
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Brando
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I don't know much about the k series little turbos but I think there is a k16? I'm sure you could get 19 psi but sooner. 3.0 is smaller than the 3.6 the k24 was designed for. I have a 3.0 930 and use a single gt30r. My aspect ratio is the .82 but I want to swap to the .63 so I get boost quicker. I see .8 bar by 3200rpm and it holds all the way to 6000rpm where my cams are done. if I wanted to raise the boost, this turbo is good for 525hp.
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Turbo powa! 1977 911s. it's cool |
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Brando
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I'd like to see your intercooler.
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Turbo powa! 1977 911s. it's cool |
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OK, you're saying 19.2psi with a fixed compression of 8.9:1?
When you rebuild your engine use a pair of K16s. |
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Crotchety Old Bastard
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We need pictures of that engine!
K16 should be a better fit for 3.0L displacement. If I were to "map" boost I would assure full boost was available in the meat of the torque curve and drop it off a touch after 6000rpm. There is no advantage in having twin turbos if early spool and torque are missing. The figures you quote should be a time bomb on pump gas. Is some info missing? Engine management system? Octane enhancers?
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RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds '78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8 |
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Registered User
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Quote:
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1980 911 SC Euro 3.0 Twin Turbo, 466whp |
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Registered User
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1980 911 SC Euro 3.0 Twin Turbo, 466whp |
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Registered User
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Quote:
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1980 911 SC Euro 3.0 Twin Turbo, 466whp |
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Brando
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K16! The reason is the same reason some here choose intercooling instead of water/meth as their cooling agent for the charge. You never run out of it. I chose to use intercooling even though I bought a meth system and now see the reason, as I have come close to running out of water in the tank.
If you use nitrous, while it seems like the easy fix to your boost issue, you'll run out at some point, If you change to the smaller k16 turbos, or even go the single turbo and use a more user friendly metrhod to boosting, you'll love the much more streetable power available. And if you want to rev, go ahead and rev to 6600rpm, but start boosting sooner, that will give you more boost time and much more usable power.
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Turbo powa! 1977 911s. it's cool |
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Location: S. Florida
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Is that a modified stock 930 intercooler? Looks like it..
I don't believe your 466 wheel horsepower because thats well over 500 HP st the crank and I don't think you can get enough CFM of air through that intercooler core to make that much HP from 3 liters, and the air coming out of that thing is going to be hot. I'm sure it's fun to drive anyway. |
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Crotchety Old Bastard
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One of the reasons I would reduce boost above 6000rpm is to allow the K16 twins to remain efficient. Max HP is not of interest to me but may be to you so this is personal preference.
For the same reason I am not a fan of relying on injection of nitrous or MeOH to produce power. Great if you have engine control systems that can change all the tuning parameters when injecting combustion enhancers then switch them back when they run dry or are not used. I quess the real question is what are your goals with this engine?
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RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds '78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8 |
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Brando
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Whats the exhaust look like?
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Turbo powa! 1977 911s. it's cool |
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Quote:
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1980 911 SC Euro 3.0 Twin Turbo, 466whp |
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Brando
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I'm no expert, but even I can see where things can be inproved. Starting with the intercooler, that is too small and ineficient for high flow and boost. Those are good for low boost and even then proven not so good. In the stock location, it had air pulled through it by the fan and a good shroud, yours is farther back and probably doesn't get quite enough airflow through it. The turbos are good but not for your application, you would do much better with smaller turbos or only one of them, though it would not be quite enough for 400 hp. But two k16's might be great though probably still too big for my tastes. If I were you, I'd get either the k16's to reduce modifications, or make up a single turbo system with a nice common and proven turbo for your application that will make a great street car. Your setup would be fine for race situations maybe, but even still probably be better with a smaller turbo even then. And with a much better intercooler. I'd bet your getting detonation with prolonged high rpm and boost runs with that setup. Thats why the timebomb comment. With your high compression, you need a small turbo and lower boost. If you did that, you'd have a faster safer car. Maybe not quite as big a rush but the final result would be a faster better driving car.
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Turbo powa! 1977 911s. it's cool |
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Crotchety Old Bastard
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What transaxle are you running?
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RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds '78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8 |
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Registered User
Join Date: May 2012
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So far, I like everything you've done! I believe Brian is on to something...915 tranaxle? He can tell you more about those than me...
I say keep it like it is if you like it!, I love the low end "grunt" these other guys are talking about, but I don't think it's a good idea to move the boost curve lower in the RPM range in YOUR case... You did say Texas right? Hot, but lots of open road where you can always have ALOT of air moving through the engine compartment, probably why your intercooler works fine The lower back pressure of the larger turbos is probably a good thing, again, in YOUR case. I'm currently obssesing over a low cost, franken-porsche monster built from hand-me-downs and pieces cast away or collected at low cost where the availability of parts sorta dictactes the build, prolly why I like your "hand me down turbos" so much ![]() ...so far I have a 993 Transaxle and an M64 RS flywheel, quite A LONG way to go... |
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Join Date: May 2008
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Your statement says it all "60-130mph"
996tt- Guys are still using them and upgraded to a billet prop. Then they want more power they go with a meth system or e85. They are showing OVER 600WHP easily...I would leave it...U will eventually break something if the internals aren't beefed up. Be careful if u have a 915. Want boost sooner, upgrade the headers ![]() I guess too much is never enough. ![]() ![]() ![]() Walt Last edited by wjfk32; 07-13-2012 at 07:29 AM.. |
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